Pultrusion - manufacturing process
Pultrusion is an automated process for manufacturing fibre-reinforced plastic profiles, also known as pultrusion profiles or GFRP profiles. In the continuous manufacturing process a profile is produced in a number of steps (see “The pultrusion process” graphic) through the targeted combination of fibre reinforcement and resin systems.
What are the advantages offered by pultrusion?
Pultrusion offers a very high degree of creative freedom. The process allows profiles to be manufactured with individual properties such as mechanical, electrical, chemical or fire-retardant properties. This is governed by three factors that can each be optimised in the process: the desired fibre reinforcement, the resin system and the mould that defines the profile cross-section. The careful selection of these factors enables profiles with individual properties and cross-sections to be produced for a range of applications.
At Röchling, we use a variety of glass fibre, carbon fibre or basalt fibre reinforcements as well as UP, VE, EP and PUR resin systems for the manufacture of pultrusion profiles. We also manufacture our own moulds in-house, enabling us to produce profile cross-sections to your requirements. That gives us considerable latitude for creativity when it comes to pultrusion and means you get pultrusion profiles that are customised for your application. More information about our comprehensive range of pultruded profiles.
The pultrusion process
1. Fibre reinforcement
The desired fibre reinforcement is introduced. At Röchling we offer the following reinforcements:
- Glass or carbon fibres in the form of rovings, mats, fabric and glass complexes
- Unidirectional roving reinforcement for high tensile/flexural strength
- Multidirectional mat complexes for high longitudinal and transverse strength
- Combinations of mat/roving/mat for highest mechanical properties
2. Impregnating trough resin system
The introduced reinforcing fibres are pulled through an impregnating trough containing a resin system. At Röchling you can choose between the following resin systems:
- polyester resin (UP), vinyl ester resin (VE), epoxy resin (EP), methacrylic resin (A) and polyurethane resins (PUR)
- Additives include hardening systems, parting agents, antishrink additives, colouring pigments, flame retardants, etc.
The reinforcing fibres impregnated with the resin system are heated in the mould and shaped into the desired profile form.
- The composite of reinforcing fibres and resin system is heated
- The resin system is cured
- The profile now corresponds to the cross-section of the mould
4. Tandem pull-off
- The profile is pulled continuously out of the mould
- How fast this is done varies according to the resin type and profile cross-section
- The profile is cut to the desired length
We offer a comprehensive range of profiles manufactured in the pultrusion process. We would be happy to advise you on the selection of the right profile for your particular application. Just use our contact form below.