The impact of the shrinkage rate of plastic barrels mainly depends on the plastic structure. For example, thick-walled plastic parts have a greater shrinkage rate than thin-walled plastic parts, but most plastic 1mm thin-walled parts have a greater shrinkage rate than 2mm. This is because the melt will The reason for the increased resistance in the mold cavity; the shrinkage rate of the plastic parts with inserts is smaller than that without the inserts; the plastic parts with complex shapes will have a smaller shrinkage rate than the simple shapes; The shrinkage rate in the direction should be small; the shrinkage rate of the elongated plastic parts in the length direction is small; the shrinkage rate of the size of the plastic part in the length direction is smaller than that in the thickness direction; the shrinkage rate of the inner hole is large, and the shrinkage rate of the shape is small.
The general materials of plastic barrels are PVC plastic products. At higher temperatures, such as about 50 degrees, it will slowly decompose hydrogen chloride gas, which is harmful to humans, so PVC products should not be used as food packaging Thing.
Bakelite contains free phenol and formaldehyde, which is toxic to the human body and is not suitable for storing food and food packaging. Dianyu is odorless and tasteless, but when it is used in 100-degree boiling water or used as a vinegar food, free formaldehyde will be precipitated, which is harmful to the human body, so it is not suitable for food utensils or food packaging.