Growth in Liquid Silicone Rubber (LSR)

Why Is LSR So Popular?

Liquid Silicone Rubber (LSR) is a very pure, platinum-cured elastomer. LSR starts out as a 2-part liquid that is heated in order to accelerate the reaction of the two parts to form solid rubber. LSR has excellent properties, such as a low viscosity and low shrink rate, that make it a great choice for 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 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!

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. As you can see, LSR is a very versatile material that is well suited for a wide range of industries – so it is not surprising that the worldwide demand for LSR continues to grow!

Growing Demand for Liquid Silicone Rubber

The LSR market has continued to steadily grow in recent years and some sources estimate the global market for LSR will reach a valuation of US$ 7.9 billion by 2026. Additionally, the global LSR market is forecasted to have a Compound Annual Growth Rate, or CAGR, of 4.5% through 2026 which is considered moderate growth.

This growth is attributed to several factors. First, enhancements to the physical properties of LSR are expected to allow LSR to continue to replace traditional rubber materials in various applications. Additionally, injection molding of LSR produces consistent parts, cycle to cycle, and is a low-cost option for part manufacturing. For these reasons, LSR injection molding continues to expand into new markets, driving the continued demand for LSR.

Demand for LSR is increasing in traditional rubber applications as well as applications where rubber materials have not historically been utilized. LSR has a broad range of applications from medical devices to consumer goods to electronics to automotive. For example, LSR can be found in catheters, stents, windshield wiper blades, LED headlights, adhesives, wearables, bakeware, microwaves, seals, and grommets. Below are some key sectors that are experiencing growth in the use of liquid silicone rubber.

  • Medical Devices: LSR has many attractive properties such as durability, low viscosity, chemical and temperature resistance, and flexibility, but 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. Additionally, wearable medical devices are also gaining traction, leading to higher LSR demand.
  • Automotive Parts: Historically, automotive parts were made of metal or other materials. Due to their lighter weight, flexibility, longevity, and ease of manufacturers, elastomers such as LSR are increasingly being used by the automotive industry. For example, LSR is found in windshield wiper blades and LED headlights.
  • Wearables & Consumer Goods: Demand for wearable devices outside the medical sector also continues to grow, specifically products used to track fitness and health. LSR is ideal for wearables due to its resistance to moisture, ozone, and UV – resulting in a long product life! In addition to wearables, companies continue to seek LSR for other consumer goods applications. For example, many kitchen products such as bakeware and spatulas are made from LSR due to its ability to tolerate high temperatures and its excellent food safety ratings.

LSR’s growth in demand is also attributed to several societal factors such as growing demand for LSR in equipment and surgical tools necessary to treat the rising geriatric population and the growing awareness about health concerns, accelerated demand within the electronics industry due to continued innovation and technology advancements, as well as global urbanization and standard of living increases. Among the various grades of LSR, medical grade is expected to continue to hold the largest global market share. Moreover, stricter regulations and compliances of many specifications for use in medical products are further projected to drive the overall market growth.

The LSR market faces a couple key challenges including minimization of the carbon footprint associated with LSR production, and improvement of LSR’s reusability and disposability. But even with these challenges, the LSR market is forecasted to have continued growth globally as usage expands to even more markets.

ProMed’s LSR Molding Expertise

At ProMed, we combine industry-leading medical-grade LSR expertise with the latest developments in silicone materials and technology. We have garnered a reputation as the world benchmark of implantable silicone components and assemblies. From helping OEMs incorporate the latest medical-grade silicone formulations into their designs to delivering rapid silicone prototypes, we serve as a premier silicone molding contract manufacturer for medical device OEMs.

ProMed has expertise in working with the full spectrum of silicones covering a wide range of properties and characteristics. Our liquid silicone rubber offerings range from 5 to 80 durometer. 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.

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


Liquid Silicone Rubber vs High Consistency Rubber for Medical Device Components

Silicone elastomers have long been a popular material for medical devices and medical device components due to their durability, ease of molding by many methods, 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 implants due to its excellent biocompatibility.

Silicone elastomers are available in two commercial forms: Liquid Silicone Rubber (LSR) and High Consistency Rubber (HCR). HCR is known for its gummy consistency and mostly comes in partially vulcanized sheets. LSR is a newer technology and starts out as a 2-part liquid that cures into a solid form when mixed. LSR generally comes in buckets and has a longer shelf life than HCR.

Medical device OEMs often face a tough decision: should we use HCR or LSR for our medical device component manufacturing? LSR and HCR are both used to manufacture medical device products; however, there are some key differences. The following compares LSR and HCR to shed some light on their differences and when each should be utilized.

Viscosity Difference Leads to Different LSR and HCR Manufacturing Techniques

The performance characteristics of HCR and LSR are relatively similar; however, viscosity is a key differentiator between LSR and HCR, and has a significant impact on the equipment and processes used to manufacture each of these elastomers.

Simply put, viscosity is a measure of a material’s ability to flow. A low viscosity indicates a material is less viscous and more readily flows where a high viscosity indicates a material is more viscous and less apt to flow well. For reference, water has a relatively low viscosity and easily flows whereas molasses has a higher viscosity and is more resistant to flow.

LSR has a lower viscosity than HCR. Due to the lower viscosity, LSR is most often processed via injection molding. LSR’s desirable handling properties and lower shrink rate make it an excellent choice for manufacturing highly complex geometries and intricate products. Additionally, due to the automated nature of injection molding, LSR can produce high volumes of components in a short period of time. For this reason, deciding whether HCR or LSR injection molding is the better choice for your project largely depends on the production volume required.

A lower viscosity makes it easier for manufacturers to mix additives into LSR. 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.

Due to its higher viscosity and more challenging handling properties, HCR is typically processed using compression and transfer molding methods, which are more labor-intensive. In some cases, HCR is used in injection molding projects.

OEMs Often Prefer LSR

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, however, LSR is often the best choice given the lower capital costs and labor associated with processing this elastomer. Due to its lower manufacturing cost and versatility with formulations, companies often prefer LSR over HCR – but the decision is on a case-by-case basis.

ProMed’s Silicone Manufacturing Capabilities

At ProMed, we combine industry-leading medical-grade LSR and HCR expertise with the latest developments in silicone materials and technology. We have garnered a reputation as the world benchmark of implantable silicone components and assemblies. From helping OEMs incorporate the latest medical-grade silicone formulations into their designs to delivering rapid silicone prototypes, we serve as a premier silicone molding contract manufacturer for medical device OEMs.

ProMed has expertise in working with the full spectrum of silicones covering a wide range of properties and characteristics. Our wide range of materials include: Liquid Silicone Rubber (LSR) 5 to 80 Durometer, High-consistency Rubber (HCR): 20 to 80 Durometer, Room Temperature Vulcanizing silicone (RTV). 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.

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


Pharmaceutical Combination Products: Why Silicone is the Perfect Match

What is a Combination Product?

“Combination product” is a term used in the medical industry that refers to a product composed of two or more of the following: drug, device, and biological product. For over a decade there has been an increasing convergence between devices and drug therapies, leading to combination devices that more effectively deliver drugs and treatments to patients. Implantable medical devices are a common pharmaceutical combination product that provide a variety of functions from vascular stents that preserve blood flow to electrostimulation devices that regulate heart rhythm or block spurious signals in the brain, to orthopedic devices that mechanically reinforce the spine or restore range of motion of hips and knees. Other examples of combination products include inhalers and insulin pumps.

Pharmaceutical combination products, in particular implantables, provide a great benefit to patients over conventional dosage methods. For example, implantable devices provide site specific drug administration where the drug is most needed – this targeted treatment often allows for lower doses, reducing side effects. Additionally, this form of drug dosage is less burdensome to the patient. For these reasons, the trend toward combination products is expected to continue as demand grows for patient-centric drug delivery and self-administration of healthcare.

Silicone – the Perfect Match for Combination Products

Silicone has long been a popular material for medical device manufacturers due to its durability, ease of molding by many methods, wide useful temperature range, chemical inertness, high tensile strength, vast range of available durometers, low toxicity, and compatibility with many sterilization methods. But the key characteristic that makes silicone the perfect match for combination products is its biocompatibility. Silicone is compatible with human tissue and body fluids, has a very low tissue response when implanted, and does not support bacteria growth. Additionally, medical-grade silicones have undergone stringent purity and biocompatibility testing that make them suitable for use in long-term implants.

LSR is a specific type of silicone used in combination products. The low viscosity of LSR makes it a great silicone material for making medical devices via injection molding, since the LSR can easily flow into and completely fill molds with relatively low injection pressures, even those with intricate and small features. Furthermore, the temperatures needed to vulcanize LSR are usually low enough that significant degradation of compounded substances like Active Pharmaceutical Ingredients (APIs) can be avoided.

One application where medical-grade silicones, such as LSR, really shine is drug-eluting implantable devices. Before molding, silicones can be compounded with APIs such as cancer drugs or hormones which can then be steadily released into a targeted area of the patient’s body over time once that molded implant is inserted. Drug-eluting implants are able to maintain the desired level of the API in the patient much more consistently and over a longer period of time than both pills and injections. Also, since the implant can usually be inserted near the targeted organ or tissue, lower total amounts of API are needed because that API doesn’t need to spread throughout the entire body before reaching the targeted area. As a result, the level of the API in the patient’s body remains inside the therapeutic window for a much longer duration.

ProMed’s Combination Product Capabilities

At ProMed, we combine industry-leading medical-grade LSR expertise with the latest developments in silicone materials and technology. From helping OEMs incorporate the latest medical-grade LSR formulations into their designs to delivering rapid silicone prototypes, we serve as a premier silicone molding contract manufacturer for medical device OEMs.

ProMed Pharma is a leading contract manufacturer of polymer-based drug releasing molded dosage forms and combination device components. Working with both established and early-stage medical device and pharmaceutical companies, ProMed develops robust manufacturing processes and platforms for extended drug release from a variety of materials, including silicones and thermoplastics. 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.

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


Why Consistency Matters Most in Medical Silicone Injection Molding

Consistency is defined as the achievement of a level of performance that does not vary greatly in quality over time. While there are many factors that OEMs should consider when partnering with a silicone injection molder – consistency is certainly at the top of the list! This is especially true for OEMs that supply medical parts and devices to the healthcare industry – you simply cannot afford to cut corners when it comes to consistency and quality as these products are often critical to the health of the individual using them.

Due to its chemical inertness, durability, stability, and low toxicity, medical grade silicone is an excellent material for implantable and other medical devices and its use throughout the healthcare sector continues to grow. The healthcare industry has high expectations for its devices – requiring compliance with tight tolerances and cleanliness requirements that offer little room for error. A molder that has a high level of quality and repeatability in its medical device production is able to deliver consistent products to customers – becoming a trusted partner! Meeting an OEM’s specifications and requirements for a given device must be the top priority for every injection molder. From both the supplier and OEM perspectives, inconsistency and poor quality can result in various negative outcomes such as slower time to market, customer complaints, tainted reputation, strained supplier-OEM relationship – and worst of all, customer loss or harm! For these reasons, consistency and quality matter most in medical silicone injection molding!

Before partnering with an injection molder, OEMs should have a firm understanding of their quality program – this is an area where excellent injection molders stand out from their competition. A silicone injection molder’s quality planning and assurance program is more than just meeting the requisite ISO and FDA requirements – it represents their proven way to ensure consistent quality of their injection molded parts. A sound quality program demonstrates that the molder monitors the effectiveness of their supply chain and demonstrates traceability related to regulations of materials and finished goods – enabling the production of medical products with consistency and repeatability.

ProMed’s Commitment to Quality

Partnering with an experienced injection molder like ProMed allows for the necessary production planning needed to meet all of the necessary regulatory, quality, and commercial standards. ProMed understands the importance of quality to your success. That is why quality is embraced every step of the way to create a product that will assure confidence in your products. Our work force is highly specialized in the manufacturing and quality requirements of medical products, much of which go into the long-term implantable market space. Every employee at ProMed is trained with the idea that quality is their most important responsibility.

Our equipment utilizes cost-effective, high-end molding technology to keep operating expenses down while producing parts with an extremely high level of precision and repeatability. Our tools are designed and manufactured to exacting tolerances. Expert toolmakers use high-tech design software and machining centers to produce molds that are durable and dimensionally repeatable from cavity-to-cavity, part-to-part!

We are an approved, certified supplier to many of the top medical device manufacturers in the world. All ProMed facilities go through routine audits by our ISO registrars and customers. Below is a sample of the standards we meet.

 

·      ISO:13485 – 2016 certified ·      ISO Class 7 Clean Room
·      ISO:17025 certified ·      REACH and ROHS compliant
·      FDA 21 CFR 820, 210/211 and part 4 compliant

ProMed’s 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.


Liquid Silicone Rubber

2019 & Beyond - What the LSR Material Market is Predicting

What is LSR?

Liquid Silicone Rubber (LSR) is aplatinum-cured elastomer that can be injected into a mold cavity to manufacture a part. LSR starts out as a 2-part liquid that cures into a solid form when mixed together. LSR is a versatile rubber in the elastomer industry and has a wide range of end-uses from medical devices to consumer goods to electronics to automotive. For example, LSR can be found in catheters, stents, windshield wiper blades, LED headlights, adhesives, microwaves, seals, and grommets.

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.

LSR has many attractive properties such as durability, low viscosity, chemical and temperature resistance, and flexibility, but 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.

LSR MarketPredictions through 2026

The LSR market is forecasted to steadily grow over the next 5-10 years and some sources estimate the global market for LSR will reach a valuation of US$ 7.9 billion by 2026. Additionally, the global LSR market is forecasted to have a Compound Annual Growth Rate, or CAGR, of 4.5% through 2026 which is considered moderate growth. (Note: CAGR is considered a good measure of an investment’s return over time compared to annual return figures that do not account for compounding).

This growth is attributed to several factors. First, enhancements to the physical properties of LSR is expected to allow LSR to continue to replace traditional rubber materials in various applications. Additionally, injection molding of LSR produces consistent parts, cycle to cycle, and is a low-cost option for part manufacturing; for these reasons, LSR injection molding continues to expand into new markets, driving the continued demand for LSR.

LSR growth is also attributed to several societal factors such as growing demand for LSR in equipment and surgical tools necessary to treat the rising geriatric population and the growing awareness about health concerns, accelerated demand within the electronics industry due to continued innovation and technology advancements, as well as global urbanization and standard of living increases.  The industries that are expected to demonstrate the highest demand for LSR are medical and automotive.

Among the various grades of LSR, medical grade is expected to continue to hold the largest global market share. Moreover, stricter regulations and compliances of many specifications for use in medical products are further projected to drive the overall market growth. In addition, replacement of latex with LSR in impactable devices is expected to provide new opportunities for LSR applications.

The LSR market is segmented across five regions: Asia Pacific, North America, Europe, Latin America, and the Middle East & Africa (MEA). Among these, Asia Pacific is expected to continue as the largest marketplace for LSR, estimated at 35% of global market share, due to demand for the product in electrical & electronics and medical applications. Other factors contributing to the market growth are the easy access to raw material and favorable government policies. China and India are the strongest country-based markets in the Asia-Pacific region since distribution networks are well established and many LSR players have a strong presence in these countries.

The North America market, the United States in particular, is also forecasted to grow due to increasing usage of LSR in the electronics industry as well asincreased expenditures on, and technological advances of, medical devices. Europe is also forecasted to grow LSR demand due to growing demand for lightweight material in the automobile sector. Additionally, multinational companies are focusing on collaboration,and perhaps even joint ventures, with distributors to achieve sustainable growth. The Latin America and MEA regions are also expected to observe LSR market growth due to increasing demand for growing usage of LSR in consumer goods and healthcare industries.

The LSR market faces a couple key challenges including minimization of the carbon footprint associated with LSR production, and improvement of LSR’s reusability and disposability. But even with these challenges, the LSR market is forecasted to have moderate growth across all 5 regions as LSR usage expands to even more markets.

Contact ProMed today at 763-331-3800 to find a solution to your medical molding needs.


silicon injection molding

The Future of 3D Printing with Medical Biomaterials Such as Silicone

3D printing, also referred to as “additive manufacturing”, is not only a game-changing innovation for rapid prototyping, but is also poised to transform many industries in the years to come, healthcare and medical devices included.

As 3D printing continues to advance and mature, novel materials, processes, and applications applicable to medical biomaterials such as silicone will continue to deliver better patient outcomes for existing treatments, while opening the doors to entirely new ones.

New Medical 3D Printing Materials

From diagnostics to growing tissues for research, recent research in new 3D printing materials illustrate the promise of this technology.

For instance, engineers at the University of Illinois have designed a 3D printer which can make structures out of isomalt, the same sugar alcohol throat lozenges are made of. The fact that isomalt dissolves in water makes it a great material out of which to fabricate scaffolding for growing tissues, providing researchers the ability to study them in three dimensions.

Another innovation, from engineers at Rutgers University-New Brunswick, involves movement rather than stationary structures. A team there has produced a smart gel which can be 3D printed into shapes which move and grab objects in salt water when an electric field is applied. Potential applications for this hydrogel-based material range from providing the “muscle” for artificial hearts to drug delivery.

Even living cells—bacterial ones, at least—can now be 3D printed. A group of MIT engineers have created an ink containing genetically programmed bacterial cells and figured out a way to 3D print it. Like the smart gel from Rutgers, this living ink is based on hydrogel, which provides the bacteria an aqueous environment they can live in. The live bacteria cells are genetically programmed to react to different stimuli, such as the presence of specific substances. The MIT team demonstrated their innovation by creating a “living tattoo”: a patch made of this new ink whose different segments are programmed to detect a different chemical and change color.

Meanwhile, silicone continues to gain adoption for medical 3D printing. The additive manufacturer Carbon recently announced the release of a biocompatible silicone resin. In addition to being biocompatible, this new silicone resin is soft and tear-resistant as well—perfect for medical wearables.

Novel Biomaterial 3D Printing Processes

Hydrogels also play an important role in the development of new biomaterial 3D printing processes. One recent example of this is a novel stereolithography 3D printing method developed at UCLA, which currently uses four different bio-inks. Up to now, biomaterial stereolithography has been limited to just a single material. Central to this new technique is a custom mircofluidics chip with multiple inlets, one for each biomaterial to be printed.

For practical medical applications, 3D printing of medical biomaterials requires the purity and cleanliness required of all other fabrication technologies used for medical devices. Recent material and process 3D printing breakthroughs in the lab are great, but patients require (and deserve) additive manufacturing solutions which reliably produce devices which are free from contamination, something currently not possible with many existing 3D printing systems.

One startup looking to change that is Kumovis, which has recently developed a 3D printer for the engineering-grade polymer PEEK (a popular choice for high-strength implants). Kumovis effectively designed a miniature cleanroom into their 3D printer, protecting the implants from being contaminated with foreign particles during printing.

Biomaterial 3D Printing Applications

Ultimately, clinical applications are the end goal of all this material research and invention of new additive manufacturing techniques. Additive manufacturing is already having a positive impact in patients’ lives, and as more advances cross over from laboratories to clinical trials and regulatory approval, biomaterial 3D printing will become even more commonplace.

Additive manufacturing is a great process for producing small batches of custom parts. When medical 3D printing is combined with imaging technologies such as CT scans, implants and other medical devices can be custom made for a patient, leading to better device performance and lower risks of complications.

A recent study involving heart valves shows how CT scanning, digital modeling, and 3D printing can work together to reduce mortality rates for patients who have a high risk of developing a paravavular leak (PVL) after a transcatheter aortic valve replacement (TAVR). The lead author of the study, Dr. Sergey Gurevich remarked on the how this technology successfully prevented PVLs, “We are very encouraged to see such positive outcomes for the feasibility of 3D printing in patients with heart valve disease. These patients are at a high risk of developing a leak after TAVR, and anything we can do to identify and prevent these leaks from happening is certainly helpful.”

Presently, 3D printing of medical biomaterials is a hotbed of experimentation and advances in printing materials and processes. Regardless of what breakthroughs actually break through to clinical use, medical device OEMs can remain confident that ProMed will stay on the leading edge of biomaterial 3D printing.


Medical Grade Silicones

The Use of Medical Grade Silicones for Prosthetics

From restoring mobility to re-enabling everyday tasks, prosthetics elevate a patient’s quality of life. Whether they take the form of artificial limbs or simpler, more cosmetic devices, prosthesis place many demands on the materials used to make them.

For instance, by their nature, prosthetics must be in contact with at least some part of the patient’s body for prolonged periods. This in turn requires that those areas of the prosthetic in contact with the patient be made of a highly biocompatible material. Likewise, the liner sections of prosthetic limbs which must fit against the residual limb must be able to absorb the shocks of regular use, including the dynamic forces of activities such as running.

Silicones possess many properties which are needed for prosthetics: a vast selection of available duromers (from soft to stiff), chemical inertness, biocompatibility, durability, the ability to bind to various substrates (often without a primer), and a wide useful temperature range. These are all reasons why liners for artificial limbs are commonly made from silicone.

Medical grade silicones have the added advantage of the exceptional purity and cleanliness needed for safe long-term contact with the patient’s body, allowing them to be used in a multitude of prosthetic applications.

For almost any prosthetic application, there is a silicone type or fabrication method that can meet the need. The low viscosity of Liquid Silicone Rubber (LSR) is perfect for quickly filling injection molds. On the other hand, High Consistency Rubber (HCR) can be a great choice for parts made by transfer molding, compression molding, or extrusion. Medical grade Room Temperature Vulcanizing (RTV) silicone rubbers are also utilized in prosthetics.

Prosthetics and the Medical Grade Silicone Market

The size and growth of prosthetic segment of the medical grade silicone market will continue to employ all these forms of medical grade silicones. According to a market report published last year, prosthetic applications of medical grade silicone accounted for almost $121 million, which the report attributes to “diversified segmentation, including orthopedic implants, cardiovascular implants, stents, structural cardiac implants, spinal implants, neurostimulators, ophthalmic implants, dental implants, and face and breast implants.” That same report projects that number to grow too due to “innovative technological innovations and increasing FDA approvals” for clinical trials, among other factors.

This growth can already be seen in the continued release of new medical grade silicones for prosthetic and orthopedic applications. Wacker’s new medical grade RTV silicones are just one example. The new low temperature curing medical grade LSRs released by Dow Corning are another. The release of materials like these enable prosthetic designers and manufactures to produce prosthetics which are more durable, higher performing, dependable, comfortable, and safer.

The quality, purity, and cleanliness of medical grade silicones set them apart from other silicone grades, and make them uniquely suitable for prosthetics, as we explained above. Increasing commercial availability and competition among silicone suppliers should make these medial grade materials more affordable.

New Uses

More affordable material choices will be key in opening the door to new prosthetic options, and ultimately better patient outcomes. This is just as true for temporary prosthesis as it is for permanent prosthesis like artificial limbs. For example, high temperature vulcanizing medical grade silicone is already being used for temporary cranial prosthesis. Among the benefits of using this medical grade silicone over acrylic and metal are:

  • Improved cosmetic appearance
  • time saved during cranioplasty surgery
  • Adequate bone closure due to the silicone’s flexibility

Medical grade silicone’s purity, sterility, biocompatibility, lack of magnetism, durability, transparency to x-rays, and low thermal conductivity make it an excellent material for cranial prosthesis, and prosthetic devices in general.

Medical grade silicones are widely used for prosthetics, and that as new applications emerge, their usage will only grow. No matter how the industry unfolds, ProMed has you covered—from injection molding LSR to compression molding HCR, from artificial limbs to implants.


Medical-Grade Liquid Silicone Rubber

The Importance of Medical-Grade Liquid Silicone Rubber

Medical-grade Liquid Silicone Rubber (LSR) is becoming increasingly crucial to the medical device industry, as the combination of the general benefits of medical-grade silicones combine with LSR’s unique advantages for medical device OEMs. As new medical-grade LSR materials become commercially available, more reliable, better performing, and more affordable medical devices will be within reach of patients.

Medical-Grade Silicones

Silicone has long been a popular material for medical device manufacturers due to its durability, ease of molding by many methods, wide useful temperature range, chemical inertness, high tensile strength, vast range of available durometers, biocompatibility, and compatibility with many sterilization methods.

Medical-grade silicones add the benefits of stringent purity and biocompatibility testing, making them suitable for use in long-term implants.

One application where medical-grade silicones really shine is drug-eluting implantable devices. Before molding, silicones can be compounded with active pharmaceutical ingredients (APIs) such as cancer drugs or hormones which can can then be steadily released into a targeted area of the patient’s body over time once that molded implant is inserted.

Drug-eluting implants are able to maintain the desired level of the API in the patient much more consistently and over a longer period of time than both pills and injections. Also, since the implant can usually be inserted near the targeted organ or tissue, lower total amounts of API are needed because that API doesn’t need to spread throughout the entire body before reaching the targeted area.

As a result, the level of the API in the patient’s body remains inside the therapeutic window (the range of concentrations between too low to be effective and high enough to be toxic) for a much longer duration.

As we’ll see shortly, medical-grade LSR is a great material for making drug-eluting implants, due to its processing advantages.

The Advantages of LSR

LSR is a type of silicone material which starts out as two separate liquid components which are then precisely mixed together before injection into a heated mold, where the silicone elastomer becomes solid (i.e. vulcanizes).

The low viscosity of LSR makes it a great silicone material for making parts via injection molding, since the LSR can easily flow into and completely fill molds with relatively low injection pressures, even those with intricate and small features.

LSR’s inherent compatibility with injection molding results in the cost-effective, repeatable, and scalable manufacture of silicone parts—including medical devices and their components.

Furthermore, the temperatures needed to vulcanize LSR are usually low enough that significant degradation of compounded substances like APIs can be avoided. Thus, medical-grade LSR an excellent material for drug-eluting implants.

Implantables aren’t the only medical device application suitable for medical-grade LSR. Wearables (such as heart rate and activity monitors), respiratory products, linings for prosthetic limbs, and other devices which must stay in prolonged physical contact with a patient all benefit from medical-grade LSR’s outstanding biocompatibility and purity.

The Future of Medical-Grade LSRs

New and improved medical devices originate from innovations in both design and materials. As new medical-grade LSRs continue to be released on the market, the medical device industry as a whole will make steady advances and improve the length and quality of life of patients around the world.

Dow Corning’s release earlier this year of two new LSRs is a prime example. These new LSR materials cure quickly at low temperatures, don’t require a primer for binding to many substrates (including polyester), need low injection pressures, and boast broad process windows.

These are all significant features for the medical device industry for the following reasons:

  • Fast cure times at low vulcanizing temperatures enable silicone injection molders to shorten the total molding cycle time (which in turn can greatly reduce the cost per molded part), and consume less energy for each silicone part since the mold will not need to heated as much as other LSRs may require. Both of these result in reduce production costs for medical-grade LSR products, and consequently, lower costs for the patients and insurance companies to purchase these products.
  • The lower injection pressures of these LSRs will allow silicone medical device manufacturers to utilize more economical, lower tonnage injection presses. These LSRs’ broad process windows can enable lower defect and scrap rates, due to a more forgiving molding process.

New medical-grade LSRs, like these from Dow Corning, will help the whole medical device supply chain ramp up production capacity to meet global demand.

At ProMed, we combine industry-leading medical-grade LSR expertise with the latest developments in silicone materials and technology. From helping OEMs incorporate the latest medical-grade LSR formulations into their designs to delivering rapid silicone prototypes, we serve as a premier silicone molding contract manufacturer for medical device OEMs. Contact us to find out how we can help you.


Silicone Molded Components

4 Steps for Confirming Bond the Strength in Silicone Overmolded Medical Devices

While silicone is great for making medical devices and their parts, the material is also a great choice for areas of those parts or devices which need the properties that only a silicone can provide, whether it’s excellent compression set, softness, or chemical inertness. Overmolding provides medical device designers the flexibility of incorporating silicone’s advantages where they’d have the most benefit. From handles and grips to gaskets and catheters, silicone overmolding is used for many medical device applications.

A strong bond between the overmolded silicone and the base material (called the substrate), is crucial to the finished device’s performance and safety. When the silicone and substrate fail to adequately jointogether, the two materials can become detached, resulting in premature failure of the device. Frequently for medical devices, this bond not only must withstand the stresses of normal use, but also the temperatures, chemical agents, and radiation used for sterilization.

Tips for Good Overmolding Bonds

Because silicone overmolding has been used extensively for medical devices, the industry has learned several tips to help ensure a good bond between the silicone and substrate.

Keep the surface of the substrate clean and dry. Contaminants such as oils and mold release agents can thwart both the chemical and mechanical bonding of the silicone to the base metal or plastic. Some contaminants can even hinder the curing of the silicone.

Design features into the substrate for mechanical bonding. Loops and other such features in the substrate allow the silicone to flow into the substrate and mechanically lock into it. This is especially true if Liquid Silicone Rubber (LSR) is used to overmold.

When necessary, treat the substrate’s surface with primers or plasma. Sometimes the silicone and substrate are incompatible when it comes to chemical bonding. Care should be taken with using primers for medical devices, since the primer can impact the biocompatibility of the finished device. That’s why plasma surface treatment is preferred, as that process doesn’t introduce new substances.

How to Confirm Bond Strength

The above tips and other industry best practices provide great guidance, but testing is what ultimately reveals the true bond strength of an overmolded part. The regulatory requirements for medical devices require such testing to provide the proof required for FDA approval, not to mention the continued testing of production samples for ongoing Quality Assurance (QA).

Medical device OEMs should follow these steps in order to verify that their chosen combination of substrate, silicone material, surface treatment (if any), and molding process can produce adequate bond strengths:

  1) Have the molder create sample plaques with your substrate material, surface treatment (or primer), and silicone material. This should be done early in the development process, before a final material selection has been made and molds have been machined. An OEM may need to experiment with several different silicone formulations or substrate surface treatments before one is found which not only delivers the required bond strength, but also meets all the other design requirements (e.g. durometer and biocompatibility).

 2) Perform thorough destructive testing on the sample plaques. The best way to measure the strength of a bond between two different materials is to measure the amount and type of stress needed to make that bond fail. Thus, destructive testing covering tensile strength, lap shear, cyclic fatigue, compression, and torsion is a must. Many OEMs may find it helpful to consult the ASTM D429 standard, which covers methods for testing the adhesion of rubber to rigid substrates.

The resulting test data will definitely guide an OEM toward making the best material and surface treatment decisions for the medical device.

3) Produce device prototypes and subject them to the same destructive testing as well. This can be done both on early stage prototypes and on production equivalent parts.

4) Once production has started, incorporate bond strength testing. This can be done in a number of ways, from quick and simple hand stripping or peeling tests to much more quantified testing using machines. Either way, bond strength testing should only be performed on a subset of parts, due to the destructive nature of the testing.

At ProMed, our passion and expertise is silicone molding for medical devices—and that includes overmolding. From selecting the best silicone formulation for a substrate to optimizing molding parameters for a strong, durable bond, we produce exceptional overmolding results for medical device OEMs. Contact us and let us know how we can help you.


Wearable Medical Product

The Wearable Medical Product Market & the Benefits of LSR for Speed-to-Market

The global market for wearable medical products is rapidly growing, driven by both demographics and maturing technology. Fortunately for the industry, the liquid silicone rubber (LSR) market is uniquely positioned to grow right along with the increasing demand for these devices. LSR’s advantages will also help wearable medical devices clear the regulatory, technological, and economic hurdles presently holding back their adoption.

Demographics, Diabetes, and Global Demand

According to one recent forecast, the global market for wearable medical devices is projected to increase at a Compound Annual Growth Rate (CAGR) of 18% over the period from 2017 to 2023. In terms of dollars, this market was worth $2 billion in 2016, with the forecast predicting triple that number by 2023.

Wearable medical devices are used to monitor health parameters including blood pressure, heart rate, and blood glucose level. Those last two items are a major driver of the adoption of medical wearables, as an aging global population and other trends are increasing the prevalence of diabetes. In fact, the International Diabetes Federation notes that incidence of diabetes in the global adult population is growing at an annual rate of 8.4%, with 625 million diabetic adults worldwide by 2040. In the US, over 29 million people are diabetic according to the CDC, which in turn is propelling the demand in North America of wearable diabetes care products.

Shrinking Components

As the worldwide demand for wearable medical devices grows, the technology needed for them has continued to shrink. Computing chips, sensors, and wireless components continue to miniaturize, and this has opened the door to constant clinical monitoring at the health care facility, at home, or even outdoors.

Potential Shackles Impacting Medical Wearables

Despite these technological and global health trends, there are several factors hindering the increased adoption of wearable medical devices. Two of the most central are:

Proving the reliability of wearable medical products. The bar for wearable medical devices when it comes to dependable operation is significantly higher than it is for consumer wearables like FitBits. As Mike Bolduc, C&K’s the Global Marketing Manager for Industrial and Medical Segments explained last year for Medical Product Outsourcing, “Whereas consumer fitness trackers can help users stay in shape, medical wearables can detect life-threatening conditions, collect biometric data to help with patient diagnoses, and even administer medicine to alleviate pain. Thus, consumer wearables can be considered a superfluous indulgence while medical wearables are more mission-critical”.

With the wearable medical device industry still relatively young, there a lot of either clinical data or industry experience to confidently conclude medical wearables are as dependable as they will need to be.

Regulatory and compliance hurdles. In that same article, Bolduc also points out that medical devices must meet “meet stringent safety and accuracy standards” and that wearable medical products need to “be validated by U.S. Food and Drug Administration and ISO standards”. Wearable medical products used clinically to monitor blood glucose levels or measure irregular heartbeats will be given the same regulatory scrutiny as other diagnostic devices. Likewise, a wearable which administers a pharmaceutical agent will have to meet the same quality standards as other drug delivery products.

How LSR Can Benefit Wearable Medical Products

LSR can help the wearable medical device industry clear these two key hurdles and shorten the time to market for new medical wearables, which will be necessary to meet the projected global demand for these devices.

Medical-grade silicone is an excellent material for wearable medical product components. It boasts excellent biocompatibility, durability, availability in a wide selection of durometers, and compatibility with a vast range of sterilization and disinfection methods. All of these features make it a great choice for wearables which must be in prolonged contact with the patient, and durable enough to operate reliably wherever the patient goes. That proven durability can benefit the reliability of a whole wearable device, and thus help that device pass the required reliability testing.

High-quality precision LSR prototypes can be made economically and quickly when choosing LSR as a material.  This expediency results in more rapid design iterations, more thorough evaluation and testing of the design, and earlier completion of product development phases.

There is another way LSR can increase the speed-to-market of wearable medical products. LSR is compatible with injection molding, wearable medical product OEMs who incorporate it will more quickly ramp up production inventory to levels needed for meeting the worldwide demand expected in the upcoming years.

Besides accelerating the market debut of new medical wearables, LSR opens entirely new doors for them. For instance, the advent of electrically-conductive medical-grade LSRs makes possible wearable medical devices which provide external stimulation to nerves or muscles—a potentially huge untapped market. Such therapeutic devices which combine conductive silicones with wearable medical devices can deliver safe and non-invasive treatment for millions of patients.

Finally, medical-grade LSR is widely available and has a proven track record of safe, reliable, use in a plethora of medical devices, including long-term implantables. The medical device industry’s—not to mention that of regulators—experience with LSR means one less material in an OEMs’ supply chain to worry about meeting the stringent FDA requirements for clinical use.

As medical device companies rush to address the global need for medical wearables, LSR can provide the solutions OEMs need to satisfy the regulatory and other hurdles this new and rapidly expanding market is up against.

As a silicone-focused contract manufacturer of medical devices, ProMed has the LSR design and molding expertise needed to launch help these companies find those solutions. Contact us today and find out how we can help you.