1. How to solve the paste phenomenon in the extrusion mold of PVC profiles
1. Improper process operation, generally this situation occurs, I personally think that the temperature of the barrel can be appropriately increased, but in the transition section, the oil temperature can be appropriately reduced, and the mold temperature can also be appropriately reduced.
If the formulation is not reasonable, the lubricant system may be wrong.
2. To solve this problem, the following measures can be taken: First, increase the traction speed;Second, a single-screw extruder with a small extrusion amount is selected to increase the screw speedThird, appropriately increase the temperature of the machine head or barrel;Fourth, modify the mold to prolong the residence time of the melt in the die by increasing the length of the die and improve the plasticizing quality. The extrusion rate is too high.
3. If it is a paste caused by insufficient stability, it can be solved by strengthening the stability of the material, and if it is a paste caused by sticky material caused by insufficient lubrication or insufficient lubrication dispersion in the later stage, simply increasing the stabilizer can not solve the problem, and the problem of strengthening lubrication or insufficient lubrication dispersion can be solved.
5. Solution Adjust the parameters of the extruder In the production process, adjust the parameters of the extruder according to different plastic materials in time, and strictly control the temperature, pressure and other parameters to ensure that it works within the appropriate range and avoid the phenomenon of extrusion mold paste.
6. Adjust the temperature of each section of the extruder appropriatelyInhibit overplasticization of materials. Appropriately reduce the feeding speed and reduce the melting pressure. Check whether the thermocouple of each section of temperature is plugged in place, resulting in the corresponding temperature exceeding the standard. The thermal stability of the mixture and recycled material was checked separately, and the dosage was adjusted appropriately.
Second, the main components of the profile extruder
1. In the extruder, in general, the most basic and versatile is the single-screw extruder.
It mainly includes: transmission, feeding device, barrel, screw, head and die and other six parts. Transmission partThe transmission part is usually composed of an electric motor, a gearbox and a bearing, etc.
2. For the protruding part of the profile, it is generally the mating part of the plastic doors and windows, and the size is mostly the same. On the basis of continuously summarizing the experience of mold trial, the modular design can be realized by using AutoLisp to write programs, which is conducive to improving the speed of design and development.
3. Briefly describe the main components of the twin-screw extruder (including motor, screw, barrel, heater, transmission, etc.) Screw and barrel The twin-screw extruder, as the name suggests, has two screws, and its function is to propel the material forward. This helps to distribute the heat into the resin in an even manner. You can use different types of twin screws.
4. Brabender torque rheometer (and extrusion granulator) The composition of extrusion molding equipment The main machine, also known as the extruder, is basically the same as the structure of the screw extruder in chemical fiber machinery, which is composed of an extrusion system, a transmission system, a heating and cooling system and a control system.
5. The main engine part of the extruder is mainly composed of the transmission system and the heating and cooling device. (Extrusion system) 1 The specifications of the extruder are expressed in . (Screw diameter) 1 The extrusion capacity of the extruder is proportional to the square of . (Screw diameter) 1 The screw length-diameter ratio refers to the ratio of the length of the screw to the diameter of the screw.
6. Screws, barrels, hoppers, machines and molds are all components of the extrusion system, and the plastic is plasticized into a uniform melt through the extrusion system, and under the pressure established in this process, the screw is continuously extruded out of the head.