Download Food Packaging Technology

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Transcript
PLASTICS IN FOOD PACKAGING
177
structures, shapes and designs which present food products cost effectively,
conveniently and attractively.
7.1.3
Types of plastics used in food packaging
The following are the types of plastics used in food-packaging
• polyethylene (PE)
• polypropylene (PP)
• polyesters (PET, PEN, PC) (note: PET is referred to as PETE in some
markets)
• ionomers
• ethylene vinyl acetate (EVA)
• polyamides (PA)
• polyvinyl chloride (PVC)
• polyvinylidene chloride (PVdC)
• polystyrene (PS)
• styrene butadiene (SB)
• acrylonitrile butadiene styrene (ABS)
• ethylene vinyl alcohol (EVOH)
• polymethyl pentene (TPX)
• high nitrile polymers (HNP)
• fluoropolymers (PCTFE/PTFE)
• cellulose-based materials
• polyvinyl acetate (PVA).
Many plastics are better known by their trade names and abbreviations.
In the European packaging market, PE constitutes the highest proportion of
consumption, with about 56% of the market by weight, and four others, PP,
PET, PS (including expanded polystyrene or EPS) and PVC, comprise most
of the remaining 46% (source BPF). The percentages may vary in other
markets, but the ranking is similar. The other plastics listed meet particular
niche needs, such as improved barrier, heat sealability, adhesion, strength or
heat resistance.
These materials are all thermoplastic polymers. Each is based on one, or
more, simple compound or monomer. An example of a simple monomer
would be ethylene, which is derived from oil and natural gas. It is based on
a specific arrangement of carbon and hydrogen atoms. The smallest independent unit of ethylene is known as a molecule, and it is represented by the chemical
formula C2H4.
Polymerisation results in joining thousands of molecules together to make
polyethylene. When the molecules join end to end, they form a long chain. It is
possible for molecules to proliferate as a straight chain or as a linear chain with
side branches. The length of the chain, the way the chains pack together and