Bearing company Bearing Man Group’s (BMG’s) belting division has extended its range to include the Super-Screw, which is a flexible rubber splice developed by Minet Lacing Technology (MLT), in France, that screws onto a conveyor belt providing efficient repair in all conditions.
“BMG originally used the Super-Screw splice as a temporary alternative to conventional hot and cold splicing, but the efficiency and high strength of this product in arduous test conditions locally proves this system to be totally reliable as a permanent splice,” says BMG belting division GM Donovan Scott.
In some cases, the Super-Screw exceeded the tensile rating of hot and cold splice samples of the same class rating.
Scott highlights that BMG has used various belt classes and widths to test the Super-Screw in different applications over the last two years and the South African Bureau of Standards has also successfully trialled the product on 100-mm-wide belts.
This new high-strength splicing system, which can withstand service tensions up to 200 N mm, is the quickest way to repair a belt in any emergency situation, which significantly reduces downtime. The mechanical joining technique is quick and easy to complete, without the need for a skilled operator and heavy, expensive equipment.
“This reliable leakproof system can be used for joining a belt, repairing a longitudinal rip, or a puncture in a belt. This splice is compatible with small pulley diameters and is scraper and tail pulley protection V-plough friendly,” says Scott.
“With training from BMG, an in-house maintenance team can quickly and efficiently install this product, using a simple tool like an electrical- or battery-powered screwdriver,” he adds.
These screws are self-drilling and self-tapping, spreading the carcass threads, without cutting them and no predrilling is required.
The rubber material, containing tensile fabric used for the splices, is manufactured in rolls up to 25 m in length, and in various strength ratings from Class 315 to Class 2 000 conveyor belting. This system is also available in a ready to install option, with maximum precut lengths of 3 m and preinstalled assembly spacers.
Steel screws are twisted into an embedded nut inside the material, forming a sandwich effect of the top and bottom cover that clamps onto the belt carcass. The surface of the splice is level with the two ends of the original belt, making the splice surface as even and as thick as the belt itself. It is fitted at the bias, like regular splices, to ensure optimal strength and flexibility around the pulleys.
This system, which is available in different qualities of rubber, suitable for various applications, is easily installed regardless of the configuration of the conveyor belt and irrespective of accessibility and weather conditions.
The materials are abrasion, heat, fire and oil resistant and heat retardant, up to 200 °C. They are also available in a Food and Drug Administration (FDA) approved grade for food conveying. The nonmagnetic system has metallic inserts made of stainless steel, with stainless steel screws.
The company notes that in selecting the correct Super-Screw fastener for each application, factors to be considered include the belt tension and strength of the belt, as well as the final belt thickness required. The rubber quality for each specific application is also important.
BMG has conducted a field test for all splice types in the same conditions, using the same belt type and width. Results show that a conventional hot splice takes several hours, a cold splice takes over eight hours (including curing), while the Super-Screw takes less than one hour to be installed.
Ambient conditions have to be considered before a cold splice can take place – if the humidity levels are too high, the adhesive may not be effective.
“The Super-Screw’s advan- tage is that it is effective in all weather conditions. It is an alternative solution that reduces total cost of ownership, while reducing risk,” notes BMG.