These notes are given in good faith for general guidance purposes only and since actual operating conditions, methods and application techniques are beyond our control we cannot accept liability for any losses however they may occur.
 

 RIGID EXPANDED POLYURETHANE FOAM.

TWO PART LIQUID MIX.  Standard density:  2½ lbs/Cu.ft.==40 kgs/Cu. Metre. Customers using this product should note the following.

The use of "CFC"(Chloro Fluoro Carbon) has been banned on environmental grounds throughout the EEC. This was the Blowing Agent contained in Component "A" (The Polyol). Manufacturers have substituted the CFC with "HCFC" ( Hydro Chloro Fluoro Carbon). This formulation results in a very fractional reduction in the Expansion rate of this Product.
More importantly it has also resulted in a reduction of the margin of error to 5% which was higher with the CFC Formulation, The correct mixing ratio continues to be 1:1: equal Parts by VOLUME of each Components i.e. One pint of Component "A" to one pint of Component "B".
Component "B" is Polymeric Isocyanurate & is slightly darker in colour than Component "A". Specific Gravities: Component "A" 1.16.Component "B" 1.25.
MIXING; Use two small vessels of identical size. Pour each Component into a separate vessel: equal parts by Volume.  Pour the contents of each vessel into a third vessel & stir rapidly with a stick so that mixing is thorough. Take care that the dregs remaining in each of the two original vessels remain equal by Volume.  Otherwise the proportion mixed of each Component will be disproportionate to the 1:1 Formulation. Promptly pour the Mix into the cavity/mould- Ideal Working Temp.is 16-20ºC (60-68F.) at which the Mix will start to cream & foam within .20 to 30 seconds: being slightly slower than with the previous CFC Formulation which was 10-15 seconds.  The working temp, should not exceed 22ºC=71ºF.
Avoid working in Temps, below 10ºC-50ºF as the Expansion rate will reduce.
 In Temps, exceeding 22ºC=71ºF the Expansion rate will increase causing Foam to be less dense & more friable. The Foam is fully hard in four minutes.

TWO PART LIQUID MIX.  HIGH DENSITY: 10 Ibs/Cu.ft.==160 kgs/Cu.Metre, The Blowing Agent is Water: NOT CFC or HCFC. The Specific Gravity  is same for both Components: so mixing ratio is 1:1 by volume or weight.  Mixing time is 50 seconds: Cream Time 1 Min. 15 seconds: Rise time 5 mins. Fully hard in four minutes thereafter. Ideal Working Temp. is 16-25ºC. (60-77ºF)

STORAGE & HANDLING. It is important that Containers should be re-sealed immediately after decanting to prevent entry of Moisture which will adversely affect the resultant Foam.  Shelf Life properly stored is 6 months.

HEALTH & SAFETY. Avoid contact with eyes & skin & inhalation of vapour. Wear gloves: goggles & Respirator.

Properties of REPF, BS 4370, method 3, Specs 1-4.
The figures relate to 2.0lbs/Cu.ft. density foam. Spec Nos-2 & 3 are higher the higher the density, i.e.- for 2½lbs density divide by 2 and multiply by 2½. Reverse this calculation for thermal conductivity, spec 4.

1. Closed cell Content: 91% (2½lbs density = 93%)

2. Compressive strength: Vertical (in direction of rise) 229 kgs Newton/sq Mtr (33.2 psi). Horizontal: 151 kgs Newton/Mtr (21.9 psi).

3. Flexural Strength: 280 kgs Newton/sq. mtr (40.2 psi).

4. Thermal Conductivity. The "K" factor 0.025 Watts/Metre thickness/ºC (101 million BTU's per hour/Metre thickness/ºC). The "U" value is the "K" factor divided by the thickness.

Positive Buoyancy. Foam of density 2½ lbs/Cu,ft is 24 times lighter than water. Water weighs 62.29 lbs/Cu.ft, divided by 2½ = 24.91. Timber avarages 42 lbs/Cu.ft, ranging white deal 29 lbs, Teak 60 lbs, White deal-29lbs divided by 2½ = 11.6. Foam is 11½ times lighter than White Deal.