Office Chair Injection Molding PP
The process parameters and characteristics of injection-molded PP material for office chairs are as follows:
Injection temperature is a key factor affecting the molding quality of PP material. The barrel temperature needs to be controlled in sections. The front section temperature is usually set between 180 - 220โ, the middle section between 190 - 230โ, and the rear section between 170 - 200โ. For example, when producing ordinary household PP plastic seats, the front section temperature is often set at 200โ, the middle section at 210โ, and the rear section at 185โ. The nozzle temperature should be 5 - 10โ lower than that of the front section of the barrel, and in actual operation, it is often set between 190 - 195โ to prevent material overheating decomposition or nozzle blockage.
Injection pressure needs to be adjusted according to the size of the seat. For small seats (1 - 3kg), the injection pressure is 60 - 100MPa, such as children's seats, which are mostly controlled between 70 - 80MPa; for medium-sized seats (3 - 8kg), it is 80 - 130MPa; and for large seats (> 8kg), it is 100 - 160MPa. The holding pressure is usually 30% - 60% of the injection pressure. For small seats, the holding pressure is between 20 - 50MPa, for medium-sized seats, it is between 30 - 70MPa, and for large seats, it is between 40 - 90MPa. Reasonable pressure settings can avoid product shrinkage or flash.
Injection speed needs to be adjusted according to the product structure. For seats with a simple structure and uniform wall thickness (such as ordinary plastic stools), the injection speed can be controlled between 30 - 60cmยณ/s, and a common setting for PP material is 45cmยณ/s; for seats with a complex structure, thin walls, or fine parts (such as office chairs with complex shapes), the speed needs to be reduced to 15 - 30cmยณ/s. For example, the injection speed of an office chair is adjusted to 20cmยณ/s to prevent uneven melt filling or bubble formation.
Mold temperature has a significant impact on the surface quality of the product. For plastic seats with ordinary precision requirements, the mold temperature is generally controlled between 30 - 60โ. Too low a temperature may lead to poor melt fluidity, while too high a temperature may cause product deformation or surface defects.
In the product example, the Yingchi series training chairs are made of PP material. The backrest supports an 18-degree forward and backward tilt, is equipped with an upgraded wide writing board that can be rotated and folded, demonstrating the lightweight and functional applications of PP material in office chairs. In addition, the chair injection mold produced by Yuyao Linghang Precision Mold Co., Ltd. is priced at 180.6 yuan, providing a cost reference for the industry.
