Resin Transfer Molding (RTM) is another type of closed molding process with low positive cavity pressure. In this process, liquid resin and catalyst are injected into a closed mold cavity containing dry fiber reinforcements. RTM manufacturing offers advantages like fast cycle times, close tolerance production, smooth surfaces on both sides of the molded panels, and suitability for low and high production quantities at varying thicknesses.

PP core fiberglass sandwich mat, also known as infusion mat or RTM mat, is a type of composite material that is designed to facilitate the flow of resin through a composite part during the manufacturing process. It is composed of one or two layers of chopped strand mat (CSM) on either side of a core material made of polypropylene (PP), which serves as the resin flow area. The flow promoter on the inside of the core material helps to accelerate the resin flow and distribute the resin evenly. This allows for faster production times and easier work on larger components.

The mat has several advantages such as reduced print-through due to the incorporated surface veil, improved visual appearance due to stitch-free construction, and good drapability.

The high-flow version of the mat has a faster flow rate, making it suitable for closed injection processes like RTM.

The tidy edges of the cut mat ensure that it is clean and free of fraying, and the composite material can be spliced without thick overlaps.

The mat is suitable for various FRP forming processes and applications, and the production line is managed by experienced staff and efficient management.