Air cushion machine and method

1. A method of producing an interconnected string of air cushions from a supply of plastic film with an air cushion machine for cushioning at least one item to be shipped in a box, the machine configured to inflate each air cushion in the string of air cushions to a variable inflation value selected from a range of inflation values, the machine having an inflation assembly for injecting air between plies of the film, a pulling assembly for pulling the film through the machine, and a longitudinal sealing assembly for sealing the plies of the film, the method comprising the steps of:

determining a void volume defined by a difference between a volume of the box and a volume of the at least one item to be shipped in the box,

determining a quantity of air cushions in the string of air cushions, each of a substantially identical length and width, to be produced and the variable inflation value for each air cushion in the quantity of air cushions such that a total air cushion volume of the quantity of air cushions in the string of air cushions produced is equal to the void volume,

wherein each air cushion in the string of air cushions is prescribed with a unique inflation value that may vary from cushion to cushion within the string of air cushions,

wherein each air cushion in the string of air cushions has a minimum allowable inflation value such that the air cushion will function effectively as cushioning material and a maximum allowable inflation value such that the air cushion will function effectively as cushioning material and not risk bursting,

wherein the step of determining the inflation value for each air cushion in the string of air cushions provides a value within a range from the minimum allowable inflation value to the maximum allowable inflation value,

and further wherein:

the inflation assembly is controlled to vary an output pressure of the inflation assembly, the pulling assembly is controlled, and the sealing assembly is controlled, to produce the determined quantity of air cushions in the string of air cushions and the inflation value for each, or

the inflation assembly is controlled to produce a constant output pressure of the inflation assembly, the pulling assembly is controlled to vary the speed of the film and thus the amount of time that the forming air cushions are exposed to the inflation assembly to thereby vary the inflation value, and the sealing assembly is controlled, to produce the determined quantity of air cushions in the string of air cushions and the inflation value for each; and

producing the determined quantity of air cushions in the string of air cushions with the air cushion machine, and then

repeating the above steps for a subsequent item to be shipped in a subsequent box to determine a subsequent different quantity of air cushions in a subsequent interconnected string of air cushions having a subsequent different total air cushion volume equal to a subsequent different void volume, and

producing the subsequently determined quantity of air cushions in the subsequent string of air cushions,

without manual input from an operator.

2. The method of claim 1 wherein the void volume is measured with an instrument.

3. The method of claim 1 wherein the void volume is calculated based on a known volume of the at least one item and a known volume of the box.

4. The method of claim 1 wherein each air cushion of the quantity of air cushions has the same volume.

5. The method of claim 1 wherein all but one air cushion of the quantity of air cushions has the same volume.

6. The method of claim 1 further comprising the steps of:

generating a signal representative of the void volume,

supplying the signal to the air cushion machine, and

causing, with the signal, the air cushion machine to produce the quantity of air cushions having the total air cushion volume equal to the void volume.

7. A protective packaging system for producing material for cushioning at least one item to be shipped in a box, comprising:

means for determining a void volume defined by a difference between a volume of the box and a volume of the at least one item to be shipped in the box, and

an air cushion machine for producing an interconnected string of air cushions from a supply of plastic film, the machine configured to inflate each air cushion to a variable inflation value selected from a range of inflation values, the machine having an inflation assembly for injecting air between plies of the film, a pulling assembly for pulling the film through the machine, and a longitudinal sealing assembly for sealing the plies of the film,

the system configured to determine a quantity of air cushions in the string of air cushions, each of a substantially identical length and width, to be produced and the variable inflation value for each air cushion in the quantity of air cushions such that a total air cushion volume of the quantity of air cushions in the string of air cushions produced is equal to the void volume,

wherein the air cushion machine is configured to prescribe each air cushion in the string of air cushions with a unique inflation value that may vary from cushion to cushion within the string of air cushions,

the air cushion machine controllable in response to the void volume to produce the quantity of air cushions in the string of air cushions,

wherein each air cushion in the string of air cushions has a minimum allowable inflation value such that the air cushion will function effectively as cushioning material and a maximum allowable inflation value such that the air cushion will function effectively as cushioning material and not risk bursting,

wherein the inflation value for each air cushion in the string of air cushions is within a range from the minimum allowable inflation value to the maximum allowable inflation value,

and further wherein:

the inflation assembly is controlled to vary an output pressure of the inflation assembly, the pulling assembly is controlled, and the sealing assembly is controlled, to produce the determined quantity of air cushions in the string of air cushions and the inflation value for each, or

the inflation assembly is controlled to produce a constant output pressure of the inflation assembly, the pulling assembly is controlled to vary the speed of the film and thus the amount of time that the forming air cushions are exposed to the inflation assembly to thereby vary the inflation value, and the sealing assembly is controlled, to produce the determined quantity of air cushions in the string of air cushions and the inflation value for each,

the system further configured to determine a subsequent different quantity of air cushions in a subsequent interconnected string of air cushions having a subsequent different total air cushion volume equal to a subsequent different void volume for a subsequent item to be shipped in a subsequent box,

without manual input from an operator.

8. The protective packaging system of claim 7 further comprising a controller for receiving a signal, representative of the void volume, from the means for determining a void volume, and for sending a signal to the air cushion machine commanding the air cushion machine to produce the quantity of air cushions having the total air cushion volume.

9. The protective packaging system of claim 7 wherein the means for determining the void volume is an instrument of measurement.

10. The protective packaging system of claim 7 wherein the means for determining the void volume is a database of box volumes and item volumes and a processor for subtracting item volumes from box volumes.

11. The protective packaging system of claim 7 wherein the air cushion machine further includes a controller, and wherein the controller sends signals to the pulling assembly, the inflation assembly, and the sealing assembly in commanding the air cushion machine to produce the quantity of air cushions having the total air cushion volume.

12. The protective packaging system of claim 11 wherein the supply of plastic film comprises an elongated continuous tubular sheet having a series of transverse heat seals formed in the plastic sheet and spaced apart along the longitudinal extent of the sheet, and a series of transverse lines of perforations spaced apart along the longitudinal extent of the sheet.

13. The protective packaging system of claim 7 wherein the air cushion machine further includes a separation assembly for separating a leading air cushion or string of air cushions from a trailing air cushion, and wherein the controller sends signals to the separation assembly to command the separation assembly to separate the leading air cushion or string of air cushions from the trailing air cushion.