outsider seeking help

hi

i'm looking for a material that has the properties of paper (ie: a thin surface that's readily deformable, but keeps the same curvature everywhere when it's deformed, without stretching, contraction or tearing). normal paper isn't suitable because i need to make it in the shapes of various nonflat surfaces. as a last resource i will simply make the surfaces out of recycled paper, but if anybody here can recommend a better way to accomplish the same thing it would be much appreciated.

peace, stm

Reply to
sean_mcilroy
Loading thread data ...

I don't get what you mean by "same curvature everywhere". If I had a long piece of this material and I curved one end, do you mean the other end would also curl up, and to the same degree? That would be really weird.

Reply to
Mark Thorson

Echoing what Mark Thorson wrote, Sean McIlroy needs to be considerably more specific if he expects a useful answer. I'm only speculating, but I'm wondering if what he wants is a thin film that can be deformed and then cured or somehow "set" to the desired shape. He doesn't, however, indicate what kind of environment in which the material will be used (temperature, humidity, pressure, gases, materials which contact the film) or the stresses this film might be subject to in actual use . . . how strong it must be and how much it must resist being pulled or pushed out of shape. Personally I would suggest he think about something like "ripstop" (woven) nylon coated with an epoxy resin and allowed to cure in situ -- but it's only my guess that the properties would suit his needs.

Think like a scientist, Mark. You can do it.

Mark 'Sporky' Staplet>

Reply to
Sporkman

This may be unobtainium in a thin sheet form.

I suspect that the fellow wants to make, say, a sphere segment surface. Paper won't do this because it wrinkles when you try to force it onto the surface of a sphere. He doesn't want rubber because it stretches ?? or so I guess.

The flat "paper" sheet has to stretch/deform to be able to conform to the spherical surface segment, or any other non-flat surface segment. However, the requestor seemingly ruled out these things.

Then, if we don't give him a solution, he will make it out of recycled paper..... probably dipped in water and bent/stretched to shape....

Unobtainium? Or not being able to explain the actual problem.

Reply to
jbuch

"same curvature" was supposed to indicate that the process of deformation doesn't change the gaussian curvature at any point.

Reply to
sean_mcilroy

choing what Mark Thorson wrote, Sean McIlroy needs to be considerably more specific if he expects a useful answer. I'm only speculating, but I'm wondering if what he wants is a thin film that can be deformed and then cured or somehow "set" to the desired shape. He doesn't, however, indicate what kind of environment in which the material will be used (temperature, humidity, pressure, gases, materials which contact the film) or the stresses this film might be subject to in actual use . . . how strong it must be and how much it must resist being pulled or pushed out of shape. Personally I would suggest he think about something like "ripstop" (woven) nylon coated with an epoxy resin and allowed to cure in situ -- but it's only my guess that the properties would suit his needs.

the intended environment is that of everyday life. strength comparable to that of paper is sufficient, but resistance to stretching and contraction should be essentially absolute (ie: like paper, the material should simply tear or crease if you insist on overpowering it). thanks for the nylon-and-epoxy-resin suggestion: i will look into that. sorry you found it all so ambiguous, but bear in mind i did warn you i was an outsider.

peace

Reply to
sean_mcilroy

essentially all i'm looking for is a way of making paper in the shape of nonplanar surfaces.

Reply to
sean_mcilroy

Are you trying to say "spherical segment" ?

Reply to
jbuch

WOW. It seems so simple when you talk that way without big words.

Learn to make paper in the traditional flat way.

Then use that information to make paper in the shape you want.

Paper egg cartons are an old fashioned way of making sculptures out of paper. Paper has long been made into objects which aren't flat.

You can buy "papermaking kits" - hand made paper is an arts and crafts hobby.

Enjoy.

Reply to
jbuch

i am not aware of egg cartons that can be 'bent' (the correct word being a simple one in this case) without alteration of gaussian curvature, or indeed in any way at all. thanks for your help.

Reply to
sean_mcilroy

Egg carton may not be the exact right analogy, but I think the suggestion is probably the way to go. Paper is only made flat because it is "cast" onto flat screens or taken off of rolls and then made flat. If you made a screen in the initial shape you want the paper, casting the fibrous slurry onto this surface should give you what you want with the exact properties of paper.

Reply to
JoeM

unfortunately my first experiment with homemade paper resembles an egg carton more closely than i would wish: it prefers to crack instead of bending. but if that's really my best prospect i guess there's nothing to do but assimilate the relevant technical knowledge and persevere until i get it right. thanks for the input.

peace, stm

Reply to
sean_mcilroy

Perhaps you mean "neither crease nor crack"?

Why not silicone rubber?

Reply to
Michael Gray

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.