How to create a good sand mould (part 2)

Published - 29th May 2018

In our last blog, we looked at the importance of using high-quality sand, chemical binders and catalysts to create a good sand mould. In this second part, we look more closely at some of the other key factors.

Accuracy of the pattern

Firstly, the accuracy of the design and pattern plays a crucial part in this process. Patterns are manufactured by specialist patternmakers from a high-quality resin. These are based on paper designs, 3D models or software drawings supplied by our customer.

Once produced, the pattern is secured in the wooden moulding box in readiness for the sand to be added. Ultimately, top-class patterns provide the base for top-class castings.

Controlling the efficiency rate

Secondly, our foundry team must carefully control the production time. Once the sand mixture has been added, it needs time to harden or set. The outside air temperature can affect the rate at which this process occurs – which can have a negative impact on production times.

To address this problem, we adjust the quantity of the catalyst used in the sand mixture for different temperatures. In cold weather conditions, a higher quantity of the catalyst is needed for the sand to set. Conversely, in hot weather, the sand will set at a much quicker rate naturally and so a lower amount of catalyst is used.

Recyclability

The third aspect is the recycling. As we’ve mentioned previously, we recycle 100% of the sand used at Haworth Castings. As well as offering huge environmental and economic benefits, recycling also allows us to control the properties and ingredients of the sand.

The chemical additives enable us to ‘shake out’ the sand from the moulds very easily and break them down for recycling. The sand is passed through a thermal cleaning area and the heat removes all the residual chemicals.

The result is pristine sand, giving our castings an excellent definition. This reclaimed sand can then be used for further casting work.

To find out more about Haworth Castings, please call us today on +44 (0)1794 512685 or email us: sales@haworthcastings.co.uk