Master Composites

Closed Molding

This is the Future!

Reasons why we use closed molding:

  • Virtually no VOC emissions
  • Consistent fiber to resin ratios
  • Improved working conditions
  • Faster molding cycles
  • Reduced labor costs and waste
  • Consistent material usage

Closed Molds are just that – closed.
There are three ways to do them:

  1. Light Resin Transfer Molding (LRTM) – Instead of spraying resin into an open mold, the mold has two sides. To make parts, unsaturated material is placed onto the surface of one side. The other side is then placed over the material on the first side and sealed using vacuum pressure. Resin is pulled into the cavity between the two sides with vacuum pressure, consistently saturating the dry material. This method of making parts makes the cosmetic surfaces of the completed part more consistent and of a higher quality.
  2. Closed Cavity Bag Molding (CCBM) – much like LRTM, except one side is a flexible bag (usually silicone). This is a better process with a higher fiber-to-resin ratio. It is also the preferred method for Carbon Fiber.
  3. Vacuum Infusion Process (VARTM) – similar to Closed Cavity Bag Molding, but using different materials and supplies allows the resin to flow into glass material.

Production Parts

Master Composites, Inc. strives to become a 100% closed molded facility and move away from the old-school ways.

We have produced parts for various industries such as Marine, Automotive, Industrial, Recreational, Aviation/Aerospace, etc.

We have dealt with part complexity ranging from very simple to extremely complex projects requiring vast experience with closed molding and advanced tooling.

Master Composites, Inc. specializes in all forms of closed molding production. We produce parts for many different industries, all requiring a tailored laminate specification for their needs. The uniqueness of closed molding vs open molding is that we can choose from hundreds of reinforcement and resin-type variations. With our advanced knowledge in this field, we pinpoint the physical and mechanical features that you are looking for out of your parts.

The key feature in closed molding vs. open molding, is resin to glass ratios. Compared to open molding, where glass content hovers around 30%, closed molding can yield as high as 70% glass content and produce a very lightweight, high-strength composite that is unachievable in open molding. This important feature allows us to tailor any composite to a polyester, vinyl ester, or epoxy resin system matched with any reinforcement type you choose. Eglass, Carbon, Aramid, Basalt, and Inegra are some examples of reinforcements we use here daily.

In the closed molding world, Master Composites, Inc. uses CCBM, VARTM, and LRTM as our production methods of choice. There are more processes in closed molding, but we specialize in these three processes because we can produce virtually any composite from them more rapidly, precisely, and cost-effectively than open molding.

It all gets done here!

We know how to produce the exact part you are looking for!