FR2946026A1 - Continuous winding integrated heat sealing machine for closing sachet i.e. sterilization type sachet, in e.g. medical field, has crushing pulley whose diameter is greater than diameter of marking pulley - Google Patents

Abstract

The machine has a sachet closing device formed by a crushing pulley (6) and a marking pulley (5). The crushing pulley is placed in a support relative to the marking pulley. The marking pulley comprises circular protuberances which extend radially on external periphery of the marking pulley with respect to rotational axis. A sachet is placed between the pullies for being sealed by the support among the crushing pulley and the protuberances. Diameter of the crushing pulley is greater than the diameter of the marking pulley.

Description

FIELD OF THE INVENTION The invention relates to a continuous-scrolling thermo-welder. The thermo-welder according to the invention makes it possible to seal a bag. The invention aims to improve the quality of closure of such a bag regardless of the type of bag. The invention relates to the medical, paramedical, veterinary, agri-food, or any industrial field requiring this type of device. STATE OF THE ART A thermo-welder makes it possible to hermetically seal a bag. A pouch is formed by a top sheet and a bottom sheet which are welded together at the time of sealing. At least one of these two sheets at least has the property of being glued to the other sheet after heating and sealing of this sheet. For this, one of these 'Games Leaves is coated with a film (plastic, aluminum, ...) that will stick the other sheet.

In the medical field, a sterilization bag is used. For example, it is known to use a sachet such as steam bag, paper-paper, Tyvek. There are different types of steam bags: one type of bag where the bottom sheet is formed by a paper sheet and the top sheet is formed by a transparent sheet or a type of steam bag (Cleantex) where the bottom sheet is formed by a sheet nonwoven and the topsheet is formed by a transparent sheet. By transparent sheet is meant, for example, a sheet which is formed of a colorless transparent polyethylene polyester complex, or a sheet formed by a transparent plastic.

The paper bag comprises as a top sheet and as a bottom sheet a sheet of paper with glue on at least one of the two sheets. The Tyvek-type bag is a bag comprising, as bottom sheet, a paper sheet formed by a non-woven synthetic material made from polyethylene fibers and as a top sheet a transparent sheet (which is not intended for sterilization at the same time). autoclave). The paper sheet of a type of sterilization bag is opaque, permeable to water vapor and pressurized gases, impermeable to microorganisms, resistant to moisture and tear, thus ensuring a good preservation of sterility in time. The transparent sheet of this type of bag, transparent or not, is very resistant, impermeable to microorganisms, moisture and gases and provides excellent heat sealing.

In one example, the sterilization bag can be designed to contain medical devices previously cleaned, washed and decontaminated. The bag is closed by gluing or sealing the top sheet on the bottom sheet. This sealing is performed by the heat sealer once the medical devices have been inserted. Once closed, the bag is placed in an autoclave to sterilize the medical devices and the air contained in the bag. After passing through the autoclave, the bag is ready for use, that is to say that it is guaranteed to contain sterilized medical devices until the sachet is opened. In the fields of agri-food, veterinary laboratories, industry, pharmaceutical abortions ..., we use a bag that can contain products that need to be placed under vacuum or not. To close the bag, the thermo-welder includes a closure device of the bag. This closure device is formed by a crushing pulley and an impression pulley. The crushing pulley is located above the impression pulley. The crushing pulley and the impression pulley are attached to a support of the thermo-welder. The impression pulley is rotated at a given speed. The crushing pulley is placed in abutment against the impression pulley so that the impression pulley rotates the crushing pulley.

During the passage of the bag in the heat-sealer, the bag is preheated and placed between the crushing pulley and the impression pulley for its closure. The bag is closed by crushing the crush pulley against the impression pulley so as to cause the upper sheet to stick to the lower sheet of the bag.

To facilitate the subsequent opening of the bag, the sealing or bonding is not performed on a wide band but is performed in several small parallel strips. To do this, the impression pulley is provided with upper protuberances with flat, circular surfaces. These protuberances are formed on an outer periphery of the impression pulley while extending radially relative to an axis of rotation of the impression pulley. The axis of rotation of the impression pulley is orthogonal to a line of displacement of the bag. The bands are the result of pressing the crush pulley against the topsheet and against the impression pulley. The upper sheet is pressed against the protuberances and imprints corresponding to the protuberances appear on the bag. The bag is stuck only on areas of the bag that have been pressed against the protuberances. Technical problem The problem posed by this type of thermo-welder is that it is often obtained imperfect bonding of the bag. By imperfect bonding is meant that during crushing, at least one of the two sheets forming the bag slides relative to each other. At least one of the two leaves then has folds or striations. The sliding sheet is positioned transversely with respect to the other sheet at the location of the gluing. The opening of a bag having such a bond with striations is more difficult. The opening of such a bag may also leave residues of the paper sheet on the other sheet after opening the bag. The residues remain attached to the bands formed after crushing. In the case of the sterilization bag, the residues of the paper sheet (lower) can also become detached from the strips and contaminate the medical devices and the inside of the bag by being deposited inside the bag. However, it is a lack of asepsis that paper particles remain stuck on at least one of the pulleys, especially on the transparent sheet. In addition, the creases or striations are areas of the bag (or tunnels) not welded which involve the risk of formation of chimneys. These chimneys are zones of the bag allowing the contaminated outside air to enter inside the bag and to contaminate the medical devices and the internal air of the bag.

It is therefore necessary to implement a crushing device to obtain a clean weld and without creasing. This is achieved by the crushing device according to the invention. SUMMARY OF THE INVENTION After several attempts to improve the bonding quality, it was found that some bags had a better seal than other bags. Better sealing means that, after crushing, the bag does not have streaks or creases at the location of the bonding. In fact, the sliding sheet is not deviated or slightly deviated from the other sheet during the crash. By chance, it has been found that by increasing the diameter of one of the two pulleys relative to the other, the welding is carried out cleanly without one of the two sheets being deflected with respect to the other sheet and vice versa. The opening of the bag is carried out correctly that is to say that the upper sheet and / or lower sheet does not show traces of paper residues on one or the other sheet. According to a preferred embodiment of the invention, it is the diameter of the crushing pulley which is increased relative to a diameter of the impression pulley.

When two sheets of A4-size paper are placed between the two pulleys, it can be seen that the upper sheet slides with respect to the lower sheet. At the outlet of the two pulleys, the upper sheet is slightly forward with respect to the lower sheet. By increasing the diameter of the crushing pulley with respect to the diameter of the impression pulley, a seal is obtained which is effected not only by crushing or compression but also by friction of the upper sheet against the lower sheet due to sliding of the upper sheet relative to the lower sheet during sealing. The invention therefore relates to a continuous-scroll heat sealer for hermetically sealing a sterilization bag, the heat sealer comprising: - a sachet driving device, - a sachet heating device, and - a bag closure device formed by a crushing pulley 35 and an impression pulley, the crushing pulley being placed in abutment against the impression pulley for its rotational drive by the impression pulley, the impression pulley having circular protuberances which extend radially on the outer periphery of the impression pulley with respect to an axis of rotation of the impression pulley, - the bag being placed, after driving the bag toward the closure device and after heating of the bag, between the crushing pulley and the impression pulley to be sealed by pressing between the crushing pulley and the protrusions of the impression pulley, cara characterized in that - the crushing pulley has a diameter greater than a diameter of the impression pulley. DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION The invention will be better understood on reading the description which follows and on examining the figures that accompany it. These are presented only as an indication and in no way limitative of the invention. The figures show: FIG. 1: A schematic representation of a heat-sealer according to the invention; - Figure 2: A schematic representation of a longitudinal section of the interior of a heat-sealer, according to the invention; FIG. 3: A schematic representation of an impression pulley, according to the invention, and FIG. 4: A schematic representation of a view from above of a heat-sealer, according to the invention.

Figures 1 and 2 illustrate a heat-sealer 1 for sealing a bag (not shown) according to the invention. In one example, a sterilization bag is used, but any other type of sachet could be used. As previously mentioned, the sterilization bag can hold medical devices or not and keep them sterile until the bag is opened. The sterilization bag may be formed by a lower sheet and an upper sheet. In a normal mode of use of the thermo-welder, the topsheet is located above the bottom sheet. The heat-sealer 1 comprises a drive 2 of the bag, a heating device 3 and a closure device of the bag 4.

The heat-sealer 1 also includes an internal printer 22 which is synchronized with the passage of the bag. This printer 22 prints the characteristics of the heat sealer as well as the sealing parameters of the bag (sealing temperature, speed of movement of the bag, pressure exerted on the bag at the time of sealing, etc.). This internal printer 22 is integrated into a body of the thermo-welder. The bodywork makes it possible to protect the interior of the heat-sealing machine, and more particularly the drive device 2, the heating device 3 and the closing device 4. This internal printer 22 makes it possible to edit a validation ticket enabling it to be raised. all the parameters and information for sealing the sterilization bag: identification of the user establishment (name, address, service, etc.); Identification of the thermo-welder (brand - type - number - date of commissioning ...); Record of the critical parameters of the thermo-welder according to the standard in force NF EN ISO 11607-2: welding temperature 20 in real time - pressure force of the sealing of the bag - speed of travel of the bag - welding meter; - Maintenance history and qualification of the heat sealer. The validation ticket is then archived with a sealed bag sample. This validation ticket makes it possible to form a traceability tool 25 for sterilization according to the standard in force NF EN ISO 11607-1. A bag guide 30 forming a tray is placed at an inlet E of the thermo-welder. This bag guide 30 makes it possible to keep the bag in place before it enters the thermo-welder. The drive device 2 enables the bag to be transported from an inlet E to an outlet S of the heat-sealer 1. In one example, the bag is transported at a speed of 10 m / min. drive 2 allows the bag to be transported to the closure device 4, 5, 6 which is located near the outlet of the thermo-welder, FIG. 2.

During its displacement, the bag is heated by the heating device 3, FIG. 2. The heating device 3 consists of at least two heating resistors such as 8. According to the preferred example of the invention, there are two resistors 8. This heating device 3 makes it possible to heat the two sheets forming the bag in order to seal them one on the other. When the bag is located at the closure device 4, it is sandwiched between an impression pulley 5 and a crushing pulley 6. In fact, the closing or crushing device 4 is formed by a pulley 5 and a crushing pulley 6. The crushing pulley 6 is located above the impression pulley 5. The impression pulley 5 and the crushing pulley 6 are arranged with their axis of rotation. rotation 10,25 orthogonal disposed with respect to a scroll line of the bag in the heat-sealer. The scroll line of the bag extends from the inlet E to the outlet S, parallel along a surface on which the thermo-welder is placed in the normal operating position, FIG. 2. The impression pulley 5 and the crushing pulley 6 are fixed to a frame 7 which has a U-shape in cross section. As will be described more precisely later in the description, the impression pulley 5 is rotated by the drive device 2. The crushing pulley 6 is resiliently placed against the impression pulley 5 in such a way the impression pulley 5 rotating causes rotation of the crushing pulley 6. The impression pulley 5 has on its outer periphery a series of circular flat protuberances 9 extending radially with respect to the central axis 10 of the impression pulley 5, FIG. 3. The crushing pulley 6 is placed above the protuberances 9. After the passage of the bag between the impression pulley 5 and the crushing pulley 6, the bag is closed and presents a series of strips parallel to each other. These bands are the result of the bonding of the zones of the bag which have been brought into contact with the protuberances 9 by pressing the crushing pulley 6 against the impression pulley 5. This is the upper sheet which has stuck on places of the lower leaf. The impression pulley 5 has a first diameter D1 and the crushing pulley 6 has a second diameter D2. According to the invention, the diameter D2 of the crushing pulley 6 is greater than the diameter D1 of the impression pulley 5, FIG. 2. The ratio of the diameter D2 of the crushing pulley 6 to the diameter D1 of the pulley footprint 5 is between 1.0752 and 1.0978.

In a preferred example of the invention, the diameter D1 of the impression pulley 5 is 46 cm and the diameter D2 of the crushing pulley 6 is 50 cm. In another example, the diameter D1 of the impression pulley 5 is 46.5 cm and the diameter D2 of the crushing pulley 6 is 50 cm. With such a ratio of diameters, the bag is properly sealed, i.e. strips appear on the bag without the bottom sheet being deflected with respect to the topsheet or vice versa. In addition, the opening of the bag is done correctly without remaining paper remains stuck on the other sheet after opening. Prior to its sealing, the bag is driven towards the closure device 4 by the drive device 2. The drive device 2 is formed by a pair of upper pulleys 11, 12, a pair of lower pulleys 13, 14 , an upper belt 15 and a lower belt 16, FIG. 2. The pair of upper pulleys is formed by a rear upper pulley 11 and an upper front pulley 12. The pair of lower pulleys is formed by a rear lower pulley 13 and by a lower front pulley 14. The upper rear pulley 11 and the upper front pulley 12 are arranged with a straight line passing through their respective axis of rotation which is parallel to another line passing through a respective axis of rotation of the rear lower pulley 13 and of the lower front pulley 14. The upper belt 15 is wrapped around the upper rear pulley 11 and around the upper pulley The lower belt 16 is wrapped around the lower rear pulley 13 and around the lower front pulley 14.

The upper belt 15 and the lower belt 16 are toothed belts. In a preferred example of the invention, a type 300 L belt is used. For this, at least one of the upper pulleys 11 or 12 is also notched. In the example according to the invention, the upper rear pulley 11 is notched and the upper front pulley 12 is smooth.

At least one of the lower pulleys 13 or 14 is also notched.

In the example of the invention, the two lower pulleys 13 and 14 are notched. They have splines 29 as illustrated in FIG. 3. By being notched, the pulleys do not allow the belt to slide on one of the pulleys on which it is placed. The flutes 29 have a pattern at L. The upper belt 15 and the lower belt 16 are arranged in such a way that they touch each other between the pairs of pulleys. At the point where they touch is slid the bag which is then pinched by the upper belt 15 and the lower belt 16. By clamping the lower belt 16 and the upper belt 15, the bag is then transported by said belts from the inlet E of the thermo-welder to the output S of the heat-sealer in a direction represented by the arrow Figure 2 and from the left of the drawing to the right of the same drawing. To facilitate, - the guide of the bag in the heat-sealer, the heat-sealer 1 is also equipped with a pair of guide bars fixed to the support 7. An upper guide bar 17 and a lower guide bar 18 are arranged between the upper rear pulley 11 and the upper front pulley 12 on one side and the lower rear pulley 13 and the lower front pulley 14 on the other side. The upper belt 15 is disposed along a lower edge 19 of the upper guide bar 17 and the lower belt 16 is disposed along an upper edge 20 of the lower guide bar 18. Where they placed respectively on the upper guide bar 17 and on the lower guide bar 18, the upper belt 15 and the lower belt 16 touch each other. The upper guide bar 17 and the lower guide bar 18 are arranged relative to each other so that the upper belt 15 and the lower belt 16 touch each other while being slidable relative to one another. to the other. Thus, by placing the bag between the upper belt 15 and the lower belt 16 at the point where they touch each other, the bag is sandwiched between these two belts that carry it and from the inlet E of the thermo-welder. towards the output S. The guide bars 17 and 18 form an additional guide for a better holding of the bag through the heat-sealer during its movement.

During its movement toward the closure device 4, the bag is subjected to a temperature rise produced by the heating resistors 8. The upper sheet of the bag is heated so that the sealing of the bag is possible once the bag The pressure exerted by the crushing pulley 6 on the impression pulley 5 is controlled and exerted via a spring 26, FIG. 4. This spring 26 is placed in abutment. against an articulated arm 21 and against the frame 7. A first end of the arm 21 is rotatably mounted on the frame 7. A second end of the arm 21 opposite the first serves to support the attachment also rotatable pulley d 6. The spring 26 is thus more precisely placed in abutment against the second end of the arm 21 and against the frame 7. Thus, the crushing pulley 6 is placed in support against the impression pulley while being able to move elastically upwards and vice versa via the spring 26. This spring 26 makes it possible to adjust the pressure exerted by the crushing pulley 6 against the impression pulley 5. This spring 26 is calibrated to a force to obtain a crush sufficient to obtain the desired result. In a preferred example, the spring 26 is calibrated to a force making it possible to obtain on the set of strips printed on the bag a sealing force of at least greater than 1.5 Newton. This value comes from the EN 868-5 standard (AFNOR standard). This value is measured and controlled by a dynamometer. For each sealed bag, we can also make a dynamometric test that will control that the bag is well sealed according to current standards. For each band formed at the location of the closure of the bag, the sealing force is measured. An average is made on all these values. It is this average that must be higher than a standard in force.

The frame 7 has an opening 27 allowing the aforementioned displacement of the crushing pulley 6, Figure 4. Advantageously, the impression pulley 5 and the lower front pulley 14 form a single pulley. The impression pulley 5 and the lower front pulley 14 are rotatably connected. The crushing pulley 6 is located above the impression pulley 5 while touching the impression pulley 5. The upper front pulley 12 is situated above the lower front pulley 14 but is not intended to touch it. . The upper front pulley 12 is smooth and the lower front pulley 14 is notched. Advantageously, the crushing pulley 6 and the upper front pulley 12 are mounted coaxially on the same axis. The crushing pulley 6 and the upper front pulley 12 rotate relative to each other independently of one another about the same axis of rotation. The upper front pulley 12 receives the upper belt 15 and the crush pulley 6 is situated above the protuberances 9 of the impression pulley 5. The crushing pulley 6 is located close to the articulated arm 21 and the upper front pulley 12 is located remote from the articulated arm 21. The driving device 2 is coupled to the closing device 4 in order to save space inside the heat-sealing machine 1. The driving device 2 is also coupled to the device 4 to optimize the functions of each of the elements contained in the heat sealer 1. Each of the pulleys 5,6,11,12,13,14 described above is an idler pulley. The upper rear pulley 11 is rotated directly by a motor shaft itself connected to a motor. This engine is located at the rear of the frame 7, on an opposite side where the pulleys 5,6,11,12,13,14 are located. The rear lower pulley 13 is engaged by the upper rear pulley 11. The other pulleys 12 and 14 are respectively rotated by the upper belt 15 and by the lower belt 16. To improve the sealing quality of the bag, the pulley 6 is provided with an elastic ring 28. This ring 28 is advantageously formed by polyurethane, a strong synthetic material and which is perfectly suited to the use that is made of it. The crushing force or the hardness is preferably 90 shores, a value corresponding to an equilibrium between a higher value beyond which the crushing would not be sufficiently marked on the paper side and a lower value below which crush would be too soft and mark too much on the bag.

Such a polyurethane material wears more slowly than a material made from a natural fiber rubber. To control the temperature to be obtained inside the thermo-welder, it is expected that the heater 2 comprises a double probe 23,24. A first temperature sensor 23 is connected to the aforementioned microprocessor which turns on at least one of the heating resistors 8 so that the heating temperature is constant with respect to the required set temperature. The choice of the set temperature depends on the type of bag that is to be sealed and the standards of use of the sachet manufacturer in question. A second temperature probe 24 is provided to control that the first probe operates and to alert the user of the heat sealer that the first probe 23 is no longer functioning. The second probe 24 is managed by another microprocessor. The first probe 23 and the second probe 24 operate independently of each other. The first probe 23 and the second probe 24 are inserted into a single tube so that the temperature can be taken by the first probe 23 and by the second probe 24 at the same location.

A pressure sensor 31 is also provided and is integrated in the structure of the articulated arm 21.

Claims (1)

CLAIMS1 - Continuously continuous heat-sealing machine (1) for hermetically sealing a bag, the thermo-welder comprising - a device for driving the bag (2), - a device for heating the bag (3), and - a device closing of the bag (4) formed by a crushing pulley (6) and an impression pulley (5), the crushing pulley being placed in abutment against the impression pulley for its rotational drive by the impression pulley, the impression pulley having circular protuberances (9) which extend radially on the outer periphery of the impression pulley with respect to an axis of rotation of the impression pulley, - the bag being placed, after driving the bag towards the closing device and after heating the bag, between the crushing pulley and the impression pulley to be sealed by pressing between the crushing pulley and the protrusions of the pulley of imprint, characteris in that - the crushing pulley has a diameter (D2) greater than a diameter (D1) of the impression pulley. 2 - Thermo-welder according to claim 1, characterized in that it comprises an internal printer synchronized with the passage of a bag and which prints on a validation ticket the characteristics of the heat sealer and the sealing parameters of the bag. 3. Thermo-welder according to one of claims 1 to 2, characterized in that the ratio of the diameter of the crushing pulley to the diameter of the impression pulley is between 1.0752 and 1.0978. 4. Thermo-welder according to one of claims 1 to 3, characterized in that the crushing pulley comprises an outer ring (28) of polyurethane, said ring being in contact with the impression pulley. Thermo-welder according to one of Claims 1 to 4, characterized in that the driving device is formed by a pair of upper pulleys (11, 12) and a pair of lower pulleys (13, 14). the pair of upper pulleys being formed by a rear upper pulley (11) and an upper front pulley (12), the pair of lower pulleys being formed by a rear lower pulley (13) and a lower front pulley (14), the upper upper pulley and the upper upper pulley being connected by an upper belt (15) and the lower lower pulley and the lower front pulley being connected by a lower belt (16), the upper belt and the lower belt being placed therein; relative to each other in such a way that the bag is wedged between the two belts, - the upper front pulley rotatably mounted on the same axis as that carrying the crushing pulley and the lower front pulley being mounted on the same axis as the one on which the impression pulley is mounted, the lower front pulley is rotatably connected to the impression pulley. 6 - Thermo-welder according to claim 5, characterized in that the upper front pulley and the crushing pulley are mounted on the same axis while being rotatably mounted independently relative to each other. 7. Thermo-welder according to one of claims 1 to 6, characterized in that the crushing pulley is mounted bearing resiliently against the impression pulley. 8 - Thermo-welder according to one of claims 1 to 7, characterized in that the impression pulley is notched. 9. Thermo-welder according to one of claims 1 to 8, characterized in that the bag is a bag type sterilization bag.