Rubber extrusions play a vital role in shaping the modern world, offering extensive versatility and functionality for so many commercial and industrial sectors, from construction, to automotive, aerospace and the rail industry. Whilst moulding is a popular process for creating 3D rubber products, for applications where a fixed cross-sectional profile is needed, extrusion is the right manufacturing route to take.
Manufacturing rubber extrusions
Rubber extrusion is a manufacturing technique where raw rubber compound is subjected to pressure and pushed through specialist tooling to create profiles of various shapes, sizes and length. Extruding can be used to create a diverse range of products, from hoses and insulation pipes, to complex seals and gaskets.
Extrusions are created through the following steps:
1 Material preparation
First the appropriate raw materials are selected. In some cases, a mixture of raw materials may be selected to create a rubber compound to achieve certain properties. The raw materials are then mixed under a controlled temperature and pressure to ensure uniform distribution of the materials in the rubber compound.
2 Extrusion
Once the desired rubber compound is mixed, it can be fed into an extruder. The extruder consists of a heated barrel with a screw mechanism inside. The raw materials are forced through a die by the barrel, which determines the shape and dimensions of the extruded product. Heat and pressure applied to the material during the extrusion process not only shapes the rubber but cures it.
A wide range of rubber materials and elastomers are well suited to the extrusion process. For example, commercial grades of EPDM, Natural Rubber, Neoprene and Silicone are commonly extruded, allowing for materials to be selected based on their unique properties to meet the specifications of any application.
3 Vulcanisation
After extrusion, the rubber profiles undergo a vulcanisation process, which involves exposing it to heat and pressure for a specified period of time. This process cross-links the polymer chains in the rubber to improve its strength and resistance to different environmental factors.
4 Cooling and conversion
After vulcanisation, the rubber is cooled to a suitable temperature to ensure that it is stable and can be cut or converted without being deformed. Once cool, extrusions can be cut into desired lengths, or fabricated to suit certain applications. Rubber extrusions of different lengths may be hot spliced together to create new shapes for seals or gaskets, or in some cases, may be vulcanised into rings or mitred joints to create o-rings, or square/rectangle profiles for sealing or gasketing purposes.
Common applications for extruded rubber profiles
Extrusion converts rubber materials into a wide array of useful products that are essential in today’s world. Using specialist extrusion die tooling, profiles can be manufactured to carry out many different purposes, for example:
Gaskets and seals
Rubber extrusion is highly useful for manufacturing quality gaskets and seals for many different industries, including aerospace, construction, automotive, energy, rail and mass transit, military and in many industrial machines. Strong extruded seals prevent fluid leaks, energy wastage and potential safety hazards.
Connectors
As well as functioning as seals or gaskets, extrusion is an ideal process for creating connectors and hoses that are essential for all kinds of industrial equipment. Hoses and connectors provide a safe and effective way for fluids or gases to pass round a machine, or even for electrical signals to pass from one part of the machine to another for it to carry out its function successfully.
Vibration isolation and shock absorption
In addition to acting as a sealing gasket, extruded rubber profiles can also be useful to create vibration isolation and shock absorption. This helps to reduce noise and vibration in vehicles and machinery, as well as helping protect against vibrations that could damage machine parts or prevent them from working effectively.
Innovative Extruded Solutions
Rubber extrusions play a vital role in shaping the modern world, from enhancing efficiency in construction and industrial processes, to ensuring safety and comfort. These versatile profiles provide a long list of benefits, including sealing, insulating and absorbing shock.
For further information on rubber extrusions and choosing the right materials and compounds for different industrial applications, you can visit the CB Frost website.