Originally Posted by sganesh

Dear all,

Please choose the most preferred and followed the method of joint by you in fabric belts.

Regards,

This topic is not going anywhere, really. I do not think 1 is superior than the other, and I'd say 80% of the longevity of the splices comes down to workmanship & administrative issues. The remaining 20% is the theorectical & manufacturer's recommended procedure, the machinery, the material & the tools. I have personally seen these types of join lasted more than 8 years in service and similarly, some which lasted less than 2 days.

Ideally, uniformed & perfectly manufactured belt, specced correctly for the conveying system with the suitable splicing technique should be the way to go. However, realistically, problems can arise from:

1. Belt defects (many belt manufacturers are making their belts somewhere else, especially during transition phase, belt quality can be inconsistent; we have seen belt delaminate at the curing temperature of 140C using the manufacturer's compound, procedure etc.),

2. More than half the splicing we carry out is using 2 ends of different belt brands, types... sometimes even different thickness, widths & hardness.

3. We assume generally belts are made with NR/SBR rubber and Peroxide vulcanised EPDM's for the Heat Resistant belts. But composition of elastomers vary, although generically possible to join the belts through hot or chemical/cold splices, quality of the joint varies as well.

4. Saturation of market for both belt suppliers and splicing service providers. Those who did not do their job professionally gives a bad rap to the industry or to a certain process (ie cold splices) allowing the less knowledgeable and gullible ones to generalised. This is pain for those responsible party to undo the stigma. case: a company who properly supervise and quality control their belt manufacturing process outsourced to somewhere vs a company who just outsource without supervision.

5. Knowledge base. Both end user and contractor could not identify correctly how the joint is to be carried out. When a belt is thrown at you, like the one described in (2.), there is no textbook way of doing things. Especially coupled with poor administration (ie, no belt stock, poor planning by the maintenance planner, tight time schedule, etc.) you will come into a situation where you can either walk away from a job which you can potentially ruin your reputation and lost time for the client, or you can rely on your experience and skill to give the best possible outcome. The worst situation would be for the contractor assuming the job can be proceeded like normal when is not.

The contractor doing the splicing is also cause of misinformation when job not carried out properly.

Ideally, each joint is carefully planned out, executed and maintained. However, what are the odds of that?

This is the administrative part which is less than ideal, both on the buyer and supplier; Purchasers in some companies are detached from their end users and have not a clue other than the cost, and sometimes, that is very misleading. case: 5 quotes for a same job. 4 quotes are quite consistent where 1 was 4-5 times more costly. The job was awarded 3 times, after 2 contractors failed and the engineer was called in to sit down to discuss the with 3rd candidate who has the highest quote to find out more about the "extended" job scope and agreed to try it. 3rd time lucky, the join is now still in service after 3 years compared to the first 2 tries where the join peeled after 3 days and suffer an 80% delamination after 2weeks. There are alot more problem to this but would take up a whole thread on its own, including plant maintenance planning.

With that said, alot, but not all of the unpredictable factors can be eliminated with an ideal mechanical fastener. Mechanical fasteners can eliminate alot of the guessing work and problems stated above. The ideal fastener which:

1. does not leak.

2. can flex on a fully loaded start up

3. can be installed with little training

4. has no carry back issue

5. can withstand heavy pin-point-impact

6. remains smooth even some parts of the joints (edges) is deformed (due belt sways)

7. remains even with the thickness of the belt (this is great for belt cleaner as well!)

I have personally used Superscrew fasteners and I feel that it is the closest to the ideals listed above, but falling off from point 4 onwards. Nevertheless, this item is often used as a fail-safe situation and has never dissapointed.

So, instead of vouching for a type of splice method, I vouch for a more ideal environment; on both administrative and physical conditions.

cheers. ■