PULTRUSION

Pultrusion is a continuous production process to produce fiber-reinforced polymer profiles of any length and constant section.

Reinforcement fibers may be roving, continuous mat, woven roving, carbon, Kevlar, basalt, or others. The fibers are impregnated with a polymer matrix (resin, minerals, pigments, additives) and passed through a pre-forming station that produces the stratification necessary to give the profile the desired properties. After the pre-forming step, the resin-impregnated fibers are pulled through a heated die to polymerize the resin.

The pulling mechanism, attached at sufficiently spaced intervals to ensure proper hardening of the product after emerging from the die and to prevent breakage or deformation due to the pressure of the gripper, may consist of a crawler system, or two alternating dollies to ensure continuous traction of the profile.

The solid profile thus produced is then ready to be cut automatically to size.

Given its continuous nature, the pultrusion process is particularly suitable, both technologically and economically, for large scale or serial production.

The pultrusion described above is possible with two types of polymer matrix: thermosetting (polyester, vinylester, epoxy, acrylic, etc.) or thermoplastic (polyurethane Fulcrum® or polypropylene Twintex®).

The only process difference is that in thermoplastic pultrusion there is a second die downstream of the first for cooling, calibrating, and application of coatings. The choice of technology will depend on the intrinsic characteristics of the materials and on the project specifics.