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Unformatted text preview: ances will result in moulded-in stress.
This is the biggest culprit for over 50% part
failure Applications of Injection moulded
• Power-tool housing
Automotive dash boards
Drug Inhalation Units
Bottle Lids/closures Types
Types of Injection Moulding Multi-shot (or 2K moulding) (where different
materials are injected into the same mould),
Insert moulding (where metal components
Structural foam moulding (where the
material is foamed to reduce density)
Gas assisted moulding (where gas is in
corporated to reduce wall thickness). Insert Moulding
• Insert moulding
• ABS, PA, PC, GPPS,PP Structural
Moulding Structural Foam is a term commonly used to
describe thermoplastic injection moulding
components made by the injection moulding
process which have a cellular core. Gas
Gas Assisted Moulding The main two types of Gas Assisted Moulding are
Either inject the gas into the component cavity
(internal gas injection),
Or to use the gas on the outside surface, but still
within the mould cavity, to consolidate the
component (external gas injection).
Internal Gas Injection - Most widely used process
External Gas Injection - used for enhanced surface
Gas Assisted Moulding Automotive Bumper
Dash Panel External
External Gas Assisted
Moulding Applications: Flat panels for office equipment.
Furniture, i.e. tabletops.
Domestic appliances EXTRUSION
EXTRUSION The extrusion process Introduction
Extrusion: (Greek) push out Pump supplies a continuous stream of material to a
shaping tool or to some other subsequent shaping
process. Materials plastics metals (Al window frames spaghetti and other noodles toothpaste Extrusion useful for shaping parts with extruder dies Extrusion is basis for injection molding and blow
The extrusion process Plastic granulate is supplied via the feed hopper to the
extruder Homogenous melted material from thermoplastic
granulate under high pressure in an extruder (screw
press) or co-extruder Shaping of the molten mass to a continuous web by
means of flat sheet dies Calibration of the emerging material to the desired
thickness using a 3-roller flattening calender Tension-free cooling of the web to ambient temp...
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- Spring '14