Foam envelope for sealing large volumes

A method for sealing an air gap 26 between building interfaces 24 and 25, the method comprises the steps of:

• providing an article 10 comprising a tube 11 and at least one thermoplastic pouch 12 inserted within the tube 11 wherein
• the tube 11 has a length L, a width W and a height H and the at least one thermoplastic pouch 12 has a length l and a width w,
• the tube comprises an upper section 13, a lower section 14, an inner section 15 and an outer section 16,
• the tube comprises an inner layer 17 and an outer layer 18, the inner layer 17 being a semipermeable membrane that is permeable to vapors but impermeable to liquids and the outer layer 18 being a nonwoven fabric,
• the tube has a through-thickness Gurley air permeability of from 1 to 2,000 seconds,
• the tube has a tensile modulus in the L direction of from 300 to 450 MPa and from 200 to 320 MPa in the W direction,
• the tube has a plurality of holes that penetrate through the inner 17 and outer 18 layers of the upper section 13 and/or the lower section 14 of the tube,
• the pouch length l is greater than the width w,
• the pouch is located within the tube such that it contacts the lower 14 and inner 15 sections of the tube and the pouch extends in a direction across the tube width W to an extent Wmax that is no more than 45% across the tube width W and
• the pouch 12 contains a foamable composition,
• inserting the article 10 into the air gap 26 between the building interfaces 24 and 25,
• activating the foamable composition within the pouch 12 so that the ingredients of the foamable composition react to form an expandable foam, the foam then bursting the pouch 12, expanding the tube 11 and escaping through the tube holes in the upper section 13 and/or the lower section 14 of the tube and, when present, between two spaced apart flow restrictors 19a and 19b and/or two spaced apart flow restrictors 19c and 19d that extend along the length of the tube, so as to fill the air gap 26 between the building interfaces 24 and 25 of the building structure and then cure in situ into a foam structure thus providing an air tight and water impermeable seal.

A method for sealing an air gap 26 between building interfaces 24 and 25, the method comprises the steps of:

• providing an article 10 comprising a tube 11 and at least one thermoplastic pouch 12 inserted within the tube 11 wherein
• the tube 11 has a length L, a width W and a height H and the at least one thermoplastic pouch 12 has a length l and a width w,
• the tube comprises an upper section 13, a lower section 14, an inner section 15 and an outer section 16,
• the tube comprises an inner layer 17 and an outer layer 18, the inner layer 17 being a semipermeable membrane that is permeable to vapors but impermeable to liquids and the outer layer 18 being a nonwoven fabric,
• the tube has a through-thickness direction Gurley air permeability of from 1 to 2,000 seconds,
• the tube has a tensile modulus in the L direction of from 341 to 441 MPa and from 207 to 308 MPa in the W direction,
• the tube has a plurality of holes that penetrate through the inner 17 and outer 18 layers of the upper section 13 of the tube,
• the pouch length l is greater than the width w,
• the pouch 12 is located within the tube such that it contacts the lower 14 and inner 15 sections of the tube and the pouch extends in a direction across the tube width W to an extent Wmax that is no more than 45% across the tube width W,
• the pouch 12 comprises first C1 and second C2 compartments, the 15 compartments being separated by at least one frangible barrier 21 or 21a and 21b,
• the pouch 12 contains a foamable composition,
• inserting the article 10 into the air gap between the building interfaces,
• activating the foamable composition within the pouch by breaking the frangible barrier 21 separating the first C1 and second C2 sections of each compartment of the 20 pouch 12 by a breaking means thereby allowing the first and second compositions to mix, react and form an expandable foam, the foam then bursting the pouch 12, expanding the tube 11 and escaping through the tube holes in the upper section 13 and/or the lower section 14 of the tube 11 and, when present, between the two spaced apart flow restrictors 19a and 19b and/or 19c and 19d that extend along the length of the tube 11, so as to fill the air gap 26 between the building interfaces 24 and 25 of the building structure and then cure in situ into a foam structure thus providing an air tight and water impermeable seal.