Extrusion: is a compression process in which material is forced to flow through a die orifice to provide long, continuous product whose cross-sectional shape is determined by the shape of the orifice.

Slit-die Extrusion of Sheet and Film;

Blown-film Extrusion Process;

Calendering.

Injection Molding: is a process in which a polymer is heated to highly plastic state and forced to flow under high pressure into a mold cavity, where it solidifies.

Compression Molding: is used for thermosetting plastics. It includes loading a precise amount of molding compound into the bottom half of a heated mold; then bring the mold halves together to compress the charge, forcing it to flow and conform to the shape of the cavity, afterwards, heating the charge, and finally opening the mold halves and removing the part from the cavity.

Transfer Molding: in this process, a thermosetting charge is loaded into a chamber immediately ahead of the mold cavity, where it is heated; pressure is then applied to force the softened polymer to flow into the heated mold, where curing occurs.

Blow Molding: is a molding process in which air pressure is used to inflate soft plastic into a hollow geometry inside a mold cavity.

Extrusion blow molding, injection blow molding.

Rotational Molding: uses gravity inside a rotating mold to achieve a hollow form.

Thermoforming: is a process in which a flat thermoplastic sheet is heated and deformed into the desired shape.

Vacuum thermoforming,

Pressure thermoforming,

Mechanical thermoforming

Casting: involves pouring of a liquid resin into a mold, using gravity to fill the cavity, and allowing the polymer to harden.

Polymer foam processing and forming: is by mixing a liquid resin with air by mechanical agitation and then hardening the polymer by means of heat or chemical reaction;

or by mixing a physical blowing agent with the polymer, then supply a gas such as nitrogen or pentane that can be dissolved in the polymer melt under pressure, so that the gas comes out of solution and expands when the pressure is subsequently reduced;

or by mixing the polymer with chemical compounds, that decompose at elevated temperatures to liberate gases such as CO₂ or N₂ within the melt.

Created by Dr. Wang