Common defects and solutions in the production of FRP pultruded profiles?

FRP pultruded machine for sale

Defect: Bubbles

Reason: Due to poor curing, styrene gas, etc. was trapped

Countermeasures: reduce the pultrusion speed, increase the mold temperature, and increase the amount of curing agent added

Defects: cracks

Reason: The resin has high reactivity, large curing shrinkage and uneven glass fibers.

Countermeasures: Reduce the amount of curing agent, lower the mold temperature, switch to low-shrinkage resin, increase the amount of glass fiber, and make the glass fiber evenly distributed.

Flaw: Ruth

Reasons: The shrinkage rate of the resin is large, the quality of the glass fiber substrate used in the surface layer is poor, and the fiber diameter is large

Countermeasures: replace low-shrinkage resin, mix filler, use surface felt or non-woven fabric as surface layer, increase mold temperature

Defects: surface pits

Reason: Insufficient amount of resin and insufficient amount of glass fiber

Countermeasures: Increase the amount of fiber-adherent resin, increase resin viscosity, and increase the amount of glass fiber

Defect: Bend

Reason: Uneven configuration of glass fiber composition

Countermeasures: Adjust according to the deformation situation, arrange the glass fibers symmetrically, and adjust the mold temperature

Defects: sticking to the mold, or even pulling the product apart

Reasons: low fiber and filler content; poor internal demoulding effect; too much curing degree

Defects: white powder appears on the surface, roughness

Reason: The shear stress at the breakaway point is too large, causing crawling; the breakaway point is too far ahead of the solidification point

Defects: uneven surface, grooves and white spots, partial whitening or exposed white yarn

Reasons: low fiber content, scratched mold, poor impregnation; impurities mixed in, surface resin is too thin

Defect: Surface cracks

Reason: Uneven curing

Defects: Ruffed surface

Cause: Too much fiber

Defects: surface wrinkles, broken surfaces

Reason: The surface resin is too thick; the fiber content is low

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.