With the introduction of technologies and the transfer of knowledge from generation to generation, the Moulding Industry has witnessed significant growth and developed on its own. What is Moulding?
The process in which any material or liquid that is melted, poured into a rigid frame called mould or matrix, and is cooled to form the desired shape, is called moulding. In the engineering world, this process gets usually done with plastic material. Thus, the entire technique is also known as custom plastic moulding.
What is Plastic Moulding?
Plastic moulding got founded in the late 19th century, and since then, it has expanded into many types. In traditional plastic moulding, liquid plastic is poured in a hollow mould and left to harden into a customized shape with the use of external factors such as heat and pressure. The products that we use in our daily routine like buckets, mugs, jars, toothbrushes, etc. are all made using the process of plastic moulding.
Modern technologies have enabled plastic moulding techniques to produce complex shapes and designs, thus, benefitting the automotive and material handling industries.
Types of Plastics used in the Moulding Industry
In the moulding industry, there are primarily two types of widely used plastics-
Once they get moulded into the desired shape, thermosets can never be re-melted and re-used, even when exposed to exceptionally high temperatures.
Examples of Thermosets include silicone, epoxy, phenolic, and polyurethane.
Unlike Thermosets, a Thermoplastic can get re-melted above a specific temperature and re-shaped multiple times accordingly. Thus, Thermoplastics are considered to be more versatile and widely preferred as compared to Thermosets.
Examples of Thermoplastics include polyester, acrylic, nylon, and Teflon.
Types of Plastic Moulding
- Injection Moulding
As the name suggests, during the process of Injection Moulding, molten plastic is injected at high pressure into a custom injection mould. The mould is cooled, and the customized shape with the desired design and size gets ejected out. These injection moulds get generally made from steel or aluminium.
Uses of Injection Moulding-
- To develop everyday products like toothbrushes, mugs, plastic buckets, plastic bottle caps, etc.
- Automotive Industry to develop auto dashboards/bumpers.
- Medical Industry to develop surgical equipment.
- Electrical Switches
- Blow Moulding
Blow Moulding is preferred when the plastic has to have a uniform wall thickness since the end product comes out to be hollow and thin-walled.
During this technique, the machine heats the raw plastic. As soon as the plastic converts into liquid form, the air gets injected into it like a balloon. As the plastic expands, it presses against the mould walls and begins to take the customized shape. After the balloon fills the mould, it is cooled and hardened to maintain the shape. The entire process takes under two minutes to reach completion. Therefore, it can produce over 1400 pieces within 12 hours.
Uses of Blow Moulding-
- Water Bottles
- Water Tanks
- Traffic Cones & Traffic Drums
- Complex Automotive Fuel Tanks
- Compression Moulding
In this technique, liquid plastic is poured into a heated mould and then compressed to form the desired end product. The final stages involve cooling the liquid plastic before trimming and removing from the mould. The exceptionally high temperature used in the process ensures maximized strength of the developed product.
Compression Moulding gets commonly used for Thermoset plastics.
Uses of Compression Moulding-
- Strong & Durable Automotive Parts
- Hoods & Fenders
- Scoops & Spoilers
- Extrusion Moulding
In Extrusion Moulding, a custom made “die” is used instead of a mould. The shape of this die determines the shape of the final product.
During this technique, the hot melted plastic gets pressed through a shaped hole, i.e., a die, which results in the formation of a long, continuous tube-like shape. The extrusion is cooled, and the end product gets ejected.
Uses of Extrusion Moulding-
- PVC Pipes
- Hoses & Drinking Straws
- Curtain Tracks
- Plastic Gutter
- Rods & Fibre
- Rotational Moulding
Rotational Moulding or Rotomoulding is preferred to develop large hollow products with evenly thick walls.
The technique begins by placing a powder or liquid resin into a mould. This mould is then rotated at high speed till the liquid resin covers the walls of the mould. When the mould gets rotated, a centrifugal force gets generated, which results in the formation of evenly thick-walled products. Finally, the mould is cooled down, and the desired shape gets taken out.
Uses of Rotational Moulding-
- Large Tubs & Containers
- Storage Tanks & Recycling Bins
- Marine Buoys & Kayaks
- Road Cones
- Car Parts
Is Rotational Moulding Right for You?
There are several reasons why Rotational Moulding is preferred worldwide to create plastic products. Let’s take a look at the benefits of Rotomoulding and whether it suits your business logistics-
- The moulds that get used in rotational moulding are highly complex to make a diverse range of customizable and changeable products.
- In Rotational Moulding, the tooling costs are way lower as compared to injection and blow moulding, which results in lower start-up costs.
- Rotational moulding is the first choice for small businesses in the plastic industry because very little material is wasted during the entire process, thus, making it economical. Moreover, all the excess material often gets re-used, making it environmentally friendly as well.
- Rotomoulding creates a high strength and highly stable product as the corners of the end product are thicker.
In Conclusion, the most suitable way to decide whether or not rotational moulding will be the right choice for your business is to figure out your annual production volume. If your product is complex, and you require smaller runs per order, Rotomoulding can fulfill your needs. However, if you are not bothered about the tooling cost and are seeking larger runs per order, it is advised to prefer a different form of moulding technique.
There are several companies worldwide that offer plastic moulding services. However, if you are looking for custom plastic moulding in Melbourne or nearby areas, there is none better than Rudplas Rotomoulders.
Rudplas Rotomoulders is an Australian family-owned and operated business involved in the rotational moulding industry for over 25 years. Rudplas specializes in the manufacture of bulk materials handling products, such as industrial trolleys, laundry trolleys, water tanks, etc. All products get manufactured from top quality UV stabilized food-grade polyethylene, which makes their products lightweight, easy to clean, and impact and weather resistant.
You can visit them in Melbourne for custom plastic moulding, or browse their website and contact them further for their services.