▲ 1. Plastic material processing
POM plastic materials have low water absorption, usually ranging from 0.2% to 0.5%. Under normal circumstances, POM can be processed without drying, but it is necessary to dry wet materials. Dry temperature above 80 ℃ for at least 2 hours, detailed according to the supplier's materials. The proportion of recycled materials used usually does not exceed 20-30%. But it depends on the type of product and its ultimate use, sometimes up to 100%.


▼ 2. Selection of Plastic Machine
POM plastic materials have no special requirements for injection molding machines, except for requesting a screw free material area. Usually, injection molding is sufficient.

▲ 3. Injection mold and gate planning
It is common to control the temperature of injection molds at 80-90 ℃, with a runner diameter of 3-6mm and a gate length of 0.5mm. The size of the gate depends on the thickness of the rubber wall, and the diameter of a circular gate should be at least 0.5-0.6 times the thickness of the finished product.

The width of a rectangular gate is usually twice or more the thickness, the depth is 0.6 times the wall thickness, and the demolding angle is between 40 ′ -130 ′.


▼ 4. Melting glue temperature
Can be measured using the aerial method
POM-H can be set to 215 ℃ (190 ℃ -230 ℃)
POM-K can be set to 205 ℃ (190 ℃ -210 ℃)

▲ 5. Injection speed
Commonly seen as medium to fast, too slow is prone to ripples, and too fast is prone to streaking and shear overheating.

▼ 6. Back pressure
The lower the better, usually not exceeding 200bar

▲ 7. Stay time
If the device does not have a glue retention point
POM-H can stay at 215 ℃ for 35 minutes
POM-K can remain at 205 ℃ for 20 minutes without severe decomposition
At the injection temperature, the melt cannot stay in the barrel for more than 20 minutes. POM-K can stay for 7 minutes at 240 ℃.
If the machine is shut down, the temperature of the barrel can be reduced to 150 ℃. If it needs to be shut down for a long time, it is necessary to clean the barrel and close the heater.

Article organization sealing glue manufacturer www.hshangli.com