CATCHING UP ON AUTOMATION.

The most rapid development in screening plant is the use of new materials for screen mats. The Trelleborg Group have introduced both rubber and polyurethane screen mats and claim that the rubber in their Trellfix plates is tougher than steel and results in lower noise levels and much quicker replacement time. Isenmann has also developed a range of polyurethane screen mats which can be supplied as made to measure replacement screen elements, flat reinforced, single and double camber, transverse or longitudinal stretched, suitable for most known makes of screen. The Allis-Chalmers subsidiary has developed many different standards of automation from simple interlocks to completely computerized production. 'In-pit' crushing certainly represents the second significant trend. Because energy and labor costs have risen steadily in recent years, research work on more economical quarrying methods has been accelerated.