JEC COMPOSITES MAGAZINE - Issue #73 - June 2012 - 74

pultrusion

High-performance resins for pultruded composite profiles
Pultrusion is a continuous, automated fabrication process for manufacturing in high volume constant cross section profiles and solid shaped parts. Pultruded FRP structural profiles with exceptional finish and performance properties can be fabricated cost effectively using reinforcements, fillers and surface veils with a suitable resin.

By
neil grAy gloBAl BuSineSS mAnAger Scott BADer

P

ultruded composite profiles are being specified in a growing number of applications worldwide, as the performance properties that can be obtained by leading pultruders enable them to supply filled and fibre-reinforced (FRP) composite profiles which can compete with metals such as steel and aluminium.

According to Scott Bader, the Crestapol® range of urethane acrylate-based resins offers pultruders a technically proven high-performance solution, which can also improve productivity and reduce overall production costs compared with other thermosetting systems.

Productivity and performance
Scott Bader is a member and sponsor of the European Pultrusion Technology Association (EPTA). The company manufactures the Crestapol range of urethane acrylate-based thermoset blend low-viscosity resins, which provide pultruders the key benefits of lower overall manufacturing costs and increased productivity compared to more traditional pultrusion resin systems such as vinyl esters and phenolics. The principal grades, Crestapol 1212 and 1214, were specifically developed to be processable on unmodified pultrusion equipment using standard initiators, additives and fillers. Both grades are suitable for wetbath and injection applications with high filler loadings (up to 2:1 filler-to-resin loadings) and achieve rapid wet-out of reinforcement fibres. These resins have a very rapid self-accelerating cure, which enables faster haul-off speeds to be used compared with typical pultrusion grade thermosetting resins. Due to this high reactivity, there is no loss of pultrusion line speed, even when heavily filled.

Pultrusion process
The process typically involves drawing continuous glass or carbon fibres through a bath of resin blended with a catalyst, which passes through preformers and then a heated die which has the sectional geometry of the final profile. Composite pultruded profiles with predictable mechanical properties can consistently be produced to a required application specification due to the uniformity of cross-section, consistent resin content, accurate fibre distribution and alignment possible with a pultrusion process. The selection of the right resin type and fillers to achieve the desired combination of properties for an application, such as shear strength, fatigue resistance and fire, smoke and toxicity (FST) performance, is critical.

Fig. 1: Pultruders benefit from higher productivity with Crestapol 1212 resin due to the higher haul-off rates possible, even at high ATH filler loadings, in demanding building and rail applications where the FRP profiles must meet Spanish M1/F0 fire test ratings

Fire, smoke and toxicity
Crestapol resins offer the flexibility of achieving a wide range of specifications by optimising the formulation for specific application and performance

74 jec composites magazine / No73 June 2012
JEC COMPOSITES MAGAZINE - Issue #73 - June 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #73 - June 2012
