Vi-Chem has developed a variety of thermoplastic elastomers (TPE) to
meet current and future market needs. These products provide
rubber-like properties with thermoplastic processing economics.
We have a variety of engineered PVC
Compounds customized for injection molding, extrusion molding, slush
molding or blow molding
Injection molding is the principal method of forming thermoplastic
materials. In this process, plastic material is put into a hopper, which
feeds into a heated injection unit. A reciprocating screw pushes the
plastic through this long heating chamber, where the material is
softened to a fluid state. At the end of this chamber there is a nozzle,
which abuts firmly against an opening into a cool, closed mold. The
fluid plastic is forced at high pressure through this nozzle into the
cold mold. A system of clamps hold the mold halves shut. As soon as the
plastic cools to a solid state, the mold opens and the finished plastic
is ejected from the press.
Blow molding is the process of forming hollow products out of
thermoplastic materials by expanding a hot plastic parison (tube of
plastic) against the internal surfaces of a chilled mold, using
Extrusion molding is the method employed to form thermoplastic materials
into continuous sheeting, film, tubes, rods, profile shapes, and
filaments, and to coat wire, cable and cord.
In extrusion, dry plastic material is
first loaded into a hopper, then fed into a long heating chamber through
which it is moved by the action of a continuously revolving screw. At
the end of the heating chamber, the molten plastic is forced out through
a small opening or die with the shape desired in the finished product.
As the plastic extrusion comes from the die, it is fed onto a conveyor
belt where it is cooled, most frequently by blowers or by immersion in
In the case of wire and cable coating, the thermoplastic is extruded
around a continuing length of wire or cable which, like the plastic,
passes through the extruder die. The coated wire is wound on drums after
In the production of wide film or
sheeting, the plastic is extruded in the form of a tube. This tube may
be split as it comes from the die and then stretched and thinned to the
dimensions desired in the finished film.
Slush molding is a process used to form hollow objects with
thermoplastic materials. The process involves heating a hollow mold,
into which is poured a liquid or powder thermoplastic. The mold is
rotated, gelling the plastic to the hot mold. The excess is poured out
of the mold, which is then cooled so the finished part can be removed.
The mold is then reheated for the next part.