Blow moulding is a moulding technique for creating hollow plastic objects. It uses heated liquid material pressed into the mould cavity under pressure, just like other moulding processes. However, blow moulding is a particular moulding process that takes advantage of traditional glass blow moulding characteristics.
Overview of blow moulding
Blow moulding, also known as blow molding in the UK, is a moulding process that blows heated plastic into a mould cavity to make a hollow object. The defining characteristic of blow moulding is that it makes hollow objects. The raw plastic is first heated, and then the preform is formed. Next, fix the plastic preform on the top of the mould. Finally, the air is blown onto the plastic preform, which stretches it through the inner wall of the mould cavity.
Blow moulding follows the same principle as glass blowing. The glassblower blows air through the heated glass to create hollow glass objects for glass blowing. The machine blows air through the heated plastic placed on top of the mould cavity in blow moulding. The air forces the heated plastic to expand through the inner wall of the mould cavity.
This is everything you need to know about blow moulding of blow moulder
Blow moulding is everywhere, and you don’t even know it. The soda you drink has a blow-moulded plastic bottle.
In the United States, the plastics industry is the third-largest manufacturing sector. Plastics make our lives easier and produce products at a lower cost.
But what exactly is it? How does it work? Please read carefully to find out!
What is it?
Plastic products can be made using this method. The process involves heating a plastic tube (called a preform or preform) to its melting point and then placing it in a mould cavity.
The molten plastic was then inflated like a balloon with compressed air, giving it the shape of a mould but a hollow inside. The thickness of the final product is determined by the amount of plastic used and the air pressure.
Blow moulding originated from glass blowing. Craftsmen heat the glass to its melting point and then blow through a tube to inflate the glass. Since the 1800s, this method has been used. According to a patent at the time, the process was used for celluloid polymers. These early methods are ineffective in mass production.
In the 1930s, they developed commercial machines to make blow-moulded bottles, allowing for mass production. The available materials are too brittle, and the production time is too long to use this process for mass production effectively.
With the advent of low-density and high-density polyethylene, blow moulding technology has rapidly become popular in the industry. Many industries, including soft drink bottling and automobile manufacturing, have been transformed due to this.
What can you do?
You can use blow moulding to make almost any hollow plastic container, but the process is not limited to bottles. The following are some typical blow moulding products:
- Construction barrels and obstacles
- Stadium seats
- Fan shell
- Toys and sporting goods
- watering can
In the automotive industry, blow moulder is also widely used, making auto parts’ design and mass production cost-effective and straightforward. The following are some common blow-moulded auto parts:
- Automotive piping system
- Liquid reservoir
- Storage System
- Appliance cover
All in all, blow moulding has a wide range of uses and is an excellent way to produce a large number of parts inexpensively.
Blow moulding comes in a variety of shapes and sizes. The main difference between them lies in how they form the preform, the size of the preform, and how the preform moves between dies. The main types of blow moulding are:
- Extrusion Blow moulder (EBM)
- Injection blow moulder system (IBS)
- Injection stretch blow moulder (ISBM)
Modern blow moulding is a highly automated process that can produce thousands of parts in a short period. The method includes the following steps:
Plastic pellets are fed into the machine through a hopper or screw, depending on the machine.
The plastic is melted and formed into a preform, which looks like a tube with a hole at one end.
Clamp in the mould.
The compressed air expands the preform.
The heated plastic balloon fills the space of the mould.
After the plastic has cooled, the machine opens the mould and removes the part, sending it to any applicable finishing (if any).
In addition, for IBS and ISBM, preforms replace preforms. Pre-made single-hole tubes are called preforms and are manufactured by injection moulding. A single execution design may be used for several different methods of blow-moulded products and is another way to simplify production in some cases.
Blow moulding material
Plastics suitable for this process include:
Low density and high-density polyethylene
- COP and COC
The wide variety of materials available for blow moulding means that you can use the process to develop parts to meet your exact needs.
The blow moulding process has a number of advantages over other types of plastic product manufacturing. Blow moulding is a less expensive alternative to injection moulding, both materials and equipment.
Single-piece products can be made with blow moulding. It can create objects that do not require assembly or the joining of two halves. As a result, it’s beneficial for containers that need external threads.
Blow moulding can also reduce burrs. Glitter is a slight burr or plastic exudate around the product’s appearance. The excess plastic produced during production requires additional finishing work to polish or remove before transporting the parts. Blow moulding technology hardly makes burrs, thus shortening the turnaround time of blow moulding products.
Different types of blow moulding
Extrusion blow moulding is one of the many types of blow moulding available. It is called Extrusion Blow moulding (EBM), and it lives up to its name by extruding heated plastic into a preform. This is a commonly used moulding process in manufacturing because it can mass-produce many objects of the same size and shape.
Another standard blow moulding process is injection stretch blow moulding. Using one or two stages, injection stretch blow moulding is commonly used to make plastic bottles. It is particularly suitable for manufacturing preforms for plastic bottles, sold to bottling companies or used to make bottles.
Blow moulding and injection moulding: what is the difference?
When referring to a moulding process, “blow-moulding” and “injection moulding” are often interchangeable. Although similar, they are not necessarily the same. Both blow moulding and injection moulding involve using liquid material—usually plastic—to be pressed into the mould cavity. The difference is that blow moulding is used to make hollow objects, while injection moulding is used to make solid objects. Only blow moulding can provide manufacturing companies with fast and effective solutions for hollow objects.
Your product is about to blow up.
Choosing blow moulding to make your products come to life is an excellent solution for massively producing simple and effective designs without spending too much money. We have a talented team of well-trained professionals who can transform your product from an idea to reality. In short, we will work with you throughout the design and production process to ensure that the result is a product you can be proud of.
So, contact us today to help you push your product from your mind to the world!