garment printing

Winter Internship Report

A

Report

On

Winter Internship

By,

Rajesh Kasetty


CHAPTER – 2

S A M P L I N G F L O W C H A R T


P R O D U C T I O N F L O W C H A R T


CHAPTER – 3

M A C H I N E R Y I N F R A S T R U C T U R E

S.No Machine Make Model Remarks

Qty

Availabl

e

1

Carousal Printing

machine / T-Shirt Chest

Printing machine

Sigma

8C8 Colour

/Pallets10

7

12

Colour

/Pallets

2

2Heat Transfer Press /

Digital FusingCheran

CF-2002 2.5 KW 4

CF- 2002 2.0 KW 5

CF-20031.3 KW

twin head1

3 Electric Curing Machine Cheran Custom 18kw 1

4Screen Preparation

&Exposing MachinesCustom Made 1

5 Colour Matching Para Mount Spetra Vision 1

M A K E

SIGMA : SIGMA INDUSTRIAL, KURICHI INDUSTRIAL ESTATE POST, COIMBATORE - 641021

CHERAN : CHERAN MACHINES INDIA PVT LTD, 65/1, CHINNAVEDAMPATTI (PO), GANAPATHY, COIMBATORE - 641 006


Plant Lay-Out


CA ROUSAL PRINTING MACHINE / T-SHIRT CHEST PRINTING MACHINE

These machines will be available both in automatic and semi automatic machines andwith 4, 6, 8, 10 & 12 multi colour models. The double spring model gives the customers a maintenance free performance of the machine. Electric heat panels included in the machine.

Features

Index pin /Bearing Registration

Multi directional Micro registration

Double spring Model

Sturdy side screen clamps

Off contact adjustment

Interchangeable pallets

Fire/Water proof pallets

High energy efficient infra-red Heating Panel

o Easy adjustmento Castor wheel mounted for easy mobility

Technical Specifications

Model 8c 7No. of Color 8 colour 12 ColorPrinting Area 20" x 30" 20" x 30"Machine Dia 12.5 feet 16 FeetMachine Height 4 Feet 4 Feet

HEAT TRANSFER PRESS / DIGITAL FUSING


This range of fusing machines is capable of generating high volume and hard pressing on garments and other fabrics. These highly powerful machines are planned in way that they would consume very minimal energy and would work with optimum efficiency.

Features Used As Heat Transfer Press, Designs To Be Transfered To The Garments /

Fabrics / Leathers/ Rexin /Nylon / Polyprpelene/ Bags & etc. Can be used for fusing like plastisol priniting, khadi, pigment & etc

Silent operation and easy to maintain

MicroSoft based digital temperature & timer controller.

Die casted aluminum heater plates are used to assure a long service life and even heat distribution.

Automatic Double Stroke operation & production monitoring.

Can Be Used As Flat Bed Fusing Machine For Collar And Cuff Fusing

Platen Size Can Be Increased Up to 20" X 30".


Model CF2002 CF2003Platen Size 400mm X 500mm 250mm X 380mm

Platens 1 2Power 230 V,50Hz,11Amps 230 V,50Hz,5.5AmpsHeater 2.5 Kw 1.2Kw

Air Pressure 0 to 8 bar 0 to 8 barTimer 0 to 99 Sec 0 to 99 Sec

Temperature 2500C 2500C


ELECTRIC CURING MACHINE

These premium quality machines are equipped with PTFE Teflon Perforated Sheet for Conveyor to give long life and hence have very powerful heating and cooling effects that help in the purpose of drying.

Electric Curing

Radiant Quarts heater for immediate heading and cooling Variable speed control system


Machine Size (l x b x h) 14 x 3.5 x 4 feetPower 440V - 26AHeater 18 KwWorking Area 900mm x 3000mmTemperature 200oCOperating Speed 33 f/minConveyor Drive 180V DCBlower 230 / 30 W AC


SPECTRAVISION

spectraVISION™ is an economic colour matching model which provides a standardized and controlled environment for visual assessment of colours with strict adhering to international norms. The cabinet having five standard light sources.

EQUIPMENT

The equipment wil have all standard tube lights & bulbs for accurate Color Matching. In order to safeguard the expensive & sensitive tube lights spectraVISION™ is fitted with Electronic/ballasts for Instant start & power saving.

TECHNICAL DETAILS

A. DIMENSIONS

Main Supply : 230V, 50 Hz, AC Single PhaseSize of viewing board : (380 x 380) mmAngle of Viewing board : 45°Hour totaliser : 0 – 10,000 Hour, L/C : 1 Min.

B. LIGHT SOURCES

Artificial Daylight Fluorescent Lamps (D-65) : 02 Nos. (18 W)Tungsten Filament Lamps (Inc A Lamps) : 04 Nos. (40 W)Cool White Fluorescent Lamp (CWF) : 01 Nos. (18 W)Triphosphor Fluorescent Lamp (TL-84) : 01 Nos. (18 W)Ultra-Violet Black Lamp : 01 Nos. (18 W)


CHAPTER – 4

SCREEN PRINTING

Screen printing is a process, where ink is mechanically applied to a substrate via the use of a screen and squeegee. In its basic form, screen printing is a very simple process.

Each colour of the design requires an individual screen so we must separate the design into its component colours. This is done on the computer and each colour separation is printed to a transparent sheet.

Original Black Yellow

Design Colors

Separations

The screen is a rigid frame of wood or aluminium that has a fine monofilament nylon mesh stretched over it. This mesh is then coated with a light sensitive emulsion that will become the stencil through which the ink will pass when printed.

Blank Screen Coated Screen

The screen is then mounted, with the separation, in an exposure unit. This machine exposes the screen to high intensity UV light.

Exposing the Screen


When the UV light hits the emulsion a chemical reaction hardens the emulsion making it water and solvent resistant. The separation acts as a shield to block the light in certain areas of the screen. These soft areas are then rinsed away with water to create the open area of the stencil.

Black Screen Yellow Screen

The screens are then mounted in the press and registered, or aligned, so that each colour prints in the proper location relative to the other colours. Ink is loaded into the screens and squeegees are installed. The actual printing is accomplished by pushing ink through the screen and onto the shirt with the squeegees. As the squeegee scrapes across the screen it fills the stencil with ink while simultaneously bending the mesh down to transfer the ink to the shirt.

To create the composite image on the shirt, individual colours are printed then the shirt is moved to the next colour. After test prints are run to check alignment, shirts are loaded one by one and printed.

PRINTING MECHANICS

Once all the colours have been applied to the shirt it is removed from the press. The ink on the shirts is still "wet" at this point and needs to be "dried".

4-COLOUR PROCESS


4-colour process is a more advanced separation and printing technique that uses 4 colours of transparent ink to produce the colours from the original design. The four colours, Cyan, Magenta, Yellow, and black (CMYK), are printed as halftones that interact with each other and the white background of the shirt to create colour and tonal values. A wide spectrum of colours can be represented but some colours are impossible to produce.

4-color process is used mostly for photographic or digitally created designs because many shades and colors can be created with only four screens. High screen counts and screen frequencies are required to create the tiny halftone dots.

One drawback to 4-color process is that the garment must be white.

Original Cyan Magenta Yellow Black

Design Colors

Separations

As Each Color is Printed

MESH COUNT

The mesh count is the number of threads per inch (tpi) used to weave the mesh. Typical mesh counts for screen printing t-shirts range from 85 tpi to 355 tpi. The mesh count defines basically two things: The thickness of the ink deposit and the size of halftones that can be printed.

The lower mesh counts, 85-110 tpi, have a relatively large thread diameter and more space between the threads (called "open area" ). This allows for a thicker deposit and more ink to pass through the screen. Typically, lower mesh counts are used for specialty inks (like glitter) and when a thick deposit is needed on dark garments.

The high mesh counts, 305-355 tpi, have a very small thread diameter and less open area. These are used when fine detail and high halftone are needed.


Mesh Count for Different Garment Prints

1. Glitter 25–602. Flock adhesive 45–1253. Puff-up colors 55–1254. Overprint 80 –1105. Pigment ink printing areas/lines 110 –1756. Plastisol 1 125–3057. Pigment inks, half-tone 155–2558. Sublimation transfer 195–305

Mesh Specifications

Mestcount

Threaddiameter

Mesh opening

Open surface

Fabricthickness

Weight

cm mesh/inch Micron micron % micron g/m25 12 500 1500 56 850 2716 16 400 1267 58 780 2087 18 350 1079 57 675 1868 20 350 900 52 685 2129 24 250 860 60 455 14510 25 300 700 49 576 19512 30 250 583 49 470 16212 35 300 533 41 585 23414 40 300 414 34 595 27316 40 200 425 46 370 13916 50 250 375 36 485 21720 50 150 350 49 375 9820 50 200 300 36 385 17324 60 150 267 41 285 11728 70 120 237 44 215 8730 76 120 213 41 225 9432 80 100 213 46 165 6936 90 100 178 41 178 7840 100 100 150 36 190 8743 110 80 152 43 135 6048 120 80 130 38 145 6256 140 60 120 44 85 4459 150 60 110 42 98 4664 160 60 100 37 105 5072 180 50 90 41 82 3980 200 50 75 36 90 43

100 250 40 60 36 65 35120 305 40 43 25 70 42130 330 40 37 23 75 45


TYPES OF PRINTS

PLASTISOL

The most common ink used in commercial garment decoration. Good colour opacity onto dark garments and clear graphic detail with, as the name suggests, a more plasticized texture. This print can be made softer with special additives or heavier by adding extra layers of ink.

Plastisole inks require heat (approx. 150°C) to cure the print. The inks contain polyvinyl Chlorides mixed with resins and pigments these inks have got a property by which the prints get dried only with the application of that. They have soft handle and resist cracking when stretched. Main thing is curing process in Plastisole printing. So it must be fused for the better finish.

Due to excess phthalate in PVC, this is banned for Children’s wear. Due to plasticity in the nature it cannot be ironed directly, it should be ironed or fused with the help of fusing paper only.

WATER-BASED INKS (Pigment Print)

These penetrate the fabric more than the Plastisole inks and create a much softer feel. Ideal for printing darker inks onto lighter coloured garments. Also useful for larger area prints where texture is important. Some inks require heat or an added catalyst to make the print permanent.

PVC/ PHALATE FREE

Relatively new breed of ink and printing with the benefits of Plastisole but without the two main toxic components - soft feeling print.

FOIL

This printing method is based on the use of metallic foil paper of aluminium or copper one. The print fixation method is similar to transfer printing. This print method is popular amongst youngsters. A glue is printed onto the fabric and then foils applied for a mirror finish. Generally gold or silver foils used.

DISCHARGE INKS

Used to print lighter colours onto dark background fabrics, they work by removing the dye already present in the garment and apply new colour. This gives a much softer texture, since this technique can only be used for pigment prints (water based colours). Rangolite-C is the main commercially using discharging agent.


FLOCKING

This process involves printing of glue on the fabric first, applying the fiber flock on the gel printed by keeping the fabric on special table (electro statically charged). And it requires a little high time for curing than normal prints. 120 seconds at 160C will be sufficient for curing.

This print technique will give unique finish of velvet touch.

GLITTER/SHIMMER

Metallic flakes are suspended in the ink base to create this sparkle effect. Usually available in gold or silver but can be mixed to make most colours.

METALLIC

Similar to glitter, but smaller particles suspended in the ink. A glue is printed onto the fabric then a nanoscale fibres applied on it.

EXPANDING INK (PUFF)

An additive to Plastisole inks which raises the print off the garment, creating a 3D feel. In this method when the paste is printed and dries it look like normal printing garments but once it is cured the prints gets raised from the surface of fabric. Thereby the print will have the embossed effect.

CAVIAR BEADS

again a glue is printed in the shape of the design, to which small plastic beads are then applied – works well with solid block areas creating an interesting tactile surface.

GLOSS

A clear base laid over previously printed inks to create a shiny finish.

NYLOBOND

A special ink additive for printing onto technical or waterproof fabrics.

SUEDE INK

Suede is a milky coloured additive that is added to Plastisole. With suede additive you can make any colour of Plastisole have ‘suede’ feel. It is actually a puff blowing agent that does not bubble as much as regular puff ink. The directions vary from manufacturer to manufacturer, but generally 50% suede additive to your normal Plastisole.


HIGH DENSITY PRINTING

This is one of the recent developments in printing which gives thick prints on the surface of garments which is achieved by using thickener indirect films used for making the screens. They are available in 100 to 70 micron thickness and Plastisole inks and printing through these screens and cured then you shall have a thick deposit of the printing ink on the surface of the fabric which gives a three-dimensional effect.

KHADI PRINTING

This is done on light or dark coloured grounds. It consists of titanium dioxide with other auxiliaries. The important factor in printing of this is right combination of titanium dioxide and proper choice of binder. It will give better fastness and soft handle.

ORGANIC PRINT

Organic print range covers the natural dyes, and the other pigment dyes which lies under the specifications made by G.O.T.S. for Printing Organic Dyes the company/ manufacturer should get the certification from G.O.T.S.


SILICONE PRINT

PVC (plastisole) and PA inks have some serious drawbacks – such as inferior wash and weather durability, poor hand feel and tackiness – that limit their use, particularly in high-end apparel applications. In addition, some of these products could contain plasticizers and have other negative environmental effects.

To counter these problems, printing mills tried silicone inks because of their good washing durability, hand feel, elongation properties and environmental friendliness.

Features

High elongation : Suitable for fabric with 15-20% spandex content

Excellent durability : Wash-resistant Good hand feel : Soft, non-sticky handle with no blocking

problem upon folding Environmentally sound : Does not contain organotin, phthalate,

formaldehyde, PVC or solvent Color fastness : No color migration (passes the 48 hours

at 70°C [158°F] test), even between red and white Improved fashion appearance : Semi-gloss finish with no creasing Heat resistant: Ironable, no-melting Suitable for dot printing : More breathable, high resolution and

alternative looks Easier to get 3D effects : Sharp edges and smooth surface


COST, M.O.Q of the Various Types of Prints

Print Type Cost of Print in Rs.

M.O.Q Curing / Fusing

Suitability for Children

Durability Rating

Sticker Print 1 2500 Fusing No 1.5Plastisole Print 1.5 1000 Fusing No 2.5Pigment Print 2 1000 Curing Yes 3Non-Pvc Print 2.5 1000 Curing Yes 2.5Distressed (Kadi) Print 2.5 1000 Curing Yes 2.5Foil Print 3.5 500 Fusing Yes 2Gel Print 3 1000 Curing Yes 3Discharge Print 3 500 Curing Yes 3Glitter Print 3.5 1000 Curing Yes 2Sugar Print 5 1000 Curing No 2Metallic Print 4 1000 Curing No 2High Density Print (6 Coats)

5 500 Curing Yes 3.5

Puff Print 3.5 1000 Curing Yes 3Flock Print 5 1000 Curing Yes 2.5Silicone Print 8 500 Curing Yes 4.5Organic Print 6.5 1000 Curing Yes 3Bits Printing 4 2000 Fusing No 2

The cost and moq will change w.r.t with the size, density, sharpness, thickness of the print. The values shown in the table and chart are for the print strike-off attached( having 3 X 4 inches with single colour)

Durability Rating : 1-Poor ……. 5-Excellent


COST M.O.Q, DURABILITY COMARISION CHART FOR DIFF. TYPES


Common Defects in Garment Printing

Improper alignmentCauses: Improper setting of two different screens of different colour

Colour spreadCauses: Less viscosity of print paste is less. Base fabric not fixed properly.

Improper mixing of print pasteCauses: As the name itself implies the print paste ingredients are not mixed properly leading to some yellowing or stain marks on print.

ScrimpsCauses: The print is done on folded fabric.

SmearCauses: Printing is done on seams which will be of different thickness leading in spreading and blurring.

Difference in textureCauses: Improper fusing

Improper colour matchingCauses: If printed colour is not matching with standard.

Stick inCauses: Some dust and lint which get chock in screen holes leads in improper design.

Doubling or blurringCauses: Improper fixing of base fabric or screen.

Lint or thread marksCauses: Any loose threads come in print area will lead to thread marks on print.

Colour stainsCauses: Improper handling of material.

Glue streakCauses: The gum which used to stick garment and/or the gel which is printed on fabric (for foil, flock etc.) strikes out of fabric through back side.

Low sharpnessCauses: Improper mesh selection , damaged screen.

Coloured/White spotsCauses: Improper screen preparation.

Distorted printCauses: printing of second coat before drying 1st coat.


SCRIMPS

Printing done on the Folded fabric causes this Defect

garment printing

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