The core and cavity are often referenced as the A and B sides or top and bottom halves of a mold. A core-cavity approach to part design can save manufacturing time and money and improve the overall part cosmetics.

Let's say you're designing a simple box. When draft is applied to the outside and inside surfaces in the same mold half, you create a very deep rib that is difficult to manufacture and increases tooling costs. It also increases the chance of mold damage due to difficult ejection and short shots due to lack of mold venting in the deep rib.

Industry standards are essential guidelines that ensure end-users are safeguarded from undue risks associated with medical molded products. Regulatory bodies like the EU MDR (Medical Device Regulation) and the U.S. FDA (Food and Drug Administration) categorize medical devices into three classes, each correlating with a distinct level of risk. They include:

Polypropylene is derived from substituting the ethylene monomer with a methyl group (CH3). It is harder than PE and offers better resistance to moisture and gases, so it's suitable for storing fluid drugs. PP is also autoclavable and chemically robust, expanding its utility for storing sterile drug products.

Radii on the other hand isn't a necessity for injection molding, but should be applied to your part for a few reasons—eliminating sharp corners on your part will improve material flow as well as part integrity.

As your partner, Crescent Industries can provide expertise in injection molding manufacturing and uphold ISO standards, ensuring high-quality medical plastic products. Contact us for unparalleled quality, speed, and value in medical injection molding.

External undercuts are the easiest and most cost effective as we accommodate through pin-actuated side-actions. These side-actions move in tandem with the mold when it is opened and closed while the cam rides along an angled pin. When opened, the cam is fully retracted so the part can be easily ejected without mold damage and closes again till the cam is in position to create the next part.

The mechanical and chemical attributes of plastics significantly influence the durability and functionality of medical devices. Some important mechanical properties include:

Our helpful design aid demonstrates part features that are too thin or too thick, bad bosses, right and wrong ribs, and other considerations to be mindful of while designing parts for injection molding.

Medical-grade plastics like polyethylene, polypropylene, PVC, polystyrene, and silicone offer exceptional durability and biocompatibility. Understanding these properties and the material standards for each ensures you produce durable, reliable devices.

Medical injection molding utilizes various types of plastic materials. Thermoplastics and thermosetting materials are prominent in this field. Thermosetting plastics have high melting points, chemical resistance, and mechanical strength due to the strong covalent bonds between polymer strands. However, these covalent linkages cannot reform once broken, resulting in permanent deformation. These properties make thermosetting plastics useful as adhesives and protective coatings.

Get machined parts anodized and chromate plated with our quick-turn finishing option. Eligible materials include aluminum 6061/6082 and 7075.

Sterilization compatibility is also crucial to maintaining the hygiene and safety of medical devices. Injection molded parts must have high heat resistance to withstand various sterilization methods such as autoclaving, gamma radiation, or harsh chemical agents.

We've learned from experience that, before production begins, there are important design elements to consider. These may improve the moldability of the parts, and ultimately, may reduce the chance of production hiccups, cosmetic defects and other issues.

PCTFE is derived from replacing all remaining hydrogen atoms on the monomers with fluorine. The resulting material is ideal for pharmaceutical packaging thanks to its excellent strength, impact resistance, and moisture resistance.

Rapid injection molding requires that your part design should be as simple as possible, right? This is another false assumption as we support complex part designs that requires undercuts, through holes and other features.

PEEK is celebrated for its unique biomimetic qualities and fatigue resistance. It's commonly used for orthopedic implants and prosthetics.

With the rapid advancements in healthcare, plastic has emerged as the favored material for prototyping crucial medical components:

Join us as we explore different types of medical-grade plastics and the critical factors in injection molding material selection.

Gating and ejector pins are a necessity for plastic resin to strategically enter the mold and plastic parts to effectively be ejected from the mold. We've learned from experience that there are several ways to gate or eject your part, and the locations should be considered before you are ready to proceed with tooling.

Thermoplastics also feature weaker intermolecular forces, allowing them to melt and reform multiple times without permanent alteration. The material’s versatility and ability to withstand the remolding processes make it ideal for medical device plastic injection molding.

Tab gates are most commonly used as they offer a mold technician the optimal processing capabilities and have the ability to be increased in size if the process requires it. A tab gate is tapered down in size from the runner, so the smallest point is at the part's surface. This allows a freeze point between the part and runner removing the heat from the surface of the part. You want the heat removed from this surface to minimize any risk of sink in the part. After molding, the tab gate needs to be manually removed leaving a gate vestige within 0.005 in.

Proto Labs, Inc. 5540 Pioneer Creek Dr. Maple Plain, MN 55359 United States P: 877-479-3680 F: 763-479-2679 E: [email protected]

You can minimize all of these concerns through a core-cavity approach. This design technique requires the outside and inside walls to be drafted so they are parallel to one another. This method keeps a consistent wall thickness, maintains the part integrity, improves the strength and moldability, and decreases the overall manufacturing cost.

PVC is derived from substituting a hydrogen atom with chlorine in the ethylene monomers, which reduces its reactivity to nonpolar liquids. It is also transparent and flexible, making it a strong choice for storing glucose and saline solutions.

In cases that are not adaptable for side-actions, we can use manually removed inserts. These are mold components that are greater than a half-inch cube and are loaded by an operator into the press before it closes. After the part has been molded, the part is ejected along with the insert. The operator then takes the part and manually removes the insert and places it back into the mold for the next part.

Our digital factories create prototypes and low-volume parts fast, while our manufacturing network, offers advanced capabilities and volume pricing.

Controlling wall thickness during part design helps manage cosmetics, weight and strength of your part. Parts that are too thick result in unsightly sink, warp and internal voids (pockets of air). To avoid this, materials have recommended wall thickness guidelines—remember this is only a general rule as not all parts may have wall thicknesses at the high and low ends indicated on the chart.

Ramps and gussets are yet another design element to strengthen and cosmetically improve your part. Again, plastic prefers smooth transitions between geometries and a small ramp helps the material flow between levels. Gussets help supporting walls or features while reducing molding stresses.

Tough Black (Loctite Henkel 3843) and Ceramic-Filled (BASF 3280) are two new advanced photopolymer materials now available for 3D printing.

Hot tip gates work well as they have minimal part waste from sprue and runner systems. A hot tip is best for parts that require a balanced fill from the center to the outside edges. This minimizes any mold shift as tab gates can create an unbalanced pressure in a mold. Hot tip gates are often the most cosmetically appealing gate (about 0.050 in. diameter) and often times can be hidden in a dimple or around a logo or text.

Chemical resistance is crucial for devices exposed to cleaning agents and bodily fluids, ensuring longevity and reliability. Understanding and utilizing these properties to their best advantage is essential for maximizing device performance in medical applications.

Sharp corners have high-stress concentration and plastic flow is hindered. Rounded corners have reduced-stress concentrations and plastic flow is enhanced.

Through UnitedHealthcare, UMR creates and publishes the Machine-Readable Files on behalf of Crescent Industries, Inc. To link to the Machine-Readable Files, please click on the URL provided: https://transparency-in-coverage.uhc.com/

Sub gates are generally used by incorporating a tunnel gate into the side of the part or into an ejector pin (post gate). Both gate styles generally can decrease the size of the vestige left on the exterior of the part. Tunnel gates still enter the part externally, but are mid-way down a parts surface, so they typically leave less of a gate vestige. Post gates leave no visible vestige on the exterior of the part as the part fills through one of the ejector pins close to the perimeter of the part. The risk is the cosmetic shadow left on the opposite side of the part due to heat and part thickness. So, be cautious when using this for highly cosmetic parts that have texture or a high polish.

Next, we'll focus on the design of the support ribs. The ideal way to design ribs is by using a rib-to-wall thickness ratio of 40 to 60 percent the thickness of adjacent surfaces. The main body of the part should be designed thick enough so any adjacent rib extruded from it is about half of the thickness. This helps you avoid thick sections that may cool at different rates than the thin sections. It also helps in reducing sink and stresses that can create warp in your part.

To adhere to these tight tolerances and standards, injection molders must implement rigorous procedures at every production stage. Some of these standards include:

Direct sprue gates are the least appealing and are used with specific materials that have a high glass content or where the middle of the part requires secondary machining. Direct sprue gates have a large diameter that is difficult to manually remove and often times require a fixture that is removed by milling.

The resin filling the mold cavity flows better around soft corners much like the flow of a river. Rivers don't have 90 degree corners as the water flow creates inside and outside corners so it moves easily towards its final destination. Similarly, plastic resin wants to take a path of least resistance to minimize the amount of stress on the material and mold. Radii, like draft, also aid in part ejection as rounded corners reduce the chance that the part will stick in the mold causing it to warp or even break.

Biocompatibility involves assessing how materials interact with living tissues. Medical devices often come into direct and prolonged contact with bodily fluids or tissues, making biocompatibility a top priority.

Parts arrive at injection molding in different ways. Some are first prototyped through 3D printing where moldability considerations are of limited concern. Others take a more traditional machining route that allows for iterative testing in engineering-grade materials similar to that of molding. And many simply jump right to injection molding.

PE consists of ethylene monomer units linked through addition polymerization. Its variants offer distinct mechanical properties suited for various applications:

A good rule of thumb is to apply 1 degree of draft per 1 inch of cavity depth, but that still may not be sufficient depending on the material selected and the mold's capabilities. Protolabs uses CNC milling to manufacture the majority of the features in the mold. The result of our manufacturing process drives a unique wall thickness and draft angle based on the end mill that we are using for each feature. This is where our design for manufacturability (DFM) analysis becomes particularly helpful as our software looks at each part feature separately and compares it to our toolset. The design analysis highlights the part geometry where increased draft and thickness may be required.

Applying draft and radii to a part is vital to a properly designed injection-molded part. Draft helps a part release from a mold with less drag on the part's surface since the material shrinks onto the mold core. Limited draft requires an excessive amount of pressure on the ejection system that may damage parts and possibly the mold.

Plastics, also known as polymers, consist of repeating monomers forming homopolymers or copolymers. These materials are arranged into linear or branched polymers, resulting in diverse plastics with unique features.

Let's begin by coring out your thick part, which will still retain the overall height and diameter of your part without necessarily sacrificing performance. There's a good chance you'll increase the part's performance and cosmetic appearance, too.

Usability involves factors like handling ease and comfort. Silicone, prized for flexibility and skin comfort, is common in wearable medical devices. Plastic mold technology provides the design flexibility to create intricate and ergonomic designs, enhancing the overall usability of medical devices.

Along with employing proper wall thickness, additional considerations should be looked at to ensure a part's design integrity remains intact. One may assume that the thicker the part, the stronger the part—this is a false assumption. A properly designed part that is intended to be structural should contain ribs and supporting gussets, which increase strength and can help eliminate cosmetic defects like warp, sink, and voids.

With a solid grasp of the techniques to improve part moldability, it is much easier to move into low-volume, and eventually high-volume injection molding. The next step is to upload your 3D CAD model online where you'll receive an interactive quote with free DFM analysis within hours. As we said earlier, the DFM analysis will highlight any moldabilty issues and even suggest solutions. We recommend pairing that design feedback with a conversation with one of our experienced applications engineers who will help with any further guidance you might need before production begins. They can be reached at 877-479-3680 or [email protected].

Thermoplastics can be hard yet highly flexible. They can resist bending but offer excellent tensile strength that protects them from breaking.

Plastic medical products have revolutionized and improved the quality of patient management globally, but not all materials are created equal. Choosing suitable plastic materials for your medical device manufacturing is essential, as it impacts the success and safety of your final product.

Selecting the right materials for your medical devices is critical for determining the final product’s performance, safety, and efficacy. Here are a few key factors guiding the intricate injection molding material selection process.

Medical device aesthetics and usability contribute significantly to patient experience and acceptance. Visible prosthetics benefit from appealing, durable molding materials like colorable polycarbonate.

This guide walks you through everything from quoting, design analysis, and shipment to best practices that ensure your model is optimized for molding.