Melting system for bags
A device is provided for successively melting a solid working material, such as a hot melt adhesive, packed in a packaging bag, and for pressing the molten working material out of the packaging bag. The device includes a cylindrical receiving chamber provided with at least one outlet opening at the end for receiving the packaging bag filled with the working material and having a front end and a back end. At least one heating element ( 30 ) is positioned in the region of the at least one outlet opening for melting the working material at the front-end of the packaging bag, which has a discharge opening for the molten working material. A pressing device with a pressing plunger can be displaced within the receiving chamber and acts on the back end of the packaging bag. The device is protected from contaminations by molten working material when used with undersized packaging bags that are extremely filled in that the receiving chamber at the outlet end thereof facing the at least one outlet opening includes a ring-like constriction with a peripherally sealing contact surface for the packaging bag at least at an edge zone thereof surrounding the discharge opening.
1. A device for successively melting a solid working material, and for pressing the molten working material out of a packaging bag, comprising
a cylindrical receiving chamber provided with at least one outlet opening at the end for receiving an associated packaging bag filled with an associated working material, and the associated packaging bag having an associated front end and an associated back end,
at least one heating element in the region of the at least one outlet opening for melting the associated working material at the associated front end of the associated packaging bag having an associated discharge opening for the associated molten working material, and
a pressing device with an ejection piston that can be moved within the receiving chamber and acts on the associated back end of the associated packaging bag, wherein the ejection piston is provided with a head plate that has a cross-sectional configuration that is smaller than a cross-sectional configuration of the cylindrical receiving space and smaller than a cross-sectional configuration of a stripper plate of the ejection piston, and moves axially relative to the ejection piston and its stripper plate toward the at least one outlet opening wherein a spring arrangement biases the head plate toward the at least one outlet opening.
2. The device according to claim 1 , wherein the spring arrangement biases the head plate toward the at least one outlet opening when the head plate nears or reaches the region of the at least one outlet opening of the associated meltable working material.
3. The device according to claim 1 , further including an annular contraction with a continuously sealing support surface for the associated packaging bag, at least at an edge zone enveloping the associated discharge opening.
4. A bag melting device for successively melting a solid working material packaged in a packaging bag, namely hot-melt adhesive, and for pressing the melted working material out of the packaging bag, the device comprising:
a cylindrical receiving space provided with at least one end-side outlet opening for accommodating an associated packaging bag filled with an associated hot-melt adhesive and the associated packaging bag having an associated front end and an associated rear end,
at least one heating element in the area of the at least one outlet opening for melting the associated hot-melt adhesive at the associated front end of the associated packaging bag having a delivery end for the associated melted working material, and
an ejection device with an ejection piston that can traverse the interior of the receiving space and acts on the associated rear end of the associated packaging bag,
and with the associated packaging bag accommodated in the bag melting device and accommodating the associated solid working material,
wherein a mouth end of the receiving space facing the at least one outlet opening includes an annular contraction with a continuously sealing support surface for the associated packaging bag, at least at an edge zone enveloping an associated discharge opening of the associated packaging bag, and
a head plate that penetrates into the zone with a constricted cross-section on the lower outlet end of the receiving space by a definable length, the head plate being biased toward the at least one outlet opening;
the ejection piston is provided with a scraping or stripping plate that contacts a cylindrical inner wall of the receiving space, the scraping or stripping plate is provided with at least one recess that is inserted in at least one of its axial upper side and axial lower side and between its axial upper and lower side, and enables at least a radial compression of the scraping or stripping plate during operation of the device as the associated melted working material is pressed out of the device, where the at least one recess is star-shaped, with radially extending strips.
5. A bag melting device for successively melting a solid working material packaged in a packaging bag, namely hot-melt adhesive, and for pressing the melted working material out of the packaging bag, the device comprising:
a cylindrical receiving space provided with at least one end-side outlet opening for accommodating an associated packaging bag filled with an associated hot-melt adhesive and the associated packaging bag having an associated front end and an associated rear end,
at least one heating element in the area of the at least one outlet opening for melting the associated hot-melt adhesive at the associated front end of the associated packaging bag having a delivery end for the associated melted working material, and
an ejection device with an ejection piston that can traverse the interior of the receiving space and acts on the associated rear end of the associated packaging bag,
and with the associated packaging bag accommodated in the bag melting device and accommodating the associated solid working material,
wherein a mouth end of the receiving space facing the at least one outlet opening includes an annular contraction with a continuously sealing support surface for the associated packaging bag, at least at an edge zone enveloping an associated discharge opening of the associated packaging bag, and
a head plate that penetrates into the zone with a constricted cross-section on the lower outlet end of the receiving space by a definable length, the head plate being biased toward the at least one outlet opening;
wherein the ejection piston is provided with a scraping or stripping plate that contacts a cylindrical inner wall of the receiving space, the scraping or stripping plate is provided with at least one recess that is inserted in at least one of its axial upper side and axial lower side and between its axial upper and lower side, and enables at least a radial compression of the scraping or stripping plate during operation of the device as the associated melted working material is pressed out of the device; wherein at least one expandable restoring element is inserted in the at least one recess of the scraping or stripping plate; wherein the expandable restoring element is resilient, and configured to be more easily elastically deformed than the scraping or stripping plate.