Heat and/or steam activated valve and method therefor

A valve operable to automatically transition from a closed state to an open state in response to heat, said valve comprising:

• a cover having at least one opening therein;
• at least one adhesive layer for sealing a perimeter of the cover to a wall of a package on which the valve is positioned;
• and,
• a deformable element that shrinks in response to being exposed to heat, the deformable element having a perimeter which is sealed by an adhesive when the valve is in its closed state, wherein shrinking of the deformable element pulls at least a portion of the perimeter of the deformable element away from a site where it is sealed by the adhesive, thereby breaking the seal about the perimeter of the deformable element and transitioning the valve from its closed state to its open state.

A method of producing a valve operable to automatically transition from a closed state to an open state in response to heat, said method comprising the steps of:

• (a) providing a first web of film in which a cover is to be formed, the cover having a first perimeter encompassing a first region which defines the cover;
• (b) providing a second web of heat shrinkable film in which a deformable element is to be formed, the deformable element having a second perimeter encompassing a second region which defines the deformable element;
• (c) forming at least one opening in the first web of film within the first region;
• (d) applying a first adhesive to a first side of the first web of film such that the first adhesive encircles the at least one opening and resides within the first perimeter at a first location adjacent to where the second perimeter will reside upon formation of the deformable element;
• (e) laminating the second web of film to the first side of the first web of film;
• (f) forming the deformable element from the second web of film by separating the deformable element at the second perimeter from a remaining matrix of the second web of film;
• (g) removing the matrix of the second web of film from the first side of the first web of film;
• (h) applying a second adhesive to a first side of the first web at a second location adjacent to where the first perimeter will reside upon formation of the cover;
• (i) laminating a third web of material to the first side of the first web of film;
• and,
• (j) forming the cover from the first web of film by separating the cover at the first perimeter from a remaining matrix of the first web of film.