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Is injection molding the same as molding? Understanding the Difference

This article discusses is injection molding the same as molding? Molding, commonly called compression and injection molding, is two distinct but related industrial processes. Even though they both entail molding materials into particular shapes, their methods and applications differ.

  • Injection Molding:

 A manufacturing technique called injection molding involves pouring molten material into a mould to create pieces. This liquid substance, which may be poured into the mold under high pressure, is often a thermoplastic or thermosetting polymer that has been heated until it becomes liquid. Typically, the mold is formed of two parts, and when the molten substance cools and hardens, it conforms to the mould’s cavity. Automotive, electronics, medical devices, and consumer products are just a few sectors that frequently employ injection molding to create complicated and detailed parts.

  • Molding (Compression Molding): 

Molding, or compression molding, is a manufacturing method where a warmed material is directly inserted into an open mold cavity. This material is often a thermosetting polymer or rubber compound. The mold is then sealed, and as the substance dries and solidifies, pressure is applied to cause it to adopt the mold’s shape. This method works well for creating bigger pieces with simple designs. Items like rubber seals, gaskets, and specific kinds of composite materials are frequently produced using molding.

Comparing the molding and injection molding processes:

Is injection molding the same as molding? Plastic and metal items are manufactured using injection molding and different molding techniques. They are comparable, yet they are also very different from one another. Here is a comparison between injection molding and a few popular molding processes:

The Process of Injection Molding:

In injection molding, molten material (often plastic) is pumped into a mold cavity under high pressure. As it cools and hardens, the substance adopts the form of a mold cavity.

Advantages of injection molding:

 Due to its many advantages, injection molding is a popular and favoured manufacturing technique for making plastic and occasionally metal parts. The following are a few of the main advantages of injection molding:

  • High precision and close tolerances:

I enables the creation of components with incredibly accurate measurements and close tolerances. This is vital for sectors like automotive, electronics, and medical devices, where precise and consistent part dimensions are important.

  • Consistent component Quality: 

Injection molding’s automated nature assures consistent component quality across lengthy manufacturing cycles. Minimizing variation between components enhances final product performance and dependability.

  • High manufacturing Volume Capability:

 Due to its effective and quick cycle times, it is well-suited for high-volume manufacturing. Because of this, it is perfect for mass-producing commodities, including packaging, consumer goods, and automobile components.

  • Flexible Material Choice:

 Injection molding, various thermoplastics and various thermosetting plastics can be employed. Thanks to this flexibility, manufacturers may select materials according to their desired strength, stiffness, flexibility, heat resistance, and other characteristics.

Is injection molding the same as molding
  • Reduced Post-Processing: 

Post-processing or finishing work is frequently optional for injection-molded products. Compared to other processes that could have more involved finishing stages, this decreases the total manufacturing time and cost.

  • Effective Material Use: 

Due to the frequent recycling and reuse of surplus material (often called “flash”) during the process, injection molding normally creates little waste.

The process of compression molding:

Compression molding is when a predetermined volume of material—typically a thermosetting plastic—is inserted into an exposed mold cavity. The mold is then sealed, and the material is heated and compressed to cure and form it.

Advantages of Compression molding:

Compression molding has several benefits, especially for specific part types and production needs. Compression molding is a manufacturing method. Some of the main benefits of compression molding are as follows:

  • Lower Initial Tooling Costs:

 The initial tooling costs for compression molding are often lower than those for procedures like it. This makes it a more affordable choice for making parts, particularly when the necessary production volume is low or moderate.

  • Well-suited for Larger items: 

Due to the size restrictions of injection molds, compression molding may handle larger items that may be difficult to make using injection molding.

  • Appropriate for Thermosetting Plastics:

 Compression molding is especially well suited for thermosetting plastics, substances that undergo a chemical reaction during curing and become stiff and heat-resistant. Due to its excellent thermal stability, it is appropriate for use in components.

  • Strength and Durability: 

Parts made through compression molding often have good mechanical qualities, such as strength and durability. Because of this, they are appropriate for uses where the components will be exposed to high temperatures or mechanical pressures.

  • Reinforced Materials: 

Compression molding can add reinforcements, such as fibers or fillers, to the material, improving the material’s mechanical characteristics and the finished product’s performance.

  • Flexibility in Material Selection: 

Although thermosetting polymers are mostly employed in compression molding, many formulas and compositions are available. As a result, producers may modify material qualities to suit certain application needs.

  • Good for Customized Designs: 

Since compression molding molds are often less expensive, producing components with bespoke designs is more practical without having to pay hefty tooling expenses.

  • Good for Low to Medium Production quantities: 

Compression molding is frequently used for production quantities that need to be higher to merit the expensive tooling expenses associated with injection molding but are still adequate to warrant a more effective manufacturing technique.


While molding and injection molding entail shaping materials using molds, molding employs warmed material compacted within a mold to make components. In contrast, injection molding uses molten material injected under pressure to form parts. The material type, the intricacy of the part’s design, and the intended production volume are just a few examples of the variables that will determine which of the two techniques is best. LOUIS MACHINE can offer you a one-stop shop for design, manufacturing, injection molding or die-casting product production, and processing bulk components thanks to our group of skilled technical members and managerial staff.

If you have any questions or need assistance with our services, please feel free to contact us.