Plastic injection molding machine to solve the problem of air bubbles generated inside the tube

Date：2016-07-26 10:17:22

Plastic pipe extrusion, we often encounter a series of problems. In addition to possible plastic tube surface cracks will appear, black lines, moire phenomenon than we may also encounter inside a plastic tube produced a bubble, then under what circumstances, will produce plastic tube inside the bubble it ?
Plastic pipe inside bubbles, in general, is related to the moisture content of resins and additives. If the water is too high, then the plastic tube pipe bubbles will be porous.

Attention to this problem, we just need the moisture content of raw materials is controlled within a reasonable range can be, general raw material moisture content is controlled within 0.3% -0.5% range. Injection molding machine in a high speed mixer can exclude only the water portion of the raw materials compounded when, at the same time when we store the raw material for stacking the choice of location is to be noted that, especially in the rainy season should pay attention to prevent material moisture. Damp PVC resin can not directly fire baked, in order to avoid thermal decomposition of the resin, the baking, if desired, add some stabilizer in advance. After high speed mixing materials in storage after the rainy days, it must first be used only after drying.

If we find the injection molding machine plastic tube inside the bubble, then the die temperature should be slightly lower at the point of extrusion speed can not too fast, in order to eliminate air bubbles inside the plastic tube. And, while cooling in shape when flash is not suitable for rapid cooling, in that case, plastic pipe will be prone to bubbles.

Of course, this is the main reason for the plastic pipe extrusion produce bubbles, does not rule out other causes. There also may be due to excessive or inappropriate financial material inflatable plastic exhaust pipe leading to the residual gas, so treat specific conditions!
When plastic hose appears scorch marks, wrinkles, mainly from the extrusion process. Extruded plastic tubes extruder screw diameter of 45-65mm, an aspect ratio of 25, a compression ratio of 3-4.

Plastic pipe extrusion, plastic hose extrusion temperature is generally higher than the hard plastic pipe extrusion temperature is lower. If the die temperature is too high, then the injection molding machine plastic pipe appears scorch phenomenon; if the injection molding machine die temperature is too low, then the plastic tube surface brightness difference phenomenon.

If the extruder screw speed is too slow, then the plastic tube surface prone to moire; if pulsation extrusion, injection molding machine plastic pipe so prone to the phenomenon of bamboo-like; if the injection molding machine screw speed is too fast, then the surface of the plastic pipe mouth friction between the mold overheating can cause the product surface scorch phenomenon. Therefore, the screw speed can be selected within 20-40r / min range.


Similarly, if you pull too fast or too slow will make the horizontal and vertical injection molding machine plastic pipe contraction increased, the surface will be prone to wrinkles. Thus, pulling speed according to the different diameter plastic pipe, make appropriate adjustments. For example, the diameter of 9-16MM plastic tube traction line speed can be selected within 8-12m / min range; 19-25mm diameter plastic tube traction line speed can be selected within 4-8m / min range.

Plastic pipe extrusion, we want to pay particular attention to the injection molding machine die temperature, extruder screw speed and traction speed and other factors, so as to prevent the injection molding machine plastic pipe extrusion scorch the surface, the appearance of wrinkles.

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