1. The structure difference between conventional, low-f […]
1. The structure difference between conventional, low-filling and high-filling
(1) Geometry and matching relationship of thread rib and thread groove
Less CaCO3: larger between screw and screw
Large calcium carbonate content: In order to increase the shearing force and plasticization, the gap between the screw edge and the screw edge should be small.
(2) The role of each area. The screw is usually divided into a feed section, a compression section, a blocking section, a mixing section, an exhaust section and a metering section.
Feeding section: In general, the screw gap in the conveying section is large and the conveying speed is fast. On the contrary, the screw gap is small. It is also related to the formula and composition of calcium carbonate.
Compression, blocking and mixing: The main influence is the plasticizing ability. If there is no blockage before compression, plasticization can be increased. If there is a blockage, it is not suitable for high calcium. Mixing and compression are set together, generally only suitable for low calcium.
Exhaust section: The plasticizing ability of the material can be observed from the vacuum port, which is in the form of granules, powder, and bands.
Metering part: The screw gap is large, the extrusion is fast, otherwise, the volume is small.
2. The pe pipe production line manufacturer introduced the structural characteristics of low packing and high packing: the feed section of the low packing spiral, compression and mixing are connected together. During the turning process, the lead of one section of the feed section becomes smaller and becomes the compression section. The compression section is slotted, and 2 turns are added to block the material, which is plasticized. The rear exhaust section and metering section are slightly larger than the gap between the screw edges. The high-packing spiral structure is composed of a feeding section, a blocking section, a compression section, a blocking section, a mixing section, an exhaust section and a metering section. The spiral edge gap between the feeding section and the metering section is small.
3. Introduction to the temperature control structure of the screw and barrel
Internal circulation: automatic circulation of distilled water
Outer circulation: Set screw temperature control to control the material temperature. The screw can be protected during start-up and production to stabilize production. Otherwise, the product will be discolored due to the processing technology of the profile.
Barrel temperature control: air-cooled and oil-cooled. Relatively speaking, oil-cooled temperature control accuracy is greater than air-cooled temperature control accuracy, but the oil circuit is easily blocked during use, and the failure rate is higher than that of air-cooled.