Various kinds of plastic used for packaging such as:
Polyethylen is a soft film, transparent and flexible, has the strength of impact and the strength of a good tear. With the heating will be soft and melt at 110OC. Based on its low permeability and good mechanical properties, polyethylene has a thickness of 0.001 to 0.01 inches, which is widely used as a food pack, because of its thermoplastic properties, easy polyethylene pouches with good density.
b. High Density Polyethylene (HDPE)
In low density polyethylene there are few branches in the chain between molecules that cause this plastic to have a low density, whereas high density has fewer branch chains than low density types. Thus, high density has stronger material properties, harder, opaque and more resistant to high temperatures. Hydrogen bonds between molecules also play a role in determining the melting point of plastics.
Polypropylene is very similar to polyethylene and the properties of its use are similar. Polypropylene is stronger and lighter with low steam penetration, good fat resistance, stable to high temperature and shiny enough. The polypropylene monomer is obtained by splitting thermally naphtha (distillation / crude oil) of ethylene, propylene and higher homologues separated by distillation at low temperatures.
Using a Natta-Ziegler polypropylene catalyst can be obtained from propylene. Popular types of plastics used for packing meat are PE (polyethylen) and PP (polyprophylen), because these two types of plastics are inexpensive, easy to find on the market, also have similar properties. The PE plastics do not show a change at a maximum of 93 ° C – 121 ° C and a minimum temperature of -46 ° C – (-5) ° C, but have a high permeability to the organic gases so that they can still be oxidized when stored for a period of time long.