Rubber Automotive Parts and Rubber Tire Components
When you think of the rubber industry, chances are the first thing that comes to mind are tires. Today, about half of the world’s rubber is used to create tires, whether for cars, trucks, bicycles, or more.
Rubber Automotive Parts
The automotive industry uses a wide variety of rubber parts: radiator hoses, spark plug housing, dampening gaskets, silicone for weather stripping, windshield frames, and exhaust accessories. And, of course, the most significant use of rubber in an automobile is for tires.
Tires are made primarily of natural or synthetic rubber, but also include other raw materials such as silica and carbon black to add reinforcement, strength and other important performance properties.
What’s in a Tire?
While tires may look simple from the outside, they are actually made of several parts: the tread, bead, sidewall, shoulder, and ply. Each component uses rubber in a unique way to create a strong, sturdy tire.
- Tread: Most automobile users are familiar with the tread of a tire. It’s the part we measure with a penny to check for sufficient tread depth–if you insert a penny between the tread grooves and Lincoln’s entire head is visible, the tire is worn to about 2/32 of an inch, and is legally worn out. Tread rubber is vulcanized and tough. It needs excellent abrasion-resistance to ensure a long lifespan. The longer a tire’s lifespan, the happier end-users will be. Longer tire lifespans also reduce the amount of tires that end up in landfills.
- Tire Bead: This tire part sits between two wheel rims, ensuring a tight seal so tubeless tires can hold air without leakage. Typically, the bead is compounded of stiff, high-strength rubber, reinforced with steel wire.
- Sidewall: The sidewall bridges between the tread and the bead. It creates traction by transmitting torque applied by the drive axle to the tread. The sidewall is also made of rubber that varies in stiffness and profile depending on the end performance needs of the tire.
- Shoulder: A tire’s shoulder is the area that transitions from tread to sidewall.
- Plies: Plies are cords used to prevent rubber from stretching due to internal pressure. Body plies can be embedded in the tire’s rubber in various different orientations. Ply orientation is a key factor in the categorization of tire types.
How are Tires Made?
To make a tire, first, you need bulk raw materials: rubber, carbon black, and chemicals. The rubber used to make tires can be either natural rubber or synthetic rubber, depending on the cost of each raw material and the end-goal of the tire manufacturer.
Carbon black is used as a reinforcing filler in tires, assisting with abrasion resistance. It is created from incomplete combustion of heavy petroleum products, like tar, coal tar, and ethylene cracking tar. While the tire industry is one of the leading users of carbon black, many consumers don’t realize that you can find carbon black in items as a dark pigment such as plastics, cosmetics, paints, and inks.
Tires typically go through a five step manufacturing process: compounding and mixing, component preparation, tire building, curing, and final finishing.
- Compounding and mixing: all the ingredients necessary for a batch of rubber compound are brought together, then mechanically blended into a homogeneous substance.
- Component preparation : components will undergo calendering or extrusion depending on their manufacturing process. Tire treads, sidewall profiles, and inner liners are often extruded. Calenders flatten rubber compounds into thin sheets to create body piles and belts.
- Tire building : once the components are prepared, they can be assembled using a tire building drum.
- Curing : pressure and heat are applied to the tire while in a mold to finalize its shape, toughening the rubber for strength and durability.
- Final finishing : manufacturers now perform tests and inspections to check for tire uniformity, steel cord structure, and various visual defects.
Synthetic Polymers in Cars
Today, 60% of rubber used for tires is synthetic. Most commonly, this synthetic rubber is styrene-butadiene copolymer. Synthetic polymers can also be found throughout the interior of a car.
Synthetic rubber, like natural rubber, must be tested for safety and strength when used in tires. It tends to be more resistant to oil, oxygen and certain chemicals, longer-lasting, and more resilient to extreme temperatures. Natural rubber tends to have more tensile strength when hot, has low damping levels, and experiences less heat buildup from flexing.
Accreditation bodies monitor quality control so the world’s rubber products remain up to par. Before rubber ends up on a trucker’s tire, a family car, or a commuter’s bicycle, it needs to undergo thorough testing to ensure its safety and effectiveness.
That’s where ACE Laboratories steps in. With decades of knowledge of the rubber and silicone industries, and an ISO/IEC 17025 accredited laboratory with state-of-the-art rubber testing instruments, our physical and chemical analyses are precise, accurate, and completed with expertise and integrity.
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