Common problems of FRP pultrusion molds and solutions

FRP Profile Pultrusion Machine

In the process of producing FRP pultrusion molds, some external factors will also affect the quality of FRP pultrusion molds. So, what quality problems will be encountered when producing FRP pultrusion molds, and what are the causes? This issue will be summarized and introduced below.

1. The side of the mold is not filled. The reasons for this include the weight of the material being placed is too low; the mold temperature is too high, and the composite clinker hardens before the mold is fully filled; the mold closing time is too long, and the composite clinker hardens before the mold is fully filled. Pre-hardening; the molding pressure is too low; the placement area is too small; the placement method is poor or the flow is insufficient due to the use of stored expired clinker.

2. A few parts of the mold edge are not filled: the weight of the cooked lining is too low; the clinker spills out before the mold is closed; the gap between the shear edges is too large, causing the clinker to spill out.

3. The mold edge is filled but there are concave and convex spots: the clinker weight is too low; air cannot escape from between the molds; there is air in the reinforcing ribs or protruding bolts, which prevents the gas from escaping during molding.

4. The hardened surface presents a semicircular bulge: air or gas exists in the composite clinker and between the clinker layers; the clinker has poor fluidity, preventing the air in the center of the material from escaping; the shear edge is enlarged; the mold The temperature is too high, causing the styrene monomer vapor to volatilize; the hardening time is too short, and the clinker is incompletely hardened, causing the monomer vapor to volatilize; the mold closing speed is too fast; the clinker is cooked or the viscosity is too low, and the air between the layers cannot escape. ;Poor impregnation caused by improper use of glass fibers.

5. Surface porosity: The material placement area is too large, the flow distance is too short, and air cannot escape; the glass fiber in the clinker is poorly impregnated.

The pultrusion process was studied as early as 1948. It was first registered and patented in the United States in 1951. It was only in the early 1970s that it truly entered the field of structural materials. After that, the pultrusion process became a widely used process technology and gradually attracted the attention of all sectors of society. With the improvement of raw materials and equipment manufacturing levels, many key technologies of the pultrusion process have made major breakthroughs and achieved rapid development.