What is Vacuum Casting and How is it Used?

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You have probably wondered how manufacturers produce copies of a wide range of functional plastic parts and make most household and commercial products like bottles.

Or maybe, you have asked yourself how manufacturers can make prototypes economically. Well, vacuum casting is your answer. So, here’s all you need to know about vacuum casting and how it is used in the process of mould making.

What is Vacuum Casting?

Vacuum casting is a manufacturing technology that uses a vacuum to draw any liquid casting material into a mould. To create accurate copies of master patterns, manufacturers use pourable casting resins with reusable silicone moulds.

It is especially effective when a mould experiences an air entrapment problem. Also, this process is used where a mould has intricate details and undercuts.

Vacuum casting is used in the food and beverage industry to make tins and bottles. In addition, it is used to produce commercial and household products such as bottles, sunglasses, etc.

Also, your everyday household products like washing detergents are made using the process of vacuum casting. The products made using this process are of high quality.

The Process of Vacuum Casting

Vacuum casting is a fast-paced, labour-intensive process that is easy to manage. This process is done in stages as outlined below:

A Master Pattern or Model is Created
Manufacturers first create a master model or master pattern on a shelf. Then, they get these patterns by performing manufacturing processes like 3D printing. To ensure that the final casting parts have the correct dimensions, manufacturers have to check that the dimensions for the master pattern are accurate.

Production of the Mould
To create a silicone mould, the manufacturers pour liquid silicone over the master model once it is placed in the casting box. The silicone mould is left to cure. After curing, they cut the liquid silicone open and removed the master model. The manufacturers now have an empty cavity with the same shape and dimensions as the master model. This silicone model can be reused up to at least 20 times as needed.

Filling the Mould With Resin
Manufacturers then mix resins or rubber-like polyurethane. They do this to ensure a match between the mixture and the industrial part. They usually have a data sheet on which they make references about all the information they require about the materials they used for casting.

This information helps them ensure that they produce a resin that matches the master model. Next, manufacturers pour the mixture into the empty cavity to get a finished product. Then, the resin goes through a curing process in a vacuum. Putting the resin in a vacuum avoids trapping air bubbles.

Vacuum casting is a good option for a company or large industries that need to meet deadlines in a short period and want to have functional and working prototype testing. In addition, it is the better choice for prototype model making since it is fast and simple.