The molding temperature of this material is too high, and the damage to the screw is serious. When the screw speed is set, the speed cannot be too fast. After the molding is finished, the screw should be quickly cleaned with PE wax, and the material of PEEK cannot be stopped at the screw.
Molding temperature 320 degrees to 390 degrees
Baking temperature 160~185 5H~8H
Mold temperature 140~180
Injection pressure is 100~130MPa
Injection speed 40~80
PEEK features: high temperature fluidity, high decomposition temperature.
PEEK is a semi-crystalline thermoplastic polymer with a melting point of 343 ° C. PEEk thermal stability: It is difficult to detect PEEK decomposition volatiles when heated to 427 ° C. Fourier infrared (FT-IR) detection of PEEK and CFR-PEEK composites The decomposition temperature is between 400 and 480 ° C. There is no significant difference in thermal decomposition between the two. PEEK is kept at 400 ° C for half an hour, the weight loss is less than 1%, and the temperature is kept at 360 ° C for 1 hour without significant degradation. The long-term stable temperature is 340 ° C. (about the melting point), continuous working temperature of 160 degrees Celsius.
General-purpose thermoplastic processing methods are suitable for PEEK materials, including: injection molding, extrusion, molding, spraying, etc.
The general process of PEEK injection molding is as follows:
1. Drying: The particulate polymer generally absorbs 0.5% w/w of atmospheric moisture. For best results, it should be dried until the moisture is less than 0.02% w/w. The material can be placed in an air circulating furnace, at least 150. Dry at °C for 3 hours, or at 160 °C for 2 hours. If it is dried in a dry box, the thickness of the raw material in the tray is not
Can exceed 25mm. And prevent pollution.
2. Recycling: The residual material can be recycled and injected into the pure material. It is recommended that the recycled material without filler should not exceed 30% of the total weight, and the recycled mixture containing the filling should not exceed 10% of the total weight.
3. Thermal stability: If the equipment is shut down during the melting process and the polymer residence time does not exceed 1 hour, there is no obvious degradation of the material at 360 ° C. However, if the downtime exceeds 1 hour, it should be The temperature of the barrel drops to 340 ° C. At this temperature, the material can be kept stable for several hours. When the processing is continued, the temperature of the barrel must be increased. If the down time is more than 3 hours, the barrel should be cleaned. Some can be used at 380 ° C. Materials that maintain stable performance at temperatures, such as polyethersulfone or polyetherimide, can also be cleaned with low MFI polyethylene.
4. Injection machine: The melting point of the polymer is 343 ° C, which can be applied to traditional machines that can keep the melt temperature at 360-400 ° C.
5. Barrel capacity: Due to the high processing temperature of PEEK polymer, the residence time of the material must be as short as possible. The ideal barrel capacity is 2-5 times the total injection weight.
6. Nozzle and latching system: The melting point of the polymer is very high. If the temperature drops below 343 °C, the melt will solidify very quickly. Therefore, it is necessary to install a heater large enough at the nozzle to prevent the temperature from falling. Material' .
7. Screw: It is recommended that the minimum length-to-diameter ratio L/D of the screw is 16:1, but the L/D ratio between 18:1 and 24:1 should be preferred. Professional plastic knowledge exchange WeChat group plus small WeChat : NB58250988
8. Barrel temperature: The unreinforced level is 360-380 ° C, and the enhanced level is 380-400 ° C.
9. Mold temperature: The surface temperature of the mold is 175-205 °C.
10. Injection pressure: The general injection pressure is 70-140MPa.
11. Injection speed: medium to high speed.
12. Back pressure: It is recommended to set the back pressure to 0-1.0MPa (0-10 kgf/cm2).
13. Screw speed: The general screw speed is 50-100 rpm. For the strengthening level, it is recommended to use a lower screw speed.
14. Mold shrinkage: Different grades of polymer have different shrinkage rates, the unfilled grade is about: 1.2-2.4%, and the fill grade is: 0.1-1.1%.
15. Secondary processing: It can be used for secondary processing such as bonding, tapping, pressing, metal inserts, cutting and surface metallization.
use
It is an engineering plastic with excellent comprehensive properties. The film can be cast or oriented, used as wire covered wire, atomic engineering component, H- or C-class electrical insulating material, flexible printed circuit board, heat pump casing or frame, oil well Couplings, valves, metal heat or anti-corrosion coatings, monofilaments, bandings, sieves, subways, mines, oil fields, electrical industry, atomic energy engineering, chemical equipment, etc.
Peek is widely used in aerospace, automotive, electrical and electronic, medical and food processing.