1. Plastic Materials.
- Plastics consist of long chains of atons which are mostly composed of carbon.
- Plasticscan be classifield into natural and synthetic plastics
- Plastic materials are resistant, insulation (against electricity, heat and sound) ductile, malleable, impermeable and ligth.
- There are three types of plastics recycling processes: chemical and mechanical recycling and energy recovery.
2. The Clasification of Plastics.
- Thermoplastics are usually made from petroleum products. The most common theroplastics are:
- 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
- Melanine
- Polyester resins
- Typical elastomers include rubber and neoprene
3. Plastics Forming Techniques.
- Various industrial techniques can be used to manufacture plastics products, such as: Extrusion, calendaring, vacuum forming and moulding.
- The main techniques for using moulds are as follows: blow, moulding and compresion moulding.
4. 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 and lines, cutting, drilling, filing and sanding joining.
- You must always pay special attention to health and safety rules.
5. Textiles
- Both natural and syntheetic fibres can be woven to make a variety of textiles
- Natural fibres may come from animal sources (wool, silk), plant sources (cotton, line, esparto, bamboo) and mineral sources (gold, silver, and copper fibre)