High Density Rubber Products - Made in the U.S.A.
CRS offers an array of high-performance parts and solutions for shooting ranges, aerospace, defense, energy, and other industrial markets. Products include high-density rubber, hybrid compounds, custom designs, and modified components.
Not all rubber is made equal, and this is especially true in the "ballistic rubber" application.
As you read this, you will gain knowledge regarding production and materials used to build ballistic rubber products. The shooting range industry has coined the term "ballistic rubber" to describe rubber used in ballistic ranges. What most companies won't tell you is there is a significant difference in quality used in ballistic rubber. You may think rubber is rubber, but the type and quality of rubber products are determined by compound structure.
This range of physical property's includes: hardness, tensile strength, tensile modulus, elongation, resilience, tear resistance, abrasion resistance, and more. The structure of the product can affect a product's ability to self-heal, keep form, handle temperature change, handle projectiles, and product life.
Importance of physical properties and rubber:
Tensile strength is the amount of force needed to tear apart rubber. It is also known as ultimate tensile strength, and it is measured in pounds per square inch. The tensile strength is a critical factor for producers and buyers because it signifies the point of failure.
Tensile modulus is the force required for producing elongation percentage in a rubber. This may sound similar to tensile strength; however, the properties are different. Harder rubber usually has a higher tensile modulus, meaning it is more resilient.
Elongation is defined as the percentage increase, or strain, in the original length of a rubber sample when applying tensile force. Certain elastomers tend to stretch more compared to others. Natural rubber can extend more than other rubber compounds.
Resilience, also known as rebound, is the ability of rubber to return to its original size or shape after bending, such as contact with a bullet. Resilience is critical when handling rounds because a moving object is penetrating a stationary surface.
Tear resistance is the resistance of an elastomer after a cut or nick when tension is applied. This property also called tear strength and is measured in kilonewtons per meter or pound-force per inch. Tear resistance is considered when selecting a compound for edge trim that will be in contact with sharp objects such as bullets.
Abrasion resistance is the resistance of rubber to abrasion by scraping or rubbing. Abrasion-resistant rubber is used in high impact industrial applications like the mining industry.
Now that you are familiar with the physical property terminology, you can understand how physical properties are pertinent to the performance of a product.
Is all ballistic rubber made equal?
The simple answer to the question is NO. Not all rubber is made equal. In most cases, the quality of low-cost parts barely passes as rubber. If they don't list rubber physical properties, you are probably looking at cold-pressed tire scrap and glue.
You need to consider the product's material and production process. The production process is how you can accurately and precisely ensure all of the valuable traits are built into the product. To build an efficient product, you need to design and use a compound like styrene-butadiene rubber, a material that holds the right balance of physical properties for the application.
What's the difference between high-quality materials and low-quality materials?
Time and pressure are vital elements when deploying a product that will perform and last. Many of the company's on the market that sell "ballistic rubber" actually build parts by using rubber granule and glue binder. This is a low-cost method, and the result is a lightweight, less dense product. Manufacturers who use crumb rubber and binder usually do not even know the specifics of the material that is in their product; however they still call it "ballistic rubber." Cold-pressed rubber is a porous product, meaning it will soak up liquid.
The bottom line is that the compound and building process is important. Being able to manufacture parts with the desired property, time, and pressure creates solid products. The density of our rubber is the element that extends the life of the product. Specifically designed products like the CRS ballistic rubber parts are 33% denser than the competition. High-quality parts are built with an uncured natural rubber compound + time and pressure molding. The rubber is then cured with 100% consistency, which results in parts that last 2-3 times longer, control rounds, self-heal, and can handle weather extremes.
Different types of Ballistic Rubber:
Cold Pressed (Common "Ballistic Rubber")
A common form of ballistic rubber is cold-pressed rubber, which is a low cost and quality process. The manufacturing process of cold-pressed rubber starts in the cement mixer. The rubber arrives in finely ground up chunks, branded recycled (contains cured and uncured), some of the mixes are vulcanized some are not. The material will only keep its shape by using an active enough binder. A binder is essentially glue. There is no scientific method to this production process, and it is challenging to implement desired physical properties.
Typically in a lower quality product, every 200 pounds of the mixture has less than 10% real natural rubber (natural rubber is very expensive). The rest could be any mixture of recycled rubber. In low-cost parts, they dump a pre-measured combination binder and a flame-resistant chemical with the rubber. This is turned in the mixer for a short amount of time then dumped out on the mold. It is finally set with a heavy steel weight on top to press it overnight into the final shape.
Long Lasting Ballistic Rubber (High Performing Rubber Compound)
The process of building high-performance ballistic rubber is a systematic and tedious process. The process begins with only natural uncured rubber. This rubber comes from a scientific compound that is designed for the application. The rubber goes through a quality control process, then is heat pressed and then cured. This process is guided by temperature, time, and weight specifics. Once finished, the parts are vulcanized. The particulars of this process are important to ensure a high density per square inch. The process enhances the desired qualities of strength, elasticity, and durability.
To the left is two photos of the different types of materials. On the right is a common form of ballistic rubber. The left is the long-lasting ballistic rubber process. The physical appearance between the two is obvious.
It is essential to understand the types of ballistic rubber. The production process will determine the lifespan and breakdown of the product. Lower quality less dense products will usually be easy to spot because they look like rubber chipboard. Low-cost production often will have an "approximate" weight due to inconsistency in density. This inconsistency usually will result in reduced performance and minimal longevity. Glue binder products will always have the bulletin board look because they lack the systematic compound and time and heat pressure combination.
Long-lasting ballistic rubber comes from specific materials like styrene-butadiene rubber (SBR), and natural rubbers are ideal for impact. These materials have excellent abrasion resistance and excellent aging stability when protected by additives. The styrene/butadiene ratio influences the properties of the polymer. The right modification of physical properties like tensile strength, ultimate elongation, modulus, coefficient of friction, and elongation will translate into enhancing the desired qualities of strength, elasticity, and durability.
To conclude, there is a vast difference in ballistic rubber products on the market. CRS products are scientifically formulated compounds that perform. Most lower quality rubber products will cost the consumer more money in the long run due to rapid breakdown. That's why we encourage potential customers to test products before they buy them. In the end, our parts save time and money due to the compound and production process.