Pultrusion is the most efficient method of strengthening polymer products with high performance fibres- such as fibreglass. Instead of pushing, or extruding, the polymer, Pultrusion calls for the product to be pulled through a resin bath and then through a heated die in order to maintain control and uniformity of the fibres being embedded within the polymer. This enhances the structural integrity, consistency, and quality of the composite product.
The inventor of the modern day Pultrusion process was the Californian, W. Brandt Goldsworthy (1915-2003), whose patent was filed in 1959. However, as early as 1944, patents for processes similar to Pultrusion were being filed, first by J.H. Watson, and later in 1950 by M.J. Meek.
W. Brandt Goldsworthy studied mechanical engineering at the University of California, Berkeley, in the 1930s. His career in the composites industry spanned nearly seven decades, and in that time he was awarded over fifty patents. His interest in composite materials began during the Second World War, when he worked on a project to combine phenolic resin with fibreglass to create one of the first fibreglass reinforced, laminated tools.
This process was important for the war effort and the composite was used to make chutes to support machine gun cartridges in aircraft.
In 1945, he founded Industrial Plastics Corporation- which he later sold in 1956. It was around this time that he first started work on Pultrusion, and later founded Glastrusions Incorporated where he invented the Glastruder Pultrusion system. In 1956 he became a consultant in composites development, and in 1966, he founded Goldsworthy Engineering Inc. to create automated equipment to process composite products.
One of Pultrex’s original founders David Shaw-Stewart worked with Brant Goldsworthy in California for a number of years developing the Glastruder Pultrusion machines. These machines were the first of their kind and paved the way for the commercial pultrusion lines and processes used today.
Following his time with Goldsworthy, David returned to the UK and formed Pultrex Ltd with colleagues he had previously worked with at an engineering company prior to his work experience in the USA.