A molded edge belt proves it has not been slit. A belt slit (for example 2000mm slit in half to make 2 x 1000mm) can cause camber (cupping) to occur in the belt after tensioning - this can also make it harder to train the belt. So unless you are sure that the belt has not been slit you would be better off with a molded edge belt.

A molded edge also protects the carcass of a fabric belt from a harsh environment that may damage the carcass. It does not have any structural advantage. ■

Hi Karthik..

Moulded edges came from the old days of cotton duck plies, where if you got moisture in them the edges of the belt would rot.

When steelcord belt came out moulded edges were used as there is no alternative.

However, we now have EP, Nylon and synthetic carcass belts which do not rot so we no longer have to put up with the moulded edges on them.

We still of course have moulded edges on the steelcord belt and this part is still the belt's Achilles heal.

Thank heavens we don't have to put them on the edges of synthetic carcass belts anymore. They are very susceptible to damage if there is a bit of belt wander, and do nothing for the strength of the belt (and in fact make it less strong) and make them more difficult to make too.

Also, if for example you want 900mm wide replacement belting, and the local supplier only has 1800mm, then simply drive the belt through their machine that accurately cuts it longitudinally, and you are sorted. Moulded edges on the mother belt would destroy this possibility.

To this day I still battle with some clients who specify them!

Cheers

Taggart LSL Tekpro ■

dear karthik

for N/N 1600/4--IT IS BETTER TO GO FOR CUT EDGE CONSTRUCTION

N.KATHIRAVAN

FORMERLY WORKED IN NEYVELI LIGNITE CORPORATION-NEYVELI ■

Dear Mr.Karthik,

If the belt wanders and rubs somewhere, the moulded edge will be detached from the main belt. As per the reply from Mr.Graham Spriggs, for NN ply belt you may not require moulded edges.

Another thought : Why are you not considering EP ply belt ? For rating of 1600, EP would be better than NN ?

Regards, ■

Cut edge belts are selected for $$$$ savings. It is cheaper to make a wider belt and then cut it into smaller sections and not worry about sealing the edges.

This also allows a distributor to carry fewer belt sections/specifications and then cut to suit.

There are not performance benefits from cut edges only potential problems as have been noted. ■

Originally Posted by nordell

Cut edge belts are selected for $$$$ savings. It is cheaper to make a wider belt and then cut it into smaller sections and not worry about sealing the edges.

This also allows a distributor to carry fewer belt sections/specifications and then cut to suit.

There are not performance benefits from cut edges only potential problems as have been noted.

Yes. This is really more of a cost cutting practice.

First time poster! ■

Originally Posted by beltpower

Yes. This is really more of a cost cutting practice.

First time poster!

Dear Experts,

This is regarding Top and Bottom Covers of conveyor belt for handling abrasive Lime Stone.

We are handling imported lime stone from OMAN,which is very abrasive and damages the belt cover.

The present conveyor was primarily designed to handle coking coal (-10),and has M24 cover and speed of 3.8Mtrs/sec.

I have been told that in Australia,some special cover is used for handling Aggregate and the same can be used for Lime stone also.

Opinion of Experts solicited.

Rgds,

Narayanan Nalinakshan. ■

Narayanan

You can specify the belt as Abrasion Resistant covers. Talk to your belting supplier for the actual spec. ■

Dear experts,

A ) Steep angle belts are in general, supplied with moulded edge. Is there any specific reason behind this ?

B ) Moulded edge conveyor belts have better joint life durability compared to cut edge belts joints.

This may be more applicable for company joints , done at manufacturers end to join the plies.

C ) Whenever new belt drums are issued from stores, one or two meters from the ends are removed to avoid weather effect on the joints to be made.

Considering the above there could be few benefits of having moulded edge conveyors, though it could not be quantified.

Regards, ■

Molded edges are required when you wish to seal the internal tensile member from ambient conditions.

Cut edge construction may allow moisture or other contaminants to enter the tensile (fabric) through the exposed edge. ■

At a conveyor belt, molded edges are always preferred to cut edges but not necessarily warranted. The coated synthetic fabrics tend to hold up well in normal use.

After all idlers are properly installed, level and square to the belt line, good belt training is done by skewing of select rollers to impart a surface scuffing that urges the belt in the desired direction. Belt training should never confront the edges of the belt with perpendicular edge rolls as any appreciable pressure will compress and break down the fabric, resulting in de-lamination and mushrooming of the edges.

The pocket belt type steep angle conveyors must maintain strict alignment as failure to do so will result in damage of the sidewalls, at the deflection wheels and at the cantilevered rolls. It is there use of the undesirable confrontational edge rolls that leads them to specify a molded edge belt to attempts to mitigate the damage of this confrontation.

Joe Dos Santos ■