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MVP offers comprehensive products, services, and training to support a variety of closed molding methods.
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What is it?

Closed molding is a consistent and repeatable manufacturing method enabling higher quality parts, faster production, reduced emissions, and with less waste compared to open molding. With this method, fiber reinforcements are laid into the base mold, the mold is closed and sealed, and the resin is injected into the closed mold cavity. Once the resin has cured, the mold is opened and the part is removed.

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Types of Closed Molding:

MVP products and technical experts support a variety of closed mold processes, and often tailor or combine solutions for the perfect application. A process is selected based on many factors such as part size, complexity, and desired production volume. MVP supports each of these processes with a variety of specialized equipment and accessories, as well as personalized training for customers.

Resin Transfer Molding (RTM)

Classic RTM is used to produce a high volume of parts per day. The process uses a composite mold reinforced by metal which is then injected under high pressure.

Light Resin Transfer Molding (LRTM)

LRTM, one of the most common closed mold methods, uses a rigid mold and simi-rigid counter mold which is sealed by vacuum. Resin is then injected with an injection machine.

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Resin Infusion Process

Resin Infusion Process is utilized for production of large parts and where higher glass content is required. MVP created a single injection port solution for simple operation and developed a unique silicone resin channel network and plastic bag closing system to speed production times for this process even more.

Flex Molding Process

Sometimes referred to as reusable bag molding, Flex Molding was developed by MVP and utilizes one rigid mold half and one flexible mold half, either a plastic bag or a silicone membrane.

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Fast Flow LRTM

The latest closed mold process from MVP, Fast Flow LRTM is a blend of the Flex Molding Process and LRTM utilizing collapsible resin channels and a unique channel layout for faster injection times. The process enables the production of larger parts with even higher resin viscosity, and eliminates the need for trimming once parts are demolded.

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Tailored Process and Training

MVP works with our customers to combine the right solutions for their needs, blending multiple techniques and methods.

Closed Molding Equipment:

Our closed molding products provide a comprehensive package including reliable injection systems, accessories and seals. MVP products enable proper and accurate injection into reinforced composite molds, LRTM molds, disposable bags, and many reusable bag methods without over pressurizing the mold or part.

Experience Matters:

MVP has been a leader in closed molding technology for decades and has guided hundreds of manufacturers to improve their production or transition to closed molding methods. Our technical support experts not only provide training and guidance, but they are leading new innovations in closed molding. Some of MVP’s latest developments include:

  • Silicone resin channel for plastic bag infusion
  • Single injection port
  • Split mold of LRTM and Flex Molding ideal for complex parts

Customer Feedback:

In reference to MVP’s Fast Flow LRTM technology:

“Very good job, as usual! This is one of the greatest improvements I’ve seen so far with the Light RTM process. This is really opening a new area of opportunity for our industry.” – Laurent Imbert, Euromere


Want to learn more? For more information or a quote on our products please contact us.