As we know the surface of transparent plastic profile products must be strict to get a high light transmittance. There should be no markings, pores, and whitening. Haze, black spots, discoloration, poor gloss, and other defects are not allowed in the entire extrusion process. So the formula of raw materials, extruding equipment, extrusion dies, and even finished products must be very carefully set to meet the strict or even special requirements.
Secondly transparent plastic profiles are mostly made of thermal plastics with a high melting point and poor fluidity. In order to ensure the surface quality of the product, processing parameters such as barrel temperature, extrusion pressure, and extrusion speed are often fine-tuned. In this way, the production of transparent plastic profiles can be fully extruded at the same time without internal stress to cause product deformation and cracking.
The above issues should be paid attention to in the whole extrusion process (including the requirements of the plastic extrusion machine) to reduce the internal stress and surface quality defects on that transparent PVC extrusion
1. A special screw and a plastic machine with a separate temperature control nozzle should be used;
2. The extrusion temperature should be higher if the plastic resin does not decompose;
3. Production pressure: generally higher to overcome the defect of high melt viscosity, but too high pressure will cause internal stress and cause difficult de-molding and deformation;
4. Extrusion speed: in the case of satisfying mold filling, generally it should be low, and it is best to use slow-fast-slow multi-stage injection;
5. Holding pressure time and molding cycle: in the case of satisfying product filling without dents and bubbles; it should be as short as possible to minimize the residence time of the melt in the barrel;
6. Screw speed and back pressure: under the premise of satisfying the quality of plasticization, it should be as low as possible to prevent the possibility of degrading;
7. Mold temperature: The cooling of the product has a great impact on the quality, so the extrusion temperature must be able to accurately control the process. If possible, the extrusion temperature should be higher.
H.D. Plastics products are specialized in the production of extruded plastic profiles. We can customize and process a variety of plastic profiles, PVC profiles, abs profiles, pp profiles, plastic corners, PC lampshades.
With in-house extrusion die capabilities and custom engineering for your personalized plastic profile extrusion needs, H.D.Plastics combines the industrial experience and expertise to satisfy the challenges of your custom plastic extruded product.