Injection molding machine to solve the problem of plastic pipe bubbles?

    In the process of plastic pipe extrusion, a series of problems are often encountered. In addition to cracks, black lines and moire on the surface of the hose, we may also encounter bubbles in the hose. Under what conditions will there be bubbles in the hose? Bubbles occur in plastic pipes, which is usually related to the water content of resins and additives. If the humidity is too high, the plastic pipe will produce bubbles and become porous.

    To deal with this problem, it is only necessary to control the moisture content of raw materials within a reasonable range and the ordinary moisture content of raw materials within the range of 0.3% ≤ 0.5%. When the raw materials of the vertical injection molding machine are mixed, the high-speed mixer can only sweep away part of the water. At the same time, when storing raw materials, we should also pay attention to the selection of stacking place, especially in the rainy season, we should pay more attention to avoid the moisture of raw materials. Wet PVC resin can not be directly baked with fire, so it will not synthesize the resin. If it needs to be baked, some stabilizers can be added in advance. After several days of storage in rainy season, the materials after high-speed mixing can also be dried before use.

    If bubbles are found in the plastic pipe of the vertical injection molding machine, the mold temperature should be slightly lower and the extrusion speed should not be too fast to eliminate the bubbles in the plastic pipe. Servo energy-saving injection molding machine the energy-saving of injection molding machine can be divided into two parts: one is the power part and the other is the heating part. Local heating energy saving: most of the local heating energy saving adopts electromagnetic heater, and the energy saving rate is about 30% - 70% of the old resistance coil. At the same time, during molding cooling, it is not suitable for rapid cooling. In this case, the plastic pipe will easily produce bubbles.

    Of course, this is only the main reason for the bubbles produced by extruding the plastic pipe, but it does not eliminate other reasons. This may also be due to excessive aeration or poor exhaust in the melt, resulting in residual gas in the plastic pipe, so the detailed situation is disposal! When the plastic hose shows scorch marks and wrinkles, the main reason is the extrusion process. The screw diameter of plastic pipe extruder is 45 ≤ 65 mm, the length diameter ratio is 25, and the tightening ratio is 3 ≤ 4.

    In the process of plastic pipe extrusion, the extrusion temperature of plastic hose is generally lower than that of plastic hard pipe. If the mold temperature transition is too high, the plastic pipe of the vertical injection molding machine will show coke marks; If the die temperature transition of the vertical injection molding machine is too low, the surface brightness of the plastic pipe is poor. v

    If the speed of the extrusion screw is too slow, the surface of the plastic pipe is easy to produce ripple. If there is extrusion pulsation, the plastic pipe of the vertical injection molding machine is easy to present the bamboo phenomenon. If the screw speed of the vertical injection molding machine is too fast, the friction between the surface of the plastic pipe and the mold will lead to scorch marks on the surface of the product. Therefore, the screw speed can be selected in the range of 20 ~ 40R / min.

    Similarly, if the traction speed is too fast or too slow, the plastic pipe of the vertical injection molding machine will shrink horizontally and longitudinally, so the appearance is easy to show wrinkles. Injection molding machine is also known as injection molding machine or injection machine. It is the main molding equipment that applies thermoplastic or thermosetting plastics to plastic molding molds to make plastic products with various shapes. It is divided into vertical type, horizontal type and all electric type. The injection molding machine heats the plastic and applies high pressure to the molten plastic to make it shoot out and fill the mold cavity. Therefore, the traction speed should be adjusted according to different diameters of plastic pipes. For example, for a plastic pipe with a diameter of 9-16 mm, the lead speed can be selected in the range of 8-12 M / min; For plastic pipes with a diameter of 19-25 mm, the lead speed can be selected in the range of 4-8M / min.

    When extruding plastic pipes, pay special attention to the temperature of the mold of the vertical injection molding machine, the speed of the extrusion screw and the traction speed. Only in this way can we avoid coke marks and wrinkles on the extruded surface of the plastic pipe of the vertical injection molding machine.