Compression molding

Compression molding

-Typical modling process with high pressure

-Material is preplaced in the molds without injected.

-Exact the same volume of polymer material for the items is used.

-Molds have overflow grooves which makes flasings with the final products.

-Cheap process

–Suitable for thermoset plastic, composites

Flash

Injection mold

-representative

-expensive: extruder + injection pump + mold

-speedy production

-undercut

-runner(plastic guide lines)

-double injection mold (multi-layer)

-sandwitch injection mold-heterogeneous material

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Extrusion mold

-extruder + die

-pipe, tube, film, wire

-continuous process

Wrap up

Blow molding

-hollow shape

-low blow pressure (~some atm)

-injection blow molding, injection stretch blow molding, extrusion blow molding

-injection blow molding needs parison (cold or hot method)

-extrusion blow molding is fast and cheap and can make multilayer structure

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3D printing

-expensive and low production rate, easy customizing and low cost for customizing

FDM(fused deposition modelling)

-photopolymerization (limited materials type)

-powder bed fusion

-binder/material jetting

Vacuum forming

-snap back forming, plug assist forming, vacuum forming

-cheap but shapes of plastic are limited.

-thin layer

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Adhesion + compression mold

Next week

-We will play the clothes game next week which we can learn supply chain and manufacturing strategy!!