BMG’s belting division has extended its range to include the Super-Screw, a flexible rubber splice - developed by MLT in France - which screws onto a conveyor belt for 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 Donovan Scott, general manager of BMG’s belting division. “BMG has used various belt classes and widths to test the Super-Screw in different applications over the last two years and the SABS has also successfully trialled it on 100mm width belts. This system, with a high tensile strength, proved to be a suitable alternative to conventional splicing methods. In some cases, the Super-Screw exceeded the tensile rating of hot and cold splice samples of the same class rating.
“This new high strength splicing system, which can withstand service tensions up to 200N/mm, is the quickest way to repair a belt in any emergency situation, significantly reducing downtime. The mechanical joining technique is quick and easy to complete, without the need for a skilled operator and heavy, costly equipment. This leak proof system can reliably 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 V-plough friendly. 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 screw driver.”
These screws are self-drilling and self-tapping, spreading the carcass threads, without cutting them. No pre-drilling is required. The rubber material, containing tensile fabric used for the splices, is manufactured in rolls up to 25m in lengths 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 pre-cut lengths of three meters and pre-installed 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 access and weather conditions. These materials are abrasion, heat, fire or oil resistant and heat retardant, up to 200°C. They are also available in an FDA approved grade for food conveying. The non-magnetic system has metallic inserts made of stainless steel, with stainless steel screws.
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’s conducted a field test for all splice types in the same conditions using the same belt type and width. Results showed that a conventional hot splice takes seven hours, a cold splice takes over eight hours (including curing) and the Super Screw takes less than one hour.
In addition, 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. An advantage of the Super Screw, is it is effective in all weather conditions. It is an alternative that reduces total cost of ownership, while minimising risk.