innovative injection molding process.pdf

8/18/2019 Innovative Injection Molding Process.pdf

http://slidepdf.com/reader/full/innovative-injection-molding-processpdf 1/42

Innovative_injection

Seite 1

BASIC-TRAINING 2003




Seite 2

Table of content

è The Multiple Component Technologies

è The Sandwich-Technologies

è The Injection Welding-Technologies

è Summary: Why Multiple-Component-Technologies?

è What does EMS-Grivory offer?




Seite 4

The Multiple Component Technologies

Sandwich Injection Moulding

Coinjection Monosandwich GIT WIT




Seite 5

Injection Welding

Injection Welding(2C-IM)

Biinjection Push-Pull-IM

The Multiple Component Technologies




Seite 6

Sandwich-Injection Moulding

Different Properties in one Part

v i r g i n

m a t e

r i a l

u n r e i n f o r c e d m a t e r i a l

high performance polymer

(flame retardant, weather-, heat-, chemical resistant)

Gas (GIT)

Water (WIT)regrind

foam

low cost

reinforced




Seite 7

Coinjection

Two melts will be injected into the cavity through one gate

one after the other.

1

2

1. Injection of the skin-material with unit 12. Injection of the core-material with unit 2

Skin/Core-structure




Seite 8

1. Metering of the core-material with the injection unit2. Metering of the skin-material with the extruder 3. Injection of the two materials in one step

Skin/Core-structure

Two materials will be injected with one injection unit, through

one gate into the cavity.

Mono-Sandwich




Seite 9

Gas-Injection-Technology

Portable compression station




Seite 10

Idea of the Gas Injection Technology

Problem with the conventionalinjection moulding

Wall-thicknesses of 3-4 mm can be moulded

without problems, higher wall-thicknesses

results in:

Possible Solution: Use of the Gas-Injection-Technology

Principle: Gas (usually nitrogen) will be injected into the part,

replaces the melt in the core and creates an hollow space.

è sink marksè long cycle time




Seite 11

GIT - Technologies

Standard - Gas Injection-Technology

è Partial filling with melt

è Injection of gas and complete filling of the cavity

è Hold-on pressure phase with gas




Seite 12

Variant:

è Volumetric filling of the cavity with melt

è short hold-on phase and injection of gas

è Displacement of the melt with gasè Hold-on pressure phase with gas

Ê Melt back into the screw

GIT - Technologies

GIT-Special Processes (Blow back process)




Seite 13

Ì Retraction of a core

GIT - Technologies

GIT-Special Processes (Blow out process)

Ë Displacement of the melt into an overflow cavity

Variant:

è Volumetric filling of the cavity with melt

è short hold-on phase and injection of gas

è Displacement of the melt with gasè Hold-on pressure phase with gas




Seite 14

Handle

Grilon BS/2

Automotive door-handleGrivory GV-5H

Backflow of the melt into the screw




Seite 15

Backflow of the melt into the screw

Motorcycle-gear-lever Grivory GV-5H




Seite 16

Displacement of the melt into an overflow cavity

Motorcycle-carrier

Grilon PVS-5H




Seite 17

Advantages of the Gas Injection Technique

production of parts with high wall-thicknessesand/or material accumulations

è increased strength and stiffness at lower or

equal part weight

reduction of weight up to 50%

è lowering of the material costs




Seite 18

Advantages of the Gas Injection Technique

reduction of the cooling-/cycle time up to 50%

lower clamping force

è lowering of the machine costs

no/less sink marks

parts with less distortion

è improved part quality




Seite 19

Development started at IKV Aachen in 1999

Target:

Reduction of cycle time for applications like:

– handles

– armrests

– media ducts

Water injection technology (WIT)




Seite 20

Process Versions (equal procedure like GIT)

Short-Shot Process – Partial filling of cavity

Full Shot Process

– Filling into additional cavity

– melt is pushed back into screw

– core is pulled back

WIT-Process




Seite 21

Short shot process

High speed shooting of the filling process in a transparent tool

water

WIT-process of IKV




Seite 22

Transparent-Tool




Seite 23

è blowing out the water with compressed air

è use of water containing blowing agents (e.g.

carbonic acid)

è evaporation of water after pressure relief

(water temperature >100°C; residual water)

Water recovery




Seite 24

è shorter cycle times (40% versus GIT)

è smaller wall thickness

è wall thickness is constant⇒ less warpage

è larger part diameters

è water is cheaper than gas and incompressible

è smoother inner surfaces

Advantages of WIT compared to GIT




Seite 25

è danger of splashing water when setting is

wrong

è precautions have to be taken for water removal

è not all materials are suitable (voids)

è injector marks are bigger (~ 6mm)

Disadvantages of WIT




Seite 26

è no special WIT grades are available

è no own WIT equipment

è experience with GIT

è first experience done for some standard

grades

è some materials are in test

è good contact to IKV and leading machinemanufacturers

EMS Activities and Support




Seite 27

Different functions and/or properties are combined

in one part.

Injection Welding




Seite 28

Target: Adhesion between two materials

Hard/Soft-Applications:

è Sealings direct injectedè Soft Touch: Improving of grip feeling and

reduction of vibration

èOperation knobs

Transparent/not transparent-applications:

è overmoulding of transparent parts

Injection Welding




Seite 29

Process Steps and Tool Construction

Principle of injection welding1. Injection of the preform

2. Transpose of the preform

3. Injection of the second material

Injection-/Tool Technology

Two injection moulding machines and two tools

è Transpose technology (hand or with a robot)

Injection moulding machine with two or more injection units

è Rotation-/Index-plate-/Core-puller mould

1

2




Seite 30

Possible Material Combinations

Grilon (PA6) + Grilon ELX (PA6 - Elastomer)

Grilamid (PA12) + Grilamid ELY (PA12 - Elastomer)

Grilamid (PA12) + Grilamid TR (PA amorph)

Grilon/Grilamid "HM" + Thermoplastische Elastomere

HM = haftungsmodifiziert (SEBS und/oder PP/Gummilegierungen)

Grilon/Grilamid/Grivory + Polyurethan-Elastomer

Grilon PV-15H HM / PV-3H HM / PV-4H HM / PV-5H HM

Grilon T XE 3187

Grilamid XE 3168




Seite 31

Hard/Soft Combination with Grilon HM

Door lock switch cover Grilon PV-3H HM + TPE (Thermoflex)

Electro plugGrilon T XE3187 + TPE (Thermoflex )




Seite 32

Hard/Soft Combination with Grilon HM

Infrared key transmitter

Grilon PV-4H HM + TPE (Thermoflex)

Steering column switch for light

Grilon PV-3H HM + TPE (Thermoflex)




Seite 33

Target: movable but not separable junction

Two-Component Injection Moulding




Seite 34

The meltfront distribution

determines the position of theweldline.

The weldline has no definedshape.

Calculations and tests arenecessary.

High numbers of material combinations because of very good

compatibility.

Two melts will be injected into the cavity through two

different gate positions

Biinjection




Seite 36

Glassfibres are oriented parallel to

the melt front (glassfibres do not

break through the matrix)

Additives and degradation products

can reduce the strength.

What is the problem?

The result is a bad weldline strength.

With ideal conditions it is possible to achieve a weldline.strength of about 40%of the tensile strength.

Weldline of Glassfibre Reinforced Materials




Seite 37

2C-IM-maschine with aspecial software

Tool with two gates

Cavity

Prinziple of the Push-Pull Process (Ferromatik)




Seite 38

StandardIM-maschine

SCORTEC-head withhydraulic pistons

Software and hydraulik system externalor integrated into the IM-machine

Tool with two or moregates

Cavity

Prinziple of the SCORIM-Process




Seite 39

Increasing of the weldline strength up to

the level of the tensile strength.

General improvement of the properties

caused with a high orientaion of fibres

and molecular chains.

Reduction of voids and sink marks.

Results:

konv. SPR GTS

P o s i t i o n o f

w e l d l i n e

Prinziple of th Push-Pull Process (GTS)




Seite 40

Standard-injection

moulding

Push-Pull process

B i n d

e naht v e r l a u f

1 mm

(Grivory GV-5H processed with the SCORIM-Process)

Glass Fibre Orientation in the Area of the Weldline




Seite 41

Summary:

Why Multiple Component Technology?

we are able to:

è produce multifunctional parts.

è Combine products with different properties.

è Reduce material- and machine costs.

è Lower part price.

è Improve mechanical properties. Solve

injection moulding problems.

è Increase the product- and production security.




Seite 42

è delivers proper materials.

è has experiences with the different process technologies

and EMS-CMEMIE materials

è knows advantages and disadvantages of the

technologies.

è has injection moulding machines for the different

technologies and these can be used for customer trials.

è We give support for new developments.

What does EMS-Grivory offer ?

innovative injection molding process.pdf

Documents