Comparison between rotational molding, blow molding and injection molding

Comparison between rotational molding, blow molding and injection molding

• Injection molding: This process is performed using an injection molding machine. Investment costs are relatively high, and molds are expensive, but product prices are very affordable, leading to a more transparent market. It's primarily suitable for smaller products, with very high monthly production volumes. Both the molds and the products are of extremely high precision, making it widely used in various fields.
• Injection molding produces a solid core, resulting in a glossy surface. Due to the injection port, the finished product may have a small, unwanted portion that is trimmed off during the molding process. While not noticeable, it's noticeable upon closer inspection.

• Blow molding: The mold is relatively simple, and air is used to create the product's shape. The molds are moderately priced and primarily suitable for hollow parts, packaging, and other specialized products. Monthly production is limited to a few thousand sets, limiting its application.
• Blow molding produces a hollow core, resulting in an uneven surface.

• Rotational molding: Products are relatively large. Plastic pellets are placed in a mold, heated, and then repeatedly rolled to form the plastic against the mold walls. Molds are cheap, but the finished product is expensive. They are primarily used for hollow parts, packaging, and oversized products. They exhibit significant shrinkage and very low constants. Rotomolding involves extrusion and compression, so uncut parts will inevitably have burrs. Detailed differences will depend on the product's characteristics and requirements.
• The most notable feature of rotomolded products is the absence of seams and injection ports.