Hi Ganesh,

I have limited conveyor experience and no conveyor manufacture experience, but I did work with rubber for some years. As no one else replied to your question, I'll share some of my knowledge.

I am not sure what was meant saying belt can't be manufactured in one go. It is quite normal to place sheeting of un-cured rubber together and press it for curing, but trying to stick another layer on already cured product is not very smart. I don't think they did that (too silly), more likely there was some problem bonding layers of uncured rubber. Generally, to make a rubber product you place layers of uncured rubber together and put it under pressure and temperture for curing. Curing elastomers is bonding molecules in longer chains and, as any other chemical process, it is happenning much faster on higher temperatures, but it does occur even on room temperature (but much, much slower).

To be able to make rubber sheeted products, uncured rubber is squeezed between rollers (calenders) in to sheeting of controlled thickness. If that sheeting is held too long in storage, or if storage room is too hot, it can happend that just surface molecules bond together (skin cure). Once cured, they would not bond properly to the other layer. Using skin cured sheeting will cause lamination of finished rubber product and that is fairly common (and well known) problem in rubber industry.

So, this may be the explanation, but you already did the right thing: find some trustworthy supplier. ■