Glass, ceramics and textiles

• • glass - sand based materials
  • ceramic - clay based
  • textiles - fibres
• glass properties

  • used for glazing windows
  • extremely brittle and will break if dropped or hit suddenly
  • has higher compression strength than tension
  • good chemical resistance
  • good optical properties (better than plastic)
• glass advantages

  • more ridged and durable than thermosetting plastics
  • more scratch resistant
  • better optical properties
  • not deformed by heat
  • used where heat resistance is required
  • sense of high quality (weight and visual properties)
• ceramics are made from clay but high end products are made from bone China which is finely ground animal bones

  slip casting is the typical manufacturing method - liquid clay is poured into a mould, before completely set it is removed from the mould so any finishing work can be done
• ceramics properties

  • alumina - 2050 C - spark plugs, cutting tools
  • beryllia - 2350 C - crucibles in nuclear reactors
  • magnesia - 2800 C - furnace linings
  • zirconia - 2690 C - rocket liners, furnace insulation
• textiles are a flexible material costing of a network of natural or artificial fibres (yarn or thread)

  • yarn is produced by spinning raw fibres to produce long strands

  textiles are formed by weaving knitting, crocheting, knotting, tatting, felting or braiding. sources can be derived from plants or other sources that can be grown can also be synthetic (made from polymers)
• types of textiles:

  • plant - derived from plant fibres
  • animal - naturally produced from animals
  • synthetic - derived from polymers
• natural textiles

  • animals and plants are sources of natural fibres which can be made into yarn or threads to produce textiles
  • silkworms produce silk (replaced by nylon)
  • sheep produce wool
  • cotton and linen come from plants
• synthetic textiles

  • many polymers derived from oil can be spun and made into threads to make textiles
  • nylon now replaces silk for many products due to the price difference
  • acrylic can be used as fake fur
  • elastane is used to help cotton stay crease free