Mechanical Technology

Mechanical Technology — November 2015

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Proactive maintenance, lubrication and contamination management

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“

his high strength splicing system is a flexible

rubber splice using self-tapping screws that en-

able Super-Screw to be installed regardless of the

configuration of the conveyor belt and irrespec-

tive of access and weather conditions,” says Donovan Scott,

divisional manager, bulk materials handling, BMG. “The current

trend in industry is to avoid the use of hazardous substances

where-ever possible. Trichloroethylene, a hazardous solvent

used in conventional hot and cold splicing procedures, can now

be replaced by using the Super-Screw system as a safe splicing

alternative,” he argues.

BMG, in conjunction with the SABS, has used various belt

classes and widths to test the Super-Screw in different ap-

plications over the last three years. Further tension tests are

currently being conducted through the CSIR on various splice

types and on wider belts (500 mm). “We expect to achieve

even better results, and these will be published in the next six

months,” he adds.

Field tests indicate that the Super-Screw is the quickest

method to repair a conveyor belt in an emergency situation,

significantly reducing downtime. The mechanical joining

technique is easy to complete, without the need for a skilled

operator and heavy, costly equipment. This system, with high

tensile strength, has proved to be a suitable alternative to

conventional splicing methods. In some cases, the Super-Screw

exceeds the tensile rating of hot and cold splice samples of

the same class rating.

“Trials, using the same belt width of 600 mm, also demon-

strate that a conventional hot splice takes seven hours, a cold

splice takes over eight hours (including curing), while the Super

Screw can be applied in less than one hour,” Scott points out.

This leak proof system can be used for reliably joining a

belt, repairing a longitudinal rip or a puncture in a belt. The

Super-Screw splice is compatible with small pulley diameters,

suitable for pipe conveyors and is conveyor scraper and V-plough

friendly. This flexible splicing system can also be used inserting

new belting into old conveyor belt systems. The screws are self-

drilling and self-tapping, spreading the carcass threads without

cutting them. No pre-drilling is required.

Super-Screw, which can withstand service tensions to

2 000 kN/m, is available in various grades of rubber, to suit

exact requirements.

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 pre-cut lengths of 3.0 m and

pre-installed assembly spacers.

These materials are abrasion-, heat-, fire- or oil-resistant

and heat-retardant at up to 200 °C. The non-magnetic system

Super-screw conveyor belt splicing

Above:

BMG’s Super-Screw belt fas-

tener system screws onto a conveyor

belt for an efficient repair in all

conditions.

Right:

The mechanical joining tech-

nique is easy to complete, without

the need for a skilled operator and

heavy, costly equipment.

BMG’s highly efficient belt fastener system – the

Super-Screw

– which was originally used as a

temporary alternative to conventional hot and

cold splicing, has proved to be totally reliable as

a permanent splice for conveyor belt repairs.

has metallic inserts made of stainless steel, with stainless

steel screws.

The steel screws are screwed 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

on the bias, like regular splices, to ensure optimal strength and

flexibility around the pulleys.

In selecting the correct Super-Screw fastener for each ap-

plication, factors to be considered include the belt tension and

strength of the belt, as well as the final belt thickness required.

Each rubber cover type has important features for specific ap-

plications, including heat and abrasion resistance, as well as

adherence to food grade specifications.

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.

With training from BMG, an in-house maintenance team

can quickly and efficiently install the Super-Screw system,

using a simple tool similar to an electrical or battery powered

screwdriver.