What is the Rubber Extrusion Process?

Rubber extrusion is a rubber manufacturing process often used in rubber industries. This method involves shaping rubber into various shapes, mostly rubber profiles.

According to the definition, a rubber extrusion process produces rubber profiles with the same cross-sectional area. Because of this method, rubber profiles get several properties. They are:

(1) This process produces long, continuous lengths of rubber profiles. Because of this, the consistency of the profile remains the same along the entire length.
(2) You can create complex shapes using custom dies.
(3) You can also improve the softness of the rubber product. It depends mainly on the curing method and type of rubber used.
(4) This method produces long, unbroken rubber profiles with the same cross-section area. This type of profile is especially ideal for sealing. You can use it as weatherstripping or gaskets.
(5) The rubber extrusion process typically allows you to make high production.

Rubber Extrusion Process Applications

The rubber extrusion process produces many everyday products. One of the best examples is seal strips, which people also recognize as weather stripping. This product is widely used in doors and windows. Rubber tubing is ideal for fluid transfer. Besides, various gaskets used in machines or equipment are also made of rubber.

Step-By-Step Rubber Extrusion Process

Throughout our discussion, we’ve provided insights into how the extrusion process works. You will learn this section step by step. In each phase, you may picture how the production process works. You can also look at the aspects that affect the overall quality of your products.

Step #1 Material Selection and Preparation

First, we have to select suitable rubber material. You might have endless choices. For instance, silicone rubber is more suited to high-temperature applications than EPDM rubber, which is more suited for applications such as weather strips. Neoprene and nitrile may be your best chances at standing up to chemicals.

Step #2 Feeding the Extruder

After the suitable rubber has been chosen, it is put in the extruder hopper. You will find three main parts if you disassemble a rubber extruder machine. (1) The insertion chamber, (2) the processing chamber, and (3) The extrusion chamber. You can find the hopper in the first chamber.

Step #3 Rubber Softening and Mixing

Once the hopper takes the material, it passes to the processing section. In the processing section, there’s a large screw which gradually pushes the rubber forward. Here, there’s also a consistent heating system. So, When the rubber moves forward, at the same time, it gets softer because of the heat.

Step #4 Extrusion Through Die

The rubber extruder machine then gradually pushes the soft rubber material to the die. Because of the die, the rubber gets a specific shape with the same cross-section area. It continues to do so until the rubber inside the machine is finished.

Step #5 Metal Insertion (If needed)

Rubber extrusion profiles are used for many purposes. They seal doors, windows, and even heavy-duty machinery. So, the strength of the rubber profile is a very important parameter here. You can achieve this by simply inserting metals in the rubber profiles. And you can do it during this rubber extrusion process.

Step #6 Vulcanization or Curing

Once the extruded rubber comes out of the rubber extruder machine, it remains soft. In this situation, a unique method called vulcanization—also known as a curing method—is used to strengthen these rubber profiles.

Step #7 Multi-extrusion (if required)

Sometimes, your product may need more than one color or material. The best example is the dual durometer rubber extrusion profile. Besides, many rubber products require more than one rubber extrusion process.

Step #8 Cooling

After the vulcanization process, cooling begins. This generally cools down the rubber profile and makes it harder. To avoid defects, an appropriate cooling system must be ensured.

Step #9 Rolling

Finally, you can remove and roll the rubber profile for better packaging. You can also cut it to a specific length, but in most cases, people prefer rolling.