Twin screw extruder operation process

Solid shape or material moisture absorption bridge affect normal feed. Such as powder and granular proportion in the blend of body difference is big, because gravity is different, solid particles may enter the screw, powder feeding, may also affect feeding; At the same time, some large hygroscopicity separately if not advance drying, blanking, because of the screw heating jacket, injection molding processing material moisture, moisture will evaporate formation on the surface of materials in the feeding mouth of water wet surface, the next mouth gradually formed bonding and bridging, resulting in poor blanking. Therefore, in this case, should be easy to moisture absorption material drying and then use, powder mixing system, mixing hopper should be adopted.

poor screw feed has the following situation. Solid conveying section of the transport capacity is insufficient. Know from double screw configuration, screw mixed zone by forward commonly thread section of the reverse and kneading section. Extruder normal movement, through the forward flow thread section and reverse thread section of flow rate and flow through the kneading section shall be equal to add shoes.

improper feeding mouth shape and size design. The feeding mouth of the twin screw extruder is rectangle commonly, its width should guarantee to join solid phase material smoothly by rotating the screw into the spiral groove. If the width of the improper design, material are likely to be feeding mouth edge scraping and accumulation in the mouth due to difficulties of feeding. Not too short the length of the feeding mouth, if its length is too short, solid conveying section C shape small room will be in a relatively short period of time after charging. Material will be due to too late to fill in the small C shape room filling feeding mouth, affect the normal feeding.

no axial pressure gradient, the single piece of kneading block has the effects of the axial transport. Reverse thread piece of reverse transmission effect. After positive thread structure decision, its biggest melt conveying ability for fixed value. Inlet to outlet, so the length of the positive thread structure set unreasonable, will lead to the transmission capacity fish feed rate, which cause feeding difficulties. Solution: 1. Solid conveying zone threaded piece of single thread should be adopted; 2. Increasing the solid conveying zone thread block spiral Angle. To improve the transmission capacity of screw thread; Has been moderately increasing the screw rotation speed.

are melt thread for maximum transmission capacity and shoes. This situation mainly lies in the melt conveying capacity is small, positive thread is actually a solid conveying zone do not agree with other work area transmission capacity, existing components form a complete set of parameter selection problem, thus increasing transport region thread spiral Angle, reduce the lo ling clearance is a good measure.

twin-screw extruder in the process of operation, due to the screw structure design is unreasonable, or improper operation, often can cause unstable extrusion. These problems will affect the normal operation of production, resulting in the consumption of raw material is growing, and even affect the injection molding processing and product quality. Kneading, reverse thread section and its corresponding back pressure period of structure design is undeserved, cause paragraphs unbalanced transmission capacity, feeding difficulties.

more wonderful words: glass fiber to join mouth screw configuration, click directly.
http://www。 csssld。 cn//html/2016/Info_0912/342。 HTML
nantong on suye's official website: http://www. csssld。 cn//