Injection molding and other medical manufacturing processes are often complex and peppered with potential pitfalls. Fortunately, nearly all of these potential issues can be resolved with a highly competent design. Achieving the best design the first time around is crucial as there is a lot at stake. If OEMs do not get the design right, product rejection rates will increase, productivity will decline, and a host of other issues will ensue – all negatively impacting the bottom line. Additionally, modifying a product or mold design during the production stage can be very costly – so it is worth the time to get the design phase right.
One approach used in medical manufacturing to ensure the best design is Design for Manufacturing, or DFM. This is the process of designing products for ease of manufacturing as well as creating a better, more cost-effective product. DFM is a vital product development step that looks to simplify and optimize the design to ensure high quality and efficiency during production.
One apThe DFM process should occur early in the design phase of any molding project and should engage key parties including designers, tool fabricators, raw material suppliers, manufacturers, and other stakeholders. The goal is to tap into the experience of each of these experts. The team will scrutinize the current design from many angles with the goal of identifying a more cost-effective solution that maintains excellent quality.
How does the DFM Process Add Value?
Simply stated, OEMs need to ensure the part is as easy to manufacture as possible. This will result in more efficient production, better quality, and lower cycle times. Below are some ways OEMs gain value from the Design for Manufacturing process.
· Save Significant Cost and Time: OEMs are often in a rush to get a new product to market so it is tempting to shorten – or even skip – the DFM process. However, it is important to keep in mind that changes to the design become exponentially more expensive and timely to implement as the product advances through the life cycle. A thorough DFM upfront will allow any optimizations to be made or issues to be resolved before the changes significantly impact the project timeline or budget.
· Optimize Functionality and Aesthetics: tooling for molding projects is often expensive to fabricate and costly to modify; thus, it is imperative to get the tool design right the first time. If the design is off even by a small margin, the product aesthetics and functionality will be altered. The DFM process often includes computer simulations of the design as well as rapid prototyping so the team can fully visualize the product. Oftentimes, these steps yield valuable insights and design optimizations that would have been lost if the DFM process was not performed – resulting in a more functional and aesthetically-pleasing product.
· Confirm Manufacturability: last but certainly not least, the DFM process ensures the part can be manufactured. This may seem obvious but there are many instances of products reaching production only to realize the part cannot actually be manufactured per its current design – costing OEMs valuable time, money, and resources
ProMed’s Approach to DFM
To avoid this situation, OEMS should team up with an experienced medical manufacturing partner, like ProMed, that has DFM expertise. ProMed’s design and manufacturing teams are integrated to allow manufacturability issues to be identified and addressed during the design process instead of after the tooling is fabricated – saving customers significant development time and cost as well as innumerable headaches. At ProMed, we works with our customers throughout the product life cycle, providing a cost-effective solution that meets the customer’s needs.
LSR is a versatile silicone that has a wide range of end-uses from medical devices to consumer goods to electronics to automotive. There are several types of LSR that can be manufactured such as medical, self-lubricating, conductive, flame-retardant, and radio opaque. The type of LSR produced is determined by the additives incorporated during the manufacturing process. Additionally, LSR is available in different grades, namely medical, food, and industrial. Given its versatility, it is not surprising that the worldwide demand for LSR continues to grow.
LSR has excellent properties, such as a low viscosity and low shrink rate, that make it a great choice for silicone injection molding and the manufacturing of complex products and intricate parts. One of the benefits of LSR is that it cures faster than most other rubber materials; additionally, due to the highly automated nature of silicone injection molding and the potential for 24/7 manufacturing, high volumes of LSR products can be produced in a short period of time – adding to its popularity.
A key benefit of LSR’s lower viscosity is that it is easier to mix additives into. Additives that can readily be incorporated into a batch of LSR include colorants, desiccants, barium, and pharmaceuticals such as hormones or steroids. For these reasons, LSR is a great option for medical devices such as combination products. The low viscosity of LSR and the temperatures needed to vulcanize LSR are usually low enough that significant degradation of compounded substances, like Active Pharmaceutical Ingredients (APIs) that are used in combination products, can be avoided.
While LSR has many attractive properties, its biocompatibility is outstanding. LSR has demonstrated superb compatibility with human tissue and body fluids, and is resistant to bacteria growth. Medical grades of LSR are temperature resistance and can easily sterilize, which makes them compatible with various medical devices and accessories such as implantable devices, liquid feeding bottles, dialysis filters, and oxygen mask instruments.
Looking for a proven and reliable medical manufacturing partner for your next silicone injection molding project?
Contact the professionals at ProMed to learn more about our range of medical manufacturing solutions and the various silicone materials we utilize.
DFM Checklist for Medical Manufacturing
There are many factors to consider when designing a molded product for the healthcare sector. Below is an example of a DFM checklist that lists key design consideration for an injection molding project. These are topics that OEMs should discuss with their medical manufacturing partner to ensure each of these items is considered in the product design. This is not a comprehensive list but these are some of the most common design parameters that will help ensure a robust design and a successfully molded product. The DFM checklist for your project can be customized to meet the specifics of your application. Visit our website for more medical manufacturing design considerations regarding material selection and part functionality.
- Can the product size or geometry be simplified or standardized?
- Can complex features such as undercuts or sharp corners be simplified or removed?
- Are all specified tolerances necessary, and which dimensions/tolerances are critical?
· Part thickness:
- Can the part be made to have a uniform thickness throughout?
- Check for thick areas of the part that could result in sinks and voids
- Check for thin areas of the part that could result non-fill
· Part Draft:
- Does sufficient draft exist? Is draft in the right direction and location for a good parting line?
- If texture is being used, is there enough draft to release the part?
· Gate location:
- Can the gate be located in a thick area of the part?
- Will the gate seal at the right time?
- Are multiple gates needed?
· Material considerations:
- Will the material have flow concerns such as excessive shear?
- If the resin does not flow well, are long or thin flow lengths needed?
- Is the fiber orientation correct?
· Operating conditions to consider:
- Maximum pressure during filling and packing
- Clamp force profile
- Fill pattern – is there a potential for material solidification, voids, or hot spots?
- Temperature profile
- Venting temperature – is there a potential for air traps?
- Consider the potential for flash, weld lines, sink marks, short shots, burn marks, shrinkage, warpage, etc.
· Tooling: potential for tool integrity concerns such as thin steel?
ProMed was founded in 1989 to address an industry need for cleanroom manufacturing of silicone components, specifically those having a medical application. Over time, we broadened our product offerings to include assembly, micro-molding of highly engineered plastics, and combination products. We have garnered a reputation as the world benchmark of implantable silicone components and assemblies – and are one of few companies in the world to provide contract manufacturing of drug-eluting products.
ProMed has expertise in working with the full spectrum of silicones covering a wide range of properties and characteristics. We will assist in your material selection to help ensure all design requirements are met. Our manufacturing facilities and equipment are designed for a single purpose—to mold medical and implantable silicone, combination components, and bio-material grade plastics with uncompromising quality and service. We currently have four divisions that are located within two manufacturing sites. All are certified class 10,000 / ISO Class 7 cleanrooms.
We can identify the right manufacturing solution for any project. We have extensive experience in a wide range of injection molding techniques including:
· Automated Silicone Injection Molding
· Multi-cavity tooling
· Micro molds and micro molding
· Servo-controlled de-molding capabilities
· Insert molds, overmolds, and automation integration
· Transfer molding
· Compression molding