Contact: Zhao Fanzhang
Contact: Xiong Jingyu
Official website: www.gdsdzz.com
Address: No. 6, Yongxing Street, Leliu, Shunde District, Foshan City, Guangdong Province
Rotational molding is very suitable for the production of small batch, multi variety, multi color large hollow plastic products, such as sporting goods, highway guardrails, luminous spheres for park art design, boats and mobile docks, vacuum cleaners and other valuable consumer goods. It belongs to the processing technology with high added value. Under the trend of diversified development of small amount of plastic products, its development prospect is more promising.
However, there are very few professionals in rotational molding industry in China. Compared with those engaged in injection molding and extrusion process research, it is difficult to find talents engaged in rotational molding process research. The number of rotational molding talents in China is small, and the theoretical research on rotational molding is basically blank, which is very unfavorable to the long-term development of the industry. In addition, the lack of talents also makes it difficult to improve the overall level of the rolling plastic industry, which has become a soft rib in the development of China's roll molding industry.
Although great achievements have been made in the research of rotational molding technology, there are still many deficiencies compared with injection molding and extrusion (hollow blow molding). The development trend of rotational molding mainly focuses on the following aspects: first, the computer simulation of heat conduction in the heating and cooling process of rotational molding, establishing the corresponding mathematical model, and precisely controlling the process parameters with automation technology; second, solving the warpage and shrinkage of products, eliminating the bubbles of products, and shortening the processing cycle. The more effective process improvement is to select the appropriate time to fill the mold (about 69 kPa), which can shorten the processing cycle by 25%, and greatly reduce the bubbles, and improve the toughness of the products. In addition, flowing air is introduced into the mold to reduce the temperature gradient between the inner and outer walls of the mold and the plastic products, so as to reduce the warpage caused by the difference in the crystalline structure of the products caused by the temperature difference while strengthening the cooling; the third is to develop new technologies, new materials and new equipment.
Some foreign companies have made progress in the research and development of resin and special additives for rotational molding. The newly developed resin has good fluidity and toughness, and can resist environmental stress cracking for more than 1000h. Rotational foaming, rotational cross-linking and multi-layer rotational molding have also been developed.
Rotational molding is the most economical and effective way to produce large hollow plastic products. In order to further promote the application of rotational molding in China, it is necessary to absorb foreign advanced technology, develop more and better rotational molding raw materials, improve the automation level of rotational molding equipment, shorten the cycle of mold design and manufacturing, and make the rotational molding go hand in hand with other processing technologies such as injection molding and extrusion.