Polyurethane Upholstery Foam As A Large Sponge? - Page 2 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th January 2013, 03:21 PM   #11
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Sofa:

Perhaps the gels have improved since the book was written, (1970's), and maybe they do freeze now. The advertising for them say they remain flexible, which would tend to indicate they are remaining in a semi-liquid state, but perhaps I got it wrong. In which case, I will try the gels-they are certainly cheap enough.

Quote:
But more importantly, for virtually any material undergoing a thaw, if it doesn't "absorb[s] all the heat in the surrounding area to make the change" where does it get the heat?
I think the point with the very cold but unfrozen salt water in the water bottle and the blue gel which I told the chemist remained unfrozen, they do not take in surrounding heat from the environment because they are not undergoing a change of state.

If the gels do in fact freeze in the freezer and then unfreeze as they are applied to the body, that would change that.
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote
Old 28th January 2013, 03:42 PM   #12
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Let's see.
I don't want to get into the physics here so I will just say I don't think so on the state of change references and the difference between the gel and water.

I'll stay out of whether this sounds safe for your health.

If you took a piece of foam as large as you are talking about and got it wet it would be very heavy, it will hold a lot of water. As far as getting an open cell foam in a spray can I highly doubt that it is either flexible foam or open cell. It is most likely closed cell low density foam for insulation or something like that. Unless this was some sort of sculpted foam shape I don/t see that you would get anything less than a flat hard block of ice with a foam filler. You would still need to put it inside of something to hold the foam and water, otherwise it will form to the freezer and stick to the walls and never come out.
  Reply With Quote
Old 28th January 2013, 05:37 PM   #13
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
I have gotten ~1ft^2 freezable gel packs from vegetable transport boxes. For free. Also from medical transport boxes. May be worth a try at those prices. The freezepop idea seems like good outside the box thinking (or more literally, inside the box) but they may not be large enough to be useful, so quite a few would be needed. Anyhow, I'm thinking of the closed-cell foam used as an insulator, with a multi-pocketed "pillowcase" that holds the frozen contents in place, decreases heat absorption from the wrong side, and the entirety is form-fitting and reusable.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 28th January 2013, 08:37 PM   #14
diyAudio Member
 
Join Date: May 2010
I use the gel packs designed specifically for medical use and they work fine. The gel can be put in a freezer or heated up in a microwave; they work just as well as heat or cool pads. They come with a liner to go on the outside to reduce the risk of frostbite or local burns. The gel kind of looks like pea-shaped blobs.

If I were you I would check them out, maybe start with a search on Amazon where you can also check out some reasonably reliable reviews.

Your foam idea is not out of the question but I don't think it would be as effective. Note (already mentioned) that most manufactured foams are UV-sensitive and break down with exposure to light. A typical example: auto upholstery; they are always covered with a UV-blocking material such as cloth, vinyl or leather, and often a UV-blocking plastic between them for good measure.

Closed cell foam would be used for things like floating docks or insulating foam (don't absorb water; hold air in the cells), you want the open cell stuff if you need sponge ability.

I can't offer much advice on what exact foam to get; the truth is polyurethane is so versatile a material that the properties are nearly unlimited (so the choices being currently manufactured are mind-boggling); softer than (natural) sponge thru harder than any (natural) rubber.
__________________
" ... Go back to the beginning of a technology before the priesthood was established; that was the time when people were communicating information, not proving why there needs to be Priests. This is why the old texts tend to be so good. ..."

Last edited by Johnny2Bad; 28th January 2013 at 08:48 PM.
  Reply With Quote
Old 28th January 2013, 11:09 PM   #15
Ron E is offline Ron E  United States
diyAudio Member
 
Ron E's Avatar
 
Join Date: Jun 2002
Location: USA, MN
Quote:
Originally Posted by kelticwizard View Post
I think the point with the very cold but unfrozen salt water in the water bottle and the blue gel which I told the chemist remained unfrozen, they do not take in surrounding heat from the environment because they are not undergoing a change of state.

If the gels do in fact freeze in the freezer and then unfreeze as they are applied to the body, that would change that.
I have some therapeutic gels - they do get hard, then soft after a while - they last a fair amount of time. I know that most gel ice packs are not meant to be in contact with skin without a (dry) cloth barrier. You can get frostbite.

The change of state issue is the latent heat of freezing, which allows the pack to stay at essentially the same temperature as long as there is a mixture of ice and water. The same thing happens as a liquid boils - the liquid stays the same temperature until it boils dry.

When I had a knee injury, I got this really neat bag that surrounded my knee and was connected by a tube to a thermos of ice water. You would raise the ice water above the knee and the bag would fill with cold, then when it got warm, you lower the thermos, water drains out and mixes with ice, gets cold again, and you raise it above the knee again.

I'm thinking you could get a long length of tubing, zig-zag it across your mattress - lay on it and pump cold water from a 5 gallon bucket full of ice water through the tubing with a pond pump
__________________
Our species needs, and deserves, a citizenry with minds wide awake and a basic understanding of how the world works. --Carl Sagan
Armaments, universal debt, and planned obsolescence--those are the three pillars of Western prosperity. Aldous Huxley
  Reply With Quote
Old 29th January 2013, 01:08 PM   #16
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Quote:
Originally Posted by sreten View Post
Hi,

Have you heard of reusable plastic ice cubes ? Might work well
placed is a cloth bag with insulation on the back and sides.
Or those freezable sheets of plastic gel pockets.

rgds, sreten.
I might have rejected this idea too quickly. Previous to this morning the reusable ice cubes I saw online seemed to be thick plastic with a little bit of water inside which I didn't think would get things very cold, and freezable sheets of gel or water seemed encased in thick, thick plastic-great for durability, not so great for thermal conductivity.

However, I saw these sheets here just now:
Amazon.com: Flexi Freeze Refreezable Ice Sheets 3 pack: Sports & Outdoors

They are large and full of genuine ice. It might take 4 or 5 sets of three to do a whole back at once, but at $14 the total price would still be well under $100 which is reasonable.

Got a couple of other things going right now, but these are fascinating and might well be the way to go.
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote
Old 29th January 2013, 01:37 PM   #17
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Sorry, came to this late.

Yes, open cell foam.
Probably OK for contact unless you have an unusual sensitivity to small concentrations of formaldehyde.
The stuff about depth of cold penetration is nonsense. Thermal flow depends on temperature gradients- as long as you keep changing out the gel packs to maintain the low temp, the skin/fat/muscle doesn't know what the thermal absorption medium is.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 30th January 2013, 04:53 AM   #18
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Quote:
Originally Posted by Ron E View Post
When I had a knee injury, I got this really neat bag that surrounded my knee and was connected by a tube to a thermos of ice water. You would raise the ice water above the knee and the bag would fill with cold, then when it got warm, you lower the thermos, water drains out and mixes with ice, gets cold again, and you raise it above the knee again.

I'm thinking you could get a long length of tubing, zig-zag it across your mattress - lay on it and pump cold water from a 5 gallon bucket full of ice water through the tubing with a pond pump
Sounds like a good idea.

For some time I have had my eye on this-I'm pretty sure I'll get one eventually. Only thing is, it would require 4 bags to cover my back, and I have to check with the seller to see if the unit can power four big back bags at once-I don't want to have to shift position 3 times.

Aqua Relief System (Pad Included) | Hot and Cold Therapy Machine
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote
Old 30th January 2013, 05:01 AM   #19
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Much thanks, SY.

Some time ago I got two tips on cooling. One is to take an 8 ounce styrofoam cup, fill with water, freeze overnight then peel the styrofoam halfway down and apply the frozen water to the area. If you can reach the area with your hand, it's the best.

However, this is my back.

The other advice was to use a bag of frozen peas or other vegetables. I tried that, it was okay. I'm going to try it tonight. I'mputting a chedap plastic dropcloth on the bed, then a towel, then a whole mess of frozen veggie bags, followed by a wet towel on top, (something I didn't use before), then lay down on top for 15-20 minutes.

I figured I can't lose. If it works, I found an easy way to cool my back. If it doesn't, after 14 one pound bags of chopped broccoli, I won't have to worry about colon cancer for quite awhile!
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous

Last edited by kelticwizard; 30th January 2013 at 05:03 AM.
  Reply With Quote
Old 30th January 2013, 05:06 AM   #20
Wizard of Kelts
diyAudio Moderator
 
Join Date: Sep 2001
Location: Connecticut, The Nutmeg State
Quote:
Originally Posted by sofaspud View Post
Anyhow, I'm thinking of the closed-cell foam used as an insulator, with a multi-pocketed "pillowcase" that holds the frozen contents in place, decreases heat absorption from the wrong side, and the entirety is form-fitting and reusable.
Definitely a unique and useful idea for the long run. If I find a convenient way to ice, I plan to do it once a week even after the back heals, (which it is doing rapidly, by the way).
__________________
"A friend will help you move. A really good friend will help you move a body."
-Anonymous
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Acoustic wedge panels - Polyurethane RyanW Swap Meet 1 12th March 2010 04:44 PM
Polyurethane PUR enclosures jzagaja Multi-Way 0 8th July 2009 01:58 PM
Oh my god! Theve kidnapped SPONGE BOB! Da5id4Vz Everything Else 8 13th December 2004 01:58 AM
Sponge Bob is the best part of having a child! Nelson Pass Everything Else 54 26th December 2003 04:54 AM


New To Site? Need Help?

All times are GMT. The time now is 02:45 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2