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Plastics are a synthetic fiber that is extracted from petroleum products or can be manufactured chemically in a factory. Plastics bottles are made from powdered plastic commonly referred to as resins. A resin is combination of many monomers to produce a mass of long polymer chains. An example of a monomer is ethylene and when many ethylene monomers are catalyzed, they combine to form a polymer known as polyethylene which is a major component in most plastic bottles. The polyethylene resin is then turned into plastic bottles by a process known as molding. The process of turning monomers into a polymer that is subsequently used to manufacture plastics is called powder processing.

THERMOPLASTICS AND THERMOSETS

Plastics can be classified into two categories depending on how they react when exposed to high temperatures. Thermoplastics are those plastics that melt when exposed to heat and harden when exposed to lower temperatures. These plastics retain their plastic properties when heated. The second type of plastics is thermosets which crack or get charred when exposed to high temperatures. This means that once set, they cannot be reset into another plastic shape.

MOLDING

This is the process of turning powdered plastic into plastic bottles. Most plastic containers are thermoplastics. The process of molding is done by exposing the resin or powdered plastic to very high temperatures and pressure and forcing them into a mold. The material is then left to cool down and when the mold is removed, a plastic bottle has been formed. As for thermosets, the process is a little bit more complex and is two staged. The first stage involves the formation of linear polymers while the second stage involves molding the linear polymers. Thermosetting involves heat, pressure and in most cases a catalyst to speed up the chemical processes. This leads to the formation of a cross linked structure which forms a hard object that is hard to remodel into any other shape. Thermoplastics have weak bonds so when heated the weak bonds break but upon cooling the bonds reform again explaining why the thermoplastics can be molded into another shape.

The process of turning powdered plastic into plastic containers is a complex process that requires specialized equipment to make the powdered plastic before it is turned into a plastic bottle. This process also requires specialized staff with the technical knowhow and the chemical knowledge of the different monomers to use.

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