AUTOCLAVE, INDUSTRIAL EXTRACTS FACTORYc. 1960
Black and white photograph.
Woman or young man, standing in centre of photo with back to the camera.
Appears to be clearing sawdust (?) from the autoclave into a hopper below.
Wood chips were fed into the autoclave, then steamed under 310lb pressure.
This caused the tannin to be released from the wood fibre.
The dissolved tannin, now in liquid form, then underwent various purification processes.
Eventually all of the water was extracted and the tannin was marketed in either powder or solid form.
The sawdust left behind the in the autoclave was used as fuel for the boiler.
Industrial Extracts was a subsidiary company of Plaimar, and was formed in about 1935.
The major factory was at Boddingon, Western Australia. Two mills there worked 24 hours a day during WW2 to meet the national demand for tanning extract. A third tanning mill was built in Toodyay and opened in May 1952. In 1971 the Toodyay factory closed when it became uneconomic.