Understanding the Evolution of Our Silicone Product Line

Silicone products are often a go-to for a variety of applications within many different markets such as military, aerospace, electronics, transportation, LED lighting, EVs, rail and more!

Have you ever wondered how our Norseal? Silicone product line evolved to serve the most challenging applications?

To help us better understand this evolution, we connected with Sr. Applications Engineer, Scott Yudkin, who has been our go-to product expert since 1983.

Q&A with Scott

Can you tell us more about the Norseal? product line and how it began?

It all started with acquiring the New Haven Connecticut plant, formerly called Connecticut Hard Rubber (CHR). The company was founded in 1921 and Saint-Gobain? acquired it in 1999, bringing its materials, some key pieces of equipment and recognized brand under the Tape Solutions product portfolio. These products are still recognized worldwide for their customizability, OEM approval and ability to meet exceptional quality standards.

If you ask anyone who buys or converts sheet silicone rubber, the name CHR? will come up!

The product line evolved from solid hard rubber into silicone sponge products. This is where we excel. Silicone has many benefits, and our goal was to maximize these benefits. Silicone is the only material that can satisfy high-temperature resistance, with a low-compression set and a non-stick surface.

Due to continued research and development and our ongoing commitment to meeting customer needs, we kept expanding and increasing the silicone sponge line. We even developed new ways to prepare silicone materials and add adhesives. Hence — the SNS product line. Our most popular SNS product is our acrylic adhesive. It provides a much longer shelf life. But, more on specific products later.

The full line of Norseal? Silicone Sponges has been specially designed for a variety of gasketing, cushioning, insulating and protecting applications. Our closed-cell sponges have benefits such as thermal stability over wide temperature ranges, excellent compression set resistance, ozone and UV resistance.

These closed cell products have lower material outgassing for cleaner operations in critical applications. This is because they have been subjected to the most extreme post-cure cycle processes in the industry.

Why is it important for these closed-cell silicone products to undergo a proprietary post-cure process?

This needs to be done for the material to pass low outgassing requirements. Non-post-cured silicone rubber is known to have high out-gassing, which causes contamination issues in electronics and safety concerns in the aerospace industry.

On a similar note, why is low compression set important?

When it comes to gasketing, compression set is often a key concern. When we test for compression set, the lower number is better. This means that the material can easily “bounce back” after it has been put under pressure. “Bounce back” capability means the gasket can return to its original thickness and not create sealing issues after pressure has been applied.

Can you tell us about how these products evolved into the various markets they serve today?

Even before Saint-Gobain acquired CHR, they were making gaskets for military and commercial applications. Based on customer requirements such as higher temperature resistance, these materials evolved and improved. By 1960, CHR was already a leader in airframe seals and other silicone rubber products for the aviation industry. And, when America got into the space race, CHR was right there, using the unique properties of silicone to meet the severe temperature extremes of outer space.

From this, we got into the commercial space, military aircraft space, and so on. Silicone sponge rubber has always found wide applications as high-performing gaskets, thermal insulation, vibration-dampening mounds and press pads.

Now, probably the largest product line we have is general industrial. These products are a catch-all and do extremely well in even the most unique applications.

Some customers refer to the brand COHRlastic, does this brand still exist?

This brand name itself has been dissolved, but the products still exist. The COHRlastic brand name essentially changed to the Norseal brand name. Norseal now covers all of the Tape Solutions elastomer products including silicones, polyurethanes, PVC, and extrusions.

When looking at the diverse Norseal product line, do you have a go-to product that serves as your “conversation starter,” meaning it has general purpose applications that could fit most gasketing needs?

I would say that my “conversation starter” product is our Norseal R10470 Medium. It is a specification grade closed-cell silicone sponge. It can be utilized in extreme temperature ranges, has excellent resistance to weather conditions, compression set resistance, electrical strength and non-stick properties. This material is flexible and compressible. It can serve as a general purpose silicone sponge in a variety of different gasketing applications.

What if a customer needs the added benefit of flame retardancy?

In that case, we can offer our standard R10460 medium which has an improved temperature rating. It is an Underwriters Lab listed product. We sell a lot of R10460 because it meets the flame retardant specs for most aerospace applications. It is a tried and true product and has been around for quite a while.

But, we also make R10400, which has UL94-V0 rating, the highest UL flame rating.

So, this is something that we would look at with the customer and evaluate which product to suggest based on specific needs. I learned that even if the engineer doesn't need it, they generally want to be on the safe side and select the product with the V0 rating. V0 is the best flame rating you can get.

Do we offer any thermally conductive closed-cell silicone sponge rubber?

Absolutely — this is one of the things that we do that many others don’t. If a customer needs thermal conductivity, electrical isolation, compression set resistance and the general properties of a gasket, we offer R10404. This product is a go-to when customers need to transfer heat and in applications such as T-shirt decals, press or coffee cup transfer machines because it gives the ability to pass the heat through the sponge. This product is also a superior choice in battery pack gap filling.

What if a customer requires a product that is resistant to solvents or high-end oils?

Naturally, silicones are not resistant to these materials. However, in applications such as aircraft engines that get warm and are exposed to hydraulic fluid, customers need a gasket that will not be broken down by these fluids. For these types of applications, we have Norseal R10490 medium silicone sponge rubber, a fluorosilicone closed-cell sponge. It is resistant to these types of materials and therefore can be utilized in military aircrafts, missiles and downhole drilling oil applications.

Tell us more about the Norseal F-12, F-15, F-20 product line.

These are our silicone foam products. In fact, Norseal F-15 is our newest product in this line. It was created when customers requested a product that was in between the F-12 and F-20 in terms of its density. All three products provide excellent flame retardance with low toxicity and smoke generation. They are conformable and comprised of expanded cellular material. These foams have low compression set and are non-corrosive. They can be used in hostile environmental conditions and with metals. Their standard color is grey but other color options such as white or black are available.

These silicone foams and their SNS counterparts are light weight, have low compression set and are flame retardant. They are ideal for applications within industrial, transportation, military, medical and other markets due to their longevity and durability.

In terms of all these products and offerings, what do you think is the biggest value add for customers?

We love to design materials with and for our customers. This is why we are the Saint-Gobain Tape Solutions group. If a customer comes to us with a specific challenge, we want to be a partner in helping to achieve specific requirements and objectives.

For me, personally, as an engineer, I love talking to different engineering teams to determine what solutions I could recommend serving them for years to come. Based on the specification, flame retardant, low compression set, solvent resistant or thermally conductive grade, I am happy to explain our product line differences and find a perfect solution — together.

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