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Additives:
A
diverse group of specialty chemicals incorporated
into plastic formulations before or during processing,
or to the surfaces of finished products after processing.
Their primary purpose is to modify the behavior of
plastics during processing or to impart useful properties
to fabricated plastic articles. (Modern Plastics Encyclopedia
1995).
Advanced
Recycling Technologies (ART):
Processes
that yield a variety of versatile and marketable end-products
that are the building blocks from which new plastics
and a variety of other products can be manufactured.
This is achieved by converting or recycling plastics
back into the raw materials from which they were made.
ART includes such processes as methanolysis, glycolysis,
hydrolysis, and thermal depolymerization. These technologies
augment existing mechanical systems as part of an integrated
approach to plastics recycling designed to increase
the volume of post-consumer plastic plastics diverted
from the waste stream and expand the variety of plastics
that are recycled into new and useful products. (The
Evolution of Plastics Recycling Technology, APC, 1994).
The
American Plastics Council (APC):
A
national organization whose mission is to actively
demonstrate that plastics are a preferred material
and a responsible choice in a more environmentally
conscious world.
Ammonolysis:
A
complete depolymerization process that breaks nylon
into its building blocks or monomers that can then
be repolymerized to make nylon in any form and for
any market. (Modern Plastics Encyclopedia 1995).
Automatic
Plastics Sorting:
The
separation of mixed plastics by resin type and/or color
via a mechanical system. A system detects the plastic
type (or types) to be segregated and removes those materials
from the stream. Common systems utilize conveyors, resin/color
detectors, computer analysis and tracking and air jet
ejectors. For plastic packaging, the separation may
be on a macro (whole container) or micro (chopped/ground
particles) basis. ("Automatic Sorting for Mixed Plastics,"
Peter Dinger, BioCycle, March 1992; "Automatic Microsorting
for Mixed Plastics," Peter Dinger, BioCycle, April 1992)
Abrasion
Resistance
The ability of a polymer to withstand mechanical action,
such as rubbing, scraping or erosion, which tends to
remove material progressively from it's surface.
Age
Resistance
The resistance to deterioration by oxygen and ozone
in the air, and by heat and light. A variety of anti-oxidants
are available which provide protection in differing
degrees to these deteriorating factors.
Aliphatic
Any organic compound in which the main structure is
a chain of carbon atoms joined to each other is classified
as being aliphatic.
Alternating
copolymer
A copolymer consisting of macromolecules comprising
two species of monomeric units in alternating sequence
Anionic
polymerization
An ionic polymerization in which the kinetic-chain carriers
are anions
Anti-blocking
and slip agents
Surface-modifying additives to reduce friction and tackiness
of polyolefin films.
Antioxidants
A group of substances being able to inhibit radical
reactions in the polymer and thus prevent degradation
processes. Different types are available: sterically
hindered phenols and phosphites as base for polyolefins,
sulphur based heat stabilisers and C-radical scavengers
for special applications.
Antistatic
agents
Surface-modifying additives to reduce surface resistance
of polyolefins, eliminating charge build-up and dust
collection; an example of a widely used antistatic agent
is glycerine-monostearate. Different types of antistatic
agents are used in polymerization reactors to prevent
the formed polymer powder from adhering to the reactor
wall.
Aromatic
Aromatics are a highly reactive group of hydrocarbons
with unsaturated rings of carbon atoms, producing a
great variety of products. As their name implies, they
have a strong odour, which is not unpleasant.
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Plastic
Brief
