Rubber Moulding Tooling Secrets
The rubber industry is boosting over days for obvious reasons. It has become a base part of the manufacturing industry. We all use rubber for different purposes, but little do we know how they are produced using certain tools. Producing rubber by using machines is not a piece of cake and needs a lot of money as well as labour. This process is called rubber moulding.
What is rubber moulding?
Rubber moulding is the process of making usable rubber products from raw rubber. Rubber is in high demand for industrial applications. Rubber products are usually made of elastomers which is a polymer having natural elastic properties, which can be collected from natural sources. Rubber essentials are produced using highly controlled chemical procedures and they are the best material when someone needs material that remembers its original shape and returns to it.
There are rubber moulding machines that are used to create moulded rubber parts. Either heat or chemical reactions are used to do this depending on which method the rubber is being moulded. Each method has different tooling secrets. The most common methods of moulding rubber are injection moulding, compression moulding and transfer moulding. Let’s discuss the methods and the processes in brief.
Different types of rubber moulding methods and the tooling secrets
It is important to choose the correct rubber moulding process to get the right result. Different kinds of results need different moulding processes, if not chosen wisely, you may not get what you want. Let’s discuss the main three types of the rubber moulding process.
What is rubber injection moulding?
It was first introduced in the year of 1960 as an extension of the plastic industry, and now it is the most famous moulding process. In this process, a heated rubber compound gets injected into a closed mould under high pressure.
The rubber parts are produced by injecting material into the rubber mould under high pressure and heat. Elastomers, metals, thermoplastic and thermosetting polymers are the materials that can be used for this. After injecting the material into a heated barrel, it is forcefully mixed into the mould cavity to create the shape. The material stays in the cavity until it gets cool and hard.
What are the advantages?
- A minimum amount of the waste
- Less time to produce
- Fast cycle
- Good dimensional tolerance.
- Many designing possibilities
- Low cost
- 3D printing
- The setup cost is pretty high
- There are some restrictions on the tooling design
- Expensive tooling and machinery.
On which materials can this be performed?
Silicone, neoprene, nitrile and EPDM, and so on.
Which materials can be made of this moulding process?
Spools, toys, musical instruments and parts, packaging, bottle caps, automotive parts and components, pocket combs, etc., are made by this moulding process.
What is compression moulding?
It is one of the most simple rubber moulding processes out there. It needs heat and pressure to create the desired shape.
In this process, the moulding material is placed in a preheated oven and heated mould cavity to make sure there is right pressure and then the mould is closed with top force. Because of this force, the material flows across the mould areas. Once the moulding material is cured, the work is done. The last part is removal and cooling.
- Fine surface finish
- Dimensional stability
- Mechanical properties
- Low wastage
- Simple tooling
- Suitable for large cross-sectional parts
- Greater capacity for processing high durometer parts
- This process can be performed on Polyester fibreglass resin systems, Torlon, Vessel, poly and other materials.
- Difficult to maintain the consistency of finished parts
- It takes more time to process
Which materials can be made by this moulding process?
Car tyres, rubber tyres, rubber gaskets or seals, handles, automotive parts can be made by this rubber moulding process.
What is transfer moulding?
It is a comparatively lengthier process which is quite similar to injection moulding.
At the first step, the raw materials are prepared as pre-forms. In this process, compression, injection and transfer moulding – all of these three processes are combined automatically. At first, a device gets built into the rubber mould to maintain the rubber into its shape. The mould remains closed while the curing process is done. Once the plunger is raised, the leftover parts get thrown away. Mould is opened after the rubber is cured entirely.
- It has high automation capability
- It is lower in cost than injection moulding
- It gives a smooth finish.
- More material wastage
- Tools need maintenance, repairing and removal
- Time-consuming process
On which materials this can be performed
On Silicone, neoprene, etc., this can be performed.
Which materials can be made by this rubber moulding process?
Materials such as pins, studs, model terminals and connectors can be made by this moulding process.
There is no method that is superior to others as all it matters is what requirements do you have. Every process has its pros and cons, but they are applicable depending on your goals. While the entire process sets in, each step is important in providing the desired outcome.
What are rubber moulding machines?
Special moulding machines are used to mould rubber. Rubber moulding press, rubber kneaders are famous for moulding rubber and nowadays, they are easily available in markets. At first, these moulding machines were so expensive that they only could be used by big companies, but nowadays these have become easily available for the sake of productivity. There are 3 basic types of moulding machines available in the market. The basic 3 types are
- jolt machines
- sand slingers
Each of them has its functionalities, pros and cons. There are machines specially made for this purpose and contain complex engineering structures.
Uses of moulded rubber
Rubber is used to create different types of materials. The examples are given below:
It is mainly used to control the vibrations and save the equipment from further damage. It comes in many shapes and sizes and anyone can customize those depending on needs. It is usually made of Synthetic or natural rubber. As an example, cylindrical mounts work as support for conveying lines and transferring equipment. Other types are also used for protecting products such as computers. They are quite easy to use and maintain.
It is mostly used in the manufacturing industry to reduce vibrations and movements to protect the equipment from further damage. It can be anything such as furniture, circuit boards, packaging, etc. A mixer of rubber and plastic called polymers are mostly used for this cause.
They are designed to absorb the vibrations and their effects on equipment. They are also often placed between two pieces of equipment to avoid vibration transfer and are highly used in the automobile industry.
It is mostly used to prevent leakage and the effects of pressure. It is also used as a barrier between two chambers. It can be either static or dynamic. Even slight pressure can set in a dynamic diaphragm.
These are shaped as rings to protect any object from opening. It is widely used where wires pass through. Made by various types of moulding, there are synthetic or natural rubbers.
These ring-shaped rubbers are made to protect from leakage. Widely used to seal gas and chemical feeding lines. They are in demand in the aerospace market, hydraulic market, vacuum flow lines, etc.
It is mainly used to distribute load, spacers, reduce vibrations, etc. Besides that, it is also used for locking seals. In pipe connections, they are used to seal leakage and secure joints. They give a tight seal.
It is used as connectors, washers, etc. Mostly utilized to cover equipment, especially wirings. It also holds different equipment together and protects the holes from contamination by moisture, water or dust.
It is used for the same purpose as rubber bumpers, mounts and isolators – to reduce vibration and protect equipment from further damage.
Used for sealing gaps, preventing leakage, etc. Sealing materials are a big market itself nowadays. It can be used in the forms of gel, film, putty, or strip. It can adhere to different types of surfaces.
Though there are many other uses of moulded rubber as well, they were the main purposes and forms of it. Nowadays, it is also being used for different purposes. It is one of the most versatile elements out there.
The rubber industry is rising over the days. From wires to tires, from the pipe industry to the manufacturing industry, the demand for moulded rubber is increasing and it is becoming one of the pillars of the manufacturing industry. The tooling process is the most important part of moulding rubber properly. As every tooling secret is different from another, one should take care while choosing the right rubber moulding methods for making certain materials.