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 permeable membrane and the outer layer (18) being a liquid impermeable nonwoven fabric of flash spun polyethylene fiber or polyester fiber or a microporous film or a spunbonded-meltblown-spunbonded (SMS) sheet or a spunbonded-meltblown-meltblown-spunbonded (SMMS) sheet,
• a central area of the upper section (13) and/or the lower section (14) of the tube has at least one slot in the outer layer (18) to reveal the inner layer (17), the at least one slot extending at least partially along the tube length (L), and
• in the part of the tube where both inner and outer layers (17) and (18) are present, 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 pouch length (l) is greater than the width (w),
• the pouch is located within the tube contacting 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 at least one slot in the central area of the upper section (13) and/or the lower section (14) of the outer layer (18) 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 permeable membrane and the outer layer (18) being a liquid impermeable nonwoven fabric of flash spun polyethylene fiber or polyester fiber or a microporous film or a spunbonded-meltblown-spunbonded (SMS) sheet or a spunbonded-meltblown-meltblown-spunbonded (SMMS) sheet,
• a central area of the upper section (13) and/or the lower section (14) of the tube has at least one slot in the outer layer (18) to reveal the inner layer (17), the at least one slot extending at least partially along the tube length (L), and
• in the part of the tube where both inner and outer layers (17) and (18) are present, 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 pouch length (l) is greater than the width (w),
• the pouch (12) is located within the tube contacting 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 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 at least one frangible barrier separating the first (C1) and second (C2) compartment of the 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 at least one slot in the central area of the upper section (13) and/or the lower section (14) of the outer layer (18) of the tube 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.