PLASTICS AND TEXTILES

KEY CONCEPTS:

PLASTIC MATERIALS

+Plastics consist of long chains of atoms wich are mostly composed of carbon.

+Plastics can be classified into natural and synthetic plastics.

+The process of manufacturing plastic is called polymerisation.

+Plastic material are resistant, insulating ( against electricity, heat and sound), ductile,malleable, impermeable and light.

+There are three types of plastic recycling processes: chemical and mechanicalrecycling and energy recovery.

THE CLASSIFICATION OF PLASTICS

+Thermoplastics are usually made from petroleum products. The most common thermoplastics are:

-Polyethylene terephthalate (PET)

-High-density polyethylene

-Polyvinyl chloride (PVC)

-Low-density polyethylene

-Polypropylene

-Moulded polystyrene

-Expanded polystyrene or Styrofoam

+Thermosetting plastics are made from petroleum products. They include:

Polyurethane

Bakelite

Melamine

Polyester resins

Typical elastomers include rubber and neoprene.

 PLASTIC FORMING TECHNIQUES

+Various industrial techniques can be used to manufacture plastic products, such as: estrusion, calendaring, vacuum forming and moulding.

+The main techniques for using moulds are as follows: blow moulding, injection moulding and compression moulding.

MODIFICATION TECHNIQUES

+Modification techniques use tools and machines to make changes to prefabricated materials, such as sheets, bars or mouldings.

+Examples of these techniques include: measuring  drawing marks ad lines  cutting  drilling  filing and sanding  joining.

+You must always pay special attention to health and safety rules.

TEXTILES

+Both natural and synthetic fibres can be woven to make a variety of textiles.

+Natural fibres may come from animal sources (wool, silk), plant sources (cotton, linen, esparto, bamboo) and mineral sources (gold, silver and copper fibres).

+Synthetic fibres, such as nylon, poliester, rayon and Lycra, are plastic materials.