SBR Gaskets

When Should You Ask for Butyl Rubber?

Synthetic rubber materials like SBR were developed to increase the supply and compensate for the limitations of natural rubber. For most of these man-made elastomers, while they excel in some regards, they fall short in others. Poor weather and ozone resistance are two of the biggest weaknesses.

Butyl rubber is a synthetic material that plugs this gap. Suitable for a range of sealing applications, it also has great damping and permeability characteristics. Here’s a closer look.

Butyl Rubber Basics

As polymerized at the factory, butyl rubber is white or colorless. It’s usually blended with carbon black to make it black, although other colors are possible.

Butyl rubber is much more dense than other synthetic rubbers, so it’s heavier, but this means it’s a very good absorber of vibration. The same chemical structure that creates high density also renders it impermeable to liquids and gases. (Other synthetic rubber materials like SBR and EPDM have a degree of gas permeability.)

Butyl rubber is on the softer side, (It’s available with Shore A ratings of 40 to 90 but is usually around 65), and has a working temperature range of -40 to 285°F. It’s also resistant to water, dilute acids, and animal and vegetable oils.

Limitations of Butyl Rubber

Butyl rubber will tend to take a compression set, limiting its use as a gasket in applications where the joint will be opened up periodically. Its abrasion resistance is only moderate and it is attacked by hydrocarbon fuels and oils.

Good Applications for Butyl Rubber

The biggest market for butyl rubber is automobile tires, where it’s used as a liner material. In terms of seals and gaskets, applications include:

  • Tank liners
  • Pond liners
  • Cushioning
  • Shock absorbers
  • Flange and full-face gaskets, especially for outdoor applications

Butyl Rubber Sheet Cut to Shape

Ask for butyl rubber when you need impermeability, weather-resistance or cushioning. Hennig Gasket & Seals has butyl rubber sheet form and a range of thicknesses. We can die, flash or waterjet cut it to the exact size and shape you need. Contact us to discuss your needs and get a quote.

SBR Gasket Material: Don’t Overthink It

You have a lot of options when you’re looking for gasket material, and some of them can get very expensive. While it may be tempting to select a highly engineered polymer with exceptional temperature and chemical resistance properties, ask whether that’s what you really need. In many cases, you may be better off using Styrene Butadiene Rubber, better known as SBR Gasket Material.

SBR Gasket Material:  An Alternative to Natural Rubber Gasket Material

SBR red rubber gasket material was developed during WWII. At the time most rubber came from Asia, and as more rubber was needed for tires, scientists were searching for an alternative. Styrene-Butadiene Rubber, derived from the Buna polymer developed in Germany in 1929, met that need.

Natural rubber has many things in its favor as a material for gaskets as well as tires. It’s soft and elastic, with good compression recovery. That lets it conform to uneven flange faces and expand to fill the gaps. However, it doesn’t fair well outdoors and its temperature range and chemical resistance are so-so at best. SBR improves on natural rubber with a wider temperature range and better weathering and chemical resistance properties. It’s also a very economical choice.

Don’t Over-Engineer the Application

SBR Gasket Material isn’t the highest performing gasket material available, but for many applications, it’s good enough. Use it when temperatures won’t go above 170° F or below -30° F and for sealing against air, water and steam. Use it when flange faces may be uneven, and use it in applications that need good impact strength and abrasion resistance.

Don’t use SBR gasket material to seal against hydraulic fluid, solvents or oils as this will make it swell excessively. Neither is it a good choice for outdoor applications with exposure to UV and/or ozone.

Many alternative gasket materials provide higher performance but at a higher price. Rather than considering what might happen in-service, focus on what’s known for sure. You may find that SBR is up to the task and will save you some money. For more information, discuss your application with the specialists at Hennig Gasket & Seals.

SBR Rubber Sheet – When (and when not) to Use

It’s hardly surprising the SBR Rubber Sheet (red rubber) is one of the most widely used gasket materials. Firm and smooth, it conforms readily to mating surfaces. Good tensile strength and abrasion resistance ensure durability, providing it’s not used in the wrong places. Here’s what you should know about using red rubber gasket material.

SBR Rubber Sheet:  A Proven Elastomer

Red rubber is produced by blending Styrene Butadiene Rubber (SBR) with natural rubber. SBR was one of the first synthetic rubber materials, produced by polymerizing styrene and butadiene in a roughly 3:1 ratio. Invented early in 20th Century, production increased rapidly during WWII as supply chain challenges limited availability of natural rubber. SBR’s strengths include resistance to cracking, abrasion resistance and low cost. Unlike natural rubber, it hardens with age.

When natural rubber is added to SBR the result is a red-colored elastomer with the best characteristics of each. Several grades are available with varying properties. Hardness is in the range 75 – 80D on the Shore A scale. (For more information, refer to “Understanding Gasket Material Hardness”.) The main limitations of red rubber are a temperature range limited to -20 to 160°F and swelling when exposed to hydrocarbons.

Applications to Avoid with SBR Rubber Sheet

Red rubber is not suitable for use with oils and fuels like gasoline and diesel. It also offers poor resistance to chemicals, solvents and hydraulic oils. In addition, it is degraded by ozone, so electrical, (especially high voltage,) applications are best avoided.

Good Applications for SBR Rubber Sheet

Red rubber gaskets perform well when sealing against air and water, both hot and cold. Saturated steam is also usually sealed effectively by red rubber.

SBR Rubber Sheet:  Often the Right Choice

Many sealing and gasketing applications don’t need high-temperature capability or high levels of chemical resistance. When that’s the case red rubber is often a better choice than newer and more exotic materials. Produced in a range of sheet thicknesses, it lends itself to die as well as water jet cutting and can be a very cost-effective choice. For more information call or email the specialists at Hennig Gasket.

Properties of Neoprene Gasket Material

Neoprene, which is also known as “polychloroprene,” is a type of synthetic rubber produced by the polymerization of chloroprene. Neoprene gasket material has become very common due to the fact that it resists the likes of ozone, sunlight, oxidation and many petroleum derivatives. Additionally, neoprene is characterized as being weather-, combustion-, water- and chemical-resistant. As you can see, it’s popular because it is resistant to many types of damages. What’s more, it’s also resistant to damage from twisting and flexing.

Here’s a closer look at the properties of neoprene so you can judge whether or not it’s a good material for your application:

  • Stretch and cushioning properties: Neoprene is elastic and form-fitting, able to conform to various sizes and shapes. It’s also cushioning, able to absorb shock.
  • Various grades available: From cloth inserted neoprene, which is reinforced with nylon for additional stability, to flame retardant neoprene, which passes a variety of flammability specifications, there are several grades available to suit any application. Other popular grades include commercial, FDA approved, diaphragm and high tensile strength.
  • General gauge thicknesses vary in size from 3/32-inch up to 2 inches.
  • Hardness ratings vary from 40 to 80.
  • Plate finish.
  • Neoprene can withstand temperatures ranging from -20 degrees F to 180 degrees F.
  • Tensile strength ranges from 900 to 1,000 PSI.
  • Elongation ranges from 350% to 400%.
  • Finally, widths are 36 inches, 48 inches or 72 inches.
  • Pressure sensitive adhesive, or PSA, are available upon request.
  • We fabricate neoprene gaskets through proven manufacturing processes that include waterjet cutting, flash cutting and die cutting.

One other neat feature about neoprene is that it’s impermeable, meaning that it can work as a tight barrier to prevent the escaping of gases or liquids.

For more information on the neoprene material and neoprene gaskets, and to speak with someone about placing an order, contact us today.