“Light Resin Transfer Molding” is similar to RTM but uses vacuum to hold the male & female tool together. This process will give you two finished sides and pretty high tolerance for part thickness & dimensions. Because it is held together by vacuum and not hydraulic pressure, heavy metal tooling is not required making it less expensive.
Process – Fiberglass mat patterns are loaded into the female tool. The male tool is set into the female tool, then vacuum is applied to pull each other together. All of the air is vacuumed out of the part and then the resin is hooked up and pulled through the part. The tool stays under vacuum till resin is cured and then the part is pulled.