Keeping plastic materials flat

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ben_mtl
Posts: 583
Joined: Mon Mar 31, 2008 1:47 pm
Location: Sherbrooke, Quebec
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Keeping plastic materials flat

Post by ben_mtl »

Hi all,

As some might have noticed I started another project in my skibuilding experience : screen printing !
One of the many difficulties I'm facing, which might not only be screen-printing related is how to get really flat plastic material so they're easier to use.

Everything that comes in rolls (and is stored in rolls) such as base material, tipspacers, topsheets is kinda wavy when you unroll it, For some it might be a problem, for some not.
For example, bases and tipspacers I use (UHWM) are not a big problem, when I need them I put them on a vacuum table, put some tape all around it and it start the vacuum to hold everything flat while I'm cutting, no big deal ! On another note I know If I pre-cut my materials to length and store them on a flat surface they'll be flat by default after not so long..

Problem comes with my topsheet material (Duravision 5050 not to name it..). I've been storing a few sample sheets flat for a couple days and they're still very wavy as shown in the next picture. It's real Duravision 5050, cut 4 days ago and stored flat (even between MDF planks for a couple days with no improvement)
As you can see there seems to be a flat strip (2-3in wide) in the middle. but on both sides it's wavy.

Image

Major issue with that is this material is gonna be used for screen printing, meaning when needed, I'll take a cut piece, drop it on the vacuum table, start the vacuum and it should suck right away so I can start printing. I don't want to take time to put tape all around the material since my ink on the screen print is gonna be drying + I can't move the silk screen too high while I change my topsheet (= not much space to apply the tape).
Anyway putting some tape would really be a mess, as you can see the "waves" are not very friendly (I believe it's because the material is quite thin), if you tape one side odds are the waves on the other side of the material are gonna be bigger, thus making the material very hard or even impossible to be taped flat !

Anyone already experiences that ? Did you find a way to restore the flatness of the material ? I've sent an email to the material manufacturer to discuss the subject but if someone here already faced this and can help it would be great too ! Of course if I can get useful tips from the manufacturer I'll write the info here !

Thanks everyone
Ben
A bad day skiing is always better than a good one at work...
ben_mtl
Posts: 583
Joined: Mon Mar 31, 2008 1:47 pm
Location: Sherbrooke, Quebec
Contact:

Post by ben_mtl »

Hi guys,

Just got a reply from Jay @ Crown Plastics. Looks like the fact that the product has some waves when unrolled is pretty normal. He told storing it flat with some weight over it in a warm room might help, but he couldn't guarantee it.
Also he reminded me the product (5050) is corona treated, so extra care has to be taken to keep the material clean : no cleaning agent, no flame, no wiping with anything.. keep it clean, that's it ! at worst run some water over it and let it air dry.

As he said : "Wiping the plastic and / or applying evaporative cleaners will remove the surface treatment"

I might have found a way to flatten my material though, this morning I basically put a piece of topsheet over an open wardrobe door just in front of my wood stove... looks like each side is getting better (with a big bend in the middle on top of the door of course)...
I'm gonna build a small" topsheet flattening device" (= attach a 2x4 with some clamps to the ceiling, and let the material fall straight from it, still in front of a heat source).
I'll report on it !
A bad day skiing is always better than a good one at work...
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