What does rotomolding mean? Rotational molding, also known as rotational molding, rotary molding, rotary forming, etc., is a thermoplastic hollow molding method. The method firstly adds the plastic raw material into the mold, and then the mold is continuously rotated and heated along the two vertical axes, and the plastic raw material in the mold is gradually uniformly coated and melted and adhered to the cavity under the action of gravity and heat energy. The entire surface is formed into a desired shape and then cooled to form a product. Rotational molding process principle: The basic process of rotational molding is simply to place the powdered or liquid polymer in a mold while the mold is rotated and revolved around a vertical axis and then cooled. At the beginning of the heating phase, if a powdery material is used, a porous layer is first formed on the surface of the mold, and then gradually melts as the cycle progresses, finally forming a uniform layer of uniform thickness; if a liquid material is used, the flow is first It is applied to the surface of the mold and stops flowing completely when the gel point is reached. The mold is then transferred to the cooling station, cooled by forced air or water spray, and then placed in the work area where the mold is opened and the finished part is removed and the next cycle is followed. Features of the rotomolding process: The rotomolding process uses powdered or liquid raw materials rather than the granular raw materials commonly used in the plastics industry; In the process of forming the raw material in the mold, it is only affected by gravity, and no additional external force is required, so the produced product theoretically has no internal stress, so it is more suitable for long-term use; Rotational molds are relatively less stressed, so the requirements for mold materials will be lower; The mold may be composed of two or more pieces, and the shape and size are not limited at all; The wall thickness of the product is generally uniform and can produce products with a very thick wall thickness. Specific to polyethylene, the wall thickness range is at least 0.5mm, the highest is 75mm, and the commonly used range is 1.5-25mm; During the machining process, the mold rotates in two vertical directions. (So ​​it’s called rotomolding!) Based on the above characteristics of the rotomolding process, we can find that its advantages include: The mold cost is low and the development time is short; For systems consisting of multiple components, the use of a rotational molding process can reduce time and process; 1. The rotational molding process is not limited by size; 2. Can be applied to hollow open or closed products; 3. Can produce multi-layer products (same kind or different kinds of materials); 4. It is easy to produce products decorated with patterns and the like; 5. It is easy to set the embedded components; 6. The finished product has no stress concentration areas such as welds; 7. There will be no scrap in production, no waste; 8. It is easy to control the uniform wall thickness and expected weight of the product; 9. The product has no internal stress and is therefore more durable. The shortcomings of the rotomolding process are also obvious: 1. The processing cycle is relatively long (usually more than half an hour); 2. The types of materials that can be selected are limited; 3. The raw materials require special processes and additives, and need to be ground into powder before processing, and the cost is high; 4. Some shapes are difficult to machine. Ok, the foundation of this process has been finished so far. Among the raw materials used in rotational molding, polyethylene accounts for more than 90%, and linear low-density polyethylene accounts for more than 80%.
Hot-dipped Galvanized Wire
Hot dipped galvanized wire belongs to the primary wire products of galvanization. The common sizes of hot dipped galvanized are from 8 gauge to 16 gauge, we also accept smaller or bigger diameter for customers' choices. Hot dipped galvanized wire with firm zinc coating provides strong corrosion resistance and high tensile strength. This kind of wire is widely used for making handicrafts, woven Wire Mesh, forming fencing mesh, packing products and other daily uses.
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