Commodity molds are easy to purchase and are often used by companies

A commodity mold is a tool that is used to produce everyday goods. Examples of products made from a commodity mold include plastic pipe fittings and plastic packaging.

Commodity molds are easy to purchase and are often used by companies that do not have a lot of capital to spend on tooling. However, if you’re looking to improve your company’s profitability with a tooling purchase, you need to understand what you’re purchasing.

Product Types

Commodity mold is a type of plastic injection molding used for mass production for everyday goods where durability and high-performance properties are not critical. It includes disposable products like drinking cups, wastebaskets, picnic condiments, file boxes and throw-away food containers.

Depending on the resin used, commodity mold may also be called engineering-grade. Engineered-grade resins are specialized for a specific application that requires stronger mechanical or thermal properties.

HIPS and GPPS are two commonly used commodity plastics that are easy to mold and fabricate, owing to the presence of rubber in discrete droplets within their polystyrene matrix. The resins offer exceptional thermoforming characteristics and are widely available in a variety of colors and textures.

Acetal is a high-performance, engineering-grade plastic that offers good mechanical and thermal performance. The resin can be reinforced with fibers or minerals for improved strength and stiffness. It is a popular choice for precision-machined parts because it can stretch to moderate elongations without breaking and returns to its original shape when stress is removed.

Raw Materials

A raw material is a product that is used in the manufacturing process. It can include petroleum, resin, or other materials. When there is a shortage of one of these materials, the price for that product can skyrocket.

Commodity raw materials for plastic molding include polyethylene (PE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP). They all have different physical properties and are intended to be used in specific applications.

The most common raw material is polyethylene, which can be used for a wide range of consumer goods. It’s durable, easy to process, and odor- and toxin-free.

PE is also a good choice for blow molding because of its toughness, flexibility, and retention even at low temperatures. Its other benefits include excellent clarity, good water barrier properties, and good electrical insulation.

Other raw materials used to make commodity mold include nylon or polyamide (PA), and polycarbonate (PC). Nylon is a popular material for bearings, bushings, gears, slides, and other mechanical parts.

Processes

The process of making commodity mold varies depending on the material and the type of product. Some of the most common processes include blow molding, injection molding and stretch blow molding.

Blow molding is a process for making hollow containers, such as bottles and gas tanks. It involves extruding a thermoplastic molten tube called a parison into a cavity.

To be successful, the injection process must be tightly controlled. This includes the injection pressure and temperature of the thermoplastic.

It also means monitoring the speed of the injection. If the speed is too high, it can cause gassing and venting to occur.

Alternatively, it could cause a small explosion within the part that leaves holes or burn marks. By keeping the temperature of the plastic and the pressures within the process under tight control, manufacturers can ensure that the parts they produce are of a consistent high quality.

Injection molding can be a cost-effective way of producing components, especially for large quantities. However, it is important to select the right thermoplastic and mold tooling for the application.

Costs

The mold costs for commodity injection molded parts vary depending on the part, application and the materials used. The material used, the size of the part and the volume of production all impact the cost.

Choosing the right resin for your application is also a critical consideration for plastic injection molding. Different resins have different properties, and can affect the strength and durability of your final molded product.

A key advantage of plastic injection molding is that it can produce parts in a near-finished state, eliminating the need for additional manufacturing steps. This saves on labor and time, making it a more cost-effective way to produce high volume parts.

Mold materials are a vital component of plastic injection molding and play a role in the part’s lifespan. The mold material selected depends on the required production volumes, cycle times and product finishes.