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Materials Processes

Processes

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Plasticize

The process of softening a material to make it plastic or moldable.

 

Platform Blowing

A special technique for blow molding large parts.  To prevent excessive sag of the heavy parison the machine employs a table which, after rising to meet the parison at the die, descends with the parison but at a slightly lower rate than the parison extrusion speed. [LW]

 

Plug-and-Ring Forming

A method of sheet forming in which a plug, functioning as a male mold, is forced into a heated plastic sheet held in place by a clamping ring. [LW]

 

Plug Forming

A thermoforming process in which a plug or male mold is used to partially preform the part before forming is completed by means of vacuum or pressure. [LW]

 

Potting

The process of encasing an article in a resinous mass performed by placing the article in a mold, pouring a liquid resin into the mold to completely surround the article, and curing the resin.  The mold is a container which remains attached to the potted article, assisted, when required, by the use of bonding agents.  The main difference between potting and encapsulation, is that in encapsulation the mold is removed from the encapsulated article.  These processes are widely used in the electrical industry.

 

Premix Molding

 

Prepolymer Molding

 

Press Polishing

A finishing process used to impart high gloss, improved clarity and mechanical properties to sheets of vinyl, cellulosic and other thermoplastics.  The sheets are hot-pressed against thin highly polished metal plates.

 

Pressure Forming

A thermoforming process wherein pressure is used to push the sheet to be formed against the mold surface, as opposed to using a vacuum to suck the sheet flat against the mold. [LW]

 

Pulp Molding

Process by which a resin-impregnated pulp material is preformed by application of a vacuum and subsequently oven cured or molded.

 

Pultrusion

A term for a reinforced plastics technique in which continuous strands of resin-impregnated reinforcing materials are pulled through the orifice of a steel di, then through a heating chamber.  The process yields continuous lengths of materials with high unidirectional strengths, used for building siding, fishing rods, pipe, golf club shafts, etc. [LW]