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Van De Graaff Belt materials

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LAN_403

Plasma Lover

Sun Jan 11 2009, 05:42PM

Registered Member #1911 Joined: Mon Jan 05 2009, 06:30PM
Location: Salem, Oregon, USA
Posts: 165

Hello, everybody,

I've been thinking about building a VDG, but I don't know what I want to use for the belt... The only thing that I can think of to use is a length of overhead sheet that i got from a teacher at my school. I took them to use in capacitors, but it turns out that plastics have pretty good triboelectric properties. My only dilemma is that I have no idea what kind of plastic it is or how it will perform. Can anybody help?

I find myself wishing I had the money to buy a rubber belt...

StevenCaton

Sun Jan 11 2009, 06:49PM

Registered Member #1845 Joined: Fri Dec 05 2008, 05:38AM
Location: California
Posts: 211

The best possible material, as far as I know, is supposed to be neoprene rubber. I believe the thinner the better. Looks like they have some 1.2mm thick. Also, making it with a fat thick belt is cumbersome.

Also, I believe gray is the best color, because a belt that is a bright color, or black might be slightly conductive.

Antonio

Sun Jan 11 2009, 07:55PM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

There are better materials, but these exercise bands are easy to find:

They now have continuous loops too.
I just hope that they are not antistatic, as some similar products are.

Finn Hammer

Sun Jan 11 2009, 11:21PM

Registered Member #205 Joined: Sat Feb 18 2006, 11:59AM
Location: SkÃ¸rping, Denmark
Posts: 741

Some very good material is conveyor belts for the food industry.

These belts can be made to order, length and width, as well as material and thickness.

If you order a belt that is specifically non antistatic, then you get a belt that can run over 100mm diameter pulleys with over 6000RPM.

Cheers, Finn Hammer

Marko

Sun Jan 11 2009, 11:44PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

SteveC wrote ...

The best possible material, as far as I know, is supposed to be neoprene rubber. I believe the thinner the better. Looks like they have some 1.2mm thick. Also, making it with a fat thick belt is cumbersome.

Also, I believe gray is the best color, because a belt that is a bright color, or black might be slightly conductive.

Antonio wrote ...

There are better materials, but these exercise bands are easy to find:

They now have continuous loops too.
I just hope that they are not antistatic, as some similar products are.

Isn't it a problem though, with so stretchy materials, that the charged belt is going to tend to stick together?

One ghetto idea I had was to impregnate nylon fiber tape with chloroprene glue or alternatively liquid latex.

Polyethylene or PVC sheet might work as well if you can manage to glue it into a belt.

Marko

Antonio

Mon Jan 12 2009, 02:21AM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

"Isn't it a problem though, with so stretchy materials, that the charged belt is going to tend to stick together?"

Maybe, with rollers with too small diameter and too small tension, but I have never seen this happen. I have several machines using this material. The belts had to be shortened after about one year of use, but since then are very stable, with only 10-20% of stretching. The produced current is close to the theoretical limit.
A double machine:

A machine with four rollers:

This one has an internal belt:

Nik

Mon Jan 12 2009, 11:39PM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

I use exersize bands in my VDG but some brands OTHER then theraband DO NOT WORK! I have some other brand's rubber bands at the moment and they break down quickly leaving a layer of rubber on the rollers stopping the VDG from working.

Antonio

Tue Jan 13 2009, 12:01AM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

I had problems with a brand of exercise band that is antistatic, and so conductive, and with another that insulates perfectly, but does not generate any charge with the rollers that I was using. A band of pure latex used for medical purposes worked well for some time, but then started to develop holes.

mikeselectricstuff

Tue Jan 13 2009, 01:02AM

Registered Member #311 Joined: Sun Mar 12 2006, 08:28PM
Location:
Posts: 253

Someone I know who's built a few big VDGs swears by mylar. Not sure of the source though. Apparently not too hard to glue into a loop.

Dieu

Tue Jan 13 2009, 08:10PM

Registered Member #1730 Joined: Thu Oct 02 2008, 08:12AM
Location: Poland
Posts: 35

Teflon belt can be good here.
Soon this belt will be my problem too.

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