Extruding silicone parts is a common manufacturing process today.
In this guide, you are going to learn some fundamental aspects about silicone extrusion. For example, you will learn the step-by-step process, benefits, applications and choosing right silicone material, just to mention a few.
Keep reading to learn more.
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.
Step by Step Silicone Extrusion Process
The following are steps you should adhere for a successful extrusion process:
Step 1: Color and Silicon Mixing
Here you will add the desired color to silicone gum and blend using a two -roll mill. This will result in a homogenous material that is consistent in terms of structure and color. Besides, it is at this stage that you can add specific compounds.
The compounds will help improve silicone properties.
Step 2: Testing of Silicon Compound
It is important to determine the possibility of the silicon material to meet the desired end product standards. You will therefore need a die rheometer to test both physical and chemical properties of the material.
Step 3: Feeding
After confirming that the silicone material is in good shape, you will feed it directly into an extruder. An extruder is a special machine used in this process to forward material to screw containing flutes.
Step 4: Melting and Forwarding Raw Material
The movement of silicon through the screw causes an increase in temperature and pressure. This in turn causes the material to melt. The molten material is then moved towards the die.
Step 5: Extrusion Through Die
Here, the silicon material goes through the die and acquires its shape. The die is usually cut-out in a unique pattern depending on the required outcome.
Step 6: Curing Extruded Silicone Part
From the die, the shaped silicon material then passes through an oven for curing. This process usually takes place at very high temperatures thus making the extrusion more robust and stable.
Step 7: Cooling
In this final stage, put the extrusion in a container and let it cool at room temperature for about 12-13hours. Thereafter, you can have the extruded material cut into desired lengths using the cutting machine. Note that the cutting is normally done at 900 for accuracy purposes.
Benefits Of Silicon Extrusions
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
Applications of Silicone Extruded Parts
With silicone rubber extrusion process, you can produce many parts for virtually all industries. Whether you want parts for the automotive, medical, or home appliances, extruding silicone is a perfect option.
1. Silicone Extruded Profiles
There are types of extruded silicon profiles which are named according to their shape. Some examples of silicone extruded products:
- e-type silicone profile
- L-type silicone profile
- Lamp shape silicone profile
- Lip seal silicone profile
- Omega type silicone profile
- Silicone D-profiles
- Silicone P-profile
- T-type silicon profile
- Trapezoid silicone profiles
- U-type silicone profile
2. Extruded Silicon Gaskets
A gasket is simply a seal. In most cases, it fills the space existing between two items or surfaces.
Today, many industries use silicone gaskets for efficient and reliable seal.
Examples of extruded silicone gaskets are:
- Solid silicone gaskets
- Sponge silicone gaskets
- Foam silicone gaskets
- Fluorosilicone gaskets
- FDA silicone gaskets
- Molded silicone gaskets
- Conductive silicone gaskets
3. Extruded Silicon Tubing
You can make silicone tubing with varying dimension and sizes. Whether you want small, medium or large silicone tube, extrusion offers a perfect alternative.
- Some examples of extruded silicone tubing include:
- Silicone peroxide cured tubing
- Platinum cured silicone tubing
- Silicone dairy tubing
- Silicone fuel tubing
Limitations Of Rubber Silicon Material
Even though silicon has replaced plastic in today’s manufacturing processes, it has some drawbacks.
Silicone rubber has got two major disadvantages:
- You should add some additives to improve silicone poor tear strength
- It is expensive compared to other rubber materials.
In most cases, extruded silicone products are affordable in the long run. That is, if you evaluate the products in terms of durability, and subsequent maintenance.
Factors To Consider In Silicone Extrusion Material
At times, choosing a silicone material for extrusion process can be a challenge. Remember, there are many silicon rubber types with varying properties.
Here are 5 points that will help you choose suitable material for silicone extrusion process:
- Type of silicone: liquid silicone rubber (LSR) or high consistency rubber (HCR)
- Durometer of the silicone material
- Color of the silicone material
- Tolerance of the silicone material
- Intend use or application
Grades Of Silicone Material Suitable For Extrusion
Silicone material exists in different grades. It is crucial to know the grades of silicone for efficient extrusion process.
Choosing the right grade for extrusion will ensure you get quality and desirable products after the process. Some common silicone grades are:
- Flame retardant
- Conductive silicone
- Platinum cured silicone
- High-temperature silicone
- Metal detectable silicone
- FDA approved silicone
The process of silicon extrusion is cost-effective and consumes less time compared to other methods. However, having the right information on how to go about this process is key. This article provides all the necessary information you will require for this good course.
Silicone Extrusion Process – Source: LegenDay
Silicone Extrusion – Source: LegenDay
Extrusion – Source: Wikipedia