PLEASE READ ABOUT REINFORCEMENTS AND CORE MATERIALS IN THE NEXT CHAPTER.
Tooling paste, often known as putty, compound, etc., is a sprayable or extrudable version of tooling board. The majority of goods are made of thermoset resin with a significant amount of filler added for machining ease. The two main categories are based on the chemistry of two types of common resins: polyester and epoxy.
Mould Tooling System
To reduce the price and duration of the tool-making process, tooling resin, a polyester laminating resin, is combined with an alumina trihydrate filler. This resin hardens quickly and experiences very little shrinkage. It also makes the tool
When touched, the gelcoat or primer won’t come off because it has been sprayed in and given time to cure.
The problem of shrinking with polyesters and vinyl-ester resins is genuine, and if you don’t take care of it, it can lead to unpleasant cosmetic issues. The use of a pre-laminated skin coat is one typical remedy. This is merely a thin (3/4 oz or 200g) chopped strand mat that has been very carefully put over the gelcoat. As few laps as feasible should be used, as thick portions will shrink and print into the gelcoat surface if there are any bubbles. This can be done uniformly throughout a section or only in vulnerable areas, such as core tapers or parts with greater reinforcements.
Skincoats must be completed using a compatible laminating resin, which must be able to chemically bond with the resin that will be infused into the part. Before adding more laminate, make sure the skincoat is dry to the touch (like gelcoat).
In order to address aesthetic problems, your part may occasionally require a surface ply that is co-infused with the laminate. This could be a nonwoven fabric that is fluffier or a thin mat like Lantor Finishmat that keeps a layer rich in resin against the surface of the part. Although a non-woven is preferable, even a light woven can aid because the fiber bundles are thinner and the resin pockets between them will shrink less.
When gloss preservation, high hardness, remarkable craze resistance, and little distortion are priorities, tooling gel coat—a gel coat resistant to abrasion—is utilized to fabricate molds.
Spray Fillers and Varnishes
By definition, spray fillers and varnishes are coating materials that, following application, form a thin layer on surfaces before hardening into a solid film that serves as a functional coating.
When producing prepreg composite moulds or components, epoxy is the material of choice since it does not interfere with the curing of prepregs at high temperatures the way polyurethane (PU) board will. This makes epoxy the material of choice for tooling boards in high temperature applications.