Rapid Injection Molding: Benefits, Applications, and Comparisons

Rapid injection molding is an injection molding that was developed to produce a comparatively small amount of plastic parts with a significantly shorter cycle time than traditional injection molding.

Typically, the equipment employed in RIM does not differ from that used for standard production injection molding; however, the molds employed in RIM injection molding are designed for rapid cycles rather than production longevity.

Compared to traditional injection molding, RIM can decrease lead times by as much as 75 percent. RIM employs more easily machinable but more expensive mold materials such as aluminium, which provides a faster turnaround for small to mid-size runs of at least 500 parts.

Rapid Injection Molding

Figure 1: Rapid Injection Molding

What is rapid injection molding?

Rapid injection molding process is specially designed to run small-batch production runs with reduced lead times. RIM is referred to this way because the tooling used in this process is developed in substantially less time than traditional injection molding. Although, as a multi-functional tool, conventional injection molding may take as long as eight weeks or more to machine, rapid injection molding reduces these tooling durations. This is the case mainly because of the low cost and relatively easy material such as aluminium in the moulds.

However, one has to take note of the following drawbacks as well. Rapid injection molds’ construction materials mean they have a shorter lifespan and do not allow such tight tolerances as high-volume impression moulds forged from expensive hardened steel.

Thus, the question arises about assessing the suitability of rapid injection molding. It depends on your requirements. If shorter lead times are essential, consider when you need your parts and which issues you are ready to face. Also, it is necessary to determine whether rapid injection molding can handle the intricacy of your design and any other needs you may have.

For more information, read our guide on the injection molding process.

Advantages of rapid injection moulding services

Advantages of rapid injection moulding

Figure 2: Advantages of rapid injection molding

When compared to alternative production techniques, rapid injection molding offers numerous benefits, here are some of the critical advantages of quick injection molding:

  • Mould Reusability:
    Rapid injection molding means one can reuse the moulds, differentiating the process from other methods in creating several parts without needing a new mold. Therefore, high-quality and fully rigid moulds should be used to ensure they can be used many times and are still functional.
  • Universality:
    This means that while the change in the material in 3D printing most of the time requires either changes in the design or equipment, injection molding provides for using different materials without necessarily requiring a change in the system. High-grade aluminium moulds help create parts from materials like thermoplastics, elastomers, and composites; rapid injection molding is suitable for producing products for different industries, such as consumer, automotive, and medical products.
  • Efficiency:
    Rapid injection molding is characterised by efficiency and is highly beneficial compared to the other prototypes. CNC machining is a traditional form of prototyping, which requires a lot of time in programming and setting, and most of the time is used to process individual parts. On the other hand, RIM technologies set an account to a minimum processing setup and cut other processing times in the process.
  • Minimal Waste:
    Rapid injection molding reduces the amount of material used by injecting the plastics correctly and only into the mold cavity. This plays a significant role in cost since an efficient way of minimising wastage in material comes in handy, especially for prototyping environments that lead to wastage of materials in large amounts. Also, the application of various materials, more specifically recycled ones, increases sustainability and decreases the negative impacts on the environment.
  • Strength and Durability:
    Rapid injection molding uses design for manufacturing and prototype techniques that will guarantee high-quality parts. Indeed, applying a high-pressure injection of the liquefied resin into the cavity reaches a constant wall thickness with preferable ejection angles, provides non-porous parts, and is superb quality. This is different from 3D printing procedures, where the fusion part at the base might stay unfinished or contain some holes, affecting the end product’s rigidity and firmness.
  • Surface Finish:
    In the cases of rapid injection molding, attention must be paid to the surface finish because it defines the look and functionality of the molded parts. With the help of CNC milling polishing and for cutting inner corners EDM, RIM control surface finishes up to Ra 0. 8 mcm, which enables uniform and glossy finishes, especially on the moulded parts.
  • Precision:
    Rapid injection molded parts can meet the same levels of precision as those made by the other techniques by selecting the appropriate part design, mould complexity, and the correct type of polymeric material and manufacturing process.Particular emphasis should be placed on collaborating with the manufacturers to meet certain precision needs per specific applications.
  • Cost-Effectiveness:
    Although higher initial costs are incurred with mould production, rapid injection molding is comparatively cheaper than other manufacturing techniques, particularly when a product is manufactured in large quantities. Due to the economies of scale, this methodology of fast injection molding is financially efficient when applied to the production of high volumes of work.

This affordability, coupled with the quality of the products made possible by this method, makes rapid injection moulding the ideal option for any firm looking for cheap manufacturing services with high-quality products.

Rapid injection molding applications:

Aplications of rapid injection moulding

Figure 3: Applications of rapid injection molding

As to the specifics, rapid injection molding has grown in popularity and is used across industries for various reasons. Here are 8 key industries benefiting from rapid injection molding, showcasing its diverse applications and use cases:

  • Automotive Industry: Relying on such equipment as the rapid injection molding for interior panels, knobs, and connectors, it satisfies requirements for creating rigid wear-resistant components with an enhanced degree of accuracy and speed, which fits the changing design aesthetics and legislation requirements.
  • Consumer Electronics: Rapid prototyping and tooling for enclosures, buttons, and cases of smartphones, tablets, and other gadgets to develop products that perfectly fit consumer requirements regarding utility and looks.
  • Medical Devices: Especially for critical instruments such as syringe pumps & diagnostic devices to have high precision & repeatability & meet rigorous stringent medical standards by using medical-grade components.
  • Aerospace: For example, HP uses rapid injection molding to produce lighter, more robust components, as seen in the interior cabin, while meeting safety and performance demands.
  • Consumer Goods: Using high-speed injection molding of different products allows a company to quickly customise their products and bring new items to the market, starting with toys and ending with sports equipment.
  • Construction: The plastic injection molding technique is used to produce high-speed fasteners, connections, and complex fittings but is very strong; this is very helpful in construction.
  • Agriculture: Advantages of utilising rapid injection molding for irrigation system parts and for the casing of machinery for producing challenging, UV-protected parts required by agricultural services held outdoors.
  • Defence and Security: Uses infusion technology for robust and highly resilient parts essential for military applications such as firearms and communication tools, mainly producing critical items quickly.

Additionally, rapid injection molding plays a crucial role in:

  • Rapid Prototyping: Critical for fast growth of new designs, being oriented on various industries, helping to decrease time spent on iteration and introducing new products to the market.
  • Rapid Tooling: Proposes a way to lower the costs in mould making, or at least offer the ways to decrease the expenses connected with making the moulds are very effective for short runs of production or for making prototypes, which can help the industries to test the market reactions and start the production without delay, which is connected with creating the traditional tools.

Rapid Injection Molding vs. Conventional Injection Molding

FeatureConventional Injection MoldingRapid Injection Molding
Speedy ProductionRapid manufacturing rate of 15-120 seconds/part, ideal for mass productionRapid turnaround, suited for low- to mid-volume production runs
FlexibilitySupports a wide range of plastics, influencing part strength and designUtilises high-grade aluminium moulds, compatible with various materials
Cut WasteCreates less waste, ability to recycle extra plasticMinimizes material waste, precise injection into the mould cavity
Managing Complex PartsProduces complex parts with intricate detailsEnables production of homogeneous parts quickly
PriceLow-cost plastic-forming procedureCost-effective solution with shorter timelines
Surface FinishingUtilises CNC milling and various finishing proceduresEnsures quality surface finish through CNC milling
PrecisionOffers a high level of precisionProvides precise molding, limited only by mould precision
ResistanceProduces parts with uniform thicknessInjection of liquid resin under high-pressure
Mould Utilization for Large BatchMolds capable of producing large batchesSuited for low- to mid-volume production runs
EfficiencyOptimised machining operations for mass manufacturingQuick turnaround time, efficient production process
UniversalityRequires minimal changes for material adjustmentsCompatible with virtually any material, offering universality

If you want to know more about conventional plastic injection moulds, please click here.

Rapid injection molding process:

Process of rapid injection moulding

Figure 4: Process of rapid injection molding

Demystifying the rapid injection molding process involves dissecting its critical stages, each contributing to the precision and quality of the final product:

Design and Prototyping:

The general procedure involves using computer-aided design to develop a part design that meets the requirements of an end product, including aspects such as wall thickness and the type of material to be used. Physical verification and validation are adopted using prototyping techniques, including 3D printing.

Mold Making:

Mould manufacturing comes into play after the design process of a product is complete. Technologically speaking, the creation of aluminium moulds, seen as being cheaper and faster than other varieties, entails using CNC machining and electrical discharge machining (EDM).

Material Selection:

Selecting the correct resin type is a critical decision involving some parameters such as end-use and mechanical properties. Due to their high strength and endurance, materials such as ABS and polycarbonate are often used for engineering applications.

Injection Molding Process:

The selected material is melted and then forced into the mould cavity to fill it by injection molding machines. This helps observe molding conditions to ensure they are perfect to give the required quality.

Cooling and Ejection:

After this, the mould feeds the part, which cools and solidifies in position with the help of cooling passages to ensure uniform hardening. However, this process is essential when the part is still hot since it has solidified; it will be ejected from the mould, ending the molding cycle.


Sometimes, with the proper designs, some finishing processes or operations may be done, such as drilling, painting or assembling, depending on the part’s intended use.

Quality Assurance:

All structure parts pass various tests to meet the required characteristics and quality. A measurement entails the evaluation of dimensions, while a test involves an examination of the material and the general quality.

Iteration if Necessary:

In this technology, injection molding can be accomplished within a concise time frame of minutes, depending on the feedback received or tests that may be carried out. The particular stages of design modification must also be understandable to demonstrate the flexibility of the process regarding the concrete project requirements.


Rapid injection molding is a revolutionary technology in companies’ production today since it provides high speed, flexibility and excellent production quality. With the constant development of the industry that rapid injection molding is part of, the future appears bright because most businesses demand faster and more efficient production methods.

We are GO4Mould, and we are preeminent pioneers of such a change at the behest of this progressive technology that happens to be our strong suit, in association with which we offer compound gearing to the client’s needs along with being on the threshold of pioneering change in the manufacturing industry. Contact us for more information.

Rapid injection molding frequently asked questions

1. Is Rapid Injection Molding Production Fast?

Yes, this methodology of using rapid injection molding is fast. Due to the employment of rapid tooling approaches, the process entails quickly producing the injection molded parts of production quality. This is because it is easier to set up, adjust, and change over with simpler tools and methods than with the formal system.

2. Is the Rapid Injection Molding Product Durable?

It depends. The durability of the RIM products depends upon appearance, material, and usage. It is generally integrated into high durability using various materials such as reinforced plastic and composites, which RIM selects based on their appropriate characteristics, such as strength or wearing level.

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