HP-RTM

HP-RTM refers to the molding process that uses high-pressure pressure to mix and inject resin into a vacuum sealed mold pre laid with fiber reinforced materials and pre embedded components. The resin is then filled, impregnated, cured, and demolded to obtain composite material products.

This process can achieve low-cost, short cycle, large-scale, and high-quality production. Compared to the traditional RTM injection pressure of 0.6-1.5 MPa (6-15 bar), HP-RTM usually injects at pressures of 1.0-6.0 MPa (10-60 bar) or even higher. The resin can fill the mold cavity in a short time, complete the infiltration process of the preformed fiber body, and promote the discharge of air bubbles from the resin, improving the surface forming quality of the product. The process can be shortened to less than 5 minutes.

The HP-RTM molding process involves injecting low viscosity resin into a mold through a mixing head, soaking the preformed fiber fabric inside, and finally rapidly curing to form high-strength composite parts. The key technology lies in two stages: resin injection and curing: first, the preformed carbon fiber woven fabric is placed into the mold cavity of the press, and then the liquid resin is injected under high pressure for curing. Due to the use of a new generation of rapid reaction type chemical raw materials, the various components in the raw material formula are always separated before mixing. When the carbon fiber preform needs to be injected with resin, multiple component raw materials are mixed. The reaction time in the raw material mixing head is very short, so during the injection stage, the viscosity of the raw material begins to rapidly decrease, and the fluidity gradually decreases, which will lead to a sharp increase in the pressure inside the mold (which is also the biggest characteristic of this process). The pressure inside the mold is usually between 5-12 MPa (50-120 bar), which can be adjusted according to the actual process flow and the workpiece.