5 Factors Affecting The Cost Of Plastic Injection Molding

Due to its ability to produce a large number of identical parts, plastic injection molding is a very popular manufacturing process. This technology can be used for many different plastics, which are melted by the application of heat and pressure. The molten plastic is then injected into custom plastic injection molds to form the required components.

The cost of injection molding can vary greatly and is usually affected by the following five factors.

1. Design of injection molding parts

The more complex the part, the more complex its custom plastic injection molds must be. Complex, customized injection molded parts are usually more expensive because they require more injection molding tooling than simple parts. Machining complex parts may require auxiliary EDM programs to achieve undercut features, which requires more production time. In addition, larger parts require more material, which increases costs.

2. Material of injection molding parts

The type of resin used also greatly affects the cost of prototype injection molding. When selecting a resin, the number of parts, additives, ingredients and molding temperature, resin availability, grade and color should be considered at the same time. The choice of resin may also affect the maintenance requirements of the mold, resulting in higher costs (as with abrasive resins).

Each type of thermoplastic requires a different temperature. High temperature resin will increase mold cost, as described below. Thermoplastics that provide lower cost include polypropylene, polyethylene and polystyrene, while liquid crystal polymers, polysulfone and polyphenylene sulfide are usually accompanied by higher temperatures and higher costs.

3. Material of injection molding tool

A variety of steels can be used for mold making, but the specific type required for the job depends on the type of material used for injection molding. High-temperature thermoplastics require higher hardness steel or steel-plated molds. When selecting mold materials, please consider the required mold maintenance and the need for mold replacement.

Different mold materials can provide different service life. The longer-life injection molding tooling has higher value, but they are made of more durable steel, which increases the cost of the mold. When choosing the mold material, please consider the cycle time, surface finish and output, because all these factors will affect the service life of the mold. Tool steel is usually chosen to improve its toughness and durability, although cheaper materials (such as aluminum) may be suitable for molds, especially when lower yields are required.

4. Volume and number of cavities

The more cavities required to form a part, the longer the pressing time. Long pressing time limits the ability to quickly produce parts, thereby increasing costs. Producing a large number of parts that require a large number of cavities will also involve higher production costs.

5. Location of plastic injection mold company

The location of the plastic injection mold company will affect the overall cost of injection molding, depending on the transportation and handling costs required to transport the mold to the processing location. For example, when using plastic injection mold manufacturers in China, please consider the minimum wage in each province. Proximity to the seaport will also affect transportation costs.

Choosing an offshore plastic injection moulding die makers for injection molding will increase transportation and handling costs. If your parts are manufactured entirely abroad, the cost of the product to reach your needs may offset any savings from low production prices.

Planning an injection molding project

Before proceeding with the plastic injection molding project, please consider various factors that may affect the final cost of the part. Wise design, best material selection and careful selection of plastic injection mold company can greatly improve the quality of parts while controlling costs.