Woodworking Sheet No 27 HSE information sheet
Figure 1 Board edge processing machine
This information sheet is one of a series prepared by HSE's Woodworking National Interest Group.
Coated or laminated particleboard and fibreboard that has been cut to size often requires a decorative edge. Several operations are involved in this process. In essence a profiled or square edge is prepared and then covered with solid lipping, veneer or plastic foil.
The combination machine illustrated is relatively sophisticated and is conveyor fed. Many of the danger areas shown are common to a whole range of machines from hand-fed table-top models to micro-processor controlled soft forming machines. The characteristics of individual machines should be considered when identifying hazards and assessing risks.
The following hazards need to be considered:
Guards should prevent anyone from coming into contact with any dangerous parts of a board-edge processing machine when it is moving or in use. Fixed guards are simple, provide the highest standard of protection and should be used as far as possible where frequent access to a danger area is not required during normal operation or for cleaning or setting. Guidance on fixed guards, on the permissible size of openings in them and on other safeguards is given in BS EN 294.1
In guard design, the prevention of accidents as well as the control of noise and dust should be taken into account. Acoustic enclosure of saws and cutters will usually be necessary. Correctly interlocked enclosures may safeguard these parts effectively. Effective local exhaust ventilation is necessary to prevent the escape or build-up of waste. The waste collection system should be designed to handle explosible dust.
Drive shafts should be enclosed unless they are safe by their position. Telescopic sleeving should be used to cover the main transmission shaft at double-sided machines, to allow conveyor width adjustment. If this is impracticable, an effective trip wire may be substituted and suitable designs can be found in BS EN 294. Fixed guarding should be provided at chain and sprocket drives and to prevent access to trapping areas between rolls or belts and the board being processed.
At the board feed, an adjustable plate may be set to just clear the thickness of board being passed, so that a hand cannot be drawn in between the top conveyor and the board surface. Alternatively, an interlocked trip switch may be mounted on a suitable nose-plate. Conveyor pads should be designed to prevent nip points, particularly at the infeed end where the pads move round the end pulley (see Figure 2).
Interlocking arrangements must prevent access to rotating cutters using either motor braking or time delay bolts. An effectively interlocked noise enclosure provides the best form of safeguarding where close approach to moving cutters is not necessary (eg at automatic machines with electronic setting). Where approach cannot be avoided, the noise enclosure may not be interlocked, but an interlocked transparent enclosure should be provided around each danger area, allowing observation and adjustment by means of extended tools or screw shafts. Arrangements for manually overriding the enclosure interlocking system should not be provided.
Fixed guards may be suitable for certain fixed cutters, provided that permissible openings described in BS EN 294 are not exceeded. Supervision and training may be necessary to ensure that non-interlocked noise enclosures are kept closed when the machine is in use.
The ability of the extraction system to remove waste depends on the cutting action; although fine waste produced by hogging cutters may be extracted, off-cuts produced by saws may require frequent access for waste removal and this should be taken into account.
A system to ensure correct, regular inspection and maintenance of edge processing machinery and associated safety devices should be implemented. The safety devices should be regularly checked by a suitably trained person, taking into account the use of the machine and the manufacturer's or supplier's recommendations.
Figure 2 Conveyor pad design
Adequate training in a safe method of work should be provided for anyone required to work at board-edge processing machinery (including demonstrators). Anyone who has to gain access to the dangerous areas described for maintenance, setting or cleaning should be given appropriate additional training.
Additional advice and information can be obtained from the HSE Information Centre, Broad Lane, Sheffield S3 7HQ (Tel: 0742 892345 or Fax: 0742 892333).
Further copies of this information Sheet may be obtained from the Woodworking National Interest Group, HSE, 14 Cardiff Road, Luton LU1 1PP (Tel: 0582 34121) or from HSE Books, PO Box 1999, Sudbury, Suffolk CO10 6FS (Tel: 0787 881165 or Fax: 0787 313995).
This publication may be freely reproduced, except for advertising, endorsement or commercial purposes. The information it contains is current at 7/94. Please acknowledge the source as HSE.
Printed and published by HSE NIS/08/27 C150 7/94