The Production Process of Epoxy Fiberglass Laminates

The epoxy fiberglass laminate is made of alkali-free fiberglass cloth impregnated with epoxy resin adhesive. Today, we’ll take a look at its production process. The first step is to prepare the pre-preg (aka. pp sheet), a composite material made from pre-impregnated fiberglass cloth as the reinforcement and a partially cured epoxy resin matrix. Pre-preg is one of the main materials for manufacturing laminates.

1. Production of Pre-pregs

1.1 Preparation for resin matrix

Add semi-finished epoxy resins, solvents and diluents, and fillers as per formulas, and mix them according to the process requirements. Main equipment is the agitated reactor, etc.

1.2 Gluing and drying

The prepared adhesive is applied to the fiberglass cloth through the gluing machine according to the technical requirements, and then the solvents are volatilized by baking and heating, so that the solids of epoxy resin are evenly covered on the base cloth. Main equipment includes the vertical gluing machine and the horizontal gluing machine.

1.3 Cutting

Cut the partially cured cloth into fixed size as per the required length, then stored them in cold areas since heat accelerates complete curing.

picture of Pre-preg sheets

After preparation of the semi-finished pre-preg sheets, they will be manufactured according to the technical specifications for laminated sheets. The main equipment is a hot press.

2. Production of Epoxy Fiberglass Laminated Sheets

2.1 Loading Materials

Pre-pregs of different thickness to be pressed are placed on the template as required, and then loaded into the hot press. The order of placement is: back up board, back up paper, single-sided steel plate, film, pre-preg, film, double-sided steel plate, film, pre-preg, single-sided steel plate, back up paper, back up board.

2.2 Hot Pressing

Make sure all the equipment is working in good condition and then load the materials and prepare for pressing. After the pre-heating of equipment, start heating up, press the equipment according to the process requirements, and calculate the hot-pressing time, adjust the pressure depending on the flow of the resin adhesive to ensure the product appearance, thickness as well as mechanical & electrical properties. After a required period, cooling to a certain temperature.

2.3 Cutting and Sorting

After cooling, the products are transferred to the cutting workshop, where their rough edges are cut off as per the standard size.

picture of the production process of epoxy sheets