Healthcare


Plastics are playing an ever-increasing key role in healthcare applications.

Conventus Polymers focuses on customers, applications, and original equipment manufacturers (OEMs) who require highly engineered resins or compounds. We can assist with metal to plastic conversion, provide design guidance, and help customers find the right material for their applications. We offer a large portfolio of ISO10993 approved resins along with ISO 13845 custom compounding capability for custom color applications. Applications generally fall into the following categories :

Medical Lighting | Medical Trays | Animal Research and Care | Pharmaceutical Manufacturing | Surgical Instruments | Respiratory and Sleep Therapy | Orthopedics | Monitoring and Diagnostics.

Drivers include improved accessibility to treatment and an aging baby boomer population. A worldwide growth of middle class populations is also fueling a demand for innovation in medical devices. Conventus Polymers has become a reliable and consistent source for high performance materials for medical manufacturers due to our high performance portfolio, as well as our understanding of key demands in the medical market. Such demands include:

Agency Regulations such as ISO10993, USP VI, and FDA
Chemical Resistance to sterilization techniques including EtO, gamma, E-beam, and Autoclave.
Chemical Resistance to aggressive cleaners used in hospitals to minimize infections.

Below we will provide an overview of each of these areas and the respective relevance of our products .

Regulations:

Biocompatibility measures a material’s (e.g. plastic) compatibility with human tissue or physiology. It provides information on whether a plastic provokes unwanted responses such as an allergic reaction. Both ISO 10993 and USP try to biologically qualify a material.

Food Drug Administration (FDA) approval is commonly asked for, but generally as a secondary requirement. Food contact is for any substance that is intended for use as a component of materials used in the manufacturing, packaging, transporting, or holding of food. ISO10993 and USP are more stringent tests.

Generally, Medical Products require ISO10993 approval USP VI and FDA documentation for medical products are useful as well.

The international standard ISO 10993 is a certification for which medical device manufacturers must gain approval for devices that come into direct body contact,. While certification procedure is performed on the final product (device), the standard can also be used to evaluate plastic resin or semi-finished parts. Resins that carry this approval provide their end customers a higher level of confidence that their final molded or machined part will be approved by the ISO standard.


The ISO 10993 standard is divided into sections 1-20 ranging from the preparation of samples and evaluation of tests through the chemical characterization of materials to immuno-toxicological tests. The requirements imposed by ISO 10993 depend not only on the type of medical product , but also on several factors including:

  • -the place of use (tissue, skin, mucous membrane, etc).
  • -intended function (contact with body surface, internal body contact, implantable)
  • -period of use (< 24 hours, < 30 days, unlimited)

USP Class VI is sometimes referenced in regulatory requirements. The United States Pharmacopeia Convention (USP) is an organization that evaluates packaging used for pharmaceutical products. However, for medical products, the role of the USP is to provide a supportive documentation for approval. Most of the biological risk assessment of the material in USP can be derived from similar tests in ISO10993. Therefore, in most new applications, ISO10993 supersedes USP. The USP <87> and <88> can be consulted for the assessment of components / products made of plastic. The USP <88> divides products into categories I-VI, whereby products of category VI have to comply with the most stringent requirements, and consequently have to complete extensive testing. This evaluates the biocompatibility of a plastic by testing acute systemic toxicity, irritation and also includes a short-term implant test.

FDA compliance is frequently used in the field of medical technology to provide users with important risk assessment information . However, it is not a requirement for the use of materials in the medical or pharmaceutical field. The American Food and Drug Administration (FDA) assess the suitability of materials for direct and indirect contact with food. Raw materials, additives and properties of plastics are specified by the FDA in the “Code of Federal Regulations” CFR 21. Materials that meet the relevant requirements are regarded as FDA compliant.

Conventus Polymers offers several materials that are ISO10993 and FDA compliant. These include our Paryls PPSU, Paryls PSU, PC, PC/ABS, and SPS product lines. On specialty compounded grades, such as those materials that use glass, carbon, or other additives, we can issue documentation stating that the constituents use ISO10993 approved components or FDA constituents if ISO10993 is not readily available. These are called our low extractable grades


Chemical Resistance to Cleaners that reduce hospital infection

Today, hospital associated infections account for $6.5B/year in North America. Sunch infections are the most frequent adverse event in healthcare delivery worldwide (World Health Organization, WHO ). In developing nations, 7% of patients will acquire an infection in the hospital.

One response to hospital infections has been the increased cleansing of equipment and caregivers. .

The Conventus Polymers portfolio focuses on addressing these needs with a variety of solutions including PSU, and PPSU portfolio of resins. All of these materials offer good to excellent impact, with an increasing level of chemical resistance, far superior to Polycarbonate or PC/ABS.

The biggest challenge in this market is assisting customers with incumbent tooling designed for PC/ABS. For many years, PC/ABS was a suitable material to use in many diagnostic devices due to its good processibility, high impact characteristic, and colorability. In the last ten years, the number of new disinfectant cleaners commercially available has increased dramatically, many of which aggressively attack polycarbonate (PC). Customers have looked for new materials that offer similar material shrinkage characteristics to Polycarbonate. An additional challenge is with diagnostic equipment applications that require a greater underwriter laboratories (UL) flame rating such as UL94 V0.

Several of the polymers that Conventus Polymers offers have been tested against common disinfectant cleaners.

Sterilization Resistance

According to the Centers for Disease Control and Prevention (CDC), “Sterilization means the use of a physical or chemical procedure to destroy all microbial life, including highly resistant bacterial endospores.” Sterilization is different than disinfection. Disinfection results in the destruction of specific pathogenic microorganisms. Disinfection is faster and less expensive. Some hospitals use high-level disinfection for medical instruments. An object should be disinfected or sterilized depending on its use. Critical objects require sterilization before use such as those that enter sterile tissue or implanted devices.

Sterilization falls into 3 categories including high temperature/pressure sterilization, chemical sterilization, and radiation sterilization.

Steam autoclave is the oldest, safest, and most cost effective method of sterilization in the medical equipment industry. The steam reaches 121-148°C (250-300°F) in the pressure chamber at 15 P.S.I. The sterilization period can range from 10 to60 minutes.

The common types of steam sterilization cycles are gravity-displacement, which removes air from the chamber by gravity displacement as steam-entering chamber exerts pressure on air; and the pre-vacuum cycle, which removes air by a vacuum pump while steam is simultaneously injected into the chamber. The following summarizes the processing parameters for each cycle:

Configuration

Temperature

Time

Gravity Displacement

121 – 123C

15-30 Minutes

132 – 135C

10-25 Minutes

Pre-Vacuum

132 – 135C

3-4 Minutes


In the steam autoclave process, microorganisms are killed by heat, and this is accelerated by the addition of moisture. Steam by itself is not sufficient for sterilization, and greater than atmospheric pressure is needed to increase the temperature of steam to destroy microbial life.

Steam autoclave is used mostly for surgical instruments. This method is not well suited for heat-sensitive materials and instruments. For such instruments alternative sterilization methods are needed such as chemical sterilization and radiation sterilization, which allow heat and moisture-sensitive materials to be sterilized.

Conventus Polymers offers a robust portfolio of materials that tolerate repeated sterilization cycles. Our featured product is Paryls PSU and Paryls PPSU, which offer over 100 and 1000 steam sterilization cycle respectively. For opaque applications that require high strength, our Xarec* Syndiotactic Polystyrene product offers over 750 cycles with virtually no changes in mechanical properties with a Delta E color shift under 1.

Ethylene Oxide gas was introduced in the 1950’s.It is an effective, low- temperature chemical sterilization method. It takes longer than steam sterilization- typically 16-18 hours for a complete cycle. Temperatures reached during sterilization are usually in the range of 50-60°C.

Ethylene oxide (EtO) is a chemical agent that kills microorganisms, including spores. EtO gas must have direct contact with microorganisms on the items to be sterilized. Due to EtO being highly flammable and explosive in air, it must be used in an explosion-proof sterilizing chamber in a controlled environment.

EtO is used to sterilize items that are heat or moisture sensitive. A disadvantage of EtO gas is that it can leave toxic residues on sterilized items, and it possesses several physical and health hazards to personnel and patients that merit special attention.

Since EtO poses several health hazards, there are currently two alternative technologies that are currently available: Sterrad, a plasma phase hydrogen peroxide-based sterilizing agent and Steris, a peracetic acid based technology.

Low temperature plasma sterilization was introduced to fill the gap between autoclave: high temperature steam sterilization (safest, fastest, and least expensive) and EtO gas sterilization, which leaves toxic residuals. In this process, hydrogen peroxide is activated to create a reactive plasma or vapor.

The Sterrad system is a Hydrogen Peroxide Gas Plasma Sterilization system with an operating temperature range of 45-50°C. Operating cycle times range from 45-70 minutes, depending on size of system.

This sterilization system uses a combination of hydrogen peroxide and low temperature gas plasma to quickly sterilize most medical instruments and materials without leaving any toxic residues. Hydrogen peroxide is a known anti-microbial agent that is capable of inactivating resistant bacterial spores. Sterilization by this method occurs in a low moisture environment.

This system is best suited to sterilize heat sensitive medical equipment such as endoscopic equipment.

The Steris System 1 is another, more common, low temperature sterile processing system. It uses the Steris 20 Sterilant Concentrate that combines peracetic acid, a chemical biocidal agent, and a proprietary anti-corrosion formulation to kill micro- organisms at low temperature.[7] The process is achieved at a temperature of 50-56°C.

Only immersible instruments can be used with this method. Only a few instruments can be sterilized at one time. No packaging required.

Gamma Sterilization

Sterilizingby gamma radiation is a sophisticated process requiring knowledge of the kinetics of microbial inactivation, polymer selection and process controls. Gamma Irradiation possesses excellent penetrative capability. The unit of absorption is the Gray, expressed in kGy. This absorbed dose is impacted by product density, pack size, dose rate, exposure time and to some degree by part design.

The main disadvantage associated with gamma irradiation concerns the potentially damaging effects of gamma rays on the product,


Electron Beam

The e-beam process achieves lethality using ionizing radiation, which acts on cellular constituents in a similar manner to Gamma radiation.
E-beam sterilization has a number of advantages over gamma irradiation including its ability to be switched on and off at will, greater product compatibility, and potentially high throughput. Disadvantages include higher machine complexity and poor material penetration. In addition, validation and control of this technology is more demanding.

Dry Heat

Dry Heat Sterilization is generally conducted at 160C-170C for a minimum of two hours. Specific exposures are dictated by bioburden concentrations and temperature tolerances of the products. Appropriate conditions will enable complete sterilization of the material. The equipment required is forced-air type ovens with temperature monitoring capabilities. This type of sterilization is highly dependent on the temperature resistance of the polymer.

Conventus Polymers portfolio of glass filled PPA, SPS, PSU,PPSU, and PEEK that do well in these environments.


Examples of our solutions:

Medical Lighting

The generation and management of heat from light sources is important in areas such as surgical suites. Handles, housings, and reflectors often require Underwriters Labratories flammability approval.

Conventus Polymers has successfully helped a leading medical company replace Ultem PEI, with Syndiotactic Polystyrene (SPS) in a halogen light handle application. The customer required a material that could withstand high temperatures generated by the lamp, was colorable, offered UL94 V0 rating, and was comparable shrinkage to Ultem PEI.

Medical Trays

Trays are most frequently used for transporting and sterilizing instruments. Common sterilization procedures include steam sterilization at 121°C or 134°C . In addition to many autoclave cycles (100-1000 cycles) these components must be very impact resistant in case of accidental drop, and colorable. Conventus Polymers offers Paryls Polyphenylsulfone in natural or colored resin. Our F1350 PPSU grade is the highest flowing PPSU grade commercially available around the globe, offering outstanding flow for large parts where Radel R5000 and R5800 cannot perform. Moreover, our grade offers less than truckload quantities for smaller batch runs in custom color. Our F1350 PPSU grade offers ISO10993 compliance, FDA compliance, BPA-Free certification, as well as REACH and RoHS. A mid-cap sized dental components manufacturer selected ParylsF1350 PPSU resin where their tray required high flow for their thin wall design features.

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Animal Research and Care

Various bins, cages, and feeding devices are used in laboratories across the country for healthcare research. These cages are most frequently used for mice or rats. While some applications exist for low sterilization cycles, they generally require hundreds of sterilization cycles. Conventus Polymers offer both PSU with mold release and PPSU to help customers in this market. We also offer high viscosity grades without mold release for blow molding.

Surgical Instruments

These applications can include access devices such as Trocars, Retractors, Speculums, staplers, and forceps, to name a few. In addition to biocompatibility and sterilization compatibility these devices are often hand or powered instruments that require high strength and stiffness. Some of these applications have mating components that wear against one another. Conventus Polymers offers a full portfolio of reinforced thermoplastics that are biocompatible and extremely strong . We can achieve these using base materials such as PEI, PPSU, PC, PPA, PEEK , and strength enhancing fillers such as glass or carbon fiber.

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For any questions related to our products or services in healthcare applications, please feel free to contact us at customerservice@conventuspolymers.com or info@conventuspolymers.com.

Conventus Polymers is a plastics distribution company based out of Parsippany, NJ that offers high performance and ultra performance materials in North America, China, and Europe. We help original equipment manufacturers select the right material for their application and sell resin to vendors in their supply chain.

Global plastics distributor and technical sales agency combining the best characteristics of resin manufacturers and distributors including material selection, application development, project risk mitigation, inventory management, and competitive pricing.

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