Structural Characteristics of Screw on the Processing and Mechanical Properties
(1) Screw structure requirements for less than 30 parts, 80 parts or less, and 120 parts or less of filler PVC pipe products
120 parts or more: the metering section gap is small, if the metering section gap is large, the compression is not enough, the mixing increases the number of slots, the number of slots determines the plasticizing effect, the high calcium screw is used; 80 parts or less, the high calcium screw is used, but The gap between the feed and the metering section is reduced; 30 parts or less: the feed mixing section and the compression section are connected together, and the other is the same, the metering section has a relatively large gap.
(2) Low-filler, high-filler screw structure ratio, influence on processing technology and mechanical properties of products
Different formulations require different screws, how much lubricant, and if there are many lubricants, the plasticizing effect is not good, and the flow performance is obviously improved.
(3) High-fill production formula for life cycle of barrel, screw, material, heat treatment, etc.
The high-filling production formula has a great influence on the wear of the barrel and the screw, and the service life is not long. Generally, it wears out in more than 100 parts in 5~6 months. Below 80, the use time is about one year, and wear begins, and blue appears. For quality problems such as grain and black line, most of the barrel wear appears above the vacuum port and the metering section. The screw has different degrees of wear except the feed section.
The cylinder and screw metering section are made of alloy, and the wear condition is relatively better than the ordinary structure, but the use time will not exceed two years.
