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Gore, Precision Associates, and Parker Join the Fight Against Covid-19

What Gore is doing to help

As the COVID-19 pandemic continues to impact communities around the world, Gore is working hard to identify ways in which they can apply their materials science expertise and production capabilities to help during this time of need.

Several initiatives are underway that bring together the knowledge, skills and capabilities from across Gore.

As an immediate and initial response to the personal protective equipment (PPE) shortage, Gore rapidly engineered prototype reusable mask covers to supplement clinicians’ primary face masks.

The effort went from a product concept to prototypes in less than one week. Gore currently has prototypes being evaluated at a limited number of U.S. facilities in COVID-19 outbreak hot spots.

Additionally, by providing their customers and other manufacturing companies with Gore's highly specialized component materials, they can use them to produce a variety of finished PPE items, such as:

• Protective medical gowns, using fabrics laminates from Gore's current inventory
• Universal filter cartridge prototypes for fixed masks that incorporate Gore's filtration materials intended to provide N95 particulate protection,
• Disposable N95 respirators, using Gore's filtration laminates

It is through these collaborations with those who have the technical capabilities and production capacity needed to produce the finished goods in volume that together, Gore and its partners truly are improving life.

Gore has even donated medical supplies and protective gear to healthcare workers in the communities in which their facilities are stationed. They've also extended a hand to provide engineering and prototyping support to address other urgent equipment needs at local hospitals.

What Precision Associates is doing to help

Precision Associates, Inc. has ramped up its production of several essential rubber components for ventilator manufacturer Ventec Life Systems. Ventec recently announced plans to partner with GM to increase the output of these crucial units in response to the COVID-19 pandemic.

Critical patients suffering from the virus have difficulty breathing and require ventilator assistance for life support. GM is now transforming one of its factories to begin assembling ventilators for Ventec in early April.

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Jarrod Cohen, marketing communications manager, Chomerics Divison.

Electrically conductive elastomers are elastomeric polymers filled with metal particles. They can be grouped by filler type and elastomer type. Then within each of these classes, there are standard materials and specialty materials.

Parker Chomerics manufacturers electrically conductive elastomers in gasket form, also known as EMI elastomer gaskets, under the CHO-SEAL brand. We won't get so much into gasket configurations and dimensions here, we'll just stick to classes of materials. So what is available? Let’s find out.

Conductive elastomers are metallic particle filled elastomeric polymers, the particles giving the shielding performance and the polymer making them “rubber." There are many materials within this generic material type, but we'll focus on the below.

Particle fillers

Setting up the grades of conductive elastomers by filler types involves six different particles:

Three types of elastomer material

• Silicone
  A polymer that has a large temperature range especially on the low end down to -55F. It is a very soft material with a low compression set.
• Fluorosilicone
  Close to silicone, but will not swell and degrade when exposed to solvents, fuels hydraulic fluids and other organic fluids. Although slightly harder than silicone, it is still relatively soft with low compression set properties.
• Ethylene propylene diene monomer (EPDM)
  Does not have the temperature range nor the softness of silicone, but is resistant to highly chlorinated solvents used for compliance with NBC decontamination and is only used for applications with those needs.

All of these materials are cured or cross linked when the gasket is made. The cure either happens with heat or atmospheric moisture.

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by William Pomeroy, applications engineer, Parker O-Ring & Engineered Seals Division.

As mentioned in part one of Parker's seal failure blog series, O-ring and seal failures are often due to a combination of failure modes, making root cause difficult to uncover. It's important to gather hardware information, how the seal is installed, application conditions, and how long a seal was in service before starting the failure analysis process. In part 1, compression set, extrusion and nibbling, and spiral failure were discussed. In part 2 of Parker's series, they will review four other common failure modes to familiarize yourself with before diagnosing a potential seal failure in your application.

Rapid Gas Decompression

Rapid gas decompression (commonly called RGD, or sometimes explosive decompression (ED)) is a failure mode that is the result of gas that has permeated into a seal that quickly exits the seal cross section, causing damage.

Detection of this failure mode can be difficult, as the damage does not always show on the exterior.  When the damage is visible, it can look like air bubbles on out the outside, or perhaps a fissure that has propagated to the surface.  The damage may also be hidden under the surface.  If the seal is cut for a cross section inspection, RGD damage will look like fissures in the seal that may or may not propagate all the way to the surface.

Parker’s guidance as to how to avoid this failure mode is: 1) Keep the depressurization rate lower than 200 psi per minute.  If this cannot be achieved, they would suggest 2) RGD resistant materials.  Parker offers these RGD resistant options from the HNBR, FKM, EPDM, and FFKM polymer families.

Abrasion

Abrasion damage is the result of the seal rubbing against a bore or shaft, resulting in a reduction of cross sectional thickness due to wear.  As the seal wears, it has the potential to lose compression on the mating surface.  This wear is compounded by the fact that dynamic applications already have lower compression recommendations.

To reduce risk for this failure mode, it requires consideration during design and seal selection.  The surface finish and concentricity of the hardware will be very important considerations.  A smooth surface results in less friction (suggest 8 to 16 RMS), which in turn results in less wear.  Increasing the durometer of the seal material helps resist wear, and there are also internally lubricated materials that could be employed.  If the application is high temperature, one should consider the impacts of thermal expansion on the elastomer being used.  The thermal expansion increases contact pressure, which would increase friction / wear.

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Nathan Wells, application engineer, Engineered Polymer Systems Division.

So, you’ve unboxed the shiny new Parker seals you ordered – now what?  Installing seals for the first time can be challenging without the right know-how and tools. In this article we’ll discuss best practices for seal installation in linear fluid power systems, and how to design your system to make seal installation fast and damage-free.

SEAL GROOVE STYLES

First, let’s look at three common groove styles:

•    Closed
•    Stepped, and
•    Open (or two-piece)

Closed groove

The closed seal groove fully encapsulates the seal and is the most common style used (see Figure 1).

Closed grooves are simple to machine and offer the best support for seals. Since seals in this configuration are surrounded by solid metal, without a well-developed process, installation can be challenging. Rod seals need to be folded to fit into internal (throat) grooves and piston seals must be stretched over the outside of the piston.

Notice how both designs shown in Fig. 2 and Fig. 3 utilize static seals (turquoise colored seal) on the opposing side of the dynamic, primary seals. Therefore, installation in either instance requires techniques and tools for both rod and piston seals.

Stepped groove

Typically utilized to ease seal installation, stepped grooves feature a reduced diameter on the low-pressure side of the seal as shown in Fig. 4 and Fig. 5.

As shown, the “step” is just wide enough to hold the seal in place as the rod or piston strokes back and forth. This way, seals don’t have to be folded or stretched nearly as much when installing. This design works well for single seals only holding pressure from one direction, like Parker FlexiSeals™.

When using multiple seals stacked in series or in systems with bi-directional pressure, a closed or two-piece groove is needed for support on both sides.

Open and two-piece grooves

Open or two-piece grooves are used when the seal is either too small to be stretched or folded into a closed groove, or if it’s made of a material that doesn’t spring back after flexing.

Figures 6 and 7 show two examples of open grooves. Figure 6 uses a washer and a snap ring to hold the seal in place. Figure 7 uses a bolt-on cap. These groove designs can be used for bi-directional seals, too. As you can see, open grooves cost more to produce but seal installation is a snap.

Open grooves also make removing the seal much easier – useful in systems which require periodic seal replacement.

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by William Pomeroy, applications engineer, Parker O-Ring & Engineered Seals Division.

There are many situations where an O-Ring may not

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Thorsten Kleinert, Business Unit Manager, Composite Sealing Systems Engineered Materials Group, Europe.

When

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Dr. Stefan Reichle, Market Unit Manager, Engineered Materials Group Europe.

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Ben Nudelman, Market Development Engineer, Chomerics Division.

Form-in-place EMI gaskets, also known as FIP EMI gaskets, is

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Fred Fisher, Technical

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Nathaniel Reis,