Method for sealing an inner bag to an outer container

A method for sealing a thin plastic bag having an open end to a continuous inner side wall of an outer plastic container, said outer plastic container having an open bottom end, a discharge opening and a midpoint, said method comprising the steps of:

• a) placing said thin plastic bag over a non-metallic mandrel, said mandrel having a top end and radial passages connected to a compressed air source, said radial passages being positioned inside said thin plastic bag, said thin plastic bag having a circumference at said open end and a closed end at said top end of said mandrel, said thin plastic bag also having a continuous stripe of heat-activated adhesive bonded to said circumference at said open end, said heat-activated adhesive having metal particles therein;
• b) inserting said top end of said mandrel, having said thin plastic bag placed over said top end, into said open bottom end of said outer plastic container;
• c) generating a magnetic induction field near said continuous stripe of heat-activated adhesive positioned at said midpoint of said outer container, said field having a strength to generate sufficient heat in said heat-activated adhesive having metal particles therein to form a bond between said thin plastic bag and said continuous inner side wall of said outer plastic container;
• d) blowing compressed air through said radial passages of said mandrel to press said thin plastic bag and said stripe of adhesive against said inner side wall of said outer container;
• e) removing said magnetic induction field;
• and
• f) retaining said mandrel inserted in said thin plastic bag until said continuous stripe of heat-activated adhesive cools sufficiently that said mandrel may be withdrawn from said thin plastic bag without disturbing said bond.

A method for sealing a thin plastic bag having an open end to a continuous inner side wall of an outer plastic container, said outer plastic container having an open bottom end, a discharge opening and a midpoint, said method comprising the steps of:

• a) thermoforming said thin plastic bag over a non-metallic mandrel, said mandrel having a top end, said thin plastic bag having a circumference at said open end and a closed end at said top end of said mandrel, said thin plastic bag also having a continuous stripe of heat-activated adhesive bonded to said circumference at said open end, said heat-activated adhesive having metal particles therein;
• b) inserting said top end of said mandrel, having said thin plastic bag thermoformed over said top end, into said open bottom end of said outer plastic container;
• and
• c) generating a magnetic induction field near said continuous stripe of heat-activated adhesive positioned at said midpoint of said outer container, said field having a strength to generate sufficient heat in said heat-activated adhesive having metal particles therein to form a bond between said thin plastic bag and said continuous inner side wall of said outer plastic container.

A method for sealing a thin plastic bag having an open end to a continuous inner side wall of an outer plastic container, said outer plastic container having an open bottom end, a discharge opening and a midpoint, said method comprising the steps of:

• a) placing said thin plastic bag over a mandrel, said mandrel having a top end and radial passages connected to a compressed gas source, said thin plastic bag having a circumference at said open end and a closed end at said top end of said mandrel, said thin plastic bag also having a continuous stripe of heat-activated adhesive bonded to said circumference at said open end, said radial passages being positioned inside said thin plastic bag underneath said continuous stripe of heat-activated adhesive;
• b) inserting said top end of said mandrel, having said thin plastic bag placed over said top end, into said open bottom end of said outer plastic container such that said heat-activated adhesive is positioned at said midpoint of said outer container;
• and
• c) blowing compressed gas through said radial passages to press said thin flexible bag and said stripe of adhesive against said inner side wall of said outer container while simultaneously activating said continuous stripe of heat-activated adhesive to form a bond between said thin plastic bag and said continuous inner side wall of said outer plastic container.