The tiles are not bonded by epoxy directly to the pulley steel shell.

Tiles are normally supplied in sheets with a rubber backing and rubber interlaced between tiles. The rubber backing is cold bonded with a chemical that fuses the rubber to steel.

Manufacturers such as: Bellbane, Rema Tip Top, and Richwood have procedures for such. Contact them.

Lawrence Nordell

Coneyor Dynamics, Inc. ■

Snymanhl:

The industry has gone to ceramic tiles imbedded in rubber for the following reasons:

1) The rubber allows the use of small flat tiles without creating problems on the circumfrence of the pulley.

2) The rubber provides an impact cushion, which helps prevent tile breakage or loss when material gets caught between the pulley and belt.

3) Production costs are lower if the tiles can be cast in sheet rubber pads.

As far as documentation concerning the use of tile directly on the pulley is cincerned, I am not aware of any studies. I can however suggest two potential problems -- cost and service life. The cost to have tile made to fit the individual pulley circumfrences and to glue them in place individually is probably higher than what is acceptable. The service life of the tiles should be lower than that of the rubber backed ones due to the lack of cushioning.

Finally, are you sure that you need ceramic lagging?

Regards, ■

Hi all,

We are finding a growing trend in South Africa, Australia and the U.K to bond ceramic tiles directly to drums with an epoxy adhesive.

Large wearing companies like multotec ( South Africa ) CUMI Wulfenia ( Australia )and Kingfisher ( U.K ) have been pioneering this application.

Our Eli-Bond FR961E1 is now an established product to bond these tiles down.

Basically a strip of back bonded tiles is laid across the drum, and diagonally bonded with a two-part thermoset adhesive ( FR961E1 or similar ). A polyethylene rod ( approx. 25mm diameter ) is laid between the tiles to form a draining channel.

We have found good results with no significant belt wear, slippage or tile loss.

Reason for moving away from ceramic-embedded lagging sheets : poor quality product coming out of India which causes the tiles to " pop " out as the sheet is being bent around the drum.

For more details, please visit :

www.elichem.co.uk

Regards,

Aram Friedrich

aram@elichem.co.uk ■

Hello Aram,

These have not shown up in the US yet (to my knowledge), probably because the lagging sheets are made properly.

The strip method would get around the application time problem.

I assume that the Eli-Bond FR961E1 has three functions -- bonding; cushioning; and void filling (to allow a flat tile to be bonded to a curved surface).

Is there a reason for applying on an angle, as opposed to transversely?

Regards and keep up the good work. ■

Hi There..

I have been doing a lot of comparisons with ceramic lagging here in South Africa over the last 6 years on numerous small as well as all of our very large installations.

There can be no doubt from my results, that ceramic tiles of the correct size, bonded with the correct epoxy (very important) directly to the sand or shot blasted steel pulley shell is the only way to go.

We are busy with Part 2 of SABS 1669 (pulleys) which deals with lagging at present.

Please feel free to e-mail me at gspriggs@global.co.za for details of my findings if you like. ■

Dear Sir,

In normal chute application, the ceramic tiles directly embeded to steel sheets come out due to the poor bonding or practical difficulty in achieving the perfect bonding. For pulleys it may be more difficult than in chute due to the pressure by main belt. Since there is some system supplied we have to see the performance after put into operation for some time.

It appears more difficult to maintain the perfect bonding with direct bonding.

regards

subra ■

Dear Mr Ken,

It is interesting if proven design already available. can we have more details to suggest to our clients?

regards

Subra

AE Automotion (M) Sdn.Bhd

10&12 Jalan mas 6, Taman cheras Mas

Cheras 43200 Selangor D.E.

Malaysia. ■

Does anyone have info on what this does to coefficient of friction between the belt and the ceramic lagging as discussed when applied to drive pulleys? ■

Dear all,

This reply is not for the purpose of joining in the ongoing discussion on ceramic pulley lagging. As an Indian and being in the ceramic wear resistant applications in the last 10 years, I take offence in the statement by Mr.A.J.Fredriech of Elichem saying "the poor quality ceramic lagging out of India". Such blanket statements admonishing products out of a particular country is unwarranted and calls for immediate retraction and apology. Understand these forums can be used for marketing products from the members' company but this should be done sensibly.

Sushil ■