What types of flock are there?
Mostly polyamide, polyester, viscose and cotton are used, there are also special fibres made of carbon, glass, Kevlar and graphite, however, these are used less frequently and only for special applications.
When is which flock used?
In most cases, polyamide can be used. Polyester is more resistant to UV light than polyamide and therefore offers advantages in outdoor applications. However, the kink resistance is much lower.
Viscose is less expensive than polyamide, but is only used on soft substrates (textiles, flexible foam) because of its lower buckling stability.
Cotton is the most economical type of flock, but its general wear and tear resistance is rather low.
It is mainly used for the insides of rubber gloves (because of its water absorption capacity).
The flock dimension is defined by the thickness, also called the titer, (measured in dtex) and the cut length (measured in mm) of the fibres.
Since textile fibres are subject to certain variations in diameter during production, thickness is defined in terms of weight/length rather than diameter: dtex = g/10,000 m. This means that 10,000 m of a fiber with, for example, 3.3 dtex weighs 3.3 g. The cut length is given in mm.
A typical fibre designation "PA 6.6 - 3.3 dtex, 1mm" stands for polyamide flock with a titre of 3.3 and a cut length of 1 mm, i.e. a classic molded part flock.
The relationship between cut length and titer affects the look and feel of the flocked surface.
- the shorter and thinner the fibres, the finer
- the thicker and longer the fibres, the coarser.
- the longer and thinner the fibres, the softer
- the thicker and shorter the fibres, the harder.
However, due to the manufacturing process, there are also some limits to the cutting lengths that can be used:
- The minimum cut length is approx. 0.3 mm due to the process.
- Theoretically, there is no upper limit to the cut length for process reasons.
However, flock becomes increasingly difficult to process with increasing length, as it tends to curl and clump. For more information, you should consult your flock supplier.
How is flock made?
A pasty mass is produced by polymerization (chemical reaction) and melting. Then the liquid mass is pressed through small openings (the spinning of the fibers).The individual fibres are combined into fibre bundles, the so-called flock cables, and placed in cardboard boxes.
Depending on the requirements of the flocked surface, flock is then cut to the required length. After that, the fibres are dyed and receive their chemical preparation so that they become conductive and can later align themselves in the electrostatic field. An optimal processing climate for flock is about 20°-23° Celsius and a RLF of 50-60%.
Which color shades can be used?
Basically, flock can be dyed with any shade possible for textile dyeing (flock fibres are textile fibres!).
A distinction is made between spin-jet dyed and batch dyed.
Special shades are also possible by mixing different colors of flock fibres together (melange).
Individual color shades are possible on request.
How robust is flocking?
By optimally matching the substrate, adhesive, flock and production process, very stable products can be achieved. E.g. sportswear, upholstery fabrics, floor coverings, glove boxes, window guide profiles, etc., which function flawlessly permanently.