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.

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.”

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.

Lastly, structural foam also features highly paintable, aesthetically pleasing surfaces. In-mold painting (IMP) is possible for all structural foam products, further saving time and money. Multiple colors can also be applied to a single part in-mold. The surface is easy to clean and can be sawn, screwed, nailed or stapled without experiencing any problems.

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 use of structural foam as a manufacturing material comes with a large number of advantages. Of course, structural foam initially became known for its ability to create parts of unparalleled size, such as the roofs or body panels of vehicles. However, it soon became apparent that structural foam promised a number of additional benefits.

In addition, structural foam retains the impact, element and temperature resistance common to thermoplastic and thermoset polymers. It experiences minimal to no thermal expansion, making it perfect for products which will be utilized in a wide variety of climates or temperatures. The acoustic and sound dampening properties of structural foam are also superior to those of standard solid polymers.

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.

However, there is one important difference necessary for the creation of structural foam rather than a solid polymer. In addition to the polyol and isocyanate, an inert gas or chemical blowing agent is added to the mix during the injection process. This changes the nature of the chemical reaction which ultimately occurs.

The process of molding parts from structural foam is very similar to the traditional method of reaction injection molding. Two components, for example polyol and isocyanate (which are combined in order to create polyurethane) are stored in liquid form in separate containers. They are mixed together to form a resin which is injected into a pre-prepared mold and cures via the means of a chemical reaction.

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.

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.

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.

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.

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

Structural foam parts are extremely lightweight – typical weights vary from 55 pounds per cubic foot to a mere 2 pounds per cubic foot. In addition to this decrease in weight, structural foam is strong, durable, and extremely stiff – in fact, up to 8 times stiffer than similar materials such as solid polymers. The modulus of the material increases along with its density, up to a fantastic 250,000 psi.  In addition to this, since it is a foam, the material makes for a great thermal and acoustic insulator.

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.

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.

The structure of the material is like that of a sandwich, with the low density core completely surrounded by the higher density skin. The texture of the core has been frequently described as resembling a “sponge” or a “honeycomb”. Because of its unique core texture, structural foam is typically anywhere from 20% to 40% lighter than solid polymers, aluminum, steel, sheet molding compound or other commonly used materials.

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.

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.

Structural foam molding is also a highly cost-efficient process. Lower pressures and clamping forces are required during the injection and curing periods, allowing the tooling and molds to be made from lower cost materials such as aluminum. Cycle times are competitive with those of injection and reaction injection molding, making this a time-saving process as well as a money-saving one.

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.

Structural foam is also highly moldable; it is able to produce variant wall thicknesses across a single part. In some cases, structural foam has even been able to generate wall thicknesses greater than the previous maximum of ½ inch (13mm). It also allows for thick ribs and bosses and reduces the risk of “sinks” over ribs or heavy cross-sections due to the lower viscosity of the mixture. Structural foam products experience less stresses overall during the molding process, and are highly resistant to warpage or deformation.

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.

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.

Due to its not quite solid nature, the base material used in the creation of structural foam is typically a thermoplastic polymer rather than a thermoset. Commonly used thermoplastics include but are not limited to: polyurethane, polycarbonate, polyphenylene oxide (Noryl), polybutylene terephthalate (Valox), and acrylonitrile butadiene styrene.

Structural foam is a composite material produced when a polymer, usually thermoset (but can be thermoplastic), is combined with either an inert physical gas, such as nitrogen, or a chemical blowing agent during the molding process. The result is not a solid material but a low-density, microcellular “core” combined with a high density outer “skin”. The core decreases the overall weight of the material while the solid skin allows it to remain strong and impact resistant.

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.

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).

Structural foam is a manufacturing material which pairs a foamed core with a solid outer “skin,” rather than remaining solid all the way through. It is lightweight and flexible while also maintaining the good strength and stiffness compared with traditional polymers such as polyurethane, polyester or epoxy. The ability of structural foam to produce parts of unprecedented size has led to revolutions in the production of vehicle roofs, interior and exterior body panels, housing for medical equipment, and even skis.

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.

Less polyol and isocyanate are used than in standard solid polyurethane reaction injection molding, so that the resin does not completely fill the mold. Instead, the gas or blowing agent is activated by the reaction between the two components. It expands, filling the empty space of the mold with foam. This creates the “honeycomb” texture for which the interior core of structural foam is known. Surface cells collapse when they come in contact with the walls of the mold, resulting in the creation of the solid skin which surrounds the outside of the material.

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.

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.

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.

Structural foam products have a lower than average risk of damage in the mold or during the removal process, making it a highly efficient and easily repeatable method. In addition, structural foam produces no potentially harmful styrene fumes, lowering the health risks for workers involved in the molding process.

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.

Sometimes, you are required to manufacture parts of a size larger than can be produced using traditional materials. How can these parts be created without sacrificing strength, stiffness and overall quality? Luckily, there is a simple, affordable solution: structural foam.