US 5,685,911 A · Apparatus for intermittently applying discrete adhesive coatings

Abstract

Apparatus for producing intermittent, discrete patterns of coating material, such as hot melt adhesive, onto discrete substrates or substrate areas, such as book spines, sift-proof carton flaps and pinch-bottom bags. The adhesive patterns have sharp, square leading and trailing edges, as well as side edges. A slot nozzle die has elongated air slots along the slot extrusion opening. In the operation of the apparatus, the air flow is initiated from both air slots prior to the initiation of the hot melt flow. Also, the air flow is continued beyond that point in time, when the hot melt flow ceases. The delays between the operations of the air flow and the hot melt flow are on the order of micro seconds. Coating weights down to 1 gram per square meter at about 350 meters per minute substrate speed are provided. Alternatively, the lead and lag air start and stop times on each side of the film of coating material are different to control the exact disposition of the square cut-on and square cut-off coating edge on the substrate. Methods are disclosed.

Claims37

Dependent claims

Apparatus for intermittently applying discrete adhesive coatings to book spines, said apparatus comprising

a slot nozzle having an elongated slot outlet through which an adhesive coating material can be extruded:
at least two air slots, one proximate each side of said slot outlet for impinging at least one air stream onto an adhesive coating material exuding from said slot outlet for carrying the adhesive coating material onto the book spine;
means for starting flow of the impinging air stream prior to extrusion of adhesive coating material from said slot outlet;
further including means for stopping flow of the impinging air stream after extrusion of the adhesive coating material has ceased;
and
further including means for delaying impinging air from one of said air slots until after the adhesive coating material exudes from said slot outlet and for continuing flow of air from said one slot until after extrusion of the adhesive coating material has ceased.

3 more elements

Apparatus for producing an adhesive coating for application to a predetermined area of a sift-proof package, said apparatus comprising:

a slot nozzle die comprising:
die halves defining an extrusion slot therebetween, said extrusion slot having an elongated slot outlet through which an adhesive coating material can be extruded said die halves having tapered projections with parallel inward facing surfaces forming said extrusion slot and tapered outer walls respectively partially defining inward surfaces of two air channels disposed at an angle with respect to said extrusion slot said air channels forming air slots which are proximate to said slot outlet for impinging at least one air stream onto the adhesive coating material exuding from said slot outlet for carrying the adhesive coating material onto the predetermined area of said sift-proof package for sealing said shift-proof package against sifting of contents therefrom;
two air blocks, each having a tapered surface juxtaposed in operative disposition near one of said tapered outer wall such that one of said air channels is formed therebetween;
an air plenum in each said air block;
an air passage in each said air bock interconnecting and upper portion of each said plenum with a respective said air channel;
and
an air passage in each said air block for feeding air to a lower portion of each said plenum;
and means for starting flow of the impinging air stream from at least one of the air slots prior to extrusion of the adhesive coating material from said slot outlet.

5 more elements

Dependencies are inferred from the claim text.

Apparatus for intermittently applying discrete adhesive coatings

Life of this patent

Apparatus for intermittently applying discrete adhesive coatings

Life of this patent

Abstract

Claims37