Chemicals used to make PUF

Have you tried any of the thermal insulation cans you can buy from buiding depots or DIY places?

I think it is the same sort of stuff that you squirt into a gap and it foams up to form a thermal seal around whatever component you have...

If its only for the occasional use, I would have thought that might be a solution?

John.

Thanks John. You're right. But then we don't get them here off the shelf.

I'll need the names of those two chemicals adding together to create that thermal barrier.

This should be a good start:http://www.touch-n-seal.com/msds.htm

In a cold country like here you can find them quite in any hardware store.

Dow Chemicals is the manufacturer of Great Stuff brand name.

For a less poluting product: http://www.biobased.net/faq.php

Capri, I don't understand. You say you mix 2 chemicals, but you don't know their names? Do I understand you correctly? Typically, PU foams may either be polyether-based or polyester-based, usually reacted with TDI. If you are buying a prepolymer system, you likely have the TDI partially pre-reacted to make a prepolymer. You should also have probably two different catalysts (a rx catalyst and a blowing catalyst) plus a cell stabilizer, such as a silicone, etc, which are likely part of the polyol package. Suggest that you find a local chemical analytical company, or a local university who can determine what your two chemicals are.

PU foam is generally a two component system :

1. Polyol

2. Isocynate - This works as hardner

Typical ratio for 400kg/m3 density is 2/3Poly+1/3Isocynate. But there are various types of PU and ratio would change to some extent.

The mixing and dispensing systems are used for application of PU.

Hope to get u solution soon.

Limbkar,

You have answered my question to the perfection.

after posting this question I was informed that it is Isocynate and something which goes as Poly.......

I will remember that it is 66.66% Polyol to 33.33% part of Isocynate.

And I will remember to put on gloves as suggested by our dear guest.

Thanks

Dear Sir,

My suggestion is as follows:

TIC 100pph

polyhol 30-50pph

water 2-4pph

Tin catalyst 0.3-0.5pph

Amin catalyst 0.3-0.5pph

It should work smoothly.

Best regards,

J a c o b

Hi,

It expands to about 20x its original volume and can build up massive pressures/forces. Try to keep each layer to about 20cm (once expanded) and use several layers if you need >20cm as you will get a more homogenius foam.

Practice with small amount first. It foams and hardens VERY quickly and once it foams if you are still mixing you just collapse the foam. I suggest you prepare everything well, mix small ammounts very quickly for 15-20 seconds and pour the lots into whatever you want to insulate.

good luck and wear gloves-- it is extremely hard to remove from skin (impossible from clothes.)

Thanks. you were a great help. Yea! the container is stong enough to take that kind of pressure.

Why not join the forum and post with a name?

Be a bit careful with TDI, as some people are very sensitive to the chemical. I once worked with someone who passed out and stopped breathing from exposure. I suggest what is called a MDI base system. You can purchase various grades at some hobby or plastics supply houses.