by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

State of the Worldwide Plastics Industry

State of the Worldwide Plastics Industry

The markets for plastics are extremely diverse, including textiles, alternative energy, automotive, fluid handling, life sciences, agricultural, medical, pharmaceutical, packaging and many more. In recent months, there has been a significant increase in the demand for polymer-based products related to PPE for medical personnel. But who is producing these plastics, and what industries are driving this demand?

Global Plastic Production

It isn’t surprising that, according to data compiled by Statista, 350 million metric tons of plastics were produced globally in 2018 alone. In that same year, data shows that China was responsible for close to 30% of the production followed by NAFTA (North American Free Trade Agreement, composed of Mexico, Canada, and the United States) and Europe, both responsible for 18%. In terms of production per capita, NAFTA countries are in the lead followed by Europe and Japan. When it comes to nations however, Japan produces more plastic per capita than any other country.

Infographic: Developed Nations Produce the Most Plastic | Statista
Source:
Statista, Developed Nations that Produce the Most Plastic

Growing Market for Plastics

There is no doubt in anyone’s mind that the market is growing for plastics: experts estimate that worldwide plastic production will reach 24 billion metric tons by 2050, and Grandview Research reported that the plastics market at the end of 2019 was valued at $568.7 billion.

Major Industries Drive the Need for Plastics 

The major industries supporting this demand for plastics are the automotive, construction, electrical, and electronics industries, although with the COVID-19 pandemic it is also possible that there will be a significant rise in demand for plastics related to the medical industry. 

Automotive applications drive much of the demand for plastics as manufacturers seek to achieve better fuel efficiency through the use of polymers with high strength to weight and strength to stiffness ratios. In the construction industry, plastics are being used for pipes, windows, flooring, and cables as well as in the equipment used, ranging from handheld nail guns to the hydraulic excavators used to dig the foundation. 

In electronics and electrical systems, polymers are used in the connectors that ensure clean signals are transmitted between components. They also provide protection and insulation for even the IC chips used in devices, and secure everything from tiny transistor chips to large smart televisions in durable packaging.

Of course, packaging is another major source of demand for plastics, accounting for up to 35% of the market. Food, beverages, medications, and consumer products depend heavily on plastics. And there is a wide variety of plastics used for packaging, including HDPE, LDPE, PET, PVC, and polystyrene.

Wide Applications of Plastics

However, these are not the only industries where plastics are critical; plastics have become almost ubiquitous in our daily lives. For example, we know that plastics are used extensively in the textile industry, and many polymers we see used in applications such as pipes (PVC), gears and bearings (Nylon) can also be found in clothing, although in a different grade and form. In alternative energy, lightweight but strong plastic components contribute to efficiency and sustainability. 

For medical and pharmaceutical applications, polymers are used for everything from medical cabinets to hold supplies, to PPE equipment to protect medical professionals working at the frontlines, to seals for ventilators and other respiratory equipment, to implantables that support human health and well-being.

Conclusion

Plastics have become a critical factor in many industries. Whether it is recyclable HDPE packaging or high strength, high speed industrial bearings, polymers are a part of our every days lives, and according to economists the market will only continue to grow and expand in the near term.

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Medical Engineering in the Age of COVID-19

Medical Engineering in the Age of COVID-19

Due to the COVID-19 pandemic, there has been an increase in worldwide demand for thermal scanners, respirators, and ventilators. This has been accompanied by an increased need for medical disposables such as gloves, respirators, medical masks, face shields, single-use syringes, and drapes. As a result, medical engineering and manufacturing both have temporarily shifted their focus and the results are fascinating.

3D printed hand sanitizer clasp

Additive Manufacturing

Shortages of some items have led to innovative design and manufacturing, much of it involving additive manufacturing using polymer materials. For example, Old Dominion University has been 3D printing masks and mask components made from PLA and designed so that they can be easily sterilized and reused. Europe has already seen companies in the 3D printing industry volunteer their equipment and knowledge to aid in manufacturing replacement parts for critical equipment such as oxygen and respirator valves, and many other countries are doing the same thing. 

Ventilator Designs

Many countries, including the United States, are worried about a potentially deadly shortage of ventilators. Various technology firms worldwide such as Nvidia are working to design critical care devices that can be produced both quickly and inexpensively. NASA has been given permission to start production of their emergency use ventilator that can be manufactured and built quickly, with the only drawback being its limited lifespan. 

In addition, ventilator manufacturers such as Medtronic have ramped up production and publicly shared their design specifications for one of their ventilator models so others can help meet this critical need.

Innovation

Engineers all over the world are looking for ways to make the treatment of COVID-19 patients easier and safer for medical personnel. For example, engineers in the Boston area have teamed up local doctors to develop a 3D printed bracket that will hold the tube and respirator hookup together in ventilator patients. The goal is to prevent release of the COVID-19 virus into air when these connections come undone, as they often do. 

Others at Boston University are looking at polymer nasal swabs that will do a better job of collecting mucus for COVID-19 tests, which could increase the reliability of testing and help with testing material shortages. At the Oxford Institute of Biomedical Engineering, engineers are leveraging wearable technology to allow nurses to track the vitals of COVID-19 patients who are not on ventilators and thus must remain mobile to recover.

Conclusion

The COVID-19 pandemic has changed how much of the world lives, and has affected a shift in the focus of many engineers. Trademarks of this shift include the use of additive manufacturing for PPE and replacement parts for life-saving equipment, a fresh look at ventilator designs that emphasizes manufacturability and availability, and the birth of innovative approaches to medical issues related to the pandemic. And, in this midst of this, companies like Advanced EMC are still working hard to make available the right polymer seals and bearings needed for medical equipment. 

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Polymers for Implantable Devices

Polymers for Implantable Devices

Due to the growing demand for implantable devices, there is also a growing demand for approved materials for use in manufacturing these devices. Polymers are an increasingly important material for use in medical implantable devices, with UHMW PE and PEEK being the most popular.

The Implantable Device Market

According to the FDA, implants are defined as devices intended to stay within the body for more than 30 days. Implantable devices are an ever growing market that was already worth $96.6 billion back in 2018 and expected to reach $143.3 Billion by 2024. These implantable devices include joint replacements, deep brain neurostimulators, pacemakers, insulin pumps, gastric stimulators, and more. 

Requirements for Implantable Device Materials

When it comes to materials, the implantable device market is divided into metals, ceramics, polymers, and biologics. For implant materials to be considered safe, they must remain stable in the presence of body fluids, not elicit an adverse response from the host, and, if applicable, meet requirements related to strength, stiffness, and performance. Long-term long-term biostability and biocompatibility are also key, as well as compatibility with medical imaging methods. For load bearing implants such as those used in hip replacements, how a polymer responds to wear can also be critical.

Implantable Polymers

The two most widely used implantable polymers are FDA approved grades of UHMW PE (Ultra-High Molecular Weight Polyethylene) and PEEK (Polyether ether ketone), although there are other polymers in use.

UHMW PE for Implantables

UHMW PE has been in use for orthopedic applications for over 30 years. UHMW PE can be found in joint replacements and spinal disc implants, where properties such as a low coefficient of friction, excellent fatigue resistance, and good impact strength are vital. Its primary drawback is a lack of strength, which is why it is not used in applications that involve significant load bearing. Note that UHMW PE can be machined or molded, but cannot be injection molded.

PEEK for Implantables

Implantable PEEK offers some properties similar to UHMW PE, including good impact strength and a low coefficient of friction. It is also self-lubricating, possesses a high compression strength, and offers good wear resistance. As a matrix material combined with carbon and graphite fibers, it can be customized to offer improved properties related to strength, stiffness, and dimensional stability. Unlike UHMW PE, PEEK is more versatile when it comes to manufacturing: it can be machined, molded, extruded, and even powder coated. One of PEEK’s more recent applications is implantable spinal cages, which requires significant load bearing capacity.

Other Implantable Polymers

Other polymers for implantables include PSU (Polysulfone), which is known for its toughness, dimensional stability, and moldability. PSU can be found in implantable devices such as shunts and access ports. Another polymer is PPSU (Polyphenylsulfone), which combines toughness with transparency and is often used as a coating for wires and leads. Both of these polymers also provide excellent tensile strength and biocompatibility.

Conclusion

Materials for use in implantable devices must be stringent requirements, and for good reason. There are a host of issues, such as biocompatibility, biostability, wear properties, friction, stiffness, and strength, that all depend heavy on the application. However, there are polymers such as UHMW PE and PEEK whose performance and safety have been well established.

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Spring-Energized Seals for Cryogenic Environments

Spring-Energized Seals for Cryogenic Environments

Cryogenic environments deal with temperatures that range from below freezing all the way down to absolute zero, which is -460° F (or -273° C). Trying to seal fluids and gases at those types of extreme temperatures, but one of the most effective sealing solutions for cryogenic environments is the use of a spring-energized seal. 

Spring-Energized Seals

Energized seals are often used in situations where standard seal designs simply cannot provide the performance needed. And when cryogenic temperatures are involved, finding a reliable seal design is extremely challenging — and failure to do so can be fatal. 

How Spring-Energized Seals Work

A spring-energized seal includes a metallic spring (usually in the form of a coil) that applies a near constant load throughout the circumference of the seal. That load enables the lip to remain in contact with the mating surface, even during pressure and temperature variations as well as dimensional changes. In addition, the spring helps the seal compensate for eccentricity, misalignment, and wear. More importantly in cryogenic environments, energized seals can compensate for dimensional changes related to temperature variations.

The result of using a spring energizer is a highly reliable, almost leak-proof seal. This can be especially important when there are safety and environmental regulations are involved, as is often the case when cryogenic materials are in use. In addition, spring-energized seals can be used with both static and dynamic applications, with dynamic including rotary, linear, and oscillating motion (as well as any combination of these).

There are several different types of spring-energizers, from simple elastomeric o-rings and familiar coil springs to V springs, helical flat springs, and cantilevered finger springs. For cryogenic applications, V ribbon springs are typically used. They are found in the harshest of applications, including vacuum pressures and/or cryogenic temperatures.

 

For cryogenic applications, the spring lip is often made of PTFE and the energizing spring is made of metal. Typical spring metals include 17-7 precipitation hardening stainless steel or 301/304 stainless steel, Elgiloy, Hastelloy, Inconel, or 316 stainless steel.

Cryogenic Applications for Spring-Energized Seals 

Spring-energized seals are successfully being used for a wide in a variety of cryogenic applications:

  • Magnetic resonance imaging (MRI)
  • Biosystems
  • LNG fueling systems and compressors
  • Pharmaceutical and medical research
  • Rocket propulsion filling systems
  • Scientific instrumentation
  • Specialty gas manufacturing
  • Infrared telescopes
  • Radio astronomy
  • Satellite tracking systems

Typical fluids and gases involved include LOX (Liquid Oxygen), liquid Helium, liquid Hydrogen, liquid Xenon, refrigerants, coolants, liquid methane, LNG (Liquid Natural Gas), and LPG (Liquid Petroleum Gas). More specific examples include LAR (Liquid Argon) used in surgical environments, LN2 (Liquid N2) used in environmental test chambers, LCO2 (Liquid CO2) for cleaning and deburring. 

Conclusion

While finding a solution for a cryogenic sealing application can be challenging, it is certainly far from impossible. Spring-energized seals can provide durable, reliable sealing power in even the harshest conditions — including extremely low temperatures. By combining the right type of coil, seal geometry, and materials, you can engineer the right spring for applications ranging from rocket development to bioengineering.

by Sara McCaslin, PhD Sara McCaslin, PhD No Comments

Canted Coil Springs: Benefits for Medical Applications

What is a Canted Coil Spring?

Canted coil springs (also known as cant or slant coil springs) are not your typical spring, and this becomes obvious when you take a look at the three different types of tasks they support:

  • Acting as a mechanical connector
  • Energizing seals for better performance
  • Providing EMI/RFI shielding
  • Serving as a multiple contact point conductor

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PEEK vs PPS: Which Do You Need?

When high-temperature performance is not a major concern, PPS can serve as a viable and economical alternative to PEEK. In this blog post, you will learn how these high performance engineering polymers are similar and where they differ (besides the price).

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2019 EPA Changes to Refrigerants: Seal Material Considerations – Part 2

 

In our last post on the subject of the 2019 EPA changes to refrigerants, we pointed out that the HVAC and refrigeration industries faced three specific design challenges as traditional refrigerants are phased out starting in 2019: efficiency, chemical compatibility with seals, and reducing leaks. Fortunately, there are seal solutions and polymer materials that can address all three of these issues — which happens to the topic of this blog post.

Commercial HVAC unitSource

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