INFLATABLE CUSHION FORMING MACHINE

Description

[0001] The present invention relates to a device for making inflatable packaging material. More particularly, the present invention relates to a device for making cellular inflatable packaging cushions from tubular thermoplastic material.

[0002] When articles are packaged in a container or box for shipping, there are frequently void spaces in the container. Protective packaging material for articles of different sizes and shapes is commonly used to cushion articles during shipping. There are numerous types and forms of packaging material for this purpose including waste paper, embossed paper, laminated bubble paper and plastic beads, known as peanuts. These forms of packaging material do not always provide the cushioning and void fill needed when shipping.

[0003] Inflatable cushion packaging material has found widespread use in the packaging industry. Various forms of inflatable cushions have been proposed for use in protecting articles during shipment. One type of inflatable cushion is a multiple use inflatable cushion which is placed around the article to be protected and inflated after the cushion is placed in the shipping container.

[0004] Certain advantages, such as ease of use, may be had by using simple, one-use rectangular cellular sealed cushions. Examples of such cellular cushioning materials are shown in U.S. Patent Nos. 3,817,803 and 5,340,632. The ability to make these types of cushions simply, efficiently and at the point of use is of paramount importance One example of such a device is disclosed in EP-B-0 513 235 which describes a machine for making inflatable cushions which includes welding sheets of material together, introducing air to the tubular material and sealing the ends.

[0005] It is an object of the present invention to provide a machine and method for making inflatable, one-use packaging material.

[0006] To this end, the invention consists in an inflatable cushion filling machine for forming inflated packaging cushions from a roll of tubular thermoplastic material, comprising:

a film supply section having means for holding said roll of tubular thermoplastic material; and

a cushion forming section comprising;

a first pair of rolls forming a nip for advancing said tubular thermoplastic material and a second pair of rolls forming a nip positioned downstream and spaced from said first pair of rolls;

means positioned between said first and second pairs of rolls for introducing air into said tubular thermoplastic material;

means displaced transversely across said tubular thermoplastic material for delimiting a volume serving to form an inflated cushion, said means forming the top seal of said inflated cushion and the bottom seal of a next cushion; and

means for advancing and retracting at least one of said second pair of rolls toward and away from each other so that said air may pass into said tubular material forming said cushion and leaving residual air in that portion of said tubular material forming said next cushion;

   characterised in that at least one of said first pair of rolls is reversibly driven, whereby said first and said second pairs of rolls are capable of providing tension on that portion of said tubular thermoplastic material between said pairs of rolls and said means for introducing air into said tubular thermoplastic material (F) is operable as the latter is held under tension.

[0007] The film supply section may include a pair of arms having channels or slots for holding a roll of tubular thermoplastic material. In a preferred embodiment, one of the arms has a brake which maintains constant web tension on the roll of tubular material.

[0008] In the cushion forming section, the first pair of rolls may be a drive roll and a nip roll forming the nip therebetween through which the tubular material also passes and the second pair of rolls may comprise a drive roll and associated nip roll forming a nip therebetween through which the tubular material passes. The first drive roll is reversible to apply tension to the web of thermoplastic material while air passes into the tube to form a pre-bubble and separate the sides of the tubular material.

[0009] While under tension, the upper end and the lower end of the tube are in an airtight relationship between the pairs of rolls. The means for introducing air into the tubular material between the pairs of rolls may, for example, be a plurality of needles. The means for advancing and retracting at least one of the second pair of rolls may be arranged to move the second nip roll toward and away from the second drive roll allowing the tubular material containing a pre-bubble of air to pass. After the tubular material is filled with air, the sealing means, such as a heat seal band or wire, is displaced transversely across the thermoplastic material, and seals the ends of the cushions above and below the area of the holes made during filling to form the bottom of the cushion. As mentioned, prior to filling the cushion with air, the walls of the tubular thermoplastic material separate from each other by the residual air from the filling operation of the previous cushion. A perforation knife may be provided to separate each cushion from the next succeeding cushion.

[0010] The present invention also consists in a method for making an inflated packaging cushion in which tubular thermoplastic material is fed through a cushion forming section having a first pair of rolls forming a nip for advancing the tubular thermoplastic material, and a second pair of rolls forming a nip and spaced downstream from said first pair of rolls; comprising the steps of
   reversibly driving at least one of said rolls of said first pair to apply tension to the portion of tubular thermoplastic material between said pairs of rolls as said material passes through said cushion forming section by introducing an amount of air into said portion of tubular thermoplastic material while said material is held under tension separating the sides of said tubular material from each other;
   removing said tension from said portion of tubular material while continuing to inflate;
   sealing across said tubular thermoplastic material to form a seal line and delimit volume serving to form said cushion; and
   perforating said seal line between each of said cushions and the next cushion;
   such that, when said inflating step is completed, the delimited volume is formed above and below said inflating point, forming the top seal of said inflated cushion and the bottom seal of the next cushion.

[0011] In order that the present invention may be more readily understood, reference will now be made to the accompanying drawings, in which:-

Figure 1 is an isometric view of a pair of packaging cushions attached to each other and made by the present invention;

Figure 2 is a front view of a cushion filling machine according to the present invention;

Figure 3 is a side view of the cushion filling machine;

Figure 4 is an exploded side view of the cushion filling section of the machine;

Figure 5 is a top views of the film supply section;

Figure 6 is a top views of the filling needles, sealing portion and perforating portion of the cushion filling machine taken along line 6-6 of Figure 4; and

Figure 7 is a fragmentary view taken along line 7-7 of Figure 6.

[0012] Referring now to the drawings and in particular Figure 1, there is shown a pair of inflated packaging cushions 10 of the present invention formed from a tube of air impermeable thermoplastic material. Each cushion is formed along weld lines 2 and inflated, as will be described hereafter. The cushions are formed in a series, attached to each other, and may be separated along perforated line 3. Depending upon the cushioning protection desired, the width and length of the cushions may vary but are generally in the range of 2.54 cm by 2.54 cm to 30.5 cm by 30.5 cm (3" by 3" to 12" by 12")or larger.

[0013] As shown in Figures 3 and 4, the inflatable cushion forming machine 100 includes a support 110, a film supply section 120, and a cushion forming section 130. The support 110 has a telescoping column 111 mounted to a moveable platform 112 having rollers 113. The telescoping column 111 is adjustable upward and downward over a range of, for example, about 610mm (24 inches). The height of the column will depend upon the height of the product conveyor 114. The moveable platform 112 is positioned adjacent the product conveyor 114 so that the cushion forming section 130 is over the conveyor. As a container, such as, a corrugated box holding an article to be protected, passes the cushion forming section 130, the operator starts the machine and a series of inflated packaging cushions 10 fall into the container. When a suitable number of cushions has been formed, the operator stops the machine and, if necessary, tears the row of cushions at a perforation line 3 and conveys the filled container to a sealing station. The operation of the machine is controlled by a controller 115, which is of conventional design. Because the platform 112 is moveable, the machine 100 can be moved from one product line to another depending upon the need at a given time.

[0014] The film supply section 120 is attached to the top of telescoping column 111. The film supply section 120 includes a pair of arms 123 mounted at the top of the telescoping column 111 and spaced apart from each other a sufficient distance to accommodate a roll 122 of tubular thermoplastic material. As shown more clearly in Figure 5, one arm has a channel 124 for accommodating one end of a roll of film. The other arm 123 has a seating member 121 for accommodating a retractable core plug 125. The seating member 121 forms a part of the inner end of brake hub 119 which in turn is attached to one end of hub spring 118. The seating member 121 maintains the roll of material 122 in a secured position and easily releases the core plug by retraction of plunger member 128 capped with hub retraction knob 128a which holds hub spring 118 in place around the outer portion of plunger member 128.

[0015] There is also provided a magnetic particle brake 129 which maintains constant web tension between the roll 122 of tubular thermoplastic material and drive roll 134 and nip roll 135. The follower arm 127 is connected through pivot 126 controlled by a potentiometer and connected through a feedback loop to controller 115 which changes the resistance of the brake depending upon the angle of the follower arm against the material roll 122. In other words, the brake 129 maintains constant tension on the roll no matter what the diameter. As shown, the brake 129 continues to apply tension to the roll as the size of the roll decreases through usage. When the roll 122 of thermoplastic material has been used up a new roll may be easily placed in position on arms 123.

[0016] The roll of material 122 may have a pair of core plugs 125 inserted in each end of the roll core. When the material roll 122 is placed in the channels 124, the core plugs 125 rest at the end or bottom of the channel. The arms are connected to roll width adjustment pivots 126 which are mounted to the column 111. The width between the arms 123 may be changed to accommodate different width rolls of material by moving pivots 126 to different fastening positions in the top of column 111. An example of one style of desirable core plug 125 is the spring tensioned plug and the plug seating arrangement shown in U.S.-A-5,322,234,

[0017] The tubular thermoplastic material F is drawn from the film supply section 120 to the cushion forming section 130. The support base 131 of the cushion forming section 130 is mounted at the top of telescoping column 111 in film receiving proximity to the film supply section 120. The cushion forming section 130 includes means for delivering the tubular thermoplastic material F from the roll 122 through the cushion forming section 130. The preferred means is a first pair of rolls 134, 135 forming a nip therebetween through which the tubular material F passes. The drive roll is reversibly driven when actuated by motor 137a to provide the required tension of the tubular material during inflation of the cushion.

[0018] Pulley 137 is provided to accommodate belt 138 and is connected to motor 137a and to the controller 115. The drive belt 138 passes around a pulley attached to the end of drive roll 134, pulley 137 and idle-pulley 136. The film web F tension is not so tight as to prevent a predetermined amount of inflation of air into the area forming the cushion.

[0019] As shown in Figures 2 and 4, set pin 139 is also provided to position or remove roll 135 and to adjust the tension on roll 135.

[0020] In order to provide a smooth delivery of the thermoplastic tubular material, the material F passes over an idler roll 132 and a dancer roll 133 positioned between the film roll 122 and the first pair of rolls 134, 135. There is a torsion spring 140 located above dancer roll 132 which serves to maintain the film against the dancer roll.

[0021] To form and inflate the cushion, it is necessary to separate the sides of the tubular material F from each other. There are several means for separating the sides of the tubular material from each other, such as by using vacuum cups. However, it has been found that when the tubular material is passed through a channel formed by walls 141, 142 that a bubble of residual air from the previous cycle is caught between the sides of the tubular material F forcing the sides against the channel walls 141, 142.

[0022] To maintain the tubular material under tension, a second pair of rolls, nip roll 143 and drive roll 144, are positioned so as to form a nip through which tubular material F passes. The second pair of rolls is positioned to form a nip therebetween for drawing the web of thermoplastic film F. Rolls 143, 144 are capable of turning in one direction only so as to provide the desired tension. Once the cushion has been formed and sealed, the rolls 143, 144 are separated from each other so that the tubular material containing residual air may pass between the rolls and additional air fills the cushion below rolls 143, 144. Nip roll 143 is connected to pneumatic cylinders 145, via links 146, for advancing and retracting the rolls toward and away from each other. To prevent the thermoplastic material from wrapping around drive roll 144, a jam plate is provided. In addition, a jam belt may be provided around one end of drive roll 144.

[0023] Downstream from the channel walls 141, 142 and before the second pair of drive rolls 143, 144, are the sealing and filling elements. As shown more clearly in Figures 4 and 6-7, there is provided means for introducing air into the tubular thermoplastic material. In a preferred embodiment, a plurality of needles 155, attached through a manifold block 156 connected to an air supply 156A, are held in restraining bar 157 positioned adjacent the channel walls. See Figure 6. While the tubular material F is under tension, pneumatic cylinder 158 moves the needles toward the tubular material piercing only one side thereof, as seen by dotted lines in Figure 6, and inflating the cushion with the desired amount of air. As the needles 155 are removed, a sealing means 150 displaced transversely across the thermoplastic material for delimiting a volume serving to limit the size of the cushion 10 is moved toward the inflated cushion and presses the cushion against the restraining bars 157 to form seal 2. This seal effectively seals the holes made by the needles and leaves residual air in the tube to form the following cushion. More specifically, the sealing means 150 are provided with a pair of sealing bands or wires 152 which when in sealing position are disposed against the surface 151 of restraining bars 157 opposite each other. A pneumatic cylinder 154 is provided for advancing and retracting the seal jaws and the perforating knife 160 toward and away from the tubular material.

[0024] The perforation knife 160 is provided for forming perforation line 3 which can be used to separate each cushion from the next succeeding cushion. A cover 165 is hingably mounted to the top of the frame support 131.

[0025] In the basic operation of the sealing bar; a voltage is applied across a metal wire that heats to a desired temperature (or temperature range) when a reasonable voltage is applied. Such techniques can be rather crude, however, because simply applying voltage to a wire may heat it to a point where it not only seals the plastic, but also burns the plastic residue, crystallizes the polymer, and breaks the seal itself. Alternatively, if the wire fails to heat evenly or sufficiently, it may fail to provide a complete seal, leading to other problems, including leakage from the inflatable cushion.

[0026] The present invention also includes a method and apparatus for precisely measuring the characteristics, including, for example, the temperature of a cutting or sealing wire, and then. controlling the wire to maintain it at a desired temperature or temperature range. Such method and apparatus is provided by the use of a measuring circuit and a storing circuit including a computer chip, such as an EEPROM, in conjunction with an individual heating element, i.e., a metal strip or wire.

[0027] In use, the sealing is band or wire calibrated to obtain measurements concerning the wire's individual characteristics, such as the resistance of the wire through the entire operational range. The computer chip is then programmed with the measured characteristics of the individual sealing wire, such as its precise temperature coefficient of resistance. Other information can also be programmed, including the history of the wire's use, as well as other characteristics of the cutting and sealing operation. The chip provides the system with the most recent information available concerning the wires used to carry out the cutting and sealing of the plastic for the inflatable cushion operation, so that the appropriate temperature or temperature range may be chosen for the operation of that wire.

[0028] Further, an alternative embodiment of this aspect of the invention records and calibrates the characteristics of motors and other components of the inflatable cushion forming machine. The use of smart components provides more precise control for the overall system which, as described above, is often a necessity for a quality final product.

[0029] A particular embodiment of the apparatus for precisely controlling the temperature of a cutting or sealing wire is represented by sealing means 150 shown in Figure 4 and includes a conventional power supply, conventional outputs and an EEPROM(not shown). The EEPROM is programmed with information about the individual cutting and sealing wire, which then updates the temperature controlling operation to produce the proper temperature or temperature range. The device may also be adapted so that the circuit configuration provides feedback to the EEPROM with updated calibrations from the cutting and sealing wire to control the temperature of the wire. By controlling the temperature of the cutting and sealing wire, a complete and accurate seal and cut can be accomplished by the inflatable cushion forming machine.

Operation of the Machine

[0030] The inflatable cushion filling machine includes, as shown in Figure 3, a supply of tubular thermoplastic material F from a roll of film 122 which is placed on a delivery rack. At the tubular material delivery site, there is a brake 129 which maintains constant tension between the roll 122 of tubular thermoplastic material and rolls 134 and 135.

[0031] As the tubular material F leaves the supply roll 122, it passes over idler roll 132 and dancer roll 133 where it then passes through the nip formed between rolls 134 and 135. The tubular material then passes between channel walls 141, 142, which size the preformed bubble inflated by residual air from the previous cycle, and past a second pair of rolls 143, 144. Roll 134 is reversed tensioning the tubular film F between the first pair of rolls and the second pair of rolls.

[0032] The needles 155 are moved toward the web to pierce one side of the web and air is injected. The second pair of rolls 143, 144 are moved apart allowing the air to pass to the area within the tubular material below rolls 143, 144, as shown in Figure 4. The film is driven forward a fraction of an inch by drive roll 134 to relieve tension in the tubular material before sealing. At this point, the needles 155 are still forward (in the pre-bubble) and the nip between the second pair of rolls is open. This allows the tension to be relieved without moving the needle puncture holes out of the area between the seal wires 152. When that step is complete, the needles retract and the cushion is sealed above and below the needle puncture holes. The seal 2 forms the top seal of one inflated cushion and the bottom seal of the next consecutive cushion. During sealing, the perforation knife 160 extends between seal jaws 151 and 152 perforating the seal 2. Then the seal jaw 151 and 152 and the perforation knife retract and the cycle is repeated or stopped.

Claims

1. An inflatable cushion filling machine (100) for forming inflated packaging cushions (10) from a roll (122) of tubular thermoplastic material (F), comprising:

a film supply (120) section having means (123) for holding said roll of tubular thermoplastic material; and

a cushion forming section (130) comprising:

a first pair of rolls (134,135) forming a nip for advancing said tubular thermoplastic material (F) and a second pair of rolls (143,144) forming a nip positioned downstream and spaced from said first pair of rolls (134,135);

means (155) positioned between said first and second pairs of rolls for introducing air into said tubular thermoplastic material (F);

means (150) displaced transversely across said tubular thermoplastic material (F) for delimiting a volume serving to form an inflated cushion (10), said means forming the top seal of said inflated cushion and the bottom seal of a next cushion; and

means (145) for advancing and retracting at least one of said second pair of rolls toward and away from each other so that said air may pass into said tubular material (F) forming said cushion (10) and leaving residual air in that portion of said tubular material forming said next cushion;

   characterised in that at least one of said first pair of rolls (134,135) is reversibly driven, whereby said first and said second pairs of rolls are capable of providing tension on that portion of said tubular thermoplastic material between said pairs of rolls, and said means for introducing air into said tubular thermoplastic material (F) is operable as the latter is held under tension.

2. The machine according to claim 1, wherein said film supply section (120) includes a brake (129) which maintains constant web tension on said roll (122) of tubular thermoplastic material (F).

3. The machine according to claim 1 or 2, wherein said means for holding (123) said roll (122) of tubular material (F) comprises a pair of arms (123), one of said arms having a spring loaded seating member (119) for retaining and releasing a core plug (125).

4. The machine according to claim 1, 2 or 3, including a dancer roll (133) and an idler roll (132) positioned between said holding means (123) for said thermoplastic material (F) and said first pair of rolls (134,135).

5. The machine according to claim 1, 2, 3 or 4, wherein said means for delimiting said volume serving to form said inflated cushion (10) is a pair of sealing wires (152).

6. The machine according to claim 5, including means for applying a voltage to said sealing wires (152) and means for measuring and controlling the temperature of said wires.

7. The machine according to any preceding claim, wherein said means for introducing air into said cushion (10) is a plurality of needles (155).

8. The machine according to any preceding claim, including a perforation knife (160) for separating said inflated cushions.

9. A method for making an inflated packaging cushion (10), in which tubular thermoplastic material (F) is fed through a cushion forming section (130) having a first pair of rolls (134,135) forming a nip for advancing the tubular thermoplastic material, and a second pair of rolls (143, 144) forming a nip and spaced downstream from said first pair of rolls; comprising the steps of:

reversibly driving at least one of said rolls of said first pair to apply tension to the portion of tubular thermoplastic material between said pairs of rolls as said material passes through said cushion forming section

introducing an amount of air into said portion of tubular thermoplastic material while said material is held under tension separating the sides of said tubular material from each other;

removing said tension from said portion of tubular material while continuing to inflate;

sealing across said tubular thermoplastic material to form a seal line and delimit volume serving to form said cushion (10); and

perforating said seal line between each of said cushions and the next cushion;

such that, when the inflating step is completed, the delimited volume is formed above and below the zone of introduction of the air, forming the top seal of said inflated cushion and the bottom seal of the next cushion.

Ansprüche

1. Maschine (100) zum Füllen aufblasbarer Kissen zur Herstellung aufgeblasener Verpackungskissen (10) von einer Rolle (122) mit röhrenförmigem thermoplastischen Material (F) mit:

einem Folienzufuhrabschnitt (120) mit Einrichtungen (123) zum Halten der Rolle des röhrenförmigen thermoplastischen Materials, und

einem Abschnitt (130) zur Bildung eines Kissens, der

ein erstes Paar von Rollen (134, 135), die einen Spalt zum Fördern des röhrenförmigen thermoplastischen Materials (F) bilden, und ein zweites Paar von Rollen (143, 144), die einen von dem ersten Paar Rollen (134, 135) auf Abstand und stromabwärts liegenden Spalt bilden,

zwischen dem ersten und dem zweiten Paar Rollen angeordnete Einrichtungen (155) zum Einführen von Luft in das röhrenförmige thermoplastische Material (F),

quer versetzt über dem röhrenförmigen thermoplastischen Material (F) angeordnete Einrichtungen (150) zum Begrenzen eines Volumens, das zur Bildung eines aufgeblasenen Kissen (10) dient, wobei die Einrichtungen die obere Dichtung des aufgeblasenen Kissens und die untere Dichtung eines nächsten Kissens bilden, und

Einrichtungen (145) zum Vorschieben und Zurückziehen von wenigstens einer aus dem zweiten Paar der Rollen aufeinander zu und voneinander weg aufweist, so daß Luft in das röhrenförmige Material fließen kann, das das Kissen (10) bildet, und restliche Luft in dem Bereich des röhrenförmigen Materials zurückbleibt, das das nächste Kissen bildet,

dadurch gekennzeichnet, daß wenigstens eine aus dem ersten Paar Rollen (134, 135) umkehrbar angetrieben ist, wodurch das erste und das zweite Paar Rollen in der Lage sind, eine Spannung auf den Bereich des röhrenförmigen thermoplastischen Materials zwischen dem Paar der Rollen auszuüben, und daß die Einrichtungen zum Einführen von Luft in das röhrenförmige thermoplastische Material (F) betreibbar ist, während das letztere unter Spannung gehalten wird.

2. Maschine nach Anspruch 1, wobei der Folienzufuhrabschnitt (120) eine Bremse (129) enthält, die eine konstante Bahnspannung auf der Rolle (122) des röhrenförmigen thermoplastischen Materials (F) aufrechterhält.

3. Maschine nach Anspruch 1 oder 2, wobei die Einrichtungen zum Halten (123) der Rolle (122) des röhrenförmigen Materials (F) ein Paar von Armen (123) umfaßt, wobei einer der Arme ein federbelastetes Sitzteil (119) zum Halten und Freigeben eines Kernstopfens (125) hat.

4. Maschine nach Anspruch 1, 2 oder 3, die eine Tänzerrolle (133) und eine Laufrolle (132) angeordnet zwischen den Halteeinrichtungen (123) für das thermoplastische Material (F) und dem ersten Paar Rollen (134, 135) aufweist.

5. Maschine nach Anspruch 1, 2, 3 oder 4, wobei die Einrichtungen zum Begrenzen des Volumens, das zur Bildung des aufgeblasenen Kissens (10) dient, ein Paar von Siegeldrähten (152) ist.

6. Maschine nach Anspruch 5, die eine Einrichtung zum Anlegen einer Spannung an die Siegeldrähte (152) und einer Einrichtung zum Messen und Steuern der Temperatur der Drähte umfaßt.

7. Maschine nach einem der vorhergehenden Ansprüche, wobei die Einrichtung zum Einführen von Luft in das Kissen (10) eine Vielzahl von Nadeln (155) ist.

8. Maschine nach einem der vorhergehenden Ansprüche, die ein Perforationsmesser (160) enthält, um die aufgeblasenen Kissen abzutrennen.

9. Verfahren zur Herstellung eines aufgeblasenen Verpackungskissens (10), bei dem röhrenförmiges thermoplastisches Material (F) durch einen Kissenbildungsabschnitt (130) gefördert wird, der ein erstes Paar von Rollen (134, 135), die einen Spalt zum Vorschieben des röhrenförmigen thermoplastischen Materials bilden, und ein zweites Paar. von Rollen (143, 144) aufweist, die einen Spalt bilden und in Abstand stromabwärts von dem ersten Paar Rollen liegen, mit den Schritten:

Umgekehrtes Antreiben von wenigstens einer der Rollen des ersten Paars, um den Bereich des röhrenförmigen thermoplastischen Materials zwischen den Rollenpaaren unter Spannung zu setzen, während das Material durch den Kissenbildungsabschnitt läuft,

Einführen einer Menge von Luft in den Bereich des röhrenförmigen thermoplastischen Materials, während das Material unter Spannung gehalten wird, was die Seiten des röhrenförmigen Materials voneinander trennt,

Lösen der Spannung in dem Bereich des röhrenförmigen Materials, während das Aufblasen fortgesetzt wird,

Siegeln quer über das röhrenförmige thermoplastische Material, um eine Siegellinie zu bilden und das Volumen zu begrenzen, das zur Bildung des Kissens (10) dient, und

Perforieren der Siegellinie zwischen jedem der Kissen von dem nächsten Kissen, so daß, wenn der Aufblasschritt abgeschlossen ist, das begrenzte Volumen ober- und unterhalb der Einführungszone der Luft gebildet ist, wobei die obere Abdichtung des aufgeblasenen Kissens und die untere Abdichtung des nächsten Kissens gebildet ist.

Revendications

1. Machine de remplissage de coussins gonflables (100) pour former des coussins d'emballage gonflés (10) à partir d'un rouleau (122) d'un matériau thermoplastique tubulaire (F) comprenant :

une section d'amenée de film (120) comportant un moyen (123) pour tenir ledit rouleau de matériau thermoplastique tubulaire; et

une section de formation de coussins (130) comprenant :

une première paire de rouleaux (134, 135) formant un pincement pour faire avancer ledit matériau thermoplastique tubulaire (F) et une deuxième paire de rouleaux (143, 144) formant un pincement positionné en aval et espacé de ladite première paire de rouleaux (134, 135);

un moyen (155) positionné entre lesdites première et seconde paires de rouleaux pour introduire de l'air dans ledit matériau thermoplastique tubulaire (F);

un moyen (150) déplacé transversalement sur ledit matériau thermoplastique tubulaire (F) pour délimiter un volume servant à former un coussin gonflé (10), ledit moyen formant le joint supérieur dudit coussin gonflé et le joint inférieur d'un coussin suivant; et

un moyen (145) pour faire avancer et retirer au moins l'un de ladite seconde paire de rouleaux vers et au loin l'un de l'autre de telle sorte que ledit air peut passer dans ledit matériau tubulaire (F) formant ledit coussin (10) et laissant un résidu d'air dans cette portion dudit matériau tubulaire formant ledit coussin suivant;

caractérisé en ce qu'au moins l'un de ladite première paire de rouleaux (134, 135) est entraîné en sens inverse par quoi ladite première paire et ladite seconde paire de rouleaux peuvent réaliser une tension sur cette portion du matériau thermoplastique tubulaire entre lesdites paires de rouleaux, et ledit moyen pour introduire de l'air dans ledit matériau thermoplastique tubulaire (F) peut être amené à fonctionner lorsque ce dernier est maintenu sous tension.

2. Machine selon la revendication 1, où ladite section d'amenée de film (120) comporte un frein (129) qui maintient une tension de bande constante sur ledit rouleau (122) de matériau thermoplastique tubulaire (F).

3. Machine selon la revendication 1 ou 2, où ledit moyen pour tenir (123) ledit rouleau (122) en matériau tubulaire (F) comprend deux bras (123), l'un desdits bras comportant un élément de siège (119) sollicité par ressort pour retenir et libérer un bouchon à noyau (125).

4. Machine selon la revendication 1, 2 ou 3, comportant un rouleau danseur (133) et un rouleau tournant librement (132) positionné entre ledit moyen de retenue (123) dudit matériau thermoplastique (F) et ladite première paire de rouleaux (134, 135).

5. Machine selon la revendication 1, 2, 3 ou 4, où ledit moyen pour délimiter ledit volume servant à former ledit coussin gonflé (10) est une paire de fils de scellement (152).

6. Machine selon la revendication 5, incluant un moyen pour appliquer une tension auxdits fils de scellement (152) et un moyen pour mesurer et contrôler la température desdits fils.

7. Machine selon l'une quelconque des revendications précédentes, où ledit moyen pour introduire de l'air dans ledit coussin (10) est une pluralité d'aiguilles (155).

8. Machine selon l'une quelconque des revendications précédentes, comportant un couteau de perforation (160) pour séparer ledits coussins gonflés.

9. Procédé de fabrication d'un coussin d'emballage gonflé (10), dans lequel un matériau thermoplastique tubulaire (F) est amené à travers une section de formation de coussins (130) présentant une première paire de rouleaux (134, 135) formant un pincement pour faire avancer le matériau thermoplastique tubulaire, et une seconde paire de rouleaux (143, 144) formant un pincement et espacée en aval de ladite première paire de rouleaux; comprenant les étapes consistant à :

entraîner en sens inverse au moins l'un desdits rouleaux de ladite première paire pour appliquer une tension à la portion de matériau thermoplastique tubulaire entre lesdites paires de rouleaux lorsque ledit matériau passe à travers ladite section de formation de coussins;

introduire une quantité d'air dans ladite portion de matériau thermoplastique tubulaire pendant que ledit matériau est maintenu sous tension en séparant les côtés dudit matériau tubulaire l'un de l'autre;

enlever la tension de ladite portion de matériau tubulaire tout en continuant à glonfler;

souder ledit matériau thermoplastique tubulaire pour former une ligne de soudage et pour délimiter un volume servant à former ledit coussin (10); et

perforer ladite ligne de soudage entre chacun desdits coussins du coussin suivant;

de telle sorte que lorsque l'étape de gonflage est terminée, le volume délimité est formé au-dessus et en dessous de la zone d'introduction d'air, en formant le scellement supérieur dudit coussin gonflé et le scellement inférieur du coussin suivant.

Drawing