Film material for air-filled packing cushions

A machine for inflating and sealing pillow patterns in a web of film while continuously and uninterruptedly advancing the web of film through the machine, said machine comprising,

• a first film transport station for gripping and advancing a web of film in the machine,
• said web of film having uninflated pillow patterns and an uninflated inflation channel which are preformed in the web of film before the web of film is gripped at the first film transport station,
• said uninflated pillow patterns comprising multiple, spaced-apart, pillow patterns aligned along one side of the inflation channel which extends longitudinally and continuously along the entire length of the web of film,
• each uninflated pillow pattern having a narrow width inlet port extending generally transversely to the longitudinally extending inflation channel and connecting the uninflated pillow pattern to the uninflated inflation channel so that when pressurized air is introduced into the inflation channel the pressurized air can be transmitted through the inlet port to inflate the pillow pattern,
• an inflating station for inflating pillows in the web of film,
• a sealing station for sealing inflated pillows by sealing the narrow width inlet port,
• a slitting station for slitting the inflation channel to permit removal of a strip of inflated, sealed pillows from the machine, and
• a second film transport station for gripping and advancing the web of film,
• said sealing station including a sealing wheel and a heated sealing element biased toward engagement with a preselected force,
• the heated sealing element being mounted at a fixed location in the machine and the sealing wheel being movable toward and away from the heated sealing element,
• and wherein a longitudinally extending portion of the web of film which contains the inlet ports is interposed between and pressed between the heated sealing element and the sealing wheel with one film surface engaged directly and in sliding contact with the heated sealing element and the other film surface wrapped in rolling contact around a part of the peripheral surface of the sealing roller as the web of film is continuously and uninterruptedly advanced through the sealing station,
• a cartridge unit which contains the heated sealing element and which is constructed so as to be removed and replaced as a unit without the need to replace any individual components of the cartridge unit,
• said cartridge unit comprising a sub-frame, a guide block having an opening in one end for the heated sealing element, at least one Nichrome wire mounted within the opening in the guide block, a storage reel and a take-up reel mounted for rotation on the sub-frame, a strip of fabric for covering the Nichrome wire and wound on the storage reel and the take-up reel, and a drive for rotating the take-up reel, said strip of fabric having a Teflon coating on a side engageable in sliding contact with a surface of the film at the sealing station, and wherein the strip of fabric extends across said opening in the guide block so as to cover the Nichrome wire when the sealing wheel is moved to a position in which the sealing wheel pushes the film against the fabric and the underlying Nichrome wire during continuous movement of the film through the machine.
• and wherein the seal is formed complete and secure at the time the web of film moves out of rolling contact with the sealing wheel without the need for additional pressing together of the web of film after the sealing station and without the need for additional cooling of the seal across the inlet port.

A method of inflating and sealing pillow patterns in a web of film while continuously and uninterruptedly advancing the web of film through a machine, said method comprising,

• gripping a web of film at a first film transport station to draw a web of film from a store,
• said web of film having an uninflated pillow pattern and an uninflated inflation channel which are preformed in the web of film before the web of film is gripped at the first film transport station,
• said uninflated pillow patterns comprising multiple, spaced-apart, pillow patterns aligned along one side of the inflation channel which extends longitudinally and continuously along the entire length of the web of film,
• each uninflated pillow pattern having a narrow width inlet port extending generally transversely to the longitudinally extending inflation channel and connecting the uninflated pillow pattern to the uninflated inflation channel so that when pressurized air is introduced into the inflation channel the pressurized air can be transmitted through the inlet port to inflate the pillow pattern,
• introducing pressurized air into the inflation channel in the web of film at an inflating station and inflating at least one of pillow patterns prior to the time the web of film is transported through a sealing station,
• gripping the web of film at a second film transport station to continuously advance the web of film from the first transport station to and through the sealing station and then to and through the second film transport station,
• maintaining pressure in the inflated pillow pattern during the time that the web of film is being transported through the sealing station,
• sealing the inlet port at the sealing station by applying a heated sealing element directly to and in sliding contact with the web of film and across the inlet port while the air in the inflated pillow is under pressure and as the web of film is continuously advanced through the sealing station,
• said sealing station including a sealing roller disposed opposite the heated sealing element,
• said sealing roller having part of its periphery engaged in rolling contact with the film at the sealing station on the side of the film opposite that engaged in sliding contact with the heated sealing element,
• positioning the sealing roller to create a dead zone in the area of the film engaged in rolling contact with the periphery of the sealing roller, and
• forming the seal complete and secure by the time the web of film moves out of contact with the sealing wheel without the need for additional pressing together of the film after the sealing station and without the need for additional cooling of the seal across the sealed inlet port.

A web of film formed with a pattern of pillows to be inflated and sealed and then used in packaging, said web of film and pattern comprising,

• two sheets of plastic film overlaid one on the other to form a web of film,
• said web of film being sealed together in a pattern,
• said pattern comprising,
• an inflation channel which extends longitudinally and continuously along the entire length of the web of film,
• multiple, spaced-apart, pillow patterns aligned along one side of the inflation channel,
• each pillow pattern having a narrow width inlet port extending generally transversely to the longitudinally extending inflation channel and connecting the pillow pattern to the inflation channel so that when pressurized air is introduced into the inflation channel, the pressurized air can be transmitted through the inlet port to inflate the pillow pattern,
• a plurality of longitudinally spaced-apart outlet ports on the side of the inflation channel opposite the side having the inlet ports,
• and wherein the outlet ports are constructed to permit exhausting the overflow of pressure in the inflation channel while the pillow patterns are being inflated and being sealed under pressure.