NOTES

• Composite materials:

  • Material made of two or more different substances
• Types of reinforced plastic:

  • Glass reinforced plastic (GRP)
  • Carbon fibre reinforced plastic (CRP)
• GRP or CRP process:

  • Prepare the mould or former
  • Apply a release agent to the mould
  • Apply a gel coat for GRP (or first resin coat for CRP)
  • Apply the glass fibre matting (or woven carbon fibre)
  • Work a second coat of resin into the material
  • Repeat layers of matting and resin coats to achieve correct thickness for the specific application
  • Clamp and leave a GRP workpiece to cure (Seal a CRP workpiece in a vacuum bag and heat in an oven to cure)
  • Release from the mould, trim and finish workpiece
• The increased functionality of a technical textile:

  • Weatherproofing
  • Strengthening
  • Adding conductivity and insulation, both thermally and electrically
• Gore-Tex:

  • Gore-Tex is a special fabric membrane that is waterproof yet breathable
  • The membrane has 150 million holes per cm2
  • This means water droplets are too big to pass through
  • Perspiration can still escape as water vapour
• Aramids (Aromatic polyamide):

  • Aramids are particularly tough fibres made from modified polyamide and offer:
  • Cut and tear resistance
  • Flame proofing
  • Thermal insulation
  • High strength
  • A hard wearing finish
  • Nomex and Kevlar are both types of aramid
• Conductive fabrics and threads:

  • E-textiles allow electricity to travel along special threads which are either woven or sewn into fabrics
  • Stainless steel or other conductive strands are mixed with other fibres providing flexibility
  • The thread can be soldered onto special sew-on components
• Microfibres:

  • Microfibres are less than one denier thick - that’s one fifth the width of a human hair
  • They create an electrostatic charge that attracts particles of dust
  • Usually made from polyester and polyamide
  • can be flammable unless treated
  • synthetic and not renewable
  • takes many years to decompose
• Microencapsulation:

  • Solids, liquids or gasses are sealed in tiny capsules
  • These active ingredients can be released at controlled rates and under controlled conditions
  • Active ingredients include:
  • Thermochromic dyes
  • Antibacterial material
  • Pesticides
  • Perfumes
  • Pharmaceuticals