Silicone extrusion process is a simple and practical way of producing various parts and components.
In this guide, you will learn all the critical stages in silicone extrusion process – from silicone and color mixing to cutting the final product.
Let’s dive right in.
What is Extruded Silicone?
Extruded silicone are parts made by passing material through a shaped die. The die is usually cut out in a specific pattern. It determines the shape and cross-section of the extrusions.
Benefits Of Silicon Extruded Parts
Silicone extrusions have several advantages over other materials. They include:
- Extruded silicone parts are durable and reliable
- Silicone parts can withstand extreme weather conditions
- It is easier to achieve a wide range of colors.
- Extruded silicone parts are popular for their biocompatibility, better dielectric strength and high temperature resistance
- Silicone rubber extrusion is economical
- Silicone rubber extrusion is continuous produces and produces less waste
Choosing Material for Silicone Rubber Extrusion
At times, choosing a silicone material for extrusion process can be a challenge. Remember, there are many silicon rubber types with varying properties.
As you choose the material, it is worth considering the following:
- Type of silicone: liquid silicone rubber (LSR) or high consistency rubber (HCR). Of course, you can choose silicone rubbers modified for specialized applications with specific additives.
- Durometer of the silicone material
- Color of the silicone material
- Tolerance of the silicone material
- Intend use or application
Remember, adding certain additives in the silicone rubber for extrusion may make the materials:
- Flame retardant
- Conductive
- High-temperature and heat resistant
- Metal detectable
- FDA certified
Step-by-step Silicone Rubber Extrusion Process
Ideally, extruding silicone rubber parts involve the following key processes:
Step 1: Color and Silicone Mixing
In this step, you can use two roll mills to process the blending of silicone gum. The option exists to add the desired color in the rolling mill with silicone.
You can add two-part silicone gum and one part of the color. The two-roll mill ensures homogenous silicone formation with consistent structure and color.
You can add chemicals or compounds to this silicone to add unique properties.
Step 2: Testing of Silicone Compound
The second step in the silicone extrusion process is to test the silicone compound using a moving die rheometer. It lets you know the rheological data, including viscosity, stress, temperature, etc.
It helps you ensure the silicone can meet the end product requirements.
Step 3: Feeding Silicone Rubber Material
The second step is to place this silicone compound directly in the extruder. The extruder then forwards the material to the screw-containing flutes.
Step 4: Melting And Forwarding Raw Material
As the material moves through the screw, the pressure and temperature gradually rise. This ends up melting the material and conveying it close to the die.
Step 5: Extrusion Through Die
The silicone compound then passes through the die. The die is a stainless-steel disc with a unique pattern per your requirement. It shapes the silicone compound as per the cut-out pattern.
Step 6: Curing
The extruded shape then passes through an oven that utilizes radiant heat. The radiant heat then cures the end product. The reaction that takes place during extrusion is irreversible. The curing ensures stabilization and strengthens the material.
Step 7: Cooling
Later in the process, you place the final product after passing through the oven in a container. The container ensures room temperature maintenance for around 12 hours for this end product.
The last step in the silicone extrusion process is pulling and cutting. The cutting machines perform this operation. They first remove the material and cut it. You can change the length of cutting as per your requirement. The blades are cut at an angle of 900 to ensure precision.
Remember, the silicone rubber extrusion process may vary slightly depending on the type of material grade and quality of the final product.
Silicone Rubber Extrusion Capability
Although the silicone rubber extrusion process is a versatile technique, the capacity varies depending on the company. Let’s look at some general capabilities when extruding silicone rubber parts:
| Silicone Rubber Extrusion Capability | Remarks |
| Cross section size |
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| Silicone rubber extrusion options |
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| Production |
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In addition to these, you can also produce extruded silicone rubber with both single-lumen and multi-lumen.
Applications of Silicone Extruded Parts
Through silicone extrusion process, you can make many parts and components for various industries. Depending on the production needs, you can make final parts or make silicone extrusions for other subsequent production processes.
Let’s look at some common silicone rubber extrusion applications:
Silicone Extruded Profiles
These silicone extrusions come in different geometrical shapes depending on the silicone extrusion equipment die design.
For instance, you can find silicone extrusion profiles with the following shapes:
- L-type extruded silicone profile
- Lamp shape extruded silicone profile
- T-silicone profile, or
- U-silicone profile
In short, you can make custom silicone profile depending on your design requirements
Extruded Silicone Gaskets
You can make rubber strips and gaskets through extrusion silicone rubber technique. Remember, silicone gaskets are versatile sealing accessories widely accepted in many industries. This is due to their superior chemical and physical properties.
Many silicone rubber extrusion manufacturers can fabricate:
- Solid silicone gaskets
- Silicone sponge gaskets
- Silicone food grade gaskets, etc.
Well, most of these companies have adopted versatile technologies allowing for silicone sponge extrusion or micro silicone extrusion.
Silicone Tube Extrusion Process
With the increasing demand for safe accessories in healthcare and food industries, medical silicone extrusion has been adopted to make many parts.
Some common tubes include:
- Silicone peroxide cured tubing
- Platinum cured silicone tubing
- Silicone dairy tubing
- Silicone fuel tubing
Extruded Silicone Rods
You can use silicone rod extrusions as final product or for subsequent rubber fabrication. In fact, they also form popular silicone extrusion profiles in today’s industries.
Like silicone tube extrusions, the silicone rods come in various configurations and shapes. Most silicone extrusion companies makes rods with different configurations and sizes.
Extruded Silicone Rubber Sheets
Through extrusion, you can make silicone extruded rubber sheets as either final product or for subsequent production needs.
Apart from these, other extruded silicone parts include silicone seals, wire insulation parts and electrical cable components.
Conclusion
The process mentioned above surely helps you in the silicone extrusion process. Even a layman can extrude the silicone using this process. In case you need further help or want to share your suggestion.
Don’t hesitate. We would love to hear from you. Seek our 24/7 online assistance.
More Resources:
What Is Silicone Made Of – Source: LegenDay
Benefits Of Silicone – Source: LegenDay
Silicone – Source: Wikipedia
Extrusion – Source: Wikipedia