Industrial visit to Thredgards

Thredgards are a company based in Alloa that specialise in Injection Moulding. We had a great wee tour around their production facility. They have a lot of expertise in the area, and as part of their service they aid their customers with design of components. Design for mass production is often slightly different than a final product concept by the designer, so feedback occurs before the product gets rolled out. There is a dialogue that is carried out between the design company and the production company to get the details just right. Sometimes, this can take several iterations of production. 

An injection moulding machine.

Nurdles - pellets of plastic that feed into the machine through a hopper.

Half of the mould

A rotating device knocks products off the conveyor belt, whilst sprues pass underneath. Good automated way to separate the wheat from the chaff.

A shot from the side. 

Multiple components are moulded simultaneously through use of a sprue, which is then separated from the products. 

Waste plastic such as sprues are fed into a machine that grinds them up.

This plastic is then reused inhouse - usually mixed 50/50 with fresh nurdles.

Due to the complexity of some products, moulds sometimes use sliding parts, which require more space. Thus some moulds are pretty big! Design and manufacture of the mould is the most expensive part of injection moulding - once actually up and running, the operating expenditure is very cost effective. However 3D printers may soon be used to cheaply manufacture injection moulds, as we learned from our trip to CA Models.

Detective work: Finding ejector pin marks on injection moulded products

Case study: This golf product took several iterations of the manufacturer and designer working together to achieve optimal characteristics of durability, springiness, light reflectivity, and touch properties.