The vacuum forming process is a technique used to shape and form plastic products from a sheet of plastic and is commonly used in making large plastic components but also has the ability to be utilised when creating smaller plastic components.
Traditionally there are six steps to the vacuum forming process which our expert team can execute perfectly, to create unique plastic parts that will meet your exact requirements.
The first step in the vacuum process is making the tool. All our tools are based on designs you provide. This allows you to have complete control over the finished component.
Tools can be made from a variety of materials including Model Board or Aluminium, depending on the complexity and quantity of the plastic part being formed. If possible moulds should have tapered sides of a minimum of 2 degrees as this allows the plastic part to be released from the mould more easily.
This next step is fairly simple; the completed tool is placed into the vacuum forming machine. A plastic sheet is then placed above the mould and clamped in place.
Once the plastic is in place, a pneumatic ram position the top heaters above and below the sheet of plastic. After a set period of time the plastic should have been heated enough to ensure that it is fully flexible and mouldable ready for the next step.
The table, on which the newly created tool sits on, is then moved upwards by a pneumatic ram towards the plastic. If the plastic has been heated correctly and is sufficiently mouldable, with the aid of Vacuum the plastic is pulled to the tool face.
Once cooled, the plastic sheet and finished part as well as the tool are removed from the vacuum former. The plastic part can then continue on to the finishing and trimming process to ensure that it meets the exact design specification.
The vacuum forming process is suitable for a range of different plastics and it will ultimately depend on the part you are vacuum forming as well as your budget.
The most common plastics are:
Acrylonitrile Butadiene Styrene – Commonly referred to as ABS, this is a hard, rigid plastic with an impressive impact strength and resistance due to its rubber content. This plastic is also weather resistant and offers good formability and as such is one of the most widely used plastics in vacuum forming.
Acrylic Perspex (PMMA) – This is a high quality plastic and, as such, is more expensive. Despite this it is used in a variety of products, typically suited to medical applications. It has good strength and excellent formability making it ideal for use where definition is essential.
Polycarbonate – Whilst polycarbonate is one of the more expensive plastics, its hard and rigid nature ensures it has a high strength with an exceptional impact resistance. This plastic also offers good formability and is ideal for machining, making it suitable for a variety of uses.
High Impact Polystyrene (HIPS) –HIPS is a more cost effective vacuum forming plastic which is relatively easy to form and paint making it ideal for detailed custom components and packaging due to its FDA approval. It isn’t, however, particularly useful for outdoor applications due to its poor UV resistance.
High Density Polyethylene (HDPE) – HDPE is easy to vacuum form and is stronger than the standard polyethylene. What makes this plastic so impressive, however, is its resistance to acids and oils as well as its ability to withstand a high temperature range.
Ultimately, there are a number of plastics available to you, all of which have their own unique benefits. If you are unsure on which plastic to use it is always best to describe your product to your plastics manufacturer and allow them to recommend a plastic best suited to your needs.
There are a number of methods and techniques available to create plastic parts and products including thermoforming and injection moulding, so what makes vacuum forming the preferred and most suitable process for creating plastic parts?
Vacuum forming is a relatively simple process and requires significantly less advanced tooling when compared to the likes of injection moulding. This means that vacuum forming is extremely cost effective and plastic components can be made on a smaller budget without compromising on quality.
Vacuum forming uses unique tools designed to very specific specifications. This means that every time the vacuum forming process is conducted the mould can be changed and multiple plastic parts can be made with varying designs.
This is ideal for making products that may change often due to the competitive nature of the market such as food packaging.
If you are interested in learning more about our vacuum forming products or would like to arrange a free consultation, please contact Ansini today on 01623 812333 or email email@example.com.
If you have a question for us, or would like to discuss a specific project, please do get in touch.