The introduction of pultrusion process
Source:未知Author:admin Addtime:2018-02-02 15:07 Click:
What is FRP/pultrusion process?
Fiber reinforced polymer or fiber reinforced plastic, FRP for short belongs to polymer matrix composites and can be produced by many crafts, such as pultrusion, hand lay-up molding, filament winding, SMC/BMC, RTM, etc.
Pultrusion is a manufacturing process for producing continuous lengths of FRP structural shapes. Raw materials include liquid resin mixture matrix（containing thermosetting resin, fillers and specialized additives）and reinforcement.
The process involves pulling all the raw materials through a heated steel forming die using a continuous pulling devices. The reinforcements are in continuous forms and saturated with the resin mixture in the resin impregnator and pulled through the die. The gelation (or hardening) of the resin is initiated by catalyst in the resin mix and then by the heat from the die and soon a rigid, cured profiles is formed that corresponds to the shape of the die. The rate of the chemical reaction is controlled by heating and cooling zones along with the length of the die. During the last step, the profiles are shorted by a saw…..
Pultrusion can be used to produce practically most constant cross sectional profiles. As pultrusion is a continuous process, the product can be manufactured to any length and the limit is only dictated by the ability to transport it.
Although the concept of pultrusion seems quite simple, there is a delicate balance that has to be maintained between raw materials, temperature and production speed, etc.