Technical Textiles and Product Development
Technical Textiles and Product Development examines functional products such as geotextiles, medical textiles, protective clothing, automotive fabrics, filtration media and composites. The exam tests property requirements, material selection, test standards and development logic.
Core concepts
- Property targets follow the application: strength, permeability, flame resistance, biocompatibility, UV stability or filtration efficiency.
- Geotextiles perform separation, filtration, drainage or reinforcement; design uses mass, permittivity and tensile strength.
- Composites depend on fibre volume fraction, interface and lay-up for stiffness and strength.
- Product development moves through needs definition, concept, prototype, validation and scale-up.
- Standards may be product-specific or test-specific; a passing test does not guarantee fitness for use.
Worked example
A composite has 60% glass fibre by mass and 40% epoxy. Densities are 2.54 g/cm3 for glass and 1.20 g/cm3 for epoxy. Per 100 g: fibre volume = 60/2.54 = 23.6 cm3; matrix volume = 40/1.20 = 33.3 cm3. Fibre volume fraction = 23.6/(23.6 + 33.3) = 41.5%. Mass fraction 60% is not volume fraction 60%; stiffness estimates must use volume fraction.
Traps
- Using mass fraction as volume fraction in composite calculations.
- Selecting a material from a single test result.
- Ignoring end-use conditions such as UV, heat or body fluids.
- Confusing prototype performance with production capability.