Dear Sir,

I had the same experience with a conveyor of 1000 mts (c-c) length. after thorough investigation we came to know that tension in the belt is on higher side which is leading to failure of splicing.

Sincerely

Ravi Kumar. ■

Not much info to go on here.

Is is steel cord or fabric belt? Hot vulcanised or cold?

Please explain the type of failure. Did it completely pull apart or is delaminating.

The more info you can give the better answer you will get. ■

Sounds like a bum conveyor/splice design. There are many contributing events that can cause the splice to fail beyond poor installation techniques.

We evaluated a large steel cord installation that just had two failures. The client asked for a design review. The splice design was predicted to fail within two years from the operating cyclic loading. He had another 10 to go.

The next three continued to fail quite rapidly, once the first failure was noted. A new splice design corrected the problem. That said, the conveyor design could have been corrected some of the conditions, but not all. The manufacture produced a bad splice design concept. ■

Dear Gareth,

I came back to forum just searing my knowledge and experiences either I am not active for several years.

Basically you have to check few factor to belt splicing :

1. Belt splice design

2. Raw Material belt splice which you use. Expired or not. Suitable with belt specification or not.

3. Weather condition when to do splice.

4. Equipment condition, means avaibility vulcanizing machine which you use.

5. Proper tools when belt splice preparation.

6. Manpower skill

7. Others factors, eg. belt mistracking, overloading, uncured/overcured splice, etc

Please you re-check base on above list. May be the problem coming from above factor.

I will be waiting your reply, so we can discuss it further.

Good luck! ■

Mr. blakeyg,

There may be any (or more) of many reasons for premature belt splice failure.

- Radius of curvature violations can result, at any point along the belt line, in local overstress or local buckling (relaxed belt) or both simultaneously. Either can initiate splice failure and accelerate the failure rate by fatigue.

- Similarly with poor transitions.

- Damage from poor belt alignment can also intiate splice failure.

- Belts bending over pulleys of too small diameter are subject to carcass crushing. This can cause premature splice failure.

- Other reasons.

You cannot guarantee a perfect splice but you can hedge against a mediocre one. For our DSI Snake Sandwich High Angle Conveyors we regularly specify an increased bias angle (typically 45 degrees) at the multi-ply fabric belt splices. This creates a more favorable orientation of the shear and tensile splice forces that vectorially make up the net tensile forces. The increased splice length also reduces simultaneous exposure to the aggravations.

Joseph A. Dos Santos ■

Hi Gareth

I went some time ago to West Africa to consult on (amongst other things) the frequent failure of belt splices on a long jetty feed conveyor.

The client was at the end of his wits as the failure of this conveyor was loosing him millions of dollars per year through waiting ships. All this and the running safety factor of his steelcord belt was over 8:1, but even Goodyear America couldn't make a splice area that would hold properly.

So.. I did some serious calcs (that even Larry would be impressed with) and found that if you take the absolute worst case for the dynamic behaviour of the belt, the safety factor drops from 8 to only 3.

I also found that the safety factor of 3 isn't really a safety factor at all as it would only apply to a perfectly flat belt in a test rig and not one negotiating transitions, pulleys etc

I changed the number and configuration of the six drive units, changed the start sequence, and met the Funke ramp requirements, got the take-up right, got viral encephalitis, and their problem was solved. (Mine just started, I've never been so sick in my life)

Anyway, all this ended up in one of my papers in Beltcon 12. The splice problem is history, as are 90% of my brain cells.

Cheers

LSL Tekpro ■

Dear Graham,

First, I am impressed with any and all who give serious thought and input to this forum.

Second, I am impressed that you can function better than most on 10% and with both hands tied.

Third, I cannot find your noted contribution to BELTCON 12, July 2003. There were 15 papers. I found your "prezel" paper. No reference to splicing. No second paper. Am I missing one? ■

Morning Larry..

I realised when I woke up this morning in my normal state of confusion, that it is in fact in one of my papers in Beltcon 13 and not 12.

(I attribute this error not to premature senile decay... but of course to the aforesaid brain damage..)

Cheers

LSL Tekpro ■

I am a vulcanizer i having exprince is 14years in this fild please tel me steel cord &farick belt

D.elangovan ■

sir

please tel me steel cord &bafric belt ■

Hot vulcanisation for belt splicing is a chemical reation between the rubber in the belt and the splice kit materials aidded by heat and pressure. There are a number of factors that will effect a belt splice. The quality of the rubber compound used in the belt has a big effect on splice quality. If the belt that is failing now is new belt. What has changed? If this is the same belt that is failing regularly, the application may have aged the belt to the point that a hot splice is not resulting in a chemical cross- linking. Either use cold bond or the belt is in need of replacing soon. Feel free to forward any othe info that this forum has raised

Regards Murray ■

Murray..

I am very glad you refer to a hot splice and a cold bond.

The term used somewhere previously above, i.e. "Cold Vulcanising" is not strictly correct. as vulcanising by definition requires heat, so a cold, hot splice is a non-sequitur.

Anyway, as stated many times before ad nausium, I have had much better better luck with cold bond on fabric with good old SC2000 than with hot splices.

Regards

LSL Tekpro ■