Injection molding is a manufacturing process used to produce parts in large volume, most typically utilized in mass production processes. When the same part is created multiple times in succession, injection molding is part of that procedure.

Why Is Injection Molding Used?

The initial cost paid per unit during the injection molding process is extremely low because the production scale is so massive. Other advantages include:

Low-Scrap Rates: Manufacturing processes, such as CNC machining, leave a percentage of material behind as scrap. Injection molding has low scrap-rates in comparison.

Easily Repeatable: Every part produced from the injection molding method is identical to the previous one. This wonderful characteristic lends itself very well to brand consistency production and high-volume reliability.

What Is The Process Before Injection Molding Can Begin?

Before injection molding can begin, the mold has to be designed, tested, and fitted to existing tools. Machinery has to be extremely streamlined when a part needs to be produced in high volumes, so the design is made to very precise micro-measurements. This includes:

  • Designing and prototyping the part to exact specifications. This is sometimes done on a 3D printer in plastic.
  • An injection mold tool is designed for a trial run production round. Usually, approximately 300 to 1,000 prototypes in the required material will be produced.
  • The prototype run parts will be closely inspected. Any refinements and details will be improved before the injection mold is sent to a manufacturing plant for mass production.

Can Injection Molding Produce Large Parts?

Sometimes large parts can’t be produced using the injection molding process. This is because the single piece is too big to be practical. Redesigning a bulky part into smaller pieces is necessary. In this way, the size limitations of the machines, and the abilities of the mold tools themselves can be factored in.

It is possible to manufacture large pieces of equipment, such as a shopping cart, using huge machinery. However, this process is costly as the bigger the production machine, the bigger the costs. That is why injection molding experts design large items into smaller pieces first.

Another consideration to take into account with the injection molding process is the prototype is initially produced on a 3D printer or CNC machine. Because these processes can only handle smaller pieces, the injection mold designer will pay a lot of attention to partitioning the original design into smaller sections. Once the printer or machine has produced the multiple pieces, then the final product is bonded together to make up the finished larger item.

Some Things To Consider With Injection Molding

Preparing a product, before it can be molded and manufactured, is where most of the professional injection molders expertise is needed. It is up to the client themselves to consider how many parts need to be produced and then offset that against the startup costs.

None the less, injection molding is the best way to mass produce a quality item with low overhead.