Heat-seal splicing assembly and method

In an improved splicing assembly for heat-seal splicing a trailing end of a running first, two-sided plastic material web and a leading end of a second, two-sided plastic material web together, and then for heat-seal splicing the leading end of a third, two-sided plastic material web and a trailing end of the then running second web together, and so on;

• where when running, the first web is being unwound from a first roll, which is located in one predetermined location relative to a web splicing assembly;
• where the first web runs along a predetermined path of travel from the first roll, past the splicing assembly, through a web festoon, and through the web processing operation;
• where the second web is adapted to be unwound from about a second roll which is located at another predetermined location relative to the web splicing assembly;
• where the third web is adapted to be unwound from a third roll which will be disposed in the one location after the second web is spliced to the first web and the second web is running along the path of travel;
• where the plastic material of the first, second and third webs are the same material and will melt when heat, above a predetermined temperature, is applied to the web material;
• where the first, second and third webs each having a first surface with the common characteristics and having a second surface;
• and where after the webs have been spliced and are running along the path of travel downstream from the web splicing assembly, the first surfaces of the webs face the same direction, the improved splicing assembly comprising:
• a first splicing sub-assembly that is disposed adjacent to one side of the path of travel, that has a first relatively movable slide bar and a first relatively fixed nip bar, and that is movable between a first position in which the first slide bar is disposed at a first location adjacent to and on the one side of the path of travel and in which the first nip bar is disposed away from the first location, and a second position in which the first nip bar is disposed in the first location and in which the first slide bar is disposed away from the first location;
• a second sub-assembly that is disposed adjacent to the opposite side of the path of travel, that has a second relatively fixed nip bar and a second relatively movable slide bar, and that is movable between a first position in which the second nip bar is disposed in a second location adjacent to the opposite side of the path of travel and facing the first slide bar of the first sub-assembly, when the first sub-assembly is in its first position, and in which the second slide bar is disposed away from the second location;
• and a second position in which the second slide bar is disposed in the second location adjacent to the opposite side of the path of travel and facing the first nip bar of the first sub-assembly, when the first sub-assembly is in its second position and in which the second nip bar is disposed away from the second location;
• means for selectively moving the first slide bar in a direction toward the second nip bar, when the first and second sub-assemblies are in their first positions, so as to clamp a portion of the running web and a portion of the web to be spliced to the running web therebetween, with the first surface of the running web facing in the opposite direction from the first surface of the web to be spliced, and so as to stop the clamped portion of the running web from continuing to run along the path of travel;
• means for selectively moving the second slide bar in a direction toward the first nip bar, when the first and second sub-assemblies are in their second positions, so as to clamp a portion of the running web and a portion of the web to be spliced to the running web therebetween, with the first surface of the running web facing in the opposite direction from the first surface of the web to be spliced, and so as to stop the clamped portion of the running web from continuing to run along the path of travel;
• the first and second slide bars each including means for applying heat, with a predetermined temperature, to a localized area, which extends the full width of the clamped web portions, so as to heat sever the clamped web portions along the area and so as to heat-seal the adjacent parts of the clamped web portions together;
• means for moving the first slide bar away in a second direction from the second nip bar when the first and second sub assemblies are in their first positions after the clamped web portions have been heat-sealed together so that the running web may begin again to run along the path of travel together with the spliced web and so that the first surface of the running web and the first surface of the spliced web face in the same direction;
• and
• means for moving the second slide bar in a second direction away from the first nip bar when the first and second sub-assemblies are in their second positions and after the clamped web portions have been heat-sealed together so that the then running web may begin again to run along the path of travel together with the spliced web and so that the first surface of the running web and the first surface of the spliced web face in the same direction.