plastics made less diffuse

hey!

i need to find examples how plastics are made less diffuse for gases and liquids. The technique of production doesn’t matter. But i just need to find ‘a’ technique. I have to talk about it for school…

sugestions?

thx!

gloriant,

Define your term; " … difuse for liquids and gases.".

The first dictionary definition of diffuse is, “spread out, less concentrated”.

Not sure what you mean by “diffuse”.

I’m sorrry for my vague description.

So, I’m looking for examples, how to make synthetic material (plastics) less permeable. That means that water or gasses can’t go through the material that easy anymore.

So I’m looking for examples like:

  • blocking layers
  • barricades
  • …

I need to discuss these methods in a paper for school…

Thanks already!
Grtz, gloriant

www.efunda.com

there you can find allot of info.

My understanding is that all plastics are permeable to some degree. The easiest/cheapest way is often to metalize the surface to act as a barrier. If the interface is plastic then it will be permeable, but if it’s a long distance, it will be very minimal. …think potato chip bag…

I mean if the seam is plastic then the seam will still be permeable. If you are using metalized sheet material like snack bags, then where the material comes together to make the seams, the film is glued or heat sealed plastic against plastic. Although it is theoretically permeable in this seam, it’s usually a very narrow gap and the molecules would need to go quite a long distance to go through.