The common production methods are as follows:
1. Long fiber method
The long fiber method involves melting granular carbonate resin through an extruder, introducing untwisted glass fiber bundles treated with coupling agents at the die head, wrapping them into strips, leading them out from the bottom, cooling them in a water tank, and cutting them into particles 6 to 12mm long. Thus, the products are produced.
There are the following advantages and disadvantages in the production of long fibers:
The mechanical strength and heat resistance of long glass fiber reinforced products are significantly higher than those of short fiber reinforced products. However, for long-fiber granular products, since the glass fiber bundles have not been evenly dispersed in the resin, injection molding must use a screw injection molding machine with a better mixing effect.
2. Short fiber method
The short fiber method involves pre-mixing short glass fibers that have been cut into 3-15mm in length with polycarbonate resin, then further blending and plasticizing them through a screw extruder. After extrusion, they are cooled and cut into particles that are 4-6mm in length.
There are the following advantages and disadvantages in the production of short fibers:
For the injection molding of short-fiber granular products, a general plunger injection molding machine can meet the requirements. Short fiber particles also have the characteristics of good fluidity, easy plasticization, high joint strength of products, and good surface gloss when formed.