Noise control in the wood processing industry

Abstract

This survey of noise in sawmilling and the wood processing industries was commissioned by ACC and carried out by the University of Otago with the aim of assessing noise within the industry and identifying simple solutions to reducing the noise.

In general, noise levels were in the 90-100 dB range, regarded as very noisy. Few workplaces in New Zealand have such consistently high levels. Although the problem might seem insoluble, simple solutions at each stage could be identified. At the source of the noise, new designs of both band and circular saws can reduce the noise by up to 6 dB (a quarter of the noise). During sawmilling operations, a significant amount of noise came from timber handling, where damping of panels and reduction of “ringing” noise by filling rollers with sand could once again reduce the levels by 3 dB (half the noise). These are all critical points for action by the industry.

Enclosures were quite often provided, particularly with planers and “four siders”, but periodic inspection and maintenance of these is necessary: door seals deteriorate, as does insulation around infeed and outfeed openings.

Similarly, noise refuges were noisier than they should have been because of door seals and uninsulated floors.

Lastly, hearing protection is not “fit and forget”. Individuals require to be trained in their use, particularly plugs which can be very effective if fitted properly. Previous reports by Welch et al (University of Auckland School of Population Health) have shown that the compressible plugs are often fitted very badly (the use of the “VeriPro” or other monitoring equipment has confirmed this).