The right injection mold tooling can come in handy for manufacturing large numbers of identical products. It is also an excellent application for creating prototypes for functional testing, or even for small-volume production runs. The difference between production tools and prototype tools is primarily in the type of material (steel vs. aluminum) used in their manufacture, which impacts the longevity of the molds. Either way, the basics of the process are the same.

Injection Mold Tooling Design and Construction

Injection molding requires careful design of the mold to ensure accuracy and functionality. The molds are precision machined from blocks of metal, creating cavities that match the design of the parts to be molded. The mold designer must consider factors such as how much the material will shrink as it cools and how completely the mold will fill with material when the mold is operating, so the final parts are dimensionally accurate. Design features such as textures or lettering also need to be incorporated into the tool. Each mold has two halves (a top and a bottom) that fit together to create the form for the parts to be molded.

Most injection mold tooling includes cooling lines to control the temperature of the mold across the entire part to maintain a constant temperature throughout. Others have moving parts to facilitate the ejection of the finished parts, particularly parts with complicated details. The mold may contain just one or many cavities. Each cavity may contain identical or unique parts to create different products. This allows efficient molding of multiple copies of one part, or of pairs of parts (for example, right-hand and left-hand sides), or sets of parts that together make an assembly.

Mold design and construction can take several months. However, this can vary depending on factors such as the complexity of the part the mold is being built for, the mold material (steel vs. aluminum), and the expected life of the tool (how many parts are needed from the tool). The experience of the tool designer and the mold manufacturer also factors into the time it takes to complete the tool.

Injection Molding Process

Once an injection mold tool is complete, it needs to be put in a “press” where the two halves of the mold are clamped into position and the heating elements and cooling lines are connected. Then the mold is ready for operation.

Injection molded parts are typically made of thermoplastics, starting from a raw resin, typically in pellet form. The color of these materials can be modified with additives, or fillers can be blended in the molding material to add more tensile strength.to change the properties of the finished product. The material to be molded is heated to a specified temperature. A helical screw is then used to mix the material before it flows into the mold’s interior. At this point, the material will cool and harden. The part or parts are removed, and the process is repeated. There is some “cleanup” of the parts required to remove residual plastic, but generally this is a minor task.

Injection molding offers a range of benefits in industrial applications.

High Volume Production

Injection molding provides an ideal solution for managing on-demand, high volume production. The typical production injection mold can manufacture anywhere from 10,000 to 100,000 parts, or even more, before it needs to be repaired or possibly replaced due to wear.

With injection molding, the cost per part is very low for high output production runs. This is largely a result of automation as well as the fast cycle times that can be achieved once the tool is operating optimally.

Prototype Applications

There are certain instances when the use of prototype injection molds, which can be made faster and at a lower cost than most production molds, makes sense. There are times when a small volume (hundreds or thousands) of parts is needed, and it is more efficient to make a prototype injection mold than to machine or manufacture the parts by another method. Sometimes manufacturers need parts made from production materials to cover a gap between when the production tools will be ready and when manufacturing needs to start. This is another use for prototype tools. Finally, in certain cases, the appearance of a part, and ensuring that it represents exactly what will be seen in production, is so important that even for a small number of prototype parts the manufacturer will decide to invest in a prototype injection tool. If you want to engineer high-quality prototype parts, it pays to talk to an expert prototype injection molding supplier to determine if this approach would fit your needs.

Get Design-Driven Solutions Near You

Injection molding is a versatile manufacturing technology for mid-to-high volume production. If you want to explore new ideas to reduce your production costs, we’re here to help. And if you need prototype parts and think an injection mold may be the way to go, we have experience with this approach as well.

At Global Technology Ventures, we can ensure your product design is unique and practical. As a reliable injection molding tools supplier, we can offer you custom-made solutions. To learn more about our services, visit our website.