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The pultrusion process is the only FRP process which has to use an Internal Mould Release agent (IMR) traditionally zinc stearate and acidified esters have been used, however problems with surface finish, adhesive bonding, poor weathering properties and rapid die erosion have led to the development of a new generation of IMR’s.

Our products have low pull forces, good surface finish and extended die life. Larger profiles can be made on your existing machines.

PAT release agents do not increase resin viscosity, they are liquids not powders.

– Low pulling force, long die life
– Good surface finish
– Improved filler dispersion and glass fibre wet out
– No effect on painting or bonding
– Easy and safe to use, store and transport
– Non-acidic, all fillers including carbonate types can be used


PAT-672 & PAT-654/M 0.5 to 1% Polyester
PAT-654/M 0.5 to 2% Vinyl Ester
PAT-672 & PAT-656/B3R 2% Epoxy
PAT-659/A 0.5% Phenolic (water)
PAT-659/B 0.5% Phenolic (solvent)
PAT-654/M 1% Modar


Always pre-coat the die before starting with release agent and apply to dry fibres just before the wet fibres enter the die.

When finishing production or storing the die coat with our release agent (which is guaranteed neutral pH).

When starting up add double release agent for the first resin mix, it is important for a smooth start up.

Also we have noted that our customers add additional release at difficult times for instance if due to poor tex control and glass packing is too high.

The mechanism is that thermoset resins cure from liquid phase to solid through a process of polymerisation and cross-linking. During this change the release agent is forced to the surface. PAT release agents are temperature stable and formulated to be mobile in the curing resin. Once cured there is no blooming or migration of the release agent.

An important note is that using our neutral products basic fillers such as calcium carbonate can be used with no reaction.

Our release agents should be stirred before use and then added to the resin and mixed well. Warm temperatures are good for this type of additive (low temperatures cause increase in viscosity).

Chemical Release Company Limited is a member of EPTA, European Pultrusion Technology Association.

For further information or assistance regarding our products, formulations and the pultrusion process please contact us, we are always happy to help.