Injection molding has long been considered one of the most versatile and useful manufacturing processes for complex parts. But did you know that there is more than one kind of plastic injection molding process? Choosing the right one is critical to ensuring the success of your product. Different techniques can impact cost, production efficiency, and overall performance in different ways. On top of that, certain methods are better for some applications than others — gas-assisted molding is ideal for complex geometries, for instance.
At Ferriot, we specialize in custom injection molding solutions tailored to complex projects. With expertise spanning multiple molding disciplines, we help OEMs navigate the selection process to achieve the best possible results — balancing cost-effectiveness with high performance and manufacturability. Let’s take a closer look at your options and which might be right for you.
Overview of Injection Molding Processes & Best Use Cases
Straight Injection Molding
The most commonly used plastic injection molding process, straight injection molding (sometimes also called traditional injection molding) is ideal for high-precision, high-volume production. It accommodates a wide range of thermoplastics, making it a versatile solution for industries requiring consistent quality and repeatability.
Structural Foam Molding
For large, rigid parts that need to be strong yet lightweight, structural foam molding is the go-to solution. By introducing a chemical blowing agent, this process reduces warpage and minimizes material usage while maintaining durability. It also allows for the production of larger parts using smaller tonnage presses, optimizing cost and efficiency.
Gas-Assist Molding
When intricate designs requiring good surface cosmetics and low warpage are priorities, gas-assist injection molding offers significant advantages. This plastic injection molding process strategically injects gas into the mold to hollow out thicker sections. This reduces material usage while still improving strength, aesthetics, and dimensional stability.
Insert Molding & Overmolding
For parts requiring enhanced functionality — such as metal reinforcement, rubberized grips, or multi-material construction — insert molding and overmolding provide the perfect solution. These techniques streamline assembly, improve durability, and enhance the end-user experience.
At Ferriot, we offer all of these molding solutions under one roof, ensuring our customers get the best process for their specific needs. Our engineering team works closely with OEMs to identify the ideal molding method for achieving performance, cost, and manufacturability goals.
Key Factors to Consider When Choosing a Plastic Injection Molding Process
Selecting the right plastic injection molding process requires balancing a number of different factors. Some of the most important are:
- Part Size and Complexity — Highly intricate designs or large components often require specialized molding techniques. Gas-assist molding, for example, is ideal for complex geometries that require some structural reinforcement without excess material, while structural foam molding allows for the production of large, rigid parts without high-tonnage press requirements.
- Material Selection — Choosing the right plastic is critical for functionality and longevity. Whether your project requires high-performance engineering thermoplastics for strength and heat resistance or commodity-grade resins for cost-effective consumer applications, different molding methods handle materials differently.
- Aesthetic and Functional Requirements — If your part requires specialized finishes, additional reinforcement, or multi-material construction, processes like overmolding and insert molding provide added value.
- Cost and Lead Time Considerations — Optimizing production costs and turnaround times starts with choosing the most efficient molding process. Factors like tooling investment, cycle time, resin type and post molding processes all influence the overall cost.
Common Pitfalls in Plastic Injection Molding Process Selection & How to Avoid Them
Clearly, choosing the right plastic injection molding process is a little more involved than many might expect. With that said, there are significant challenges involved, but they can be avoided with proper planning and engineering expertise. Here are a few of the common pitfalls and how you and your manufacturing partner can mitigate them:
Misjudging Tolerances and Material Behavior: Different plastics behave in unique ways during the molding process, and failing to account for shrinkage, warping, or thermal expansion can lead to defects and costly redesigns. Engineering-grade resins, for example, require precise control of processing conditions to achieve tight tolerances.
Underestimating Tooling Requirements and Costs: The complexity of a part directly impacts tooling costs, and choosing the wrong mold design can result in higher expenses and longer lead times. Multi-cavity molds, hot runner systems, and tool longevity must all be factored into upfront decisions.
Choosing a Process That Limits Design Flexibility or Scalability: Selecting a molding process without considering future production needs can lead to unnecessary limitations. For example, straight injection molding is ideal for high-volume runs but may not offer the weight reduction benefits of structural foam molding for larger parts. Similarly, failing to plan for design modifications or secondary operations can create bottlenecks down the line.
Avoiding these pitfalls starts with the right partner. Ferriot’s engineering team works with OEMs early in the development process to evaluate design, material selection, and process feasibility — ensuring that the chosen injection molding method aligns with performance goals and production requirements. By engaging with our experts upfront, customers can prevent costly mistakes and streamline their manufacturing strategy.
How Ferriot Helps You Choose the Best Plastic Injection Molding Process
Selecting the right plastic injection molding process requires balancing performance, cost, and manufacturability. With Ferriot as your partner, you gain access to industry-leading expertise and a full range of services to optimize your project from design to production.
- Expert Design for Manufacturability (DFM) Analysis: Ferriot’s engineers collaborate with OEMs early in the design phase to assess manufacturability, material selection, and process feasibility. This proactive approach helps identify potential design challenges before they become costly issues.
- Mold-Flow Simulations to Identify Potential Defects Early: Using advanced mold-flow analysis, Ferriot predicts how molten plastic will fill the mold, pinpointing areas where defects like warping, sink marks, or air pockets may occur. By optimizing mold design upfront, we ensure smoother production and higher-quality parts.
- Prototyping for Real-World Testing Before Full-Scale Production: Before committing to full-scale production, Ferriot offers prototyping services that allow OEMs to validate designs, test material performance, and make necessary refinements. This step reduces risk and ensures products meet functional and aesthetic requirements.
- Full-Service Contract Manufacturing for Streamlined Production and Assembly: Beyond injection molding, Ferriot provides comprehensive contract manufacturing services, including assembly, secondary operations, and logistics. This one-stop approach helps OEMs simplify their supply chain while maintaining quality and efficiency.
Contact us today to discuss your injection molding needs and discover how Ferriot can help optimize your manufacturing strategy.
