Re: Specification Of Belt
Dear Sir,
I fully agree with you. We have seen customers who demand very extensive requirements in their purchase of belts. The top cover thickness could be as thick as 20mm. When we inspect their damaged belts, most of the belt thickness was around 18mm. The cause of damaged was due to severe cuts.
We would have readily recommend some cut resistant belts but red tapes at Goverment owned companies prevent them from trying newer technologies where competitor does not have or at higher price.
It really depends if the end user is willing to listen, accepting the difference and paying for the difference. Worst case, if the engineering department listen, willing to accept, and request for assistance from supplier but materials management people will call everyone for price war. It is obviously unfair for those that have made the initial hardwork.
Just my personal opinion. I believe material management personnel should join in the engineering discussion so that they realised the difference between the work done and the price they pay. ■
Participationof Material Management
in every industry the belt purchase should be finalised comprising of TECHNICAL EXECUTIVE,MATERIAL MANAGEMENT EXECUTIVE AND FINANCE EXECUTIVE
IT SHOULD BE A TEAM
ANY PURCHASE A COMMON DECISION AGREED BY ALL THE THRE SO THAT THE AREA OF THREE CAN BE TAKEN CARE OF
WITH REGARD TO GOVERNMENT ALL THOSE IT IS THE SYSTEM IT CANNOT BE CHANGED
PRICING FORMULA IS SUCH WHOEVER QUOTE LOW THEY GET THE ORDER HOWEVER YOU INVOLVED SELECTING CORRECT SIZE OF COVERS ETCBEFORE
IT IS AN ART
THE TECHNICAL EXECUTIVE SHOULD BE SHRUED ENOUGH TO GET WHAT TYPE OF BELT HE NEED
N.KATHIRAVAN ■
Specification Of Belt
Specifying a belt and understanding or even getting what you expect requires quite a lot of knowledge about how a belt is manufactured in todays market where price is king. This is especially true with fabric belt and most of the standards to which we purchase a belt is of little assistance. As an example a EP1250/5 10mm +4mm RMA Grade 1 covers purchased from 2 different manufacturers can have performance outcomes as wide as 2-300% dependent on the application. On one hand to get the price down a manufacturer can specify everything to a minimum to minimise costs, on the other hand by heavier skims, improved fabric weave, making the covers to exceed the RMA standards by say 20% in tensile and elongation and with a superior abrasion resistance the belt well exceeds expectations because it has much better cut/gouge properties and much higher resistance to impact. When you see samples of these 2 belts side by side the differences become evident, the fabric in one appears thicker, the overall carcass could 2-3mm thicker overall, the surface finish is better and the rubber appears and feels more elastic overall.
All these differences can be evaluated and measured but because in todays market there is the lack of understanding of how to evaluate these differences price rules. The only alternate becomes recording the performance differences between manufacturers or asking manufacturers to meet performance guarantees and making the effort to ensure they live up to them.
Col Benjamin ■
Re: Specification Of Belt
The belt life does not depend upon the belt alone. The belt life depends upon the belt and the complete design, manufacture and installation of the conveyor. Even high quality belt will have a lesser life if conveyor design etc. is not proper and matching to the belt. Primarily the belt life is depending on following parameters, in addition to the belt itself :
1) Belt tension during continuous operation, as actually occurring. Simple mention in somebody’s design does not mean that it is following the stated value. This will depend upon the expertise of the design set-up.
2) Belt tension during starting condition, as actually occurring.
3) Belt tension during braking, as actually occurring.
4) Pulley diameters.
5) Transition length.
6) Take-up design.
7) Layout arrangement of pulleys.
8) Chute arrangement for loading of the material.
9) Quality of the idlers.
10) Quality of the erection.
11) Quality of the cleaning and maintenance.
The belt life can be calculated / predicted by the supplier or by the designer. Procurement by individual or a team is an administrative issue. The technical consequences can only be decided by the technical people, so involving the non-technical people cannot improve the situation. The participation of non-technical people will be equally important considering the price / business limitation etc.
So, the outcome about the belt life is sum effect of the perfectness and the efficiency of everyone involved in the matter. This is applicable to all the items.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyors.
Advisor / Consultant for Bulk Material Handling System & Issues.
Email : parimul@pn2.vsnl.net.in
Tel.: 0091 (0)20 25882916 ■
Specification
dear mulani
you are talking about the the design aspects
the design aspects has to be studied before initiation of project design,erection and commisionig and full load test say 1000hrs test etc
i am talking about belt performance ,life etc not about design which has been taken care of earlier
so kindly suggest your opinion about how we can increase the
life of the belt
n.kathiravan ■
Specification of belt
the specification of belt requires a great amount of application oriented rather than what readily available in world having different standards
engineers in the end user should study the behaviorial attitude of the present installed belt in the systems and the perpormance should be watched closely
based on the life and performance the belt ,specification should be revised suitable to the particular type of material handling
to obtain a life as guarnteed by the belt manufacturer
mostly i could see less life is obtained than the prescribed life due to various factors governing the nature of opreation
also the belt manufactured by the industries could not be able to be tested due to non availablity of necessary lab equipments in the end user side
suitable documentation is necessary so that the specification could be modified to increase the life of belt
another major point to be considered is there is no required interaction between the belt supplier and the end user
so i request that the bulk on line members could open your mind
on this subject which will be use ful to the belt industry
n.kathiravan ■