Extruded rubber have a wide range of applications in commercial, industrial, and residential settings due to their versatility and durability. In the commercial sector, rubber extrusions are commonly used in the automotive industry for sealing and weatherstripping applications. These extrusions help maintain the integrity of vehicles by preventing water, dust, and noise from entering the cabin. Additionally, rubber extrusions find use in the construction industry for creating seals around doors and windows, providing insulation and enhancing energy efficiency in buildings.
In the industrial realm, rubber extrusions play a crucial role in various applications. One prominent use is in manufacturing conveyor belts, where rubber extrusions form the belt’s edges, ensuring smooth and efficient material transportation. Moreover, rubber extrusions are used in heavy machinery to create gaskets, seals, and O-rings, providing airtight and watertight seals that are essential for preventing leaks and maintaining machinery performance. The resistance of rubber to chemicals and extreme temperatures makes it suitable for applications in the chemical, oil and gas, and food processing industries, where it can be used for hoses, tubing, and protective covers.
In residential settings, rubber extrusions contribute to improved living conditions and safety. Weatherstripping made from rubber extrusions is used around doors and windows, reducing drafts and enhancing energy efficiency in homes. Rubber extrusions also find use in home appliances, such as refrigerators and ovens, where they act as gaskets and seals to maintain proper insulation and prevent leaks. Additionally, rubber extrusions are commonly used in household plumbing for creating seals and gaskets that prevent water leaks and ensure smooth water flow.
Overall, rubber extrusions offer a cost-effective solution for various commercial, industrial, and residential functions. Their ability to provide effective sealing, cushioning, and protection against environmental factors makes them indispensable in many industries, contributing to improved product performance, increased energy efficiency, and enhanced safety in numerous applications.
Rubber is a naturally occurring elastomer, cultivated from the Pará Rubber Tree. Researchers believe that the cultivation of rubber has been taking place since prehistory; they estimate that Mayans were sapping rubber trees and boiling natural latex to make crude oil as early as 1600 B.C.E. The rubber extrusion process as we know it today, by which natural and synthetic rubber materials are modified and shaped into rubber products, did not begin to develop until the 19th century. During the 19th century, manufacturers began using textile rubber profiles.
By the early 20th century, scientists were synthesizing rubber. In 1909, Bayer employees working out of Elberfeld, Germany polymerized Isoprene. Just a year later, Sergei Vasilievich Lebedev, a Russian scientist, developed another synthetic rubber, this one derived from butadiene. This synthetic rubber went on to be an important material for Russia during World War I.
In 1931, not long before the Second World War, scientists at DuPont successfully synthesized neoprene. This polymer was hailed as a highly durable and corrosion resistant rubber, useful for many things, especially vehicle fuel hoses. As the material grew in popularity, scientists around the world, mostly the US, Germany and the Soviet Union, competed to create better and cheaper neoprene-esque polymer products. At the advent of World War II, US production of synthetic rubber kicked up several notches, as most of the world’s rubber supply was in Axis-controlled hands. During the war, rubber materials were important to the engineering of military vehicle tires and other components of war machines.
After the war, synthetic rubber production continued, and by the ‘60s, synthetic rubber production and use exceeded that of natural gum rubber. In the modern world, there are more synthetic rubber varieties than ever and rubber extrusion occupies a position of importance. It serves innumerable consumer, commercial and industrial applications.
The properties of an individual finished product depend on the raw rubber stock used to make it, the extrusion process it undergoes, and any secondary processes. Since rubber exists in many unique forms, rubber extrusion manufacturers are able to further develop their products through raw material selection.
Natural rubber, which is also called gum rubber, is sought after for its qualities of excellent acid and abrasion resistance.
Silicone rubber is an FDA-certified non-reactive elastomer. It is chemically inert and does not react to biological fluids. In addition, it maintains its form and properties when exposed to both high and low temperatures, typically between -55℃ (-67℉) and 300℃ (572℉). Because of its superior qualities, silicone is popular for use in food service and healthcare.
This rubber compound has qualities of superior heat, chemical and weathering resistance. For this reason, it is also popular in food service and healthcare.
Nitrile, a synthetic rubber copolymer, is highly resistant to oils, and so it is used to make rubber products that will encounter oil, like O-rings, hoses or hydraulic seals. Nitrile is also known as nitrile rubber, NBR (nitrile butadiene rubber), acrylonitrile butadiene rubber, Perbunan or Buna-Nis.
Neoprene resists heat, fire, UV rays, water and oil. It also has a high tensile strength.
Butyl has low air flow permeability.
SBR (styrene-butadiene rubber) is high abrasion resistant. For this reason, it’s used in a lot of automotive applications, like motor mount fabrication and belt cover fabrication.
EPDM (ethylene propylene diene terpolymer) is resistant to many potential damages, including: heat, aging, ozone, oxidation and ultraviolet rays. It has many applications, including: sponge rubber, foam rubber, weather-stripping, tarp straps, door gaskets, window gaskets and roofing membrane.
Manufacturers conduct a standard rubber extrusion job with a standard rubber extruder. After they have completed the design phase, which involves creating the die and selecting the material, they move on to extrusion with the extruder.
- Optional: Pre-heat the stock until it is molten for hot extrusion. If you skip this step, you are doing what is called “cold extrusion,” or depending on the application, “cold feed extrusion.”
- Feed unvulcanized rubber into the hopper, a container suspended above the conveyor.
- With the help of gravity, send the rubber stock through the bottom of the hopper and out onto the conveyor.
- The conveyor, along with a rotating screw, moves the rubber towards the die. The screw creates pressure and temperature, which also helps push the rubber onward.
- After it has reached the end of the conveyor, and has softened enough, the rubber passes through the opening of the die.
- As the rubber passes through the die, it swells and takes on its shape.
- After passing through the die, the rubber emerges from the other side of the extruder, now a shaped profile that matches the die.
After you’ve processed the rubber profile, you may engage in any number of post-processing or secondary processes. Examples include: vulcanization, dusting (powder is applied to rubber to prevent it from adhering to something else), cutting, drilling, coiling, splicing and taping end joining. Of these, vulcanization is not optional.
Vulcanization is a popular method of strengthening extruded rubber. During vulcanization, you cure the extruded rubber with Sulphur or other curative compounds.
Manufacturers face several critical considerations when creating rubber extrusions to ensure the successful production of high-quality products that meet specific requirements and standards. One primary consideration is the choice of rubber material. Different rubber compounds offer varying degrees of hardness, flexibility, resistance to chemicals and weather, and temperature tolerance. Manufacturers must carefully select the appropriate rubber material that aligns with the intended application and performance needs of the extruded product.
Another crucial factor is the design of the extrusion profile. Manufacturers need to develop precise and accurate profiles that match the desired shape and dimensions of the final product. This involves considering the complexity of the design, the required tolerances, and the feasibility of the extrusion process itself. Design considerations also extend to choosing the appropriate cross-sectional geometry, such as solid or hollow profiles, to meet functional requirements like compression, sealing, or impact resistance.
Furthermore, manufacturers must optimize the extrusion process to achieve consistent product quality and efficiency. This involves determining the right extrusion temperature, pressure, and speed to ensure proper curing of the rubber while avoiding defects like air bubbles or voids. Proper tooling design and maintenance are also essential for consistent product output and minimizing material waste.
Quality control is another critical aspect of rubber extrusion manufacturing. Manufacturers need to implement rigorous inspection and testing procedures to identify any defects or variations in the final product. This includes monitoring dimensional accuracy, hardness, tensile strength, and other relevant properties to meet industry standards and customer specifications.
Cost considerations are always at the forefront of manufacturing decisions. Manufacturers must balance the costs of raw materials, equipment, labor, and energy with the desired product quality and performance. Finding ways to optimize production processes, reduce material waste, and improve overall efficiency are crucial for cost-effective rubber extrusion manufacturing.
Finally, manufacturers need to be aware of environmental and regulatory considerations. Compliance with environmental regulations and sustainability initiatives is increasingly important for businesses. Selecting rubber materials that are eco-friendly, and implementing responsible waste management practices are crucial steps in minimizing the environmental impact of rubber extrusion manufacturing.
In summary, manufacturers must carefully navigate material selection, design optimization, process efficiency, quality control, cost management, and environmental concerns when creating rubber extrusions. By addressing these considerations effectively, they can produce high-quality extruded rubber products that meet the diverse needs of various industries and applications.
A standard rubber extruder, also called a screw extruding machine, consists of two main parts, a heated shearing screw conveyor and a die.
Shearing Screw Conveyor
A shearing screw conveyor is made up of a conveyor and a screw. The screw, which sits parallel to the conveyor, pushes rubber material onto the conveyor channel, where it is heated, pressurized and plasticized.
A die is a pre-designed chamber that serves as a shaping tool. Newly pressurized and plasticized rubber material is squeezed through it to create a shape. The material is pressured by the conveyor screw to squeeze through the die, located at the end of the conveyor, from which the new shape will emerge. Only once a rubber shape has cooled is it considered “extruded.” Note that a die can be made into nearly shape and so, rubber can be extruded into nearly anything, no matter the shape or size requirements.
Variations and Similar Processes
Variations on standard rubber extrusion are often related to the type of rubber being extruded. For example, to successfully conduct silicone extrusion, manufacturers must modify their rubber extruder temperature output to compensate for silicone’s heat-resistant characteristics. Also, in order to undergo extrusion, natural rubber stock must first be divided into pellets. Some types of extrusion are not based specifically on a rubber material.
Injection rubber molding is a popular alternative to rubber extrusion. Manufacturers perform injection molding by heating the rubber material until it is warm or molten and then injecting in into a mold cavity. Inside the mold cavity, often with the help of heat and/or pressure, the rubber takes on the mold’s shape before it cools and hardens. Injection molding is a good alternative choice when you’re working with elastomers, thermosetting polymers or exceptionally complex designs.
Plastic extrusion is very similar to rubber extrusion. In this case, the raw material takes the form of plastic nuggets or kernels. When fed into a column with a screw, the material turns semi-fluid and passes through the die. After extrusion, plastic extruded parts undergo their own secondary processes.
Co-extrusion is a variation on basic extrusion that allows for the creation of extruded rubber parts that contain the properties of more than one rubber material. Co-extrusion works when two separate extruders and two or more separate batches of mixing rubber material are connected to a single die. They separate batches of rubber are fed into the die at the same time, allowing for their convergence. While extruded rubbers can be used after they have cooled, they may also undergo secondary treatments to improve them in some way.
Producing items through rubber extrusion offers a wide range of benefits that make it a preferred manufacturing method in various industries. One of the key advantages is cost-effectiveness. Rubber extrusion allows for the efficient use of raw materials, minimizing waste and reducing production costs. The process also enables high-volume production, leading to economies of scale and lower per-unit costs, which is particularly beneficial for mass-produced items.
Another significant benefit of rubber extrusion is the versatility it offers in creating complex shapes and profiles. Manufacturers can design and produce a wide variety of products with different cross-sectional geometries, sizes, and lengths, tailored to specific applications. This flexibility allows for customized solutions that meet diverse requirements in industries such as automotive, construction, aerospace, and more.
The seamless and continuous nature of the extrusion process is another advantage. Rubber extrusions can be produced in long lengths, reducing the need for additional assembly steps and potential weak points in the final product. This results in stronger, more reliable items with improved structural integrity.
Rubber extrusions also provide excellent sealing capabilities, making them ideal for applications that require airtight, watertight, or dust proof seals. The ability to create precise and consistent profiles ensures a reliable seal, enhancing the performance and longevity of the products.
Additionally, rubber extrusions offer exceptional resistance to various environmental factors, including chemicals, UV radiation, and extreme temperatures. This durability makes them suitable for a wide range of challenging conditions, expanding their applications across different industries.
Meanwhile, the inherent cushioning and shock-absorbing properties of rubber make it an excellent material for impact protection and vibration dampening. Items produced through rubber extrusion can absorb and disperse energy, making them valuable components in impact-sensitive applications.
Furthermore, rubber extrusions are often preferred for their ease of installation. Their flexible nature allows for straightforward fitting and positioning, reducing assembly time and labor costs.
Finally, the environmentally friendly aspect of rubber extrusion contributes to its appeal. Many rubber materials used in the extrusion process are recyclable, supporting sustainability efforts and reducing the environmental footprint of the manufacturing process.
In conclusion, producing items through rubber extrusion offers a plethora of benefits, including cost-effectiveness, design versatility, seamless production, reliable sealing, durability, impact protection, ease of installation, and environmental sustainability. These advantages make rubber extrusions a popular choice for various industries seeking high-performance and reliable solutions for their diverse applications.
Choosing a Manufacturer
In order to get a high-quality product, you must work with a high-quality manufacturer. In the Google age, it can be hard to know which companies are reliable and which are not. That’s why we’ve taken the time to put together a list, complete with profiles, of leading rubber extrusion companies. All of these companies have proven their worth to customers many times over. To choose from among them, we recommend you start by browsing their profiles with your application in mind, and pick out three or four in whom you’re interested. When you’re ready, call each of them and talk over your specifications, requirements and questions. Remember to include questions related to: order volume/quantity, price, delivery date Compare and contrast each conversation. Identify which supplier offers not only the best deal, but also the best customer service. It’s better to bypass a manufacturer that doesn’t demonstrate good customer service, because miscommunications may end up costing you more in the long run. Once you’ve figured out which supplier is best for you, reach out again and get started. Good luck!
Rubber Extrusion Informational Video