Mohandes,

Thank you for one of the more comprehensive threads of recent times. You've clearly done your homework & couldn't find the solution you wanted. Many recent thread starters don't even know what homework is!

You could safely approach your intended supplier(s) about tolerance & fixing issues. Standards probaly do not exist because of the nature of the polywhatnot panel which would swell when wet and shrink when dry, what else. This could affect fixing stability. Suppliers should probably offer inserts which might be prorietary and outside a Standard's scope.

Try to worry less. ■

Well, it would be good if the polyurethane deck or rubber panels....was a fore-thought vs an after thought when purchasing a vibrating screen.

if the screen box is built for flat polyurethane or rubber panels......they typically are installed on a aluminum or steel grid that installs ontop of the support members of the screen.

if you do this on original order quite easy.....

but, if you do it for example: changing from wirecloth to these....somewhat more difficult but, not impossible.

We do either way in our mfg plant...no...standard ....just careful calcs by engineers to ensure the machine will in fact have enough speed, throw to allow the panels to work with the extra wgt being carried vs wirecloth.

A fantastic company who will guide you completely with their absolute expertise.....is an outfit called POLYDECK...in USA.

Goggle them and give em a call. Many details like OPEN AREA lost by going to polyurethane or rubber vs wirecloth.....must be thought about clearly.

George Baker - MODERATOR.

Originally Posted by louispanjang

Mohandes,

Thank you for one of the more comprehensive threads of recent times. You've clearly done your homework & couldn't find the solution you wanted. Many recent thread starters don't even know what homework is!

You could safely approach your intended supplier(s) about tolerance & fixing issues. Standards probaly do not exist because of the nature of the polywhatnot panel which would swell when wet and shrink when dry, what else. This could affect fixing stability. Suppliers should probably offer inserts which might be prorietary and outside a Standard's scope.

Try to worry less.

■

Originally Posted by mohandes

Dears,

We have a vibrating screen and I would like to buy polyurethane media.

However I worry about the installation of panels in screen.

Is there any international standard for polyurethane media?

Is there any standard for tolerance of overal dimensions?

I have seen standard for other type of media such as:

ISO 7085 for plate screens and

ISO 4783 for wire screens

but I have not found anything for polyurethane or rubber.

If you have time visit the www.trellborg.com home page they have

lot of screens that are coated.

just be sure to have handfull of screen check cards to check you screens

after installation as you wil be adding more weight. ■

The answer to the two questions below are quite firm and easy:

1. if you use a "REPUTABLE" manufacturer/supplier of polyurethane, they will guarantee it will work and they will have ZERO issues with the polyurethane panels coming loose from the GRID that they are secured into. The issue of panels coming loose is a non-starter with a "brand name reputable company" at all.......it really does not happen....in my experience.

2. Those mfrs make the poly panels to a tight tolerance on all dimensions and the same with the grid they supply to take those panels. You must make sure the screen manufacturer guides you, and really OK's the installation and makes the adjustments to the weights on the wheels to ensure proper speed and proper stroke....to operate with the extra weight of poly panels on the deck vs wirecloth.

3. My company mfrs vibrating screens: we go to POLYDECK 1ST..WHY? WE trust them, they have knowledge, they specify the opgs to do the job vs wirecloth, they work with you to get the setup right, they help to fine tune after the sale either onsite or by phone, they are in fact, seriously, EXPERTS. They will NOT leave you hanging...at all.

4. Tema and Trellex and a couple of other major suppliers in NORTH AMERICA...quite good in their own right.

Not a problem to install, tolerances are normally met by the poly manufacturer, as long as you give them proper dimensions on your screen box setup.

IT IS SIMPLE...really.

Originally Posted by mohandes

thanks for your attention.

As you know every dimensions include tolerances.

for example if the nominal width of screen is 2000mm, it doesn't mean that the real dimension is exactly 2000. Maybe It can be a number between 1996mm to 2004mm.

So when I would like to install polyurethane panels in a screen, (purchase from another one and install it by mysself)

how I can become sure that the polyurethane manufacturer will consider the screen dimension tolerances?

how I can become sure that the polyurethane panels will not loose during operation?

■

George's advice here is good, go to a reputable panel supplier and you won't need to worry about the tolerances, retainment, reinforcement frame design or material.

Most modular poly panels are designed to fit a specific fixing system, such as longitudinal bars that hold the panels down or pin systems that fit through the deck stringers

The fixing system will take care of the panel tolerances and ensure they don't pop out.

You also should consult with the screen manufacturer, different deck constructions have different masses, this can mean too much or too little screen acceleration, overloading the crossmembers and build up on the deck.

Pegging/Blinding/build up on the deck, whatever you want to call it, is not only going to affect your screening efficiency, it may also overload your screen crossmembers.

A different deck construction can also change the dynamics of the screen, so again consult the manufacturer, they may advise the screen gets a bump test after you fit the new deck to ensure you are not running on resonance.

As to the material of the reinforcing frame, if the panels are moulded properly, you won't need to worry about corrosion until the panels have worn down to the metal and by that time they will be way past their use by date...

So IMHO for stainless, you are probablly going to end up paying more, and get very little benefit.

Can I ask, what kind of screen do you have?

Simon

Originally Posted by mohandes

I have asked about the material of reinforcement steel frame of polyurethane panels for a wet screen of iron ore plant:

some offered stainless steel and

others offered carbon steel

which of them is correct?

■