PTI Engineered Plastics provides medical device manufacturers with full-service advanced product development delivered in a compressed timeframe. With superior design for manufacturability, tooling, and molding capabilities, PTI turns product visions into reality and gets your product to market first.

Furthermore, we have over 5,000 square feet of controlled environment space.  This segregated area is temperature controlled and pressurized, and can accommodate part decorating, assembly and packaging needs.

Insert molding involves placing a pre-manufactured component, such as a threaded fitting or an electrical contact, onto a mounting pin or other fixture in a plastic injection molding tool. During the molding cycle, thermoforming resin surrounds this insert and solidifies, thereby permanently sealing it into place.

Get 7-day standard lead times on simple parts between 0.5 in. x 0.5 in. and 4 in. x 3 in. Upload your part to see if it’s eligible.

Now, if that design logic is applied to a fleet of aircraft or millions of automobiles on an assembly line, then the reduction in weight and cost becomes substantial.

Product developers should consider overmolding in order to improve the grip and texture on parts that need to be held in the hand or to protect the end user against vibration, heat, or electricity. Overmolding is also a great way to permanently bond rubber to metal, as is found on wheels and casters.

You should consider using insert molding for a few main reasons. The first is that your product application needs strong mechanical fittings to hold two or more parts together, typically for an enclosure or housing. Threaded nutserts are great for this but there are many types of snap connectors as well.

The injection molding process generates minimal material waste compared to other manufacturing methods. This not only contributes to cost savings but also aligns with the increasing focus on sustainable and environmentally friendly manufacturing practices.

Injection molding is scalable, which means it can cater to a variety of production volumes, from small-scale prototypes to mass production. This scalability offers manufacturers the flexibility to meet different market demands.

Inserts can be either male or female. Female inserts are used to make circular fittings inside the surrounding plastic. When these types of inserts have internal threads, they’re called nutserts. There are many advantages to using both male and female inserts to enhance a product’s appearance and utility.

Process validation is the best way to ensure the production of safe parts, to reduce rejection rates, to prevent part failures in the field and to ensure the part meets with application, specification and regulatory obligations.

Meeting stringent regulatory requirements is a non-negotiable in the medical device industry. Injection molding excels in this regard. The ability to use FDA-approved materials and consistently produce parts that meet these standards ensures compliance from the outset.

Injection molding allows medical design engineers the freedom to design complex or intricate parts, a vast selection of suitable materials and the consistency to produce both low and high volumes of devices.

This is just a partial overview of insert molding and overmolding. Are they the right solutions for you? Not sure how to apply them to your next project? Just contact our technical experts and we can offer helpful advice about how to get the best results from both processes.

Mold Design is a crucial step in the injection molding process.  Once you’ve finalized your part in CAD software for fit and function, it must then be transformed into a design for molding to ensure the capture of all the specified details.  In some cases, certain features of the part design may not be manufacturable via the injection molding process.

Remember that overmolding is rarely used to cover the entire base substrate. Instead, apply overmolding in sections. For each of these, keep in mind these useful design tips:

Overmolding uses a special type of plastic injection molding tool, one that has a cavity for the substrate portion and another separate cavity representing the overmolded section.

While there are many advantages to insert molding, there are some potential drawbacks that designers should be aware of.

Careful selection of materials is extremely important within the medical industry. Materials must meet FDA and other regulatory standards, ensuring patient safety, biocompatibility, sterilizability and durability.  As Injection molding allows for a vast selection of both thermoplastic and thermoset materials to choose from, there is certain to be a material suitable for just about any application.

Overmolding is a special form of plastic injection molding. Unlike conventional molding, where a finished product is made in one cycle, overmolding requires at least one additional injection cycle using a dissimilar material. This method is also known as 2K overmolding, two-shot molding, or even multiple material molding.

At PTI, we have over 16,000 square feet of ISO Class 8 cleanroom space that we utilize in our injection molding process to ensure as little contamination as possible.  We adhere to strict protocols that meet the demands the medical industry requiring ISO 14644 Cleanroom specifications, including bioburden and electrostatic discharge (ESD).

Some of the most common materials used in medical devices are: Polypropylene, ABS, Polyurethane, Polyvinylchloride, Polycarbonate, Polystyrene, Polysulfone, Acetal and Polyethylene.

Neither overmolding nor insert molding is restricted in their use to any particular industry or product type. Because both methods are so useful and adaptable, new practical applications are being found all the time that take advantage of their benefits. Here are a few examples:

Get 7-day standard lead times on simple parts between 0.5 in. x 0.5 in. and 4 in. x 3 in. Upload your part to see if it’s eligible.

There are some unique engineering challenges that designers might face when using insert molding. The advantages of added strength and versatility must be weighed against the need for a more careful design for manufacturing review. Here are some useful guidelines to consider:

At PTI, we collaborate with you to achieve the best possible design for manufacturability.  In fact, we have a FREE guide to help you with this.

In many cases, our medical device customers look to process validation to ensure quality parts.  After all, patients lives depend on PTI to deliver high quality parts each and every time.

Injection molded parts can undergo a variety of post-processing operations, such as assembly, machining, laser marking, pad printing or surface finishing, to meet the exact requirements of the medical device.

We have been serving the medical industry for nearly 40 years, specializing in handling complex, multi-part programs and medical device molding for a variety of customers. Our direct contact with doctors and other medical professionals gives us insight into their needs and helps define and assist with final product solutions.

Injection molding for medical devices represents the perfect synergy of precision engineering and advanced manufacturing technology. Its benefits, from precision and consistency to cost-efficiency and regulatory compliance, make it a top choice for design engineers and medical device manufacturers. The process empowers engineers to innovate, create intricate components, and bring lifesaving devices to market faster than ever before. The future of medical device manufacturing is being molded with precision, and injection molding is at the forefront of this revolution.

Overmolding starts with a base substrate, on top of which a relatively softer TPE or TPU material is bonded. The base can be metal or plastic, although, in this article, we will focus on plastic applications primarily.

Having served the medical industry for nearly 40 years, we understand medical device manufacturing.   Plastic Injection Molding remains one of the best manufacturing methods for achieving precision and cost-efficiency as well as maintaining patient safety.

In this article, we discuss insert molding and overmolding, the advantages of each, and the applications they’re best suited for. We hope these manufacturing insights, along with useful design tips, will help you get great results on your next plastic injection molding project.

The first conventional injection cycle forms the substrate, using a standard thermoforming resin. This resin fills the gate, runner, and cavity system of only one part of the mold, while the section representing the overmold is blocked.

Once the base cools and is semi-hardened, the mold is then rotated to a new position and connected to a separate nozzle, gate, and runner system. The remaining void of the mold tool cavity is filled with TPE or TPU elastomer, creating the overmold that bonds to the substrate.

Inserts should be used whenever a plastic case needs to be occasionally opened for service and then locked tight again, such as when performing routine maintenance or changing batteries. They cost a little more but that cost is offset by making a much more durable end product.

And overmolding adds cushioning and shock absorption to many common household items that might protect users from accidental injury.

Injection molding offers unmatched precision and consistency in the production of medical device components. The process allows for intricate designs and tight tolerances, ensuring that each part is identical to the next. This uniformity is crucial in the medical field, where reliability and precision are paramount.

In this video, Gordon Styles, the founder and President of Star Rapid, goes into greater detail explaining how these processes work, and he gives examples of each. Be sure to check it out for more useful information.

Insert molding is used to put a rubber or plastic handle on a metal part, such as you might find on hand tools or kitchen knives. And insert molding is ideal for sealing wires and electrical connectors into permanent plastic housings that block out dust and moisture.

The high initial tooling costs can be a barrier to entry for some manufacturers. However, once the molds are in place, injection molding is incredibly cost-effective for large production runs. The ability to produce a large number of parts in a short time reduces unit costs significantly, making it an ideal choice for mass production.

The process is not limited to just two materials, and can theoretically be expanded to include an indefinite number of additional overmolds. However, in practice, more than two becomes increasingly complex and expensive.

With streamlined production processes, injection molding can significantly reduce time-to-market for medical devices. This is crucial in a rapidly evolving industry where innovations can make a significant impact on patient care and outcomes.

To get the best results from this process, product developers should be aware of the following limitations and potential disadvantages.

Get 7-day standard lead times on simple parts between 0.5 in. x 0.5 in. and 4 in. x 3 in. Upload your part to see if it’s eligible.

If the substrate is a plastic base, then it’s customary to mold it in the same production cycle. This is done because it’s more cost-effective to make the entire finished piece at one time, rather than paying to transport and store semi-finished goods. But the more important reason is that the elastomer will adhere much better to a still-warm, semi-cured, and “sticky” substrate.

Which process is right for you depends entirely on your application. Keep in mind that they aren’t mutually exclusive molding methods because they serve different purposes. In fact, it’s not uncommon to find both used on a single product. Think, for example, of a power tool that has overmolded grips on the handle, but that also uses nutserts to bolt the case together.

Injection molding produces parts with a high level of structural integrity, ensuring they can withstand the rigors of their intended application. These parts are less prone to defects and offer superior performance over their lifecycle.

One of the most significant advantages of injection molding is its design flexibility. Engineers can create complex, customized components with minimal tooling changes. This adaptability is essential in a field where the demand for innovative and unique medical devices is ever-expanding.

Overmolding also offers more opportunities to be creative by applying colorful designs to improve the appearance of the part as well as its performance.

Process Validation as defined by the FDA is “The collection and evaluation of data, from the process design stage throughout production, which establishes scientific evidence that a process is capable of consistently delivering quality products.”

Many medical devices must be in direct contact with the human body. Injection molding allows manufacturers to choose biocompatible materials, ensuring patient safety. These materials can be sterilized without affecting their properties, making them suitable for a wide range of medical applications.