Author Archives: Promed

  1. Ten Injection Molding Tips

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    Plastic injection molding is an effective and popular method of producing large quantities of identical components with high precision. This process entails melting thermoplastic flakes or pellets before injecting them into a mold. After the mixture cools or hardens, ejector pins push the finished part out.

    Injection-molded parts can have intricate structures, and making design changes after manufacturing the product is difficult. As such, it is critical to carefully craft and lay out the plastic component to reduce the likelihood of tool issues, achieve the desired results, and save injection molding costs.

    Here are ten design tips for plastic injection molding:

    1. Choose the Most Appropriate Surface Finish for the Design

    Making the right decision regarding the surface finish is vital to ensure a proper molding design. Aside from its aesthetic value, it improves grip, increases paint adhesion, and allows gases to escape the mold during the process. However, the surface finish you select is related to the molding type required based on production volume and the material type from which you will make it. For instance, steels are more durable and have more surface finish options than aluminum ones. You can also polish them for a smoother finish.

    2. Uniformly Design the Parts

    Any thickness limitations or changes in the components can disrupt the injection molding flow, potentially leading to other negative consequences. Therefore, keeping the thickness constant between 2 mm. and 3 mm. is recommended because layer thicknesses less than 1 mm. or greater than 4 mm. might lead to manufacturing issues.

    3. Add Drafting to the Parts

    Adding a draft angle allows the parts to be ejected from the injection mold. The angles should be at least 1° on an untextured surface and 3° on a textured one to properly let the components loose without prying. For applications that require a tight mating area, position the zero-draft area as close to the mating portion as possible rather than a complete surface.

    4. Add a Radius Wherever Possible

    Sharp corners on any injection molded part are challenging to form because they trap air. The most secure solution to this problem is to design them out. A radius also extends to a draft angle, aiding in smooth transitions and ensuring you can remove the part from the mold.

    5. Always Design Resin Flow From Thick to Thin Sections

    Thicker sections are needed for structure and strength. Because molten resin loses pressure and temperature as it continues to flow through the mold, it must first cover the thicker sections before moving on to the thinner areas.

    6. Determine Which Molding Defects Are Acceptable

    Injection molding defects are to be expected during the process. For example, sinks caused by bosses designed into the backside may occur on thicker sections, whereas adding structure to the part by strengthening the ribs may increase the possibility of visual defects. While advanced molding conditions can reduce some of these defects, they cannot eliminate them. As a workaround, determine which defects are acceptable and which are not, and then design around them.

    7. Reduce Strengthening Rib Sizes As Much As Possible

    Rib strengthening plays an essential role, but having too large of a feature can cause complications. Therefore, each rib must meet three primary design criteria: base thickness, rib height, and overall thickness.

    First, the rib base must be structured at 60% or less of the wall thickness to reduce a sink mark on the surface. Second, the rib height should be as low as possible (at least less than three times the part thickness) to avoid getting stuck in the mold. Lastly, the overall thickness should be less than the rib base, which is connected to the designed draft angle.

    8. Avoid Tooling Undercuts

    An undercut in an injection molding tool occurs when the device’s opening and closing prevent the formation of a feature. A lifter and slide are recommended to form the component rather than complicated shapes. Therefore, it is best to maintain simplicity because they can create complex structures while still allowing the part to be removed.

    9. Design for Manufacturing and Error Proofing

    Most injection molded products are intended to be part of more extensive manufacturing. Use coordinates or datums when designing to ensure that each one is assembled the same way every time. Moreover, remember that huge businesses require manufacturing-ready designs, and minimizing error potential should be a part of every configuration.

    10. Use Rapid Prototyping To Immediately Detect Problems

    Rapid prototyping can help improve your design, manufacturing, and secondary processes. It can also detect early design flaws in a model that you might overlook. You can choose one from many rapid prototyping options, including metal 3D printing, digital light processing, CNC machining, binder jetting, rapid injection molding, and laminated object manufacturing.

    ProMed for Your Injection Molding Needs

    ProMed uses cutting-edge technology, relies on a highly experienced technical team, and uses a creative system to give our customers dependable, high-quality, and cost-effective service options for their production needs! We also specialize in small, finely crafted silicone and plastic components that can be implanted for short or long periods, with or without drug-releasing agents.

    Contact us today to learn more about ProMed’s molding solutions and services! You can also request a quote now.

  2. ProMed Pharma Press Release April 2022

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    ProMed Pharma announces a preclinical rat study to assess pharmacokinetics of a novel long-acting contraceptive implant


    Bioresorbable implant aims to address key unmet needs for
    family planning at an affordable price in low and middle
    income (LMIC) settings

    /EINPresswire.com/ — ProMed Pharma is pleased to
    announce the initiation of preclinical evaluation of a novel
    fully resorbable contraceptive implant. The implant,
    developed in a project funded by the Bill & Melinda Gates
    Foundation, aims to address key unmet needs for family
    planning at an affordable price in low and middle income
    (LMIC) settings.

    Commercially available contraceptive implants, while safe
    and highly effective, require removal by trained health care
    providers any time the user wants to discontinue the
    method, including when pregnancy is desired, or when the
    implant reaches the end of its effectiveness. This
    requirement imposes a strain on resources in LMIC

    The implant being developed by ProMed is specifically designed to address the needs of LMIC settings.
    First, it aims to expand women’s contraceptive options by providing 18 months of contraception by long-term release of levonogestrel. This duration fills the gap between that offered by existing injectables and longer-acting methods such as non-erodible implants.
    Second, the implant is fully biodegradable, eliminating the need for women to return to medical clinics for removal at the end of the period of effectiveness.
    Finally, the implant, which comprises a levonogestrel-releasing outer sheath surrounding a drug-free polymer core, is designed to retain sufficient mechanical integrity to allow removal if or when desired. Removability is important to respond to women’s needs, such as in cases where pregnancy is desired prior to exhaustion of the contraceptive.

    The preclinical evaluation of the implants follows selection of four lead formulations combining levonogestrel with cost-effective, commercially available biopolymers that yield near-linear release without the need of a rate controlling membrane. The preclinical study will evaluate the pharmacokinetics of levonogestrel, establish duration of removability, and track length of biodegradation of the designs. The results will allow further narrowing of formulations for clinical evaluation.

    Dr. James Arps, Director of Business Development at ProMed, noted “the implant designs have shown promising mechanical integrity and drug release profiles based on in vitro tests to date and have a form factor which is similar if not superior to other implants on the market.” The study will be carried on for a minimum of 6 months with the option of gathering drug release and polymer degradation data up to 1.5 years.

    About ProMed Pharma:

    ProMed Pharma specializes in the molding and extrusion of drug-loaded silicones, thermoplastics, and bioresorbable materials, leveraging this expertise to manufacture long-term implants and combination devices under cGMP. Working with both established and early stage companies, we utilize robust manufacturing processes for controlled release of APIs utilizing a variety of materials. From clinical trial materials to commercial products, ProMed supports
    pharmaceutical and medical device companies developing controlled release formulations including subcutaneous, orthopedic, cardiovacular, and ophthalmic implants, intravaginal rings, and steroid-eluting combination components. The company has facilities in Plymouth and Maple Grove, Minnesota. Please visit www.promedpharmallc.com for more information.

    James Arps
    Promed Pharma
    +1 763-331-3800
    email us here
    Visit us on social media:

    Download the Press Release Here

    This press release can be viewed online at: https://www.einpresswire.com/article/569066201
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  3. DFM Checklist for Medical Manufacturing

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    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.

    · Simplification:

    • 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?

    · Defects:

    • 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?

    About ProMed

    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

    Click here to see why ProMed is your silicone injection molding partner. Contact ProMed today at 763-331-3800 to discuss your next silicone injection molding project.

  4. The Basics of Medical Silicone Injection Molding

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    For companies seeking high-quality and cost-effective parts and devices for the medical sector, silicone injection molding is an ideal solution. Below are the basics of medical silicone injection molding including the process, materials, advantages, and how it differs from other silicone molding techniques.


    Common Silicone Molding Methods

    To better understand the basics of silicone injection molding it will be useful to understand how this process compares to other silicone molding techniques. Below are the most common methods used to manufacture silicone into a final product.

    • Compression Molding: silicone is compressed between two heated mold cavities to force the material to fill the desired mold shape.
    • Transfer Molding: silicone is pushed into the heated mold using a plunger, where it takes the shape of the cavity.
    • Extrusion: melted silicone is pushed out of a die to form the shape of the desired finished product.
    • Injection Molding: melted silicone is injected into a mold cavity to form the shape of the mold.

    It is important to note that each of the primary molding techniques above may have variations of the basic process. For example, rotational molding is an extension of the techniques above where silicone is inserted into the mold at the desired temperature while the mold continuously rotates to form hollow parts with uniform wall thickness. Additionally, blow molding is another variation where heated silicone is blown into a mold along with air and as the silicone expands, it presses against the walls of the mold forming a thin-walled, hollow shape.


    Materials Used in Medical Silicone Injection Molding

    Silicone elastomers have long been a popular material for medical devices and components due to their durability, wide temperature range, chemical inertness, high tensile strength, vast range of available durometers, low toxicity, and compatibility with many sterilization methods. Furthermore, silicone is compatible with human tissue and body fluids, has a very low tissue response when implanted, and does not support bacteria growth – making it a perfect option for medical implants!

    Silicone elastomers are available in two commercial forms: Liquid Silicone Rubber (LSR) and High Consistency Rubber (HCR). LSR and HCR are both used to manufacture medical device products. For companies already using HCR to manufacture medical device components, it may make sense to continue using this elastomer especially since the initial capital equipment costs have already been made. For new product development, LSR is often the best choice given the lower capital costs and labor associated with processing this elastomer. However, the decision to use LSR or HCR should be made on a case-by-case basis and OEMs should consult their molding partner.


    Silicone Injection Molding Process and Equipment

    There are also variations within medical silicone injection molding, however, the main equipment and process are generally the same. Below are examples of injection molding equipment. The process begins when silicone is fed into a heated barrel. In the picture below, solid raw material is stored in a hopper and then fed into the barrel. In the case of LSR manufacturing, the two liquids LSR components are stored in separate containers and then fed simultaneously into the barrel.

    Next, a screw is used to mix, heat, and transport the silicone toward to the mold. The melted material is then injected through a nozzle into the mold and travels via a gate and runner system into the mold cavity; the proper design of the gate and runner system is essential to ensuring the mold is filled properly. As the silicone enters the mold, excess air can be released via vents. The pressure and temperature of the mold are maintained to allow the silicone to conform to the desired shape and harden quickly. Once the part is adequately cooled, the mold opens and the part is ejected, sometimes with the help of ejector pins. The mold is then ready to receive the next charge of silicone. The injection molding process is a continuous operation with minimal downtime, resulting in high output rates.

    Medical Silicone Injection Molding
    Medical Silicone Injection Molding

    (photo credit: Wikipedia)


    Advantages of Medical Silicone Injection Molding

    Silicone injection molding has several benefits compared to other molding processes, and below are some of its key advantages.

    • High Quality & Very Reproducible: Silicone injection molding produces products that are virtually identical from part to part which provides excellent brand consistency and part reliability during high volume runs – this is especially crucial for parts and devices used in the medical industry! High reproducibility also allows for production to be scaled up to very large volumes, resulting in low costs per unit after the upfront equipment set-up costs are paid.
    • Excellent Versatility: silicone injection molding is a good choice for a wide range of part sizes, materials, and colors. Additionally, injection molding allows for the use of multiple materials simultaneously, allowing for a high degree of customization.
    • Able to Produce Complex Parts: silicone injection molding is typically performed at high pressure which forces the silicone into small crevices in the mold (that other molding processes are unable to reach), enabling the production of intricate and complex parts.
    • Efficient Production: silicone injection molding is a very fast process that generates high-output production compared to other molding methods, making injection molding a more efficient and cost-effective solution.
    • Automation Reduces Cost: silicone injection molding is highly automated via the use of machines and robotics, requiring less oversight by operations personnel. Automation reduces labor costs which decreases the manufacturing costs per unit.
    • Low Waste Generation: silicone injection molding manufactures smooth products that have minimal finishing requirements after removal from the mold – resulting in less waste generation compared to other molding techniques. Oftentimes, injection molding waste is able to be reused, resulting in a more environmentally-friendly and lower cost process.


    ProMed’s Medical Silicone Injection Molding Capabilities

    ProMed was founded in 1989 to address an industry need for cleanroom manufacturing of silicone components, specifically those having a medical application. 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 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

    Contact ProMed today at 763-331-3800 to discuss your next medical molding project.