wb_basic course tba

Basic Course TBA

Training DocumentThis Training Document is intended for Training purposeonly, and must not be used for other purpose.The Training Document is not replacing any instructionsor procedures (e.g. OM, MM, TeM, IM, SPC) intendedfor specific equipment, and must not be used as such.

Note!For safe and proper procedures, refer to the equip-ment specific documentation.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or trans-mitted in any form or by any means: electronic, electrostatic, magnetic tape, mechanical photocopying,recording or otherwise, without permission in writing from Technical Training Centre.

Issue 3/0109

2001, Tetra Brik Packaging Systems AB, Technical Training Centre

Technical Training Centre

Contents1 Guide to the Basic Course TBA2 Basic Machine Introduction3 Documentation4 Pasteurisation and UHT5 Sterile System6 Peroxide7 Cleaning In Place8 Central Lubrication System9 Hydraulic System

10 Cooling Water System11 Pneumatic System12 Steam System13 Electrical System14 Maintenance Routines15 Packaging Material16 Hygiene17 Package Integrity

Guide to the BasicCourse TBA

1

Technical Training Centre 1/9902 1-1TM-00066 Training Document. For training purpose only.

Guide to the BasicCourse TBAIntroductionThe Basic Course TBA provides basic knowledge about the function andconstruction of Tetra Brik Aseptic filling machines. It is a self-instructionalcourse which describes and explains the components, functions and systemsthat are common to Tetra Brik Aseptic filling machines.

Students guideThe course intends to prepare you for higher level machine courses. Byperforming the studies according to this schedule, you will achieve a level ofknowledge that will make further training more efficient.To be able to to achieve the full value of the course, you will need help andsupport from a more experienced colleague, who will be your mentor.

Schedule Study Study the sections Basic Machine Introduction, Documen-tation and Pasteurisation and UHT. Also study the attachedbrochures, containing general information on Tetra Pak.

Discuss Discuss the above mentioned sections with your mentor. Askhim/her to explain, if you have any questions.

Study Study the sections Sterile System and Peroxide.Watch Watch the video Clean Conscience referred to in the Hygiene

section.Study Study the section: Cleaning In Place.Discuss Discuss the above mentioned sections with your mentor. Ask

him/her to explain, if you have any questions.Visit Visit at least one production plant together with your mentor.

Study the various Tetra Pak equipment during production.Follow the packaging material from the storage room, throughthe filling machine and distribution equipment, all the way to thestorage for finished products. Let your mentor explain theroutines to you.

Study Study the sections: Central Lubrication System, HydraulicSystem, Cooling Water System, Pneumatic System, SteamSystem, Electrical System and Maintenance Routines.

Discuss Discuss the above mentioned sections with your mentor. Askhim/her to explain, if you have any questions.

Visit Visit a production plant together with your mentor. Focus on thefunction of the filling machine and the operators task. Study thedifferent diagrams for the supply systems and try to follow themin the machine. Locate the electrical components that arementioned in the section Electrical System.

Technical Training Centre 1/99021-2 TM-00066 Training Document. For training purpose only.

Study Study the section Packaging Material.Discuss Discuss the above mentioned sections with your mentor. Ask

him/her to explain, if you have any questions.Perform Perform the Package Integrity TBA Computer Based Training

Program referred to in the Package Integrity section.Discuss Discuss the above mentioned sections with your mentor. Ask

him/her to explain, if you have any questions. Practice how tocheck package integrity together with your mentor.

Visit Visit a packaging material plant. Let someone guide you andexplain the different processes. Compare this information towhat you have learned in the section Packaging Material.

Mentors guideAs the students mentor you have a very important role. You must support thestudent with your knowledge and experience during the studies. It is you whowill introduce the student, theoretically and practically, to the Tetra BrikAseptic systems, and answer questions that arise.You should also make sure that the student get enough time to perform thestudies. After certain sections of the students schedule, you must devote timeto discuss the various subjects with the student. You should also supervise thatthe student has fully understood all sections.

Basic MachineIntroduction

2


Basic Machine IntroductionWhat does the filling machine do?Starting out from a reel of packaging material, the TBA filling machine pro-duces filled packages. The packaging material is first sterilised and then for-med into a tube. The tube is filled with product and then shaped and cut into individual packages.

The packageThere is a range of Tetra Pak packages, all deriving their origin from the same forming technique.

Reel of packaging material

The packaging material is sterilised

The packaging material is formed into a tube

The tube is filled with product

The tube is shaped and cut into individual packages.

Tetra Brik, Base Tetra Brik, SlimTetra Brik, Sqare Tetra Prisma

Tetra WedgeTetra Fino


Package terminologyCreasesCreases are the folding instructions on the packaging material, to ensure the

packages final shape. The creases are pressed into the material by the creasing tools in the converting process.

SealsThe longitudinal seal (LS) is accomplished when forming the packaging ma-terial into a tube. It seals the package along the side. A strip of laminated plas-tic, the LS-strip, covers the seal on the inside. The area of the overlap joint is called the longitudinal overlap. The transversal seal (TS) is made when the tube is filled with product. It seals the package at top and bottom. The sealing takes place below the product level in the tube.

Fins The fins are the areas, at top and bottom of the package, where it is sealed and cut.

FlapsThe flaps would be the corners of the package, if you flattened it out. When shaping the package, the flaps are folded down and in, and then sealed to the package body.

Machine introductionTetra Brik filling machines are built from so called modules or main groups with similar functions in the various machines. The machines may also have different additional equipment and accessories.To learn more about this, please unfold the next page. The example shows a Tetra Brik Aseptic TBA/19 filling machine, equipped with an Automatic Spli-cing Unit (ASU).

bottom transversal seal (TS)

bottom finbottom flap

bottom flap

longitudinalcreases

top flap

top transversal seal (TS)top fin top flap top flap top flap

LS-striptop crease

bottom creasebottom flap

bottom flap

longitudinal seal (LS)

longitudinaloverlap(L.S. overlap)


1. 2. 3.

cut

Aseptic chamberThe packaging material will be dried with heated air. In machines with deep baths, as shown in the example, an aseptic environment around the sterilised packaging material is maintained with an over-pressure of heat-sterilised air. This takes place in the aseptic chamber.In machines with shallow baths, which have no aseptic chamber, heat-sterilised air will be blown into the tight tube. This way a sterile area is maintained where the tube is to be filled with product.The packaging material will be formed into a tube and sealed longitudinally. Finally, the tube will be filled with product.Learn more about sterilisation in the Sterile system chapter.

Strip applicatorThe strip applicator applies a plastic strip, the LS-strip, along one edge of the packaging material. The strip is applied on the inside of the packaging material and is intended to prevent product from being soaked into the raw paper edge of the longitudinal seal. The strip will also support the seal.Only half of the LS-strip is sealed to this edge of the packaging material. The other half will be sealed to the other edge later, when the packaging material is formed into a tube.Learn more about the LS-strip in the Packaging material chapter.

ASU Automatic splicing unit The automatic splicing unit splices reels of packaging materi-al. This means that production can continue uninterrupted when one reel of packaging material comes to an end. During splicing though, the packaging material has to remain still in the splicing head. The magazine provides the neces-sary supply of material so that the machine does not have to stop.

Learn more about packaging material in the Packaging material chapter.

Peroxide bathThe packaging material will be sterilised in the peroxide bath.In machines with deep baths, as shown in the example, the packaging material will be immersed into warm peroxide and both sides will be sterilised.In machines with shallow baths the inside of the packaging material will merely be covered with cold peroxide and the sterilisation will be finished in the tube heater.Learn more about sterilisation in the Sterile system chapter.

Jaw systemIn the jaw system the tube is sealed transversally and cut into separate packages. The sealing is made by induction heating, using the aluminium in the packaging material to melt the plastic. It is important that the package design, with the creases, appear in accordance with the jaws. This is controlled and corrected by the jaw system.

Final folderIn the final folder the separate package gets its final shape. The fins are folded and the flaps are folded and sealed. Hot air is used to seal the flaps. The plastic outer coating on the package material is heated and the flaps are pressed against the sides and the bottom of the package. When the plastic gets cool the flap is sealed.

Drive systemThe drive system includes motor, gear and cam package. These parts run the jaw system and also the final folder on certain machines. How the drive system gets the jaw system to perform its movements, differs between the machine systems.

Operator panelThe operator panel allows the operator to communicate with the machine. It is used to start and stop or make the machine take any other action.

PullTab unitNote! The PullTab unit is not shown in this example.

The PullTab unit is additional equipment, providing the packaging material with a PullTab opening be-fore it enters the peroxide bath.The PullTab opening is created by punching a hole in the packaging material. The hole is sealed with plastic on the inside and aluminium on the outside.Learn more about the PullTab in the Packaging material chapter. 1

3

5

6

7

4

3 4

5

6

7

LS-strip

longitudinal seal

lastic

aluminium

2

reel ofpackaging material

operator panel

fin flap

finflap

sealed

shallow bath

Electrical cabinetIn the electrical cabinet a great part of the electrical components are included, such as: temperature regulators control system (PLC) contactors IH-unit, etc.Learn more about the electrical components in the Electrical system chapter.

Service unitThe service unit includes parts and supply systems needed for the machine function, for example: the water- and air system the lubrication- and hydraulic oil system parts of the sterile-, pneumatic- and peroxide

systems (TBA machines)Learn more about this in the respective chapter.

8 9 11

9

10

8

10

11

2

1

Documentation3


DocumentationIntroductionA certain number of manuals are delivered together with each filling machinefrom Tetra Pak. They can be either machine specific, i.e. they are valid onlyfor one specific machine, or they can apply to several machine types. If themanual is not machine specific you must ensure that the information requiredis valid for the correct variant.Each manual starts with an introduction, describing its contents and how to usethe manual. The manuals that are included with a machine delivery are markedwith series and machine numbers which must correspond with the numbers onthe machine.This section describes the types of manuals that are included in the machinedelivery.

IM Installation ManualThe Installation Manual is not machine specific. It describes what is importantregarding the installation of the actual machine type.It describes areas such as: safety technical data preparations before the installation installation drawings installation checks and preparations for commissioning. Commissioning

refers to the procedure when Tetra Pak hands over the machine and theresponsibility to the customer.

disassembly and return of the machine to Tetra Pak

OM - Operation ManualThe Operation Manual describes the steps to be taken by the operator andhow to handle the machine. It is not machine specific, since it contains e.g.information about the optional equipment for the machines.

MM - Maintenance ManualThe Maintenance Manual contains information about service and maintenanceof the machine. The manual is divided into sections according to the maingroups.It describes among other things: how to check and replace components how to perform the settings special tools and templets required for settings TPMS, the maintenance system of the machineTPMS = Tetra Pak Maintenance

System


EM - Electrical ManualThe Electrical Manual is machine specific. This means that you have to ensurethat the manual used is registered for the actual machine. Even if two machineshave the same development step, the contents in the electrical manuals maystill separate them. Each change in the electrical machine system has to bedocumented in the Electrical Manual. The manual also contains spare part listsfor two main groups of the machine; the electrical cabinet and the operatorpanel.

SPC - Spare Parts CatalogueThe Spare Parts Catalogue is divided according to the main groups of themachine. A Spare Parts Catalogue contains for instance: spare parts numbers information about machine parts exploded drawings of components and accessories

Two of the main groups, the electrical cabinet and the operator panel, are notincluded since these spare part lists are part of the Electrical Manual.

Pasteurisation and UHT4


Pasteurisation andUHTIntroductionPasteurisation and UHT are different methods for heat treatment of products,like milk. The product is heat treated in order to extend the shelf life and toensure that the product does not contain any bacteria able of causing illness forpeople.Fresh milk from a healthy cow is practically free from bacteria, but must beprotected against infection as soon as it leaves the udder. Bacteria capable ofspoiling the milk are everywhere. Careful attention must be paid to hygienewhen producing milk. Anyhow, it is impossible to completely excludebacteria from milk. As soon as bacteria gets into milk they start to multiply,and unless the milk is chilled, it will be spoiled by the bacteria.

Heat treatment All types of heat treatment are made to kill micro-organisms. Examples ofmicro-organisms are bacteria, yeast, mould and virus. When the raw materialarrives at the production plant, it most truly contains micro-organisms, thatsooner or later will spoil the product. To extend the shelf life, you have to treatthe product with heat. The raw material may also have been infected bymicro-organisms able of causing illness for people. The heat treatment will killall such micro-organisms.What type of heat treatment you use, depends on the product and the wantedshelf life of the product.

Pasteurisation of milk When pasteurising milk the aim is to kill all unwanted micro-organisms andall micro-organisms able of causing illness for people. The term pasteurisationcommemorates Louis Pasteur, who in the middle of the 19th century made hisfundamental studies of the lethal effect of heat treatment on micro-organismsand the use of heat treatment as a preservative technique.Pasteurisation followed by quick and immediate cooling, is one of the mostimportant processes in the treatment of milk. If carried out correctly, theseprocesses will supply milk with longer shelf life without the product beingdamaged. Temperature and pasteurisation time are very important, whichmust be specified precisely in relation to the quality of the milk and its shelflife requirements, etc. One example of a common type of pasteurisation is75 C for 15 seconds.

UHT = Ultra High Temperature


UHTUHT treatment is a technique for preserving liquid food products by exposingthem to brief intense heating, normally to temperatures in the range of135-140 C during 4 seconds. This kills micro-organisms which wouldotherwise destroy the products. UHT is a continuous process which takesplace in a closed system that prevents the product from being contaminated byairborne micro-organisms. The product passes through heating and coolingstages in quick succession. Before start of production, the plant must bepre-sterilised in order to avoid reinfection of the treated product.

Rawmilk

Separation

Cream

Standardi-sation

Homoge-nisation

Pasteuri-sation

Milkstorage

Fillingmachine

Skim milk

When the rawmilk arrives at themilk production,the cream isseparated fromthe skim milk.

Then the milk isstandardised, i.e.you set the fatcontent of themilk. This is doneby returningsome of thecream to the skimmilk.

In order to pre-vent forming oflayers it ishomogenised.Then you dividethe fat globalesinto smallerparts.

At pasteurisationthe micro-organ-isms that maycause illness forpeople are killed.

The milk iscooled andpacked eitherimmediately orstored in storingtanks before it ispacked.

Milk production

Rawmilk

Separation

Cream

Standardi-sation

Homoge-nisation

Pasteuri-sation

Milkstorage

Fillingmachine

Skim milkUHT

When the rawmilk arrives at themilk production,the cream isseparated fromthe skim milk.

Then the milk isstandardised, i.e.you set the fatcontent of themilk. This is doneby returningsome of thecream to the skimmilk.

In order to pre-vent forming oflayers it ishomogenised.Then you dividethe fat globalesinto smallerparts.

At pasteurisationthe micro-organ-isms that maycause illness forpeople are killed.

The milk iscooled andpacked eitherimmediately orstored in storingtanks before it ispacked.

UHT treatmentkills all micro-or-ganisms able ofdestroying theproduct.

UHT milk production


Pasteurisation of high acidproducts

To be considered as an high acid product, the pH value must be below 4.6.Most fruit juices are high acid products. High acid products are heat treated inorder to kill the micro-organisms able of multiplying in a product with a pHvalue of below 4.6. The product will then be commercially sterile and gets along shelf life if packed aseptically.

Note!The examples above show the principle for the most common variants of milkand juice production. However, there are several other variants.

Commercially sterileproduct

A UHT treated product or a pasteurised high acid product is commerciallysterile. A commercially sterile product contains no micro-organisms able ofmultiplying. This means that the shelf life is very long if packed aseptically.

PackagingThe package should protect the product and preserve its food value andvitamins on the way to the consumer. The package should also protect theproduct from mechanical shock, light and oxygen

Packaging of chilledproducts - Dairy

Chilled products tend to be perishable, so a clean, taintless package isabsolutely essential. The product also has to be kept cool all the time, frompasteurisation until it is consumed.

Aseptic packaging Aseptic packaging has been defined as a procedure consisting of sterilisationof the packaging material, filling with a commercially sterile product in asterile environment, and producing packages which are tight enough toprevent recontamination. The packages are hermetically sealed. For productswith a long non-refrigerated shelf life the package must also give almostcomplete protection against light and atmospheric oxygen. An unopenedpackage thus protects the product from the environment - there is no need forstoring it cool until it has been opened.An aseptic package also requires that the product is transported aseptically,from the UHT treatment or pasteurisation, to the filling machine. This meansthat all pipes, storage tanks, etc must be sterile.

ConcentrateMixing Pasteuri-

sationWater

Concentrate andwater are mixed.

At pasteurisationthose micro-or-ganisms able ofmultiplying in ahigh acid environ-ment, i.e. pH val-ue below 4.6, arekilled.

The final fruitjuice product ispacked either im-mediately orstored in asepticstoring tanks be-fore it is packed.

Juice production

Juicestorage

Filling ma-chine

Sterile System

5


Sterile SystemIntroductionThe sterile system sees to that the product is packed with a sterile packagingmaterial and in a sterile environment. The sterile system is part of the fillingmachine and is found in all machines that produce aseptic packages.The following is required to get the product aseptic: A commercially sterile product, i.e. a product free from micro-organisms

that may multiply. Aseptic transfer to the filling machine. Sterilised packaging material, i.e. free from micro-organisms. A sterile surrounding, where the package is filled with product. An aseptic package.

The sterile system has three main functions. Their principles are a bit differentdepending on whether the machine has a closed aseptic chamber and a deepbath or an open chamber and a shallow bath. Machine sterilisation - A machine with a closed aseptic chamber is steri-

lised by peroxide, while machines with an open chamber are sterilised byheat-sterilised air.

Sterilisation of packaging material - The packaging material is sterilisedby peroxide, before it touches with the product. In machines with deepbaths the packaging material is covered on both sides with warm peroxide,and with that the sterilisation is finished. In shallow baths the packagingmaterial is only covered on the inside with cold peroxide, but the sterilisa-tion is not finished until after the heating of the tube heater.

Maintain sterile surrounding - After the sterilisation heat-sterilised airmaintains the sterile surrounding and the peroxide is vaporised.

Aseptic = Prevents reinfection

Sterilizedpackagingmaterial

Sterilesurrounding

Aseptictransfer

Commerciallysterile food

Aseptic packages

The Sterile System

Peroxide = Hydrogen peroxide =H2O2


Deep baths

Machine sterilisationBefore start of the production the machine has to be sterilised. The followingdescribes the most important moments for machine sterilisation. At preheating the elements are warmed up to enable that the packaging

material can be sealed. In order to make the machine sterile the aseptic chamber has to be closed.

This is done by creating a tight tube of the packaging material. The sterilisation starts with spraying peroxide into the aseptic chamber. A

thin film of peroxide will cover all the surfaces.When the spraying has started you cannot open the aseptic chamber withoutlosing the overpressure and, thus, losing the aseptic surrounding. Therefore,there are door monitors on all doors of the aseptic chamber. If a door isopened after the spraying has started you will have to start again from thebeginning with the machine sterilisation. If there has been product in themachine, then you have to clean the machine too.The aseptic surrounding is also lost if the packaging material tube is opened.This is the operators task to watch, since there is no other monitoring.

At drying heat-sterilised air is blown into the aseptic chamber in order tovaporise the peroxide. The overpressure from the heat-sterilised air willnow keep the aseptic chamber sterile.When the machine sterilisation is finished you will get a message that themachine is ready for production.

Aseptic chamberSquee-gee rollers

Air

Peroxide

Product

Water

Peroxide tank

Filling machine with a deep bath.

Water ring compressor

Peroxidebath Packaging

material

Water separator

Air superheater

Heat exchanger Product

Tight tube


Sterilisation of packagingmaterial

Before the tube is filled with product the packaging material has to be sterile.The packaging material will be sterilised when it passes a bath with warmperoxide. Squee-gee rollers will remove surplus peroxide and let it flow backto the bath.The peroxide is stored in a peroxide tank. You fill up the peroxide bath byoverfilling, i.e. overfill the bath and let the surplus flow back to the peroxidetank. During production overfilling takes place continuously in order tomaintain the level of the bath and to screen off particles from the peroxide.This is called top filling.Heat exchangers with warm water are used to warm up the peroxide. Sinceperoxide is corrosive you cannot use electrical heaters in the peroxide.The packaging material may not stay too long in the peroxide bath since theedges of the packaging material are unprotected and will soak the peroxide.Thus, the bath is filled just before the packaging material starts to move and isemptied when it stops.Critical factors for the sterilisation: Peroxide concentration - The operator has to check that the peroxide

concentration is correct. Peroxide temperature Time - By checking the level of the peroxide bath and the speed of the

packaging material, the sufficient contact time between the packagingmaterial and the peroxide will be ensured.

Maintain sterile surrounding With an overpressure of heat-sterilised air in the aseptic chamber, the machineis kept sterile and all residues of peroxide vaporise. An air superheater will warm up the air so that it becomes sterile. The heat-sterilised air is cooled in the heat exchanger in order not to

expose the packaging material and the product to too high temperatures. The water ring compressor is the motor in the circulation and soaks air from

the aseptic chamber. The air is cooled in the water ring compressor or in aseparate cooler by the mixture with water. Then the residues of peroxidevapour in the air will condense. This will prevent the peroxide concentra-tion in the aseptic chamber from getting too high.

A water separator will separate the water. As the water contains peroxideit cannot circulate.

After finished production the machine must stay in WEAC position during afew minutes before the operator is allowed to open the doors to the asepticchamber. In the WEAC-position you switch off all heaters so that the air cancirculate and remove the peroxide vapour from the aseptic chamber. This isdone to avoid that the operator might risk to get in touch with the peroxidevapour when the aseptic chamber is opened.

WEAC = Work EnvironmentAseptic Chamber


Shallow baths

Machine sterilisationBefore start of the production the machine has to be sterilised. The followingdescribes the most important moments for machine sterilisation. At preheating the elements are warmed up to enable that the packaging

material can be sealed. Since the chamber is open you cannot make it aseptic. By creating a tight

tube, however, and blowing down sterile air into the tight tube, a sterilearea is formed where the tube is to be filled with product.

The pipes of the machine are sterilised with heat-sterilised air. The air and the machine are slightly cooled before the machine is ready for

production.Sterilisation of packagingmaterial

Before the tube can be filled with product the packaging material will have to besterilised. The packaging material will be sterilised when the applied peroxideis vaporised in the tube heater.The shallow peroxide bath is always filled and provided with peroxide from acan. Rubber rollers pull up cold peroxide from the bath and apply it on theinside of the packaging material. By adjusting the pressure between the rubberrollers you can set the amount of peroxide to be applied to the packagingmaterial.

Product

Airsuper-heater

Water separator

Air

Peroxide

Product

Water

Rubber rollers

Peroxide can

Packagingmaterial

Tube heater

Peroxide bath

Water ring compressor

Filling machine with a shallow bath.

Tight tube

Sterile area

Cooler


The peroxide is mixed with a wetting agent, PSM, to enable that the peroxidecovers the surface with a uniform film and does not split up because of surfacetension.Critical factors for the sterilisation Peroxide concentration The surface tension of the peroxide - The mixture between peroxide and

wetting agent and peroxide is circulating between the bath and the tank toremain well mixed.

Peroxide vaporisation - It is essential that a sufficient amount of peroxidevaporises in the tube heater. The amount depends on the temperature and thehumidity in the filling chamber. This is estimated by means of a table. Toestimate the total consumption you can measure the amount that disappearsfrom the peroxide can.It is also important that all peroxide is vaporised before the packagingmaterial reaches the product. If not, residues of peroxide might get into theproduct.A weakness for shallow baths is that all peroxide consumed by the machinewill be vapour in the air. Therefore, an exhausting device above themachine is needed.

Maintain sterile surrounding By blowing heat-sterilised air into the tube the machine is kept sterile and theresidues of peroxide vaporises. An air heater will warm up the air to make it sterile. The heat-sterilised air is cooled in the cooler in order not to expose the

packaging material and the product to too high temperatures. The water ring compressor soaks air from the chamber. The air is cooled in

the water ring compressor or in a separate cooler by the mixture with water.Then the residues of peroxide vapour in the air will condense.

A water separator will separate the water. As the water contains peroxideyou cannot let it circulate.

Machine stopThis part about machine stop only concern machines with deep baths.Different stops mean different steps to restart the machine. At a normal stop the tube is emptied before the machine stops. When you

restart the machine the packaging material, located in the aseptic chamberand in the peroxide bath during the stop, must be disposed of.

The machine stops with the tube filled with product during a short stop.Since the product in the filling pipe is exposed to high temperature themachine may be idle only during a limited time. When restarting themachine the packages, that might not have been fully sealed, will have to bedisposed of. Also the packaging material, being in the peroxide bath duringthe stop, will have to be rejected. Short stop is only available on machineswith deep baths.

If a door with a door monitor is opened while the machine is running, themachine will stop immediately in so called safety stop. Start after a safetystop takes place as after a normal stop.

At an emergency stop the machine will stop immediately. The motors stopand all pneumatics are vented. You will have to clean the machine andperform machine sterilisation before it can be restarted.

Pneumatic = A way of producingmovements by means of compres-sed air.

Peroxide

6


PeroxideIntroductionHydrogen peroxide, H2O2, is often called Peroxide. Peroxide is used as asterilisation agent in Tetra Pak filling machines. It is a clear, colourless fluidwhich is odourfree in small concentrations but has a somewhat pungent smellat higher concentrations. The peroxide is not particularly toxic and it is simpleto handle, since the residues of water and oxygen gas are harmless.

DecompositionIn pure form and at a low pH-value peroxide is a relatively stable compound.The decomposition into water and oxygen gas takes place when the peroxidegets polluted, for instance by metals.It is accelerated by: heat high pH-value light

When the peroxide is polluted by metallic chlorides, e.g. chlorides of copper,chrome, or iron, it can decompose very quickly. The decomposition can alsotake place at very low proportions of pollutions, a few ppm.When the peroxide concentration is higher than 30% it might cause ignitionin case of contact with wood, paper, cloth, or such. Peroxide itself is notflammable but the oxygen gas, created by decomposition, may facilitateignition and maintain the burning.Some metals have catalytic influence on peroxide. This means that the metalaccelerates the decomposition into water and oxygen gas. Pure passivatedacidproof metals, such as steel or aluminium, does not have any catalyticinfluence on peroxide and can be used as construction materials. At thepassivating process coatings inside e.g. pipe lines are removed by rinsing withdistilled water and peroxide.

SafetyPeroxide is a chemical product, which is corrosive in contact with eyes andskin as well as by consumption. Furthermore, inhalation of peroxide steamor peroxide mist is very irritating for nose and throat.Where the peroxide is handled and stored: an emergency shower and eye flushing equipment shall be easily

accessible, a water hose must be reachable in order to dilute and wash away any

spillage, persons working with peroxide shall wear tight-fitting safety glasses,

protective rubber gloves, shoes made of plastic or rubber, and a protectiveapron.

Hydrogen

Hydrogen

Oxygen

Oxygen

Peroxide molecule

ppm = parts per million = 10-6

Catalysis = Change of reactionrate.


Persons working with peroxide must be aware of the risks involved as wellas the local safety rules and they must follow the safety instructions aboutperoxide provided in the Tetra Pak manuals.

Personal injuriesBelow is a brief description of injuries that could occur when working withperoxide Skin - Peroxide with a higher concentration than 10% is corrosive in

contact with skin. The skin turns white because small blisters of oxygen gasare formed in the skin, called emphysema.

Eyes - Peroxide is very irritating to the eye and might cause permanentdamage on the cornea.

Inhalation - Inhalation of peroxide vapour or peroxide mist may causesevere pain in nose and throat as well as sneezing and coughing. In highconcentrations there is risk of bronchitis and fluid in the lungs, so calledpulmonary edema.

Consumption - Consumption of peroxide causes smarting pain, stomachpain, and corrosive damages. The peroxide will quickly decompose intowater and oxygen gas, which distends the stomach and there is a risk thatit may burst.

HandlingPeroxide is a chemical with relatively small handling risks. However, thosewho handle the peroxide must know the risks. Peroxide must be handled with care in order to avoid any spillage. If peroxide is spilled, remove it with lots of water. Keep the peroxide in its original packing as long as possible. Emptied peroxide must never be returned to the original packing. Tetra Pak recommends that the special filling station is used when

emptying the original packing into the container.

StorageAccording to the safety precautions peroxide must be stored: in a dark and cool place. protected against every risk of pollution. separate from combustible material. in a properly ventilated area.

Cleaning In Place

7


Cleaning In PlaceIntroductionCleaning In Place is usually shortened CIP. It is a method used for cleaning offilling machines and process equipment without having to disassemble them.A production cycle is always completed with CIP. It is important to cleandirectly after the end of the production in order to prevent the product fromgetting dry and that the microbiological growth does not start.

What is cleaned with CIP?On a Tetra Brik machine the following parts are cleaned without dismantling AP valve Control valve Upper filling pipe

The filling machine is cleaned separately, in most cases with a separatecleaning device, intended only for cleaning of the filling machine.On machines with a lower filling pipe, the lower filling pipe is cleanedmanually. This method is called COP which is an abbreviation of CleaningOut of Place.

AP = Aseptic product

Cleaning device

Upper filling pipe

Control valve

AP-valve

The figure shows two filling machines. The uppermachine is in production and the lower one isbeing cleaned.

Hot air

Preheated andcooled air resp.SteamProduct

Detergent

Lower filling pipe

AB

C


What is required for cleaning?There are four important cleaning factors Flow

A turbulent flow of water is required to remove product remnants. This isachieved by the speed of the detergent which is 1.5-3.0 m/min. The flowmust be at least 8000 l/h in order to reach this speed in the AP-valve.

ChemicalsChemicals are used to dissolve the product remnants.

TemperatureCorrect temperature of the detergent is important to dissolve the productremnants.

TimeIt is essential that the detergent maintains contact with the product remnantslong enough in order to be able to dissolve them.

The effects of the chemicalsThe product remnants contain sugar, fat, protein, salt, and minerals. Warmwater is sufficient to dissolve sugar. But to dissolve fat and protein a strongalkali is required. Salt and minerals are a very small part of the product andthey usually disappear with the other dissolved components of the productremnants. In cases where salt and minerals do not disappear, acid has to beused. The quantity of salt and mineral deposits varies due to the degree ofhardness of the rinsing water and the pH-value of the product.

Alkali = NaOHNaOH = Caustic soda

WATER

ALKALI

ACID

Fat

SugarSalt andmineral

Protein

The figure shows applicable chemicals that dissolvethe product remnants. Water is used to dissolvesugar. But to dissolve fat and protein alkali isneeded. When salt and mineral deposits remain,acid is required.


The ladder in the cleaning programmesThe contents of a cleaning programme may vary. On the whole, however, twocleaning programmes are used, daily cleaning and weekly cleaning.

Daily cleaning Daily cleaning is done once per day and includes the following steps:1. Cold rinsing

Cold water forces product remnants out of the pipes.2. Warm rinsing

Warm water dissolves sugar and heats the pipes before the alkali cleaning.3. Alcali cleaning

Alcali dissolves fat and proteins.4. Cold rinsing

Cold water forces alkali and product remnants out of the pipes.5. Final rinsing

Final rinsing takes place until the pH-value of the rinsing water, whichcomes out of the pipes, is equal to incoming water.

Weekly cleaning If too many lime deposits have been built up in the pipes, a weekly cleaning isperformed after the daily cleaning. This can be done as often as required.Weekly cleaning includes the following steps:6. Acid cleaning

Acid cleaning dissolves salt and minerals.7. Cold rinsing

Cold water forces the acid out of the pipes.8. Final rinsing

Final rinsing takes place until the pH-value of the rinsing water, whichcomes out of the pipes, is equal to incoming water.

Final cleaning and intermediary cleaningThe worst that can happen in connection with the production of food is thattoxic components enter the product. Since strong alkalis and acids are used forcleaning it is important to check that no detergent can leak into the product.

Final cleaning Before final cleaning can start, make sure that there is no product in theproduct line. Then turn a key and choose final cleaning. This is one of the ac-tions for the daily care. Tetra Pak recommends that final cleaning takes placeonce per day.

AP-valve, cleaned by final cleaning.

SteamWaterAirDetergentDetergent

A

B

C


Intermediary cleaningIntermediary cleaning is used only if you have to clean the filling machinewhile there is still product in the product line. The AP-valve has a steam bar-rier which prevents the detergent from leaking into the product. This alsomeans, however, that the space in the steam barrier will not be cleaned. Thisspace will be cleaned only at the final rinsing procedure.

AP-valve, cleaned by intermedi-ary cleaning.

SteamProductWaterAirDetergent

A

B

C

Central LubricationSystem

8


Central LubricationSystemGeneralThe central lubrication system provides lubrication to the machine.Lubrication reduces wear and prolongs the lifetime of components in themachines.

At a pressure stroke, the oil is fed from a lubrication pump through the mainline to the dosing valves. From the dosing valves the oil is dosed to thebearings, bushings, sliders etc. that should be lubricated. The quantity oflubrication oil to each lubrication point, is dependent on the size of the dosingvalve, compare A and B in the figure above.The central lubrication system used in Tetra Brik machines, is a high pressuresystem. The lubrication pump is pneumatic and the oil pressure is 5-7 MPaat the pressure stroke. It is a one way system, which implies that the oil isconsumed at the lubrication points.The central lubrication system of each machine is documented as a diagram.In order to simplify and make the diagram easier to read, the variouscomponents are shown as symbols. It is very important that the correct centrallubrication diagram is used when working with a particular machine. There aremany models and versions of machines, and some of them have been rebuiltor modified and differ from their original design.

Basic function of the lubrication system

BA

To lubrication point

Lubricationoil

Lubrication pump

Main line

Dosing valve


ComponentsA description of the main components in the central lubribrication systemfollows below.

Oil tankThe lubrication oil is kept in a tank with a built in pump.

The lubrication oil tank is equipped with filling connection, venting pipe,level sensor, level glass and a built in pump.

Pressure guardThe pressure guard monitors the oil pressure. If the pressure does not reach thepreset value, an alarm will be activated. The pressure guard can also monitorthat the discharge pressure is continued properly after a pressure stroke.

Levelglass

Venting pipeFilling connection

Built in pump

Main line

Level sensor

Main line


Pressure gauge The central lubrication system can be equipped with a pressure gauge whichshows the pressure in the high pressure side of the system.

Central lubrication pump The lubrication pump is a pneumatic single acting piston. The pump feeds theoil with a required pressure at each pressure stroke. The oil pressure is ninetimes higher than the incoming air pressure. The pump is also responsible forthe important decompression, i.e. the discharge pressure, in the main line afterreaching the end of the pressure time.

The central lubrication pump consists of an air cylinder with an air pistonwhich put pressure on the pump cylinder piston. The pump also contains amounted locating head, which includes all the necessary valves, connectionsto the suction pipe and the main line.

Level sensor The lubrication oil tank is equipped with a level sensor that will activate analarm when the oil level is too low.

Main line Suction pipe

Mounted locating head

Return spring

Pump cylinder piston

Air cylinder

Air piston

Incoming air pressure

Maximum level

Minimum level


When the level is below the minimum level a signal is sent to the controlsystem of the machine. The minimum level is set at a level which prevents thesuction tube from sucking air into the system. The maximum level can be usedto control automatical filling.

Oil filterWhen refilling the central lubrication tank, the oil is fed through a hoseprovided with a filter mounted in line in the hose. The filter will take away dirtand particles that may interfere with the function of the pump, dosing valvesetc.

Distribution blockDistribution blocks are used as junctions for the hoses that distribute the oil todifferent dosing valves in the machine.

Dosing valveThe dosing valves ensure that the correct amount of lubrication oil is fed to thelubrication points. It works like a mechanically operated volumetric pistonpump.

The dosing valve consists of a piston housing with a piston that at a pressurestroke, forces the oil upwards, through the non return valve and into thelubrication pipe. It also contains the return spring which forces the pistonback into its rest position after the pressure stroke.

Lubricatingpipe

Non returnvalve

Piston

Piston housing

Return spring

Dosing chamber


FunctionThe oil is fed from the central lubrication pump through the main line andthe distribution blocks to the dosing valves. From the dosing valves the oilis distributed to the lubrication points with set quantities of 10 mm3, 30 mm3,or 50 mm3, independent of each other. It is the size of the piston in the dosingvalve that determines the amount of oil to be dosed. The PLC of the machinecontrols and supervises the lubrication system.

PLC

Basic sketch of a central lubrication system

Dosing valves

Distribution block

Dosing valves

Pressure guard

Filling connection

Lubrication oil

Compressed air

Central lubricationpump

Main line

Button for manuallubrication


The lubrication cycle can be devided into three phases:

Rest position - At the rest position the air piston does not move.The lubrication pump and the dosing chambers are filled with oil.

Pressure stroke - At the pressure stroke oil is fed to the lubrication points.

The air piston in the lubrication pump goes up and forces the oil into thesystem. The oil passes a non return valve and continues through the mainline to the dosing valves. The dosing valve piston goes up and forces the oilthrough a non return valve into the lubrication pipe and out to a lubricationpoint.

Air piston

Dosingchamber

Lubrication oil

Compressed air

Main line

Non returnvalve

Lubricatingpipe

PistonAir piston

Non returnvalve

Lubrication oil

Compressed air


Discharge pressure - At the discharge pressure, the lubrication pump andthe dosing chamber in the dosing valve, will be refilled with oil.

The return spring of the air piston, forces the piston back to its rest position.Lubrication oil flows from the lubrication oil tank through the suction pipeinto the pump cylinder. At the same time the main line is decompressedthrough the non return valves.The dosing chamber is then refilled with oil through the small gap betweenthe piston housing and the piston. The non return valve in the dosing valveis closed which prevents a return flow of the oil.At the discharge pressure, the system is decompressed to a lower pressure ofapprox. 0.2-0.5 MPa. The lower remaining pressure is important for refillingthe dosing valves. If there is no remaining pressure, air might enter the systemthrough leaks. The time needed for the discharge pressure depends on: the viscosity of the oil the running temperature the size of the system

The next pressure stroke must not occur until the dosing valves have beenrefilled i.e. the system has been decompressed.

Pump cylinder

Pistonhousing

Dosingchamber

Suction pipe

Non returnvalves

Air piston

Returnspring

Non returnvalve

Piston

Lubrication oil

Compressed air


Lubrication cyclesThere are two different lubrication cycles. The diagram below shows anexample.

Single lubrication pulse - During production the machine will beautomatically lubricated with one lubrication pulse every 15 min. Theinterval may vary from one machine to another.

Long lubrication cycle - A long lubrication cycle consists of a number oflubrication pulses within a set time interval. It is automatically initiatedfrom PLC at different occasions e.g. when:- the machine is initially started- the machine has been cleaned by external cleaning

A long lubration cycle can also be initiated by pushing the button for manuallubrication e.g. when: the main lines need to be filled up after an interference or a service

RefillingInformation on the proper type of oil to be used in the central lubricationsystem, can be found in the Maintenance Manual and the Operation Manual.The central lubrication tank can be filled manually or automatically. Manual refilling - The central lubrication tank is refilled by using a

transportable pump and tank. The hose is connected to the oil tank in themachine by way of a quick release coupling. The oil is then pumped fromthe transportable oil tank into the lubrication tank.

10 s 10 s

10 s10 s10 s10 s10 s

15 min

30 s

8 s2 s8 s

8 s 8 s

2 s

2 s 2 s

30 s 30 s 30 s

Single lubrication pulse

Long lubrication cycle

Lubrication

Checking- oil level- pressure

Lubrication

Checking- oil level- pressure

A transportable oil tank connected to the oil tank in the machine


Automatic refilling - In an automatic filling set up, the lubrication tanks ofeach machine are connected to a central storage. The oil is pumped out tothe machines.

A solenoid valve is mounted at each oil tank, and when the oil level is low,the solenoid valve opens and refilling take place. When the proper level hasbeen reached, the filling valve closes and the filling ends.

Bleeding The central lubrication system does not work if air enters the system. If air hasentered the system, it must be bled to restore its proper function.

Function check A function check of the lubrication system is made according to the serviceinterval and at every interference in the system. Then for example oil pressureand the function of the dosing valves are checked.

PLC PLC

Set up for automatic refilling

Hydraulic System

9


Hydraulic SystemGeneralHydraulics are a way to create movement by means of hydraulic oil under pressure. In Tetra Brik filling machines, hydraulics is used in order to create the high pressures, the distinctive positions and fast movements, which are needed for sealing and cutting as well as for movements in the final folder.

When the hydraulic oil is fed at a high pressure to the hydraulic cylinder, the piston moves outwards. When the pressure releases, the return spring will press the oil out of the cylinder and the piston will move inwards.The hydraulic system of the machine is documented as a diagram. In order to simplify and facilitate the understanding of the diagram, the various components are shown as symbols. The shape of the hydraulic system varies according to the machine type, development step, and possible rebuilding of the machine. Therefore, it is essential that the appropriate hydraulic diagram is used when working on the machine.

ComponentsBelow is a description of the main components of the hydraulic system.

Hydraulic oil tank The hydraulic oil tank functions as a reservoir for the hydraulic oil in the system. Some components of the hydraulic system, are placed on the oil tank.

The hydraulic oil is filled into the tank by an external pump. At the time of filling, the hydraulic oil is filtered through a filter attached to the filler hose.

Hydraulic oil with pressure

Hydraulic oil not under pressure

Functional principle for hydraulics

Hydraulic oil Hydraulic oilPiston

Hydraulic cylinderHydraulic cylinder

Return spring

Filling connection

Pressure reducing valve

Pressure gauges

Level- and temperature transmitter

Pressure regulator

Hydraulic oil tank


The hydraulic oil in the tank may be drained through a drain valve. The tank is open to the surroundings and thus not pressurised.

Level transmitter and temperature transmitter

The level transmitter can indicate two or three levels; high, low and if a third exist, soon low level.The built in temperature transmitter, senses the temperature. It is normally set at 70 C. If the temperature exceeds the set level, an alarm will indicate that the temperature is too high.

Oil coolerThe oil cooler cools the hydraulic oil.

The oil cooler is a type of heat exchanger in which water is used as a cooling media. The cooling water can be re-circulated. The heat is created by the friction, formed when the oil is transported in the hydraulic system.

Hydraulic oil pumpA hydraulic oil pump is used in order to pressurise the hydraulic oil. The pump is a gear pump, driven by an electric motor.

Oil cooler, length section

Hydraulic oil Hydraulic oil

oolingater

Cooling water

Oil cooler, cross section

Inlet

Outlet




Filter A filter strains solid particles and other impurities, which may block valves and cylinders. Particles and impurities could also in other ways, have a negative influence on the function of the hydraulic system. The filter has an indicator, which shows whether the filter is blocked and needs to be replaced.

An internal overpressure valve protects the filter against too high pressures. This may happen if the filter is blocked and the oil cannot pass. In order to prevent damage to the filter, the overpressure valve will open at a set pressure and let the oil pass through.

Non-return valve Non-return valves are used in order to control the flow directions of the hydraulic system.

Accumulator The accumulator is used in order to keep an even pressure in the system when the various valves open and close.

An accumulator is a pressurised vessel, divided into two chambers. The upper chamber is filled with pressurised nitrogen and the lower one is filled with hydraulic oil. The upper chamber functions as a counter pressure, i.e. it will press oil out to the system when the consumption is higher than the pump supply, and it will let the oil in, when the consumption is lower than the pump supply.

Inlet Outlet

Filter

Indicator

Overpressure valve

Pressurised nitrogen

Hydraulic oil


Pressure regulatorA pressure regulator sets the system pressure. The system pressure is used for the catch cylinders, for example. A pressure gauge shows the system pressure.

Pressure reducing valveThe pressure-reducing valve is used in order to reduce the system pressure, for example to the cutting cylinders. A pressure gauge shows the pressure.

ThrottlingThe throttlings are used to reduce the flow in the pipe, for exampel to the cylinders. A lower flow during the pressurisation, reduces the speed of the pistons in the cylinders. This reduces the risk of mechanical damage when the cylinder reaches its final position. However, the throttling will not influence the final pressure in the cylinder.



Hydraulic oil with full pressure

Hydraulic oil with reduced pressur


Valve Valves direct the hydraulic oil to and from the cylinders. When the valve is open, oil is fed into the cylinder at high pressure. When the valve is closed, the pressure is released and the oil flows back into the tank. The valves are either electrically controlled by a signal from the machine control system, or mechanically controlled by a cam.

Impulse transmitter When mechanically controlled, the valve functions as part of a, so-called, impulse transmitter. This transmitter is connected to the jaw system by a timing belt in order to remain synchronised with the jaw system. The impulse transmitter consists of cams and valves. The cams affect the valves by one high part of the cam and one low part of the cam.

The low part of the cam opens the valve and the cylinder is pressurised.The high part of the cam closes the valve and ensures that the cylinder is unaffected. During high cam, the oil from the cylinder is directed back to the tank.Note!The situation can also be reversed, i.e. the low part of the cam closes the valve while the high part opens the valve and pressurises the cylinder. It depends on how the system is designed.

Open valve Closed valve

Cylinder

Flow outlet Flow inlet



Cylinder

Cam


FunctionThe working principle of a hydraulic system is shown below.

The motor-driven pump (1) suctions hydraulic oil from the hydraulic oil tank (2) through the cooler (3). The level transmitter (4) and the temperature transmitter (5) are mounted in the tank. The pump forces the hydraulic oil through the filter (6) and pressurises the accumulator (7). On the filter there is an indicator (8), which shows when the filter is blocked and needs to be replaced. The pressure regulator (9) sets the system pressure. In front of the cylinders there are throttlings (10) in order to reduce the speed of the pistons in the cylinders, and by that, prevent damage to these components. To some parts of the system, the pressure is reduced by a pressure reducing valve (11). A cam (12), or an electric signal from the control system, operates the valves (13) to the cylinders (14).The hydraulic cylinders perform mechanical movements in the machines. The catch cylinders are connected to the catches. When the cylinder is

activated, the inductor and the pressure jaw are pulled together, causing pressure on the packaging material tube. This pressure is used for sealing the transversal seal, and as a hold-down for the cutting. The return movement takes place when the oil pressure is released and the spring forces the catches back.

The cutting cylinder is connected to the knife, which cuts the packaging material tube into single packages. When the cylinder is pressurised, the knife will move forwards, cutting the tube. The return movement takes place when the oil pressure is released and the spring forces the knife back.

The pull-down device and the pressure device, shape the package in the final folder. This is valid for machine types TBA/9 and TBA/19 only. The cylinders in the pull-down device and the pressure device, are operated by hydraulic oil and have spring returns.

Force The hydraulic pressure determines the force, by which the hydraulic cylinder will affect the load. When the pressure decreases, also the force decreases. Consequently, when the pressure increases, so does the force. The pressure is set by a pressure regulator.

M

2

1345

79

8

10

1312 13

14

11

10

14

6


Speed By throttling the flow to the cylinder, the speed of the piston movement can be regulated. This is done by the use of throttlings on the con-nections between valves and cylinders.

Hydraulic oil In order to maintain an efficient flow of energy in a hydraulic system, the correct type of hydraulic oil must be used. Information about which oil type to be used for the different machines, is found in the Maintenance Manual as well as in the Operation Manual.The following is required for an oil to function properly in a hydraulic system. The hydraulic oil must have a viscosity to seal small gaps and clearances, in

order to avoid leakage. The hydraulic components often lack elastic seals. The hydraulic oil must lubricate the components in order to reduce the

wear. Since the clearances and gaps in the hydraulic components are small, there is a risk of direct contact between the parts in a components. When there is direct contact, the material is worn off and the gaps in the compo-nents increase. Worn components cause capacity losses and leakage risks.

The hydraulic oil must chill and carry off the friction heat from efficiency losses in the system.

Impurities, which enter the hydraulic oil, may damage the system. Air Under normal pressure the hydraulic oil binds only a small amount

of air. However, under pressure, the hydraulic oil is capable of binding much more air. Air is released when the pressure decreases and small air bubbles are formed. In the tank, the air is separated from the hydraulic oil.When hydraulic oil containing air, is pressurised, it turnes elastic and it will take a longer time to reach the correct pressure. This may affect the function of the system. Furthermore, air in the hydraulic oil will decrease the possibility to build up a lubricating film, and thus reduce the lubrication effect on the components.

Water Hydraulic oil naturally contains 0.01-0.02% of water. At higher concentrations, the water may appear in a free state, which may damage the system. The water may appear from condensation, leaking water coolers, or leaking components.Water in the hydraulic oil may cause corrosion on the components in the system and decrease the capability to build up a lubricating film. When the proportion of water in the hydraulic oil is high, the oil may get thicker and thus block the filter.

Solid impurities Solid impurities in the hydraulic oil could cause problems in pumps, valves and cylinders. The solid particles are filtered out into two filters; one in the filling hose and one after the pump.

Safety The pressure must be discharged when working in hydraulic systems. An accumulator is pressurised up to 70 Bar. When the system is to be vented, the pressure must be reduced to a maximum of 40 bar, in order to decrease the risk of splashing.Furthermore, the handling instructions from the manufacturer must be followed, since the hydraulic oil may be health hazardous and allergenic.


SymbolsThe table below contains the symbols that normally are used in Tetra Pak hydraulic system diagrams.

Symbol Meaning

Accumulator

Non-return valve

Valve, electrically operated

Valve, cam operated

Manual valve

Cylinder with oil return

Cylinder with spring return

Filter

Throttling

Cooler

Pump


Tank

Motor

Level transmitter

Temperature transmitter

Pressure gauge

Pressure indicator

Pressure regulator

Pressure reducing valve

Symbol Meaning

M

Cooling Water System

10


Cooling WaterSystemGeneralTetra Brik filling machines use water to cool different components, like: inductors in the jaw system guide rails in the final folder oil in the hydraulic system air in the electrical cabinetThe cooling water system can either be open or circulating. Circulatingcooling water is used when the temperature of the ordinary water supplyis too high, over 20 C. In an open system, the water is consumed, whilea circulating system uses the same water over and over again.

Many machines have a separate water cooling system. This means that thereis some kind of heat exchanger between incoming water and water to becooled. In an open separate water cooling system, the cooler is part of themachine.

The cooling system of the machine is documented by means of a diagram.To simplify the construction and make it easier to understand, the diagram ismade up of symbols for the different components. The design of the coolingwater system varies depending on machine type, development step andrebuilds. Thus it is important to use the correct cooling water diagram whenworking on the machine.

Open cooling water system

Chilled unitFrom cooler

Return to cooler

Cooler

Drain

Chilled unit

Circulating cooling water system

Circulating separate cooling water system

Chilled cold waterChilled unit Chilled unitCold water

Cool

er

Hea

t exc

hang

er

Hea

t exc

hang

er

Hea

t exc

hang

er

Open separate cooling water system


Cooling waterIn order to be able to cool efficiently, the water must be of adequate qualityand temperature. Data on water quality to be used for the different machinescan be found in the IM, MM or OM.

The kind and quality of the water differs. Below some examples: Raw water is a surface or ground water. Depending on where it is taken, it

contains different ingredients and impurities. Drinking water is produced from raw water. Drinking water must not

contain components that may cause illness. Deionized water is produced from drinking water. In deionized water you

control the amount of hardening ions. Totally desalinated water is also produced from drinking water. All salt

ions, both positively and negatively charged ions, are removed.

ComponentsA cooling water system is built up of many components. The most importantand frequent ones, are described below.

Manual valveManual valves are opened and closed manually.

Electrically controlledvalve

An electrically controlled valve receives a control signal from the machinecontrol system when to open and close.

Pressure gaugeA pressure gauge displays the pressure in the cooling water system.

Over-pressure valveIn order to protect the cooling water system, there might be an over-pressurevalve included in the system.

The overpressure valve opens up if the pressure in the cooling water systemexceeds a preset pressure. Water is then released, causing the pressure todecrease in order to avoid damages to the cooling water system.

FilterThe filter is used to filter off solid particles and other impurities which mayclog valves and narrow passages, or in any other way affect functions in thecooling water system.

Overpressure valve


Magnet device The magnet device prevents forming of lime deposits in the cooling watersystem. It is built up of a mechanical filter and a magnet device.

Mechanical filter - The filter basket (1) collects any solid impurities in thewater. Inserted in the filter basket there is a magnet rod (2), collecting anymagnetic impurities like iron chips. The magnet has a plastic cover toprevent corrosion.

Magnet separator - This consists of two permanent magnets (4) forminga gap (3), through which the water flows.

The function of the magnet separator can be described like this:Between the magnets (4) there is a heavy magnet field. The magnet fieldaffects the lime in the flowing water so that the lime deposit formed in thecooling water system does not adhere to the cooling water channels. Insteadthe lime deposit will follow the cooling water out to the return line. Thefunction of the magnet device is temporary.

Water tank There is a water tank in some machines, and it works as a reservoir forthe water.

12

34

Magnetically treated water. Thecrystals do not gather and do not stickon surfaces.

Magnet field

4

4

Untreated water. The crystals gatherand stick easily on surfaces.


AccumulatorThe accumulator is a vessel containing air. The air can be compressed, to takeup any pressure variations caused by temperature variations.

Temperature sensorA temperature sensor monitors the temperature and signals the control systemif the temperature raises above or falls under the preset values.

ThermostatThe thermostat is used to keep a constant temperature by regulating the flowand thus the supply of colling water to a component.

Pressure guardA pressure guard monitors the pressure and signals the control system if thepressure raises above or falls under the preset values.

Heat exchangerHeat exchangers are used in a cooling water system to transfer heat from onecircuit to another, without any direct contact between the medias. The twomain types used are tube heat exchanger and plate heat exchanger.

Water pumpThe water pump circulates cooling water, used to cool various components.

Non-return valveNon-return valves are used in the cooling water system to direct the flows.

ThrottleA throttle is used to set a desired flow through a component or a part of thecooling water system. The throttle can be fixed or adjustable.

Flow meterThe flow meter is a floating body meter used to measure small liquid flowswith high accuracy.

Plate heat exchanger

Cold water

Hot water


In the valve housing of the flow meter, made of transparent plastic, there is aconical passage with its narrowest part turned downwards. In the passage thereis a ball affected by the flow of the water.

When the flow increases, the ball is lifted. Due to the fact that the passage isconical, the ball will stabilise in a specific position, and the flow can be readon the graduated scale.

Constant flow valve In order to make the water flow to the water ring compressor independent ofthe pressure in the water line, there is a constant flow valve fitted just beforethe compressor.

The acting part of the valve is a soft rubber washer. In the middle of the washerthere is a hole, through which the water flows. The size of the hole variesdepending on the water pressure, and thus keeps the water flow through thevalve constant.

Low water pressure - The shape of the rubber washer makes the hole inthe middle relatively large, i e water with low pressure flows through alarge hole.

High water pressure - The rubber washer is deformed so the diameter ofthe hole is small. This will cause the rubber washer to reduce the water jet,but as the water pressure is high, the same amount of water will flowthrough the valve as when the pressure is low.

Low water flow High water flow

The constant flow valve is designed for a fixed flow.

Low water flow High water flow

The shape of the rubber washer at low and high water pressure, respectively in aconstant flow valve.


LIME SEPARATOR

VALVE PANEL

Cold water A1 Z3 Z5

B4

GUARDB7

JAW SYSTEM

TSsealingL R

Y32M5

Sealingunit

FINAL FOLDER

(K50)

CoolerhydraulicsystemFM2 FM3

Compressor (M7)Scrubber

Separator

SERVICE UNIT

Z1

Cirk. coldwater inlet

A2

Drain

Cirk. coldwater outlet

M

A4

Conductivity sensorThe conductivity sensor monitors the electrical conductivity in the water, andsignals the control system if the conductivity raises above or falls under thepreset values.

Softening filterA softening filter is a container with a bed material, often consisting of smallpolystyrene balls. When the water gets in contact with the bed material, thereis an exchange of ions. Thus the amount of hardening ions in the water isreduced and you get a soft, so called dehardened water.

FunctionThe cooling water is used to cool the inductors, the guides in the final folder,the hydraulic oil and the sterile air. The diagram below describes a system thatmay be run both open and recirculated.

Water connection B shall always be connected and valve A1 open, as thereis always a need for consumption water to cool components in the service unit.For circulated cooling water, the water connections A and E shall also beconnected, and the valves A2 and A4 be closed.The circulating water enters the system at connection A, is filtered in filter Z1and flows further on to the jaw system and final folder. The pressure ismonitored by the pressure guard B7. The water flow through the inductorsin the jaw system can be read on flow meters FM2 and FM3. At point D thecirculated cooling water turns back and flows out at outlet E.For an open cooling water system only water connection B shall beconnected and the valves A1, A2 and A4 be open. The cooling water enters atconnection B, is filtered in filter Z3 and flows through the lime separatorZ5.

A

D

B

E

Simplified cooling water system for a TBA/19

C


At point C the water flow is branched and the consumption water flows on tothe service unit. The remaining water flows pass the open valve A4 and intothe system. The pressure is indicated on the pressure gauge M5. At branchingpoint D the cooling water is drained through valve A2.The following is a separate closed cooling system with three separate circuits

One circuit is cooling the heat sources on the machine and it is called the watercooling unit. It is a closed circuit. The water used in this circuit must be totallydeionized in order to remove all particles that could clog the cooling pipes inthe transversal sealing inductors. Approximately 10% of the total flow iscirculated through a total deionizing filter C/A.The second circuit is called compressor unit. It is a closed circuit and it isactually the cooler in the machine. In this system, which is identical to arefrigerator, gas is used as media.The third circuit is an open circuit, meaning that the water is drained off afterbeing used to cool the compressor unit.When the water cooling unit is filled with water, valve V is open and thewater flows through the deionizing filter, C/A. The temperature of the waterin this circuit should be 12 C. This is monitored by sensor B2 after the heatexchanger K2. To maintain that temperature, the compressor unit takes upthe heat energy needed from the water cooling unit in the heat exchanger K2(evaporator) in which the gas will be evaporated. This energy will then betransferred by the gas to another heat exchanger K1 (condenser), where theenergy will be transferred to the water in the open circuit. The gas will becondensed after the condenser.

M

C/A

Q

P

T

MM1

P1

A2

B5U1 F1

B2

B1 O2

K2

O1

K1 B4

P2

M2

TP

PB3P

Z2

Water panel

Compressor unit

Jaw unit Final folder Pull Tab

TSsealing

Water cooling unit

Guide cooling

Inductor

Heat

exc

hang

er

Heat

exc

hang

erCold water

V

Simplified cooling water diagram for a TBA/21


SymbolsThe table below contains the symbols that normally are used in Tetra Pakcooling water system diagrams.

Symbol Meaning

Accumulator

Deionizing filter

Non-return valve

Electrically controlled valve

Manual valve

Filter

Throttle, adjustable

Constant flow valve

Cooler

Water pump

Motor

Water tank

C/A

M


Heat exchanger

Cooling coil

Deaerator

Flow meter

Pressure gauge

Conductivity sensor

Temperature sensor

Pressure guard

Pressure regulator

Symbol Meaning

Q

T

P

Pneumatic System

11


Pneumatic SystemIntroductionThe technology of using compressed air to create movement is termed Pneumatics. In the Tetra Pak packaging machines and distribution equipment, compressed air is used to:make components move, operated by pneumatic cylinders make components move, operated by pneumatic cylinders control and operate valves create vacuum and supply air nozzles with air

The pneumatic system consists of two parts. One part is located external to the machine; in it, the required pressure is generated. The external pneumatics include compressor, air conditioning unit, main air supply line, etc. The other part is inside the machine and includes regulators, valves, cylinders, etc.The air used in the pneumatic components must be clean and dry; pressure and flow rate must also be as required. The recommended values are specified in the installation manual (IM) for the machine concerned. In some systems, the components are factory prelubricated once and for all, requiring no further oil or grease; air for these components must be as free from oil as possible. However, if such a component is once mist lubricated, it must always be mist lubricated from then on.The pneumatic system of each machine is documented in the form of a diagram. In order to simplify its construction and make the diagram easier to read, the various components are shown as symbols.

As there are many models and versions of machines, and some of them have been rebuilt or modified to differ from their original design, it is very important that the correct, updated, and currently valid pneumatic diagram is used when working with a particular machine.

CylinderValvePressure regulator Shutoff Pressure


Air conditioning unitsThe first unit the air passes through on its way to the machine is the air conditioning unit. It consists of a separator, pressure regulator with pressure gauge, and, on some machines, lubricator. Normally, a shutoff valve is built into the conditioning unit.

SeparatorThe purpose of the separator is to remove water and other pollutants that might be present in the compressed air. The separator consists of a filter element and a reservoir with a drain valve. The filter element may be made of sintered bronze. The input air is made to rotate, so that water drops and the larger solid particles are flung outwards against the inner surface of the reservoir. Condensated liquid runs down to to bottom of the reservoir, where it is removed through the drain valve when the input air is turned off.

Pressure regulatorThe purpose of the pressure regulator is to provide air at a constant pressure, independent of the load on the system. It is a form of pressure reduction valve, and its function will be explained under the heading of Valves.

Pressure gaugeThe pressure gauge indicates the pressure setting.

LubricatorThe lubricator (mist lubricator) provides the compressed air with oil. The injected amount of oil is proportional to the flow rate of the air and can be preset. In systems whose components are factory prelubricated, no oil must be added to the compressed air, as oil would wash out the grease in the prelubricated components.

Separator

Pressure gauge

Pressure regulator

Lubricator

Shutoff valve

Air conditioning unit symbol


ValvesThe purpose of valves is to regulate the flow rate and pressure of the compressed air and control its flow direction. The valves are controlled and operated either manually, by means of electrical signals from the PLC, or pneumatically by other valves.Valves are subdivided into two groups seat valves and slide valves. These groups differ in their design.

Seat valve The seat valve controls the flow of air by means of its valve head and seat. The valve head only has to move a short distance to change over but needs considerable changeover force.

Slide valve The slide valve controls the air flow by means of a movable slide. To change over, the slide has to move a relatively long distance, but the force needed for it is small.

In respect of their purpose, valves are grouped as follows: directional valves, controlling the flow direction of the compressed air, for

instance to operate the reciprocating movement of the piston in a pneumatic cylinder.

flow rate regulating valves, controlling the amount of air per time unit, for instance to control the speed of the piston in a pneumatic cylinder.

pressure regulating valves, controlling the pressure in the pneumatic system.

Before proceeding, we shall take a look at the symbols for the valves, and how they are constructed and function.

SeatValve headHousingReturn spring

Nonactuated Actuated

Housing

Return spring

Nonactuated Actuated

Slide


Valve symbolsThe valve symbols denote the function of the valves but not their design. This means that valves that look differently, due to the way they are designed and constructed but function in the same manner, are shown with the same symbol.The illustration shows the working principle of a slide valve, which may be in either of two positions.

This valve can be shown simplified as a symbol.The symbol consists of a square, with the ducts through which the air is able to pass shown as arrows. To the left and right of the square, the manner in which the valve is controlled is symbolised, for instance with a horizontal line for pneumatic control. The lines above and underneath the square represent the ports connected to the input and output air lines.

Valve

Pilot air

Outlet.

Vent.

Pilot airSlide

Position 1The valve has received pilot air on the lefthand side. The passage between in-let and outlet is open, and the vent is closed

Position 2The valve has received pilot air on the righthand side. The inlet is closed, and the passage between outlet and vent is open.

Inlet.

Valve housing

Inlet

Pilot air

Outlet

Vent

Pilot air

Position 1The valve symbol is shown with open passage between inlet and

Position 2The valve symbol is shown with open passage between outlet and


The function of the valve is illustrated by means of symbols. Each position the slide may be in is shown as a symbol, and the symbols are drawn after one another. The ports are only shown on the symbol in active position in the pneumatic diagram, which is the starting position of the valve.

To make it easier to identify them, the ports are numbered: input air port No 1; output air port No 2; vent port No 3. The pneumatic signal ports take their numbers from the ports they provide passage between; for instance, port No 12 connects input and output air.

As the valve in the example has three ports and a slide which may be in two positions, it is termed a 3/2 valve. Similarly, a fiveport valve with a threeposition slide becomes a 5/3 valve.The valve may be operated in several ways. Other than pneumatically, it can be operated manually, by a spring, or electrically. The different ways are shown as symbols. In the following example, an electrically operated 5/2 valve with spring return operates a double-action pneumatic cylinder.

The various forms of valve symbols used in our pneumatic diagrams are explained in greater detail in the section of this text where the function of the valves is described.

Pilot air

Active part of

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