Second Greymouth Plant For Timber Treatment

Press, Volume C, Issue 29523, 26 May 1961, Page 15

Second Greymouth Plant For Timber Treatment

A timber treatment plant is to be installed by the Greymouth Timber Company in its yards in Gresson street, Greymouth. The first treatment plant to be established in the Greymouth area was that at Karoro by Duncan Hardie. Ltd., which was opened last year. This plant operates under the diffusion treatment system. whereas the new one is of the pressure vacuum type —the first of its kind to be installed on the West Coast. Sheds have already been erected, and some of the laboratory equipment has arrived from an Auckland firm, whose employees will undertake its erection.

The manager of the Greymouth Timber Company (Mr D R. Holcroft) said yesterday that, although the West Coast was the centre of the timber industry. Greymouth was one of the last major centres to have such a plant installed

In describing the pressure processes for the treatment of sappy timber. Mr Holcroft said that in the full ceil method, such as was being installed in Greymouth. the timber was loaded into a pressure cylinder and a vacuum was drawn to reduce the pressure of air on the wood cells Then the cylinder was flooded with preservative and the pressure was built up to 2001 b per square inch, until no more preservative could be forced into the wood. At the end of the treating cycle, which takes several hours, the amount of preservative salts injected into the timber could be ae-

curately measured. By varying the strength of the preservative solution, different loadings could be obtained. With solutions such as creosote, which could not be economically diluted, a variation of the process, involving compressed air instead of the initial vacuum could be used. This was known as the empty cell method, said Mr Holcroft.

The equipment would cost thousands of pounds, but he could not estimate the figure, added Mr Holcroft, who said it was anticipated that the new plant would be operating in about two months’ time.