Friction materials

• Pages: 52-54

16. Friction materials

16.1. Fibre preparation and mixing

16.1.1. (1) Raw fibre should be supplied only in closed containers, such as

impermeable paper or plastic bags.

(2) Where practicable, these containers should be opened by automatic

means and discharged directly into enclosed mixing systems.

16.1.2. Where bags of fibre have to be opened manually, this operation should

be carried out only within a partial enclosure equipped with air extraction ventilation

sufficient to control all asbestos dust emissions during bag opening.

16.1.3. Dry mixing operations should be undertaken only in enclosed systems

under negative pressure.

16.1.4. Local exhaust ventilation (dust extraction) should be provided at feed

points for additives and at discharge openings.

16.1.5. Where wet mix or plasticised materials are used in open systems, waste

and dried out residues should be cleared by vacuum-cleaning equipment or by other

dustless methods.

16.2. Transfer of mixed compound to moulding and forming

16.2.1. Wherever practicable, totally enclosed systems should be provided for

the transfer of compounds from the mixing area to the processing machinery.

16.2.2. Where manual methods of transfer have to be employed, closed

containers should be used and arrangements should be made for coupling the containers

direct to the processing machinery in a manner which eliminates dust emission.

16.2.3. If tipping or manual transfer of compounds from transit containers to the

processing machinery is necessary, suitable dust extraction equipment should be

provided to prevent the dispersion of dust into the workplace.

16.3. Pre-forming, forming, curing and moulding machines

16.3.1. Automatic systems for dispensing fibre compounds to press moulding

boxes should be used where practicable.

16.3.2. Suitable dust extraction equipment should be fitted to all points of

possible asbestos dust emission.

16.3.3. Fettling of moulded components should be carried out only under local

exhaust ventilation.

16.3.4. When goods which are being processed are in transit from one machine

or section to another, they should be conveyed in closed systems or containers.

52