DIFFERENT ConstructionS

Biaxial ±45° or ‘double-bias’

 
Applications
  • when good conformability or torsional strength are required
Important features
  • available as high drape (HD) for difficult shapes
  • available as stabilized (ST) for stability
  • adds torsional rigidity for tubular applications
  • increases shear strength over frames in boat hulls
  • ideal for secondary bonding as the load is shared by both axis 
  • excellent fibre coverage minimizes print-through

 

Triaxials

 
Applications
  • to increase torsional rigidity in combination with longitudinal (0°/±45°) or transverse (-45°/90°/+45°) strength  
Important features
  • used for long & tubular structures such as rotor-blades or girders
  • heavyweight fabrics reduce the amount of layers needed
  • ratio of 0° (or 90°) to ±45° is variable – 50:50 is typical

 

Quadaxials

 
Applications
  • quadaxials are ‘quasi-isotropic’, offering strength in all 4 directions
Important features
  • the optimum composite reinforcement for designers – strength ‘in all directions’
  • excellent for ‘spread-pressure’ applications such as boat hulls or pressure vessels
  • for putting down as much reinforcement as possible in one layer – up to 2.4 Kg/m2
  • ideal in blast and ballistic protection applications
  • straight fibres in 4 directions allow resin to flow unhindered in 8 directions
 

Biaxial 0°/90°

 
Applications
  • used in similar applications to woven rovings, offering improved laminate performance - increased tensile and flexural strength,  less weight and improved surface finish (less ‘ print-through ’)
Important features
  • unidirectional layers are structurally optimized (uncrimped)
  • improved resistance to fatigue and impact
  • quicker and easier to wet-out than wovens
  • the fabrics remain intact even when cut

 

Combinations

 
What are combinations?
  • Combinations are fabrics with an added layer of Chopped Strand Mat (CSM), Continuous Filament (CFM), or other substrates such as polyester or glass surface veils
Important features
  • improved interlaminar bonding, especially when using orthothalic polyester resins
  • saves labour – can lay down fabric + CSM layer in one go
  • improved surface finish (the primary purpose of polyester or glass surface veils)
  • CFM acts as ‘flow medium’ for resin during infusion
  • adds bulk and therefore rigidity to part