Rubber Compound Manufacturing
A rubber compound is a mixture made from one or more base polymers, fillers, and other chemicals. The result is a finished rubber material. Rubber compounds can be formulated to address a number of concerns and necessary strengths for the material’s desired application.
A rubber compound manufacturer will likely add reinforcing agents to an elastomer, including carbon black, vulcanizing agents, anti-oxidants, and even colored pigments. Rubber compounds can be customized in a plethora of ways to fit the exact needs and specifications of the material.
The most important consideration for creating a compound is the compound type. Thermoplastic polyurethane (TPU) and Thermoplastic elastomers (TPE) are two of the most common compound types.
Below, we’ll discuss the manufacturing process for several common rubber compounds, as well the benefits of rubber compounding in general.
Benefits of Rubber Compounding
Rubber and latex compounding, in the simplest sense, is the process of adding chemicals and additives to a base polymer. These additives customize the rubber for its intended use. Rubber compounds are used for late rubber molding compounds, tubing, wires and cables, and more.
Why is compounding useful? It allows companies to create custom materials specifically for their products. Innovative compounds can change the way a product functions. For example, natural rubber latex is extremely susceptible to temperature, becoming sticky and gooey in heat and brittle in the cold. In order to create tires, companies need to vulcanize the rubber by creating a compound.
Compounding can also be used to reduce the cost of producing a rubber material. For example, certain additives extend the rubber without taking away from certain qualities or performance. That way, expensive rubber can be stretched a longer way for a lower cost per unit.
What are the most common rubber fillers?
Carbon black is by far the most common reinforcing filler in the rubber industry. Carbon black is derived from soot. It increases rubber’s tensile strength and abrasion resistance.
Apart from carbon black, rubber and latex compound manufacturers may use anhydrous aluminum silicates, other polymers, recycled rubber, antioxidants, plasticizers, and softening oils.
When working with a TPU or TPE compound manufacturer, an expert will consult with you about the best additives for your product’s end use.
Thermoplastic Elastomers (TPE)
TPE, also called thermoplastic rubbers, make up a class of copolymers which possess both thermoplastic and elastomeric properties.
Most elastomers are thermosets. Thermoplastics are easier to use in manufacturing, which makes them the preferred option for many companies. By using thermoplastics instead of thermosets, companies reap the benefits of both rubbery and plastic materials. They have excellent elasticity, allowing them to return to their original shape after stretching. This increases their life and gives them a great physical range.
The chemical difference between thermosets and TPE is the type of cross-linking bond in their structures. The specific type of cross-linking present in TPE compounds is what gives them their high elastic properties.
Thermoplastic Polyurethane (TPU)
TPU is a melt-processable TPE that features both high durability and flexibility.
As a compound, TPU is incredibly versatile. A TPE compound manufacturer can customize a TPU compound blend based on the demands of the materials application. TPU compounds can stand up to even the most rigorous applications, like wires, cables, and automotive tires.
In general, TPU has excellent tensile strength, high elongation, and good load bearing capacity. The specific capabilities of your compound will depend on the intended application.
TPU is produced using three basic raw materials:
- Polyol or long-chain diol
- Chain extender or short-chain diol
The copolymer is composed of soft and hard segments:
- Soft Segment (polyether or polyester): provides flexibility and elastomeric qualities.
- Hard Segment (aromatic or aliphatic): constructed from a chain extender and isocyanate for toughness and physical performance properties
Polyvinyl chloride is the third most widely produced synthetic plastic polymer, with about 40 million tons produced each year.
PVC is available in two basic forms: rigid and flexible. Rigid PVC is used for pipe and profile applications including doors and windows, as well as bottles, food-covering sheets, and bank cards. Flexible PVC is used in plumbing, electrical cables, imitation leather, and flooring. It is also used with linen or cotton in producing canvas.
Compound manufacturers produce PVC using suspension, emulsion, and bulk (mass) methods. These methods allow chemists to polymerize vinyl chloride monomers to create a reduced PVC slurry.
Kent Elastomer Products Manufacturing
KEP produces rubber compounds made to your specifications. From the medical industry to food and beverage, companies trust KEP to provide quality compounds for their products.
Click here to learn more about thermoplastic elastomer compounds from KEP.