Injection molding – mass production of complex parts, with minimal waste

Injection molding is one of the most widely used production methods for plastic products in today's industry. The method is known for its efficiency, precision, and ability to mass produce complex parts with minimal material waste.

Portrait of Jon Jørundland in a light sweater in front of a white background.

Jon Jørundland
COO Plexx

Injection molding of blue plastic components in an industrial machine.

What is injection molding?

Injection molding is a manufacturing process in which molten plastic is injected into a mold under high pressure. The mold, which is made of metal (often steel or aluminum), gives the plastic the desired shape. After the plastic has cooled and solidified, the mold is opened and the product can be removed.

This process is fast and efficient, and can produce large quantities of identical parts with high precision. Injection molding is used for everything from small components in electronics to large parts in the automotive industry.

Close-up of an injection mold in an industrial machine.

STEEL TOOLS FOR INJECTION MOLDING

Advantages of injection molding

Injection molding has a number of advantages compared to other manufacturing methods. Here are some of the most important:

High precision and repeatability

Injection molding produces parts with precise dimensions and little variation from part to part. This is especially important in industries that require high accuracy, such as the automotive and medical industries.

Efficient mass production

Once the tool has been made, thousands or millions of parts can be produced at a low unit cost – an economically attractive method for high-volume production.

Minimal material waste

Compared to CNC machining, injection molding gives close to 100% utilization of the plastic material. Any waste material can often be recycled.

Complex shapes

Great design freedom – detailed shapes with complex geometries, thin walls and various textures without extra finishing.

Material selection and flexibility

Plastic comes in many variants – heat-resistant, impact-resistant, flexible or biodegradable materials depending on the need.

Short cycle time

Each production cycle often lasts only a few seconds to minutes, depending on the complexity and size of the part.

Integrated features

You can integrate hinges, snap-fit connections or overmolding multiple materials into a single part – reducing assembly and manufacturing costs.

Injection molded plastic parts with serrated surface in a machine

COMPLEX PART MANUFACTURED WITH INJECTION MOLDING

Injection molding and sustainability

Injection molding can be a more sustainable manufacturing choice compared to other methods, especially when combined with recyclable and bio-based materials.

Reduced material waste: High material utilization results in less waste than with traditional machining. Plastic residues can be reused.

Recycled Plastic: Many plastic materials can be recycled and reused, reducing the need for virgin plastic.

Lighter products with a long lifespan: Plastic components are often lighter than metal alternatives, which contributes to reduced fuel consumption in transportation.

Colorful plastic granules sorted into rows for injection molding.

PLASTIC GRANULATE – THE RAW MATERIAL FOR INJECTION MOLDING

"At Plexx, we have extensive experience with injection molding and help you through the entire process — from design to finished product."

Injection molded plastic part for speaker element

PRECISION IN COMPLEX DETAILS

Applications for injection molding

The automotive industry

Dashbordkomponenter, lykter, interiørdeler.

Electronics

Enclosures, connectors, keyboards.

Medical equipment

Syringes, container lids, surgical tools.

Packaging

Corks, lids, containers.

Consumer goods

Toys, tool handles, household items.

A lone black chair among rows of white chairs.

Injection molded plastic components in a production line.

Injection molded plastic parts with barbs for mass production

INJECTION MOLDING PROVIDES MASS PRODUCTION WITH LOW WASTE, HIGH COMPLEXITY AND LONG LIFE

Questions and answers about injection molding

Injection molding is best for mass production of identical parts, while 3D printing is more suitable for prototypes and small series with high design flexibility.
Production of a tool usually takes 4–12 weeks, depending on complexity and material choice.
It is usually most cost-effective for large volumes, but with the right tool design it can be profitable for smaller series as well.
Yes, many manufacturers use recycled plastic, but quality and material properties must be considered in relation to the requirements of the end product.
The cost depends on factors such as tooling costs, material selection and production volume. High initial costs can be offset by low unit costs in large production runs.

Injection molding is a cost-effective, precise and flexible manufacturing method with a wide range of applications. Whether you need robust automotive parts, medical devices or advanced plastic components, this method offers the opportunity to create high-quality products with minimal material waste.

Do you have questions about injection molding?

We help you through the entire process — from design to finished product. Contact us to see how we can help you with your production.