Selection method of mold gel coat
Performance requirements of RTM/LRTM process for gel coats
The RTM/LRTM process is a FRP molding process developed on the basis of hand layup technology and widely used. It has been promoted as early as 30 years ago, but due to the level of mold production and material matching, it has only been fully applied in recent years.
How to choose mold gel coat?
For the closed mold forming process, the repeated heat resistance and cavity pressure requirements of the mold require higher performance requirements for the mold gel coat than ordinary hand layup processes. We recommend users to use vinyl based mold gel coats with higher heat deformation temperatures and higher fracture elongation.
▪ It is recommended to use a specialized vinyl curing agent to greatly reduce the occurrence of bubbles and ensure better product mechanical properties.
▪ In most cases, we use a small spray gun to spray the mold gel coating. It is not recommended to dilute the mold gel coating on our own when the atomization effect is poor, as both acetone and styrene will affect the final quality of the product. It is recommended to heat up or contact the manufacturer to adjust the viscosity.
▪ The proportion of curing agent shall not be less than 1%.
▪ The construction of the mold gel coat is recommended to be completed in three passes, with a thickness of 0.4mm-0.3mm-0.2mm for each pass. The proportion of curing agent is recommended to be gradually increased by 1.5-2.0. The previous pass of mold gel coat should be dried before proceeding to the next pass. This greatly helps to defoaming the mold gel coat and prevents sagging.
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