Since the advent of rotational molding technology in the 1930s, after more than 60 years of development, its equipment and technology have become increasingly perfect. From small children's toys to common automotive plastic parts to huge engineering plastic products, especially super large and non-standard special-shaped hollow plastic products, due to the limitations of the characteristics of other plastic processing processes, they can only be completed by the rotational molding process. At present, rotational molding process has become an important branch of plastic molding process.
The characteristics of rotational molding process mainly include:
·The edge strength of roto molded products is good - roto molded products can achieve a thickness of more than 5 mm at the edge of the product, completely solving the problem of thin edges of hollow products;
·Rotational molding can place various inserts;
·The shape of rotational molding products can be very complex, and the thickness can exceed 5 mm;
·Rotational molding can produce totally enclosed products;
·Rotational plastic products can be filled with foaming materials to achieve thermal insulation;
·There is no need to adjust the mold, and the wall thickness of the roll molded product can be adjusted freely (more than 2mm).
At present, roll molded products can be used in transportation tools, traffic safety facilities, entertainment industry, river and waterway dredging, construction industry, water treatment, medicine and food, electronics, chemicals, aquaculture, textile printing and dyeing and other industries.
Rotational plastic parts for containers: This kind of plastic products are widely used in storage and feed boxes, water storage tanks, storage and transportation containers for various industrial chemicals, such as acid, alkali, salt, chemical fertilizer, pesticide storage tanks, chemical enterprises, industrial painting, washing tanks in rare earth preparation, reaction tanks, turnover containers, garbage cans, septic tanks, domestic water tanks, etc
Rotational plastic parts for vehicles: It mainly applies polyethylene and polyvinyl chloride paste resin to roll plastic various auto parts, such as air conditioner elbow, vortex tube, backrest, armrest, fuel tank, mudguard, door frame and gear lever cover, battery shell, fuel tank of snowmobile and motorcycle, aircraft fuel tank, yacht and its water tank, boat, and shock absorber between ship and dock.
Rotational molded parts of sports equipment, toys and handicrafts: There are mainly PVC paste roll molded parts, such as water polo, floating ball, small swimming pool, recreational boat and its water tank, bicycle seat cushion, roll molded palletizing plate, surfboard, etc. Toys such as ponies, dolls, toy sandboxes, fashion models, handicrafts, etc.
All kinds of large or non-standard roll molded parts: Shelves, machine shells, protective covers, lampshades, agricultural spray, furniture, canoes, camping vehicle roofs, playground devices, planters, bathrooms, toilets, telephone rooms, billboards, chairs, highway isolation piers, traffic cones, river and sea buoys, anti-collision barrels, building construction barriers, etc
From the product level, rotational molding products have developed from ordinary civilian products to key industrial products, and their functions have also changed from single container performance to structural performance. With the development of rotational molding equipment and molds, the structural complexity of rotational molding products has developed beyond imagination. It can even be said that products that cannot be completed by injection molding, blow molding, extrusion and other processes can be completely completed by rotational molding, and the geometric dimensions of products can be completely from 0.5L to 50M3. If it is not restricted by transportation conditions, it can even be greater. According to the classification of products, they can be roughly divided into cylindrical water tank (0.25M3~50 M3), circular open barrel (20L~3000L) and square open barrel (30L~2000L). With the needs of functions, they can also be shaped into various closed containers to meet the needs of different industries. The disadvantages of rotational molding products are high single piece cost and low production efficiency. Without special equipment, it is difficult to form mass production, and because of light weight, large volume and high transportation cost.