Is Plastic Injection Molding Right for My Project?

Plastic injection molding press machine

Injection molding has gained popularity in recent years due to its ability to achieve high levels of repeatability when mass-producing plastic parts. Whether plastic injection molding is right for your project will depend on several factors, including your budget, schedule, desired volume, tolerance requirements, and more. In this blog, we break down the advantages and disadvantages of injection molding, as well as the top considerations to keep in mind before continuing with your project.

What is Plastic Injection Molding?

Injection molding is the process of injecting melted plastic into a pre-manufactured mold and then allowing it to cool and solidify. Injection molding is used to create high-quality plastic parts for a wide range of industries and applications, including automotive engine parts, aerospace housings, and components, wearable sporting goods, furniture, medical devices, prosthetics, and more.

What are the Advantages of Injection Molding?

1.   Precision, Complexity, & Enhanced Strength

Very few mass volume manufacturing processes also have the ability to achieve high levels of precision and accuracy. Injection molding can. Compared to other techniques, injection molding allows you to incorporate intricate design features at very tight tolerances. The use of fillers allows for enhanced part strength. This process also opens up the possibility of special surface finishes, engravings, or custom prints.

2.   Highly Repeatable Designs

Not only can injection molding meet your tolerance requirements, but it can also meet them on a mass-produced scale. The molds used in this process have a long service life, meaning once the initial 3D mold is made, thousands of identical parts can be produced consistently and with a high degree of quality.

3.   Versatile Material Selection

Injection molding is compatible with a wide variety of plastics and thermoplastics, including but not limited to ABS, HDPE, LDPE, PEEK, PET, polycarbonate, polyethylene, and many others. The materials used in this process can also be colored according to your design specifications. The plastic best suited to your project will depend on things like strength, elasticity, temperature resistance, & compliance with various industry standards.

4.   Low Cost Per Part

While injection molding tends to have higher up-front costs, the cost per unit is significantly lower than other techniques, like 3D printing. For this reason, injection molding offers a cost-effective solution for high-volume production runs of intricate plastic parts.

5.   Fast Cycle Times

Injection molding uses multi-cavity molds, allowing for upwards of fifty parts to be produced at one time. Not to mention, cycle times can be as low as 10 seconds. Where CNC machining might take half a day to get through one cycle, injection molding can yield up to 1,000 parts in a single minute.

6.   Low Waste

This process produces much smaller amounts of post-production scrap compared to other manufacturing methods, offering increased sustainability and reducing the amount of money wasted. Even the waste plastic produced from the sprue, runners, and flash material can be reground and recycled for future use.

What are the Disadvantages of Injection Molding?

1.   Higher Upfront Costs

While cost-per-part is low, injection molding requires significant design, testing, tooling, and prototyping, which can lead to higher initial costs. However, the more parts produced, the lower the costs become. For this reason, injection molding is still an economical option for mass production, despite higher initial costs.

2.   Little Room for Error

Injection molding can achieve large volumes of high-quality parts, if the necessary precautions are in place. Since the scale of most injection molding projects is so large, minor defects can be extremely costly. This is why it’s important to rely on experts who are knowledgeable about the prototyping and tooling design processes essential to rendering consistent, high-quality products.

3.   Longer Initial Lead Times

While cycle times are extremely fast with injection molding, the time it takes to design, tool, prototype, and test the initial mold can take months. However, if you know what you want, it can be as quick as a few weeks. To help speed the process along, you may want to consult qualified experts who can help you hone in on the most important considerations for your injection molding project.

4.   Part Size Limitations

Large machines are used to create injection molded parts. As such, the size of your design will be restricted to the capabilities of the machine. Larger-sized items may be better suited to a different plastic fabrication process.

Why Should I Outsource My Injection Molding Project?

The most crucial part of the injection molding process is the initial design and prototyping of the mold. These first steps have major implications for the overall cost, lead time, and quality of the end parts produced. As a sourcing company with years of experience, we have accommodated a variety of injection molding projects and work wide network of manufacturers. We know the capabilities of each, and can help you propose projects that will reduce lead times and cost and ensure optimal part quality.

Benefits of outsourcing your injection molding project include:

  • Reduced lead times and costs
  • Guaranteed quality
  • Focus on core competencies
  • Streamlined design & prototyping process
  • Access to the most advanced equipment
  • Adherence to project priorities and restraints

Receive a Quality Guarantee When You Outsource with Compass & Anvil

At Compass & Anvil, we do the heavy lifting of locating a plastic manufacturer with the capabilities to accommodate your budget, schedule, industry compliance, and design specifications. We maintain a quality guarantee on all plastic parts sourced through us, meaning the parts you receive conform to your unique requirements or your money back. Request a quote or contact us to begin discussing your injection molding application.


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