How to deal with plastic hose bubbles in vertical injection molding machine

Update:23-01-2021
Summary:

In the process of extrusion of plastic pipes, a series […]

In the process of extrusion of plastic pipes, a series of problems are often encountered. On the surface of the high-pressure hose, in addition to cracks, black bars, moiré and other problems, there are also bubbles in the high-pressure hose. The bubbles are generated in the plastic hose, which is generally related to the moisture content of the resin and modifier . If the environmental humidity is too high, the plastic hose will cause bubbles and will have a porous structure.

To deal with this problem, it is only necessary to manipulate the moisture content of the raw materials within the effective range, and manipulate the usual moisture content of the 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 remove part of the water. In addition, when storing raw materials, special attention should be paid to the selection of stacking locations, especially when it is rainy, to avoid moisture in the raw materials. Wet and cold pVc epoxy resin cannot be baked by fire immediately, so that it is not easy to dissolve the epoxy resin. If it must be baked, some thickeners can be added in advance. After a few days of rainy storage, the fast-mixed raw materials can also be air-dried before application.
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If bubbles are found in the plastic hose of the vertical injection molding machine, the mold temperature should be slightly lower, and the extrusion rate should not be too fast to remove the bubbles in the plastic hose. Servo energy saving injection molding machine The environmental protection and energy saving of injection molding machine can be divided into two parts: one is the driving force part and the other is the heating part. Environmental protection and energy saving of heating part: Most of the environmental protection and energy saving of heating part are energy saving by using electromagnetic boiler, and the environmental protection and energy saving rate is about 30%-70% of the old resistor circle. In addition, when the forming water is cooled, it is not advisable to quickly water cool. In such a thing, the plastic hose will also easily cause bubbles.

There is also a high probability that too many aeration tanks or poor exhaust pipes are in the solution, resulting in residual vapor in the plastic hose, so the specific situation is to deal with! When the plastic hose has scorch marks and wrinkles, the key reason is the extrusion process. The extruder screw diameter of the plastic pipe extruder is 45≤63 mm, the aspect ratio is 20, and the compression ratio is 3≤4.

In the extrusion process of plastic pipes, the extrusion temperature of the plastic hose is usually lower than the extrusion temperature of the plastic rigid pipe. If the mold temperature is too high, the plastic hose of the vertical injection molding machine will have scorch marks; if the temperature of the mold mouth of the vertical injection molding machine is too low, the surface of the plastic hose will have poor brightness.

If the speed of the extruder screw is too slow, the surface of the plastic hose is very likely to cause wavy lines. If there is extrusion pulsation, the plastic hose of the vertical injection molding machine is very prone to slub problems. If the screw speed of the extruder of the vertical injection molding machine is too fast, the friction between the surface of the plastic hose and the abrasive tool will cause scorch marks on the surface of the craft. Therefore, the screw speed ratio of the extruder can be selected within the range of 20-40r/min.

When the traction belt speed is too fast or very slow, the plastic hose of the vertical injection molding machine will be folded horizontally and vertically, and the surface layer is very prone to wrinkles. Injection molding machine is also known as injection molding machine or injection machine. This is the key forming machinery and equipment for making thermosetting plastics or thermosetting plastics into various forms of plastic products using plastic forming molds. It can be divided into column type, vertical type and all-electric type. The injection molding machine can heat the plastic, release high pressure on the molten plastic, make it shoot out and fill the mold cavity. Therefore, the traction rate should be adjusted according to the different diameters of the plastic hose. For example, for plastic hoses with a diameter of 9-16 mm, the lead rate can be selected within the range of 8-12m/min; for plastic pipes with a diameter of 21-20 mm, it can be within the range of 4-8m/min. Pick the lead rate within.

When extruding plastic hoses, attention should be paid to the temperature of the abrasive tools of the vertical injection molding machine, the speed of the extruder screw and the speed of the traction belt. Only in that way, can avoid scorch marks and wrinkles on the extrusion surface of the plastic hose of the vertical injection molding machine.

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