jueves, 18 de mayo de 2017

TEXTILES


  • Natural and synthetic fibres can be woven to make a variety of textiles.
  • Natural fibres may come from animal sources (wool, sik), plant sources (cotton, linen, esparto, bamboo) and mineral sources (god, silver and copper fibres)
  • Synthetic fibres, such as mylon, polyester, rayon and Lycra, are plastic materials.
         
                     
                              MODIFICATION TECHNIQUES

  • Modifications techniques use tools and machines to make changes to prefabricated materials, such as sheets, bars or mouldings.
  • Examples of these techniques include: measuring→marking→cutting→drilling→filing and sanding→joining
  • You must always pay special attention to health and safety rules

Resultado de imagen de measuring, marking, cutting, fling
PLASTING FORMING TECHNIQUES

  • Various industrial techniques can be used to manufacture plastic products such as: extrusion, calendering, vacuum forming and moulding.
  • The main techniques for using molds are as follows: blow moulding, injection moulding and compression moulding.


THE CLASSIFICATION OF PLASTICS

  • Thermoplastics are usually made from petroleum products. The most common thermoplastics are:
  1. Polyethylene terephthalate (PET)
  2. High-density polyethylene
  3. Polyvinyl chloride (PVC)
  4. Low-density polyethylene
  5. Polypropylene
  6. Moulced polystyrene
  7. Expanded polystyrene or Styrofoam

  • Thermosetting plastics are made from petroleum products. They include:
  1. Polyurethane
  2. Bakelite
  3. Melamine
  4. Polyester reisns

  • Typical elastomers includ rubber and neoprene
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 mechanical recycling and energy recovery.