Kunshan Hongxin Engineering Plastics Co., Ltd.
Contact: Mr. Zhou
Fax: 0512-5017 3952
Factory Address: Yangzhou Ganquan Zhen Yang days Road
Office Address: People's South Road, Kunshan, Babylon International Plaza, No. 13, 1108
PPS material: PPS plastic injection molding process
Although PPS plastic is less hygroscopic, pre-drying at 140 ° C for 3 hours or 120 ° C for 5 hours is still required to improve the appearance of the molded article and prevent salivation.
To prevent bridging during drying, it is recommended to pre-dry at 105 ° C for 5 hours according to the grade.
Due to the high moisture absorption of carbon fibers, carbon fiber reinforced grades (2130A1, 7140A4, etc.) require pre-drying in particular.
In the case of natural colors, the drying conditions should be kept uniform for a more stable hue.
Precautions when setting molding conditions
(1) barrel temperature
When the barrel temperature under the hopper is excessively lowered, the barrel and screw friction will tend to increase.
If there are no problems with liquidity, a slight cooling will help reduce retention discoloration. In particular, it is preferable to set the temperature to 300 to 320 ° C when molding a non-black molded article.
(2) mold temperature
Mold temperature has a great influence on the characteristics.
From the appearance of the molded product, dimensional stability at high temperature, heat resistance and creep resistance, the mold temperature is preferably higher than 130 ° C and not lower than 120 ° C.
(3) injection pressure
It is usually best to use 30 ~ 100MPa injection pressure. In order to reduce the flash, it is recommended to make low pressure molding.
(4) injection speed
For good appearance, high-speed injections should be performed. However, high-speed injection tends to cause warping and scorching of the molded product, so high-speed injection is not required as long as good appearance can be achieved. Zhenghao special engineering plastics specializing in the production and marketing of PPS plastic raw materials, model complete, price concessions, please call to discuss, wealth Hotline: 13656263509, Contact: Mr. Yen.
(5) back pressure
In order to keep the measurement stable, it is recommended to set the back pressure to 2 ~ 5MPa. Back pressure can be slightly increased to 8 ~ 10MPa when the measurement is unstable.
(6) Screw speed
Usually 40 ~ 100rpm is appropriate. Speed is best not to exceed 200rpm, otherwise it will lead to fiberglass cutting and resin heating.
(7) barrel retention
Even if PPS plastic remain in the barrel for a long time, its viscosity will not increase significantly. This shows that the use of hot runner is effective.
After forming cleaning
It is recommended that in general, while maintaining the barrel temperature during PPS plastic molding, first wash with polycarbonate containing glass fibers followed by polyethylene and then alternately with both. It will be more efficient if the cleaning material in the barrel is completely drained before loading the next cleaning material. Commercially available acrylic cleaning materials can also be used in place of fiberglass-containing polycarbonates.
The following describes the molding machine to stop and open, as well as material switching methods.
(1) Molding stops
It is advisable to wash DURAFIDE while maintaining the barrel temperature at the time of molding of DURAFIDE and then to wash with resin (high density polyethylene, commercially available acrylic cleaning material, etc.) having good thermal stability at the same molding temperature as DURAFIDE . If you want to continue DURAFIDE molding, but also can only use DURAFIDE to clean.
(2) Molding begins
If the resin in the barrel is stable within the PPS plastic molding temperature range, heat it to the PPS plastic molding temperature intact and clean it with PPS plastic.
If the molding temperature range of the resin is different from that of PPS plastic, it is advisable to adjust the cylinder temperature to the molding temperature of residual resin in the barrel and then to be usable at the molding temperature of both the PPS plastic and the residual resin, and have good thermal stability Resin (HDPE, polycarbonate, as the case may be), and then set to the PPS plastic molding temperature and cleaned.
If the resin in the barrel is PPS plastic, it can be heated intact to the PPS plastic molding temperature and cleaned.
(3) Resin switching
If it is a resin that can be directly switched to PPS plastic, refer to the above-described molding stop and start method, and clean it as it is while maintaining the barrel temperature. Zhenghao special engineering plastics specializing in the production and marketing of PPS plastic raw materials, model complete, price concessions, please call to discuss, wealth Hotline: 13656263509, Contact: Mr. Yen.
In the case of a resin that can not be switched with PPS plastic as it is, it is advisable to wash it with a resin having a good thermal stability (high-density polyethylene, etc.) at the molding temperature of both the PPS plastic and the resin to be switched, and then set For the molding temperature.
If the long-term retention in the barrel, PPS plastic natural color sometimes discoloration, it should be fully cleaned.