high pressure resin transfer molding (HP-RTM)

High pressure resin transfer molding (HP-RTM) uses preformed parts, hp-rtm molds, vacuum assisted exhaust, high pressure injection to complete the impregnation and curing process of high performance thermoset composites to achieve low cost, short cycle time (high volume) and high quality production.

Keywords introduced in the above presentation.

High Pressure: High pressure here is relative to the traditional RTM (Resin Transfer Molding) process, HP-RTM increases the injection pressure to 80 bar. the benefit of high pressure injection is that the resin can reach each corner faster, thus increasing the fiber content of the product, improving product performance and making it more suitable for parts with complex shapes.

Pre-laid: here pre-laid fiber reinforcement is fiber material that has been cut and pre-shaped.

Pre-placed insert: the insert is the part placed in the mold before molding, the material has metal and non-metal, so that after molding the product, the insert is wrapped into its own structure and is not removable. The need for pre-positioned inserts is determined by the structural design of the product.

HP-RTM molding process

It is a molding process in which resin is hedged and mixed using high pressure and injected into a vacuum-sealed mold pre-lined with fiber reinforcement and pre-molded inserts to obtain composite products through resin flow filling, impregnation, curing and demolding. These processes allow high performance structural components to be obtained by directly combining the reinforcement with the matrix. In-line high-pressure impregnation allows manufacturers to minimize raw material costs. This process is well suited for complex 3D geometries and long fiber reinforcement.

RTM vs HP-RTM

In the standard RTM process, the system components (resin and hardener) are usually mixed at relatively low pressure (<15 bar). In HP-RTM, mixing is managed by reacting the components at high pressures (typically over 50 bar) in a cylindrical mixing chamber. The laminar fluid is quickly transferred into the cavity through the injection nozzle, which is mounted in a hole drilled in the mold without waste.

With standard RTM, production of parts in the mold can take anywhere from 15 minutes to over an hour. In most cases, post-curing is required to achieve final performance. With the HP-RTM optimized resin system, finished parts can be produced in less than 5 minutes.

Key Benefits of HP-RTM

• Rapid filling of the mold cavity with resin.
• Improved quality of resin impregnated reinforcements.
• Accelerated resin reactivity system allows for short curing cycles.
• Significant for air removal and product porosity reduction.
• Excellent surface properties and quality of the product.
• Low dimensional deviations in thickness and three-dimensional shape of the product.
• High process stability and repeatability.
• Use of internal mold release agents and self-cleaning systems.

Advantages of HP-RTM parts

• Very good material and very high performance of the other part.
• Parts with very high surface quality requirements.
• Conditions with the ability to use fast curing resins.
• Industrial production on a large scale
• Short processing cycle times.

MDC HP-RTM is used in multiple industries such as automotive manufacturing, aircraft manufacturing, agricultural machinery, rail transportation, wind power, and sporting goods. Contact us immediately for HP-RTM mold projects.