MX2011012973A - Plastic bag for stacked soft hygienic products. - Google Patents

Abstract

Plastic bag (WB) containing stacked soft hygienic products (FCS), e.g. sanitary napkins, panty liners, diapers, or the like, which can be made on-line from a roll of film. The plastic bag comprises one MD seal (35) along one closure corner (46) and is without a fold line in the center of a side panel. An artwork may be present which is continuous in the area of the MD seal. The products may be in a compressed state in the closed plastic bag.

Description

PLASTIC BAG FOR SOFT HYGIENIC PRODUCTS STACKED FIELD OF THE INVENTION The invention relates to plastic bags for stacked soft hygiene products, for example diapers or feminine care products such as sanitary napkins, pantiliners or the like.

BACKGROUND In the field of packaging techniques, it is known from a previous use that for an online production of plastic bags made of a continuous film and containing stacked soft sanitary products, a battery forming unit is provided for packing product items. in a pile. By means of a battery transport unit, the formed stack is supplied to a packing station. The latter comprises a supply tunnel through which the piles formed in the packing station are left in a row. To package the incoming piles, a polymer film supplied by means of a film supply unit from the film stock is used, for example, a roll of film.

To wrap the film web around the piles, a funnel-shaped molding edge placed around the supply tunnel having a substantially rectangular cross-sectional design is provided. The supply film is rotated on this molding edge and is led into the supply tunnel which forms a tube-like film wrap around the piles leaving the supply tunnel. Generally, the funnel-shaped molding edge shows a design symmetrically, so that the longitudinally placed edges of the tube-like film wrap around the piles are located in the center line of one of the side faces of the bag. Accordingly, a sealing unit in the machine direction (abbreviated "MD" in the present invention) seals these longitudinally placed edges and thus provides a welded seam of plastic on the associated side face of the bag.

Finally, to complete the plastic bag around a stack of sanitary products, a cross-machine direction sealing unit (abbreviated "CD" in the present invention) is used to form and seal the transversely placed edges of the wrapper. of film similar to a tube for each bag, and simultaneously separate the bags in series.

Due to the welded seam centered on the side face applied by the sealing unit in the machine direction, this side face does not work for any stamping that completely covers this side face without being interrupted by the welded seam.

The patent no. WO97 / 20737 describes a method and an apparatus for supplying articles compressed flexibly towards a forming / filling / sealing machine.

Plastic bags for feminine hygiene items that have a single seal in the machine direction along one corner of the bag have been distributed in Asia. However, it is believed that these bags have been produced by a process, in which the plastic film used has been pre-sealed in the machine direction and folded at least once before being supplied in the packaging line. Therefore, you can see a fold line in the center of a side panel in these finished plastic bags.

It is an object of the invention to provide plastic bags that can made in line from a roll of raw material and having a seal in the machine direction along one of the corners of the bag. The plastic bags of the invention comprise four side faces that can be printed completely in the machine direction. This and other aspects of the invention will be described in more detail below.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a plastic bag containing stacked soft sanitary products, wherein the bag comprises a seal in the machine direction along a closing corner and the bag does not have a fold line in the center of either panels.

The plastic bag may comprise a continuous graph in the area of the seal in the machine direction. In this mode, the seal in the machine direction is not comprised within a white or transparent band.

In addition, the stack of products contained in the plastic bag are conveniently compressed in a direction transverse to the machine, ie in a direction perpendicular to the machine direction, for example, a direction transverse to the horizontal machine as depicted in FIGS. figures, but this can also be a direction transverse to the vertical machine. The degree of compression (IBC, for its acronym in English) can be at least 15%, or more, for example, at least 20% or 25%. A range of 20% to 30% may be more appropriate. However, tests have shown that the degree of compression within the bag can reach 50%, that is, the degree of compression underway can even reach 70%.

The claimed plastic bags can be manufactured in accordance with a process and in a packaging device as described in detail below. In particular, the bag forming machine can comprise these new features compared to the known bag forming machines described in the background section: the funnel-shaped molding edge has an asymmetrical shape to guide the longitudinally moving edges of the film to align with a longitudinal corner of the supply tunnel and the piles, respectively, and the sealing unit in the machine direction is located in the adjacent area of said longitudinal corner to produce a seal in the machine direction in the plastic bag placed along a longitudinal closing corner of each plastic bag.

Due to the asymmetric funnel-shaped molding edge it is possible to guide the film to form the tube-like envelope in such a way that the edges of the longitudinally moving film align with a longitudinal corner of the respective stack. The sealing unit in the machine direction thus moves to one side so that the seal in the machine direction produced in the plastic bag is positioned along the corresponding longitudinal closing corner of each bag of plastic. plastic. Apparently, all the side faces in the machine direction of the bag are thus free of any welded seam and, therefore, offer the possibility of printing texts and images on the four side faces with a high quality.

The edges of the funnel of the molding edge can end at the corners in the machine direction of the supply tunnel. In addition, it is possible to design the upper surface of the molding edge as an oblique groove which can be completed by a free roller for the film supplied from the raw material roll whose free roller is located in front of the oblique groove.

All the above-mentioned design features serve to optimize the film guide and tube-like wrap around the batteries supplied through the supply tunnel.

The sealing unit in the machine direction may comprise a pair of cooperative sealing rollers forming a sealing gap in front of the longitudinal sealing corner for the longitudinally placed edges of the film envelope similar to a tube of the plastic bag . The axis of parallel rotation of these sealing rollers adopts a sharp angle towards the adjacent side walls of the plastic bag. Due to this construction, the longitudinally placed edges securely grip as they extend from the longitudinal locking corner in as little deflection as possible.

By means of the integrated circular cutting blade, the steps of sealing the film and cut edges of the welded seam produced are integrated into a cutting and sealing tool.

At least one traction unit may be disposed along the tube-like film wrap to be transported on par with the stacks exiting the supply tunnel. This design helps to carefully guide the tube-like film wrap with the same speed with which the batteries exit the supply tunnel. Conveniently, the traction unit can be added by endless conveyor belts which couple the side portions of the tube-like film wrap. This results in a high contact surface between the film wrapping and the endless conveyor belts with a high friction due to the fact that the conveyor belts are generally made of rubber material.

The battery compression unit described in the present invention is a component of the packaging device which is advantageous for this device with the packaging station described. However, it can also be used in conjunction with conventional bag forming devices that do not result in plastic bags with welded seams in the machine direction along the bag closing corner. In any case, the compression of the product stack before it is supplied in the plastic bag results in a packing of the product with a reduced volume when a certain amount of product items are packaged. This means the decrease in the number of containers and warehouses with a high cost efficiency. In addition, due to the compressed state of the pile, the plastic bag becomes stiffer and acquires a well defined cuboid shape.

Conveniently, the battery compressor unit comprises a lifting platform and a telescopic compartment therein. The telescopic compartment can be contracted by the lifting movement of the platform, in such a way that an uncompressed stack of articles of the product produced by an accumulator and loaded in a compartment is compressed and placed in an elevated position to be delivered to the battery transport unit that can push the stack towards the packaging station of the packaging device.

For this purpose it is convenient to place the compressed batteries in a loading position in front of the supply tunnel of the packing station.

A push rod unit can be conveniently provided which includes a push bar driven alternately to push the compressed stack through the supply tunnel into the tube-like film wrap formed by the packing station. The alternative thrust of the push bar can be a servomotor connected to the push bar through a belt endless conveyor. This produces a fast and perfectly controllable movement of the compressed batteries towards a supply tunnel or through it.

With respect to the lifting platform, it is advantageous to suspend it on a lifting bridge that raises and lowers the lifting platform and, consequently, generates the compression function of the compartment that accommodates the stack of products during its upward movement. Therefore, raising and compressing the stack is achieved by a single pass of the lifting platform.

The plastic bags of the invention can be produced in a packing device as described above and comprise a single seal in the machine direction along a corner of the wrapper similar to a tube surrounding the stack of products. The graphic can be, conveniently, free in the area of the stamp in the machine direction.

In summary, new plastic bags produced online are provided from a roll of raw material, wherein the seal in the machine direction is located along a side corner of the bag. The graphic may be free in the area of the stamp in the machine direction. In addition, high compression in the bag can be achieved. The bags can be produced illustratively with the use of the packaging device described in the present invention.

BRIEF DESCRIPTION OF THE FIGURES Other features, details and advantages of the invention become apparent from the following description of advantageous embodiments, with the accompanying drawings in which: Figures 1 and 2 show perspective views of a device of packaging that can be used to manufacture the bags of the invention, Figure 3 shows a side elevational view of the packaging device, Figure 4 shows a view of the battery compression unit in the machine direction, Figure 5 shows a top plan view of the push rod unit, battery compression unit and supply tunnel of the packaging device, Figure 6 shows a view of the packaging station and the sealing unit opposite to the machine direction, Figure 7 shows a partial elevation view of the push rod unit, the battery compression unit, the molding edge with the supply tunnel and the sealing unit in the machine direction.

Figure 8 shows a perspective view of a plastic bag that can be produced with the packaging device of Figures 1-7.

Figures 9 to 15 show other embodiments of the plastic bags according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Figures 1 and 2 provide an overview of the illustrative packaging device that can be used to manufacture the plastic bags of the invention. The main components are a battery forming unit 1 followed by a battery compression unit 2. A battery transport unit 3 serves to supply the FCS battery formed and compressed towards a packaging station 4 which cooperates with a storage unit. sealing in the machine direction 5 and a sealing unit in the direction transverse to the machine 6. The finished wrapped bags WB are finally removed from the packaging device by means of an extraction unit 7 shown schematically.

The battery former unit 1 is only represented, in the same way, as a schematic block because it can be any conventional stacker that stacks soft hygiene products, such as feminine care products (sanitary napkins, pantiliners) particularly folded. The stack FS formed of these products has a stacking direction SD oriented horizontally and transverse to the machine direction (see Figures 1 and 4).

The batteries FS formed by this battery-forming unit 1 come in series one by one towards the battery compression unit 2, which is described in more detail below. As can be seen in Figures 2, 3 and especially Fig. 4, the stack compression unit 2 comprises a lifting platform 8 which is suspended on a lifting bridge 9 at its two ends. As can be clearly seen in Fig. 4, the lifting platform 8 can be raised from a low position to an elevated position. It is striking that the compression unit 2 comprises only one lifting platform 8 shown in its low and elevated position in FIG. 4.

A telescopic compartment 10 is provided on the lifting platform 8, in which the formed stack FS is pushed in its uncompressed state when the lifting platform is in its lowest position. By moving the lifting bridge 9 upwards and due to the inclination of the columns 1 1 of the lifting bridge 9, the compartment 10 is pushed at the same time, which vigorously compresses the stacked products thereby to form a compressed FCS stack in the raised position of the lifting platform 8.

In this position, the compressed FCS stack is placed in alignment with a supply tunnel 12. The cross section of the supply tunnel 12 is adapted to the contour of the compressed FCS stack, so that it can be transferred through the supply tunnel without appreciably changing the state of compression. To move the FCS batteries through the supply tunnel 12 in a row, the stack transport unit 3 is implemented by means of a push rod system comprising a push rod 13 driven alternately by a servomotor 14 connected to the push rod 13 through an endless conveyor belt 15 (see Figures 1). and 5). By rotating the drive gear 16 of the servomotor 14 in the clockwise direction, the push rod 13 is moved towards the supply tunnel 12 and by an opposite movement of the driving gear 16 it is retracted again. Careful guidance of the conveyor belt 15 is achieved by the deflection pulleys 17. Clearly, the push rod 13 is linearly oriented by sliding rails which are not shown in the figures.

At the same time as the pile pushes towards the tunnel and later toward the closed film sleeve, the air pressure increases and inflates the sleeve. Conveniently, air evacuation channels are installed to minimize inflation of the sleeves. These channels can be located within the supply tunnel that cover their entire length from the entrance of the tunnel to the end. The cross section of these evacuation channels can be constant. For bag widths less than 80 mm, the air pressure within the supply tunnel is generally marginal because the air can evacuate through the evacuation channel in time. For larger bag widths, it may be advantageous to install vacuum pipes connected to a vacuum system to reduce the air pressure, because this can, in any other way, not evacuate sufficiently quickly through the exhaust channel. These vacuum pipes can be connected to a vacuum system located near the supply tunnel.

The packaging station 4 serves to supply and guide a packaging film 18 (indicated in shading in Figures 1, 2, 3 and 7) from a roll of raw material 19 to form a film wrap similar to a tube 20 around the the compressed FCS batteries supplied by the stack transport unit 3 with push bar through the supply tunnel 12. At this end the packaging station 4 includes a funnel-shaped forming edge 21 arranged around the supply tunnel 12 with a practically tapered rectangular cross-sectional design shown in greater detail in Fig. 4 and especially in Fig. 6. The molding edge 21 tapers towards the machine direction and has an inclined upper surface 22 and two side faces 23 and 24. The bottom face of the funnel-shaped molding edge is more or less insulated. The upper surface 22 and the side faces 23, 24 terminate with a small gap in the adjacent area of the supply tunnel 12. Their edges are circular to prevent the packaging film 18 from being damaged. In addition, the edges of the funnel 25 of the molding edge 21 are directed towards the corners 26 in the machine direction 26 of the supply tunnel 12 located parallel to the machine direction. As can be seen especially from Figures 4 and 6, the upper surface 22 of the molding edge 21 is an oblique groove, likewise the side faces 23, 24 are biased and tilted, which gives an overall asymmetrical shape of the funnel-shaped molding edge; the purpose of which will be explained in the present invention on the basis of the operation of the packaging film 18. The latter is extracted from the raw material roll 19 and is left on a free roll 27 located in front of the oblique groove of the upper surface 22 of the molding edge 21. Accordingly, the film 18 smoothly travels on the upper surface 22 and bends around the side faces 23, 24 and thereby wraps around the supply tunnel 12. At the inner ends of the molding edge 21, the film 18 is suddenly bent to modify its gross movement direction opposite the machine direction to the machine direction. Accordingly, the tube-like film wrap 20 is formed around the supply tunnel 12. As can be seen in Fig. 6 due to the asymmetric shape of the molding edge 21, the longitudinally moving edges 29 of the wrap The film 20 travels along the corner 26 in the machine direction of the supply tunnel 12 which remains opposite the projecting side in much of the upper surface 22 and the side face 23. The packaging film can be made of any conventional and suitable plastic material.

Upon leaving the molding edge 21, the longitudinally moving overlapping edges 29 of the film wrap 20 are supplied in the sealing unit 5 in the machine direction described in Fig. 1 and 6. The sealing unit 5 in the machine direction comprises a pair of cooperative sealing rolls 3031, which form a sealing gap 32 between them, and are driven by a sealing roll drive unit 28 (Fig. 6). The longitudinally moving edges 29 of the film wrap 20 are supplied through the seal gap 32 and are thus heat sealed together to form a longitudinally closed film tube with a seal 35 in the direction of machine in the closing corner 46 of the plastic bag that will be produced. The parallel axes of rotation 33 of the sealing rolls 30, 31 adopt sharp angles and A2 towards the adjacent side walls of the plastic bag that will be produced. As can be seen in Fig. 6, the sealing roll 31 which remains under the film wrap 20 comprises a circular cutting blade 34, by which the seal 35 in the machine direction of the wrapped plastic bag WB is Trims to provide an impeccable appearance of the WB bag. In Fig. 2 and 3 the remains D of the clipping action are shown. The longitudinally moving edges of the film can be provided with an ink print on its outer surface, so that the The sealed bag has a graph that is not capped, continuous along a complete periphery of the bag. In conventional plastic bags, the graphic is normally capped along the seal line in the machine direction by a band of non-engraved material that appears white or transparent. In the present invention, the longitudinally moving edges of the film are sealed with their inner faces oriented to each other, so that printing ink on the outer surface of the film will not interfere with the sealing of longitudinally moving edges. .

To assist movement of the film casing 20 in synchronization with the incoming compressed FCS batteries, a traction unit 36 is disposed along the film casing similar to a tube 20. This traction unit 36 comprises two tapes. endless conveyors 37 arranged along each lateral face of the film casing 20 and frictionally engaged therewith.

In short, with the aid of the packing station 4 and the sealing unit in the machine direction, a closed film wrap 20 is formed around the row of compressed FCS cells exiting through the supply tunnel 12.

Now, in order to separate and completely close the individually wrapped WB bags, the sealing unit 6 in the transverse direction to the machine continues towards the packing station 4. The sealing unit 6 in the direction transverse to the machine itself can be conventional and comprises vertically moving sealing bars 38, 39 which not only create a seal 41 in the direction transverse to the machine closing the bag WB wrapped at both ends, but also separates the film casing 20 between two wrapped WB bags successive In addition, it should be considered that the sealing unit 6 in the direction transverse to the machine it comprises sheets with V-shaped side cuts 40 which engage the film wrap 20 to form perfect V-cuts 47 (Fig. 8) in the film wrap 20.

The sealing unit 6 in the transverse direction to the machine can apply the seal 41 in the transverse direction to the machine in the film casing 20 before the compressed FCS product stack is pushed through the supply tunnel 12 towards the tube of film. For this purpose, the sealing unit 6 in the direction transverse to the machine can be moved alternately in the machine direction, so that it can be displaced together with the film wrap 20 in the machine direction during the sealing process. Accordingly, when the remaining seal 41 is sealed in the cross-machine direction of a bag, for example, the bag WB left in the sealing unit 6 in Fig. 3; a tube similar to a bag is presented in front of the supply tunnel 12. Within this bag, a highly compressed FCS stack can be pushed by the push bar 13 through the supply tunnel 12 which hits the bottom of the tube similar to a bag formed by the seal 41 in the direction transverse to the machine. Pushing the stack FCS on the right side of the sealing unit 6 in the direction transverse to the machine further allows the sealing unit 6 in the direction transverse to the machine to apply the second seal 41 in the direction transverse to the machine behind this stack, and simultaneously form the similar tube that is ready to push into the next FCS stack. Accordingly, the second seal 41 in the machine-transverse direction of the wrapped bag WB leaving the sealing unit 6 in the direction transverse to the machine simultaneously provides that the first seal 41 in the transverse direction to the machine forms the transversely closed initial end of the tube for the next wrapped bag WB.

The packaging of a FS stack of feminine care products or the like is summarized briefly as described below: the non-compressed FS stack is formed by a conventional battery-forming unit 1. The FS stack is pushed towards the telescopic compartment 10 of the lifting platform 8 and then moves upwards. Consequently, the FS stack is compressed. Then, the push bar 13 pushes the compressed FCS stack through the supply tunnel 12 and leaves it inside the film casing similar to a tube 20. The FCS stack is located a short distance behind the previous stack in the film wrap 20. During the supply movement of the film wrap 20, the longitudinally moving edges 29 are provided with a seal 35 in the machine direction and the seal 41 in the direction transverse to the machine 41 at the edge of a respective WB bag, before the FCS batteries are pushed inwards. Finally, the second seal 41 is created in the direction transverse to the machine at the trailing edge by the sealing unit 6 in the direction transverse to the machine; and therefore the bag WB is terminated.

Fig. 8 shows a completely wrapped bag WB with four integral side faces 42 to 45 and the seal 35 in the machine direction at the so-called closing edge which is the bottom of the longitudinal edges or so called corner 26 in the direction of machine. In addition, there are two seals 41 in the transverse direction to the machine with side cuts in V 47 applied to the small faces of the wrapped bag WB. The seals in the transverse direction to the machine may be without cut-outs, that is, the outwardly extending cutout may have a width of less than 2 mm or 1 mm, along the length of the cutout.

The opening means may conveniently be present on one or more side faces 42 to 45, for example, a continuous perforated line 48 in the machine direction on the upper face 42 as shown in Fig. 8. The roll of raw material 19 can comprise said continuous perforated line along its entire length, so that it is not necessary to perforate the film in the bag-forming line, or the perforation can be made in the same bag-forming line as the roll or film are unrolled. The opening means 48 can be oriented parallel to the plane defined by the products 49. It was found that this is especially advantageous when the product stack is in a compressed state, because in such configuration it was discovered that the compressed products are easier of removing from the bag with the opening means oriented in the same plane. In Fig. 8, it is shown that the perforated line passes through the middle of the upper panel 42, but could clearly be located asymmetrically on either side of the middle of the top panel, or anywhere on any of the side panels 43 to 45 what is desired Fig. 9 shows a bag with a perforated line segment for opening and dispensing the products contained therein which is applied in the machine direction. The perforating position can be anywhere along the longitudinal axis of the bag, located in the side panels 42-45 or on the front or rear panel. Having a discontinuous perforation can be advantageous to allow consumers to only partially open the bag without losing its structural integrity.

Fig. 10 shows a bag with a perforation for opening and dispensing the products contained therein that is applied in the transverse direction to the machine (CD) and is continuous along the entire circumference of the bag. The piercing position can be anywhere within the circumferential axis of the bag (front, center or back of the bag). The perforation can be applied to the material stock roll 19 before the roll is installed in the line, or it can be applied to the roll of bag forming line material.

Fig. 1 1 shows a bag with a perforated line segment to open and dispense the products contained therein that is applied in the cross machine direction (CD). The perforations can be located anywhere within the circumference axis of the package (top, center or bottom of the package).

Having a discontinuous perforation can be convenient to allow consumers to only partially open the bag without losing its structural integrity.

Fig. 12 shows a bag containing perforations for opening and dispensing the products contained therein that define a two dimensional area on the surface of the bag. The user can open the bag along the perforations to form a dispensing flap. The shape and position in the cross machine direction / drilling machine direction can be designated according to product dimensions and consumer needs for convenient extraction and can be anywhere in the package. Having a two-dimensional area defined by the perforations can allow consumers to only partially open the bag without losing its structural integrity.

Fig. 13 shows a bag similar to the bag of Fig. 12, wherein the perforated flap is further provided with a resealable tape 50 that allows easy opening, as well as the reclosure of the dispensing flap by the user, for example , with the use of a multi-purpose glue component. The material, shape and placement of the tape can be defined according to consumer manipulation and the design needs of the bag. The tape 50 can be applied in line or outside it.

Fig. 14 shows a bag containing an extended trimming area of transverse seal 51 in one of the seals in the cross-machine direction (but could also be in both seals in the cross-machine direction). The width of the cutout may be, for example, between 5 and 100 mm in width, and may consist of the same material as the rest of the bag. The extended cut can be printed or not and have different types of shapes (rectangular, triangular, oval, as necessary for the design and functionality provided). The extended space can be used to place a means to hang 52 by introducing at least one hole. Clearly, it can also be used to add a printed decoration, or as a space for propaganda. Technically, the extension can be done online by using a redesigned cross seal station by introducing a cross seal adapted to form the desired cut.

Instead of hanging means or in addition to hanging means, the extended trimming area can be provided with added functionality with the use of added components that can be applied online. The components of added functionality may be of various types serving different purposes, for example: batten materials or the like to an adjustable cord for a decorative function and / or for reclosing as shown in Fig. 15, components of zip-lock base for a reclose feature, "hook and loop" fastener base components for a reclose function etc. If such opening and closing means are provided in the extended trimming area, it will not be A perforated line is necessary.

The online production of the described packages can allow the economic and efficient production of attractive bags for consumers, at the same time as they provide functionality during daily use.

As indicated above, the plastic bag may comprise a graphic that is continuous in the area of the stamp in the machine direction. By continuous, it is understood that the graphic is not covered in the area of the stamp in machine direction, p. eg, by a non-printed band (usually white or transparent) as is usual for previous products. The graphic can be obtained by a conventional technique, for example, by printing the outer surface of the film with a suitable ink.

Compression measurement protocol in the bag This protocol defines the actions and measurements required with the purpose of measuring the compression in the stock market (IBC, for its acronym in English). The described method can be applied to any type of bag making technology.

The IBC quantifies the amount of compression between loose products at a defined time during production and products packed in the primary bag after the bagging process.

The quantity is determined as a delta (in%) between the height &of loose products and the stack height in the bag. The IBC definition does not assume / describe any compression other than that in stack height.

For gauge measurements of loose products, a sample of 5 products is collected during production in the stacking chain, and measured within 5 minutes of production.

• The products can not be taken from any other waste in the converter, because the pressurized air significantly changes the sizes of the product • The products can not be measured after more than 5 minutes after production, because the size of the product can change as the time increases • The products can not be sampled outside of the bags or in any other intermediate storage condition, because this will not allow a definition of the appropriate IBC.

The bags have to be sampled during the same production series as the pads, they can not be stored in the middle of boxes, but they need to be sampled after the packer and measured immediately afterwards (within the first 60 minutes after production).

The stack height measurement of the 5 & free products and the full bags can be done with any standard motorized test bench normally used for this purpose. The motorized test bench comprises a product fastener and a compression plate that can slide vertically. The equipment evaluates the distance between the base plate and the point of contact between the test piece and the compression plate. This device measures the Force and Length at the same time. This type of measuring device is common in the field of absorbent articles to perform gauge and height measurements. A suitable device can be purchased, for example, at Alluris Gmbh & co. Kg, from Baslerstrasse 65, 79100, Freiburg, Germany.

For the purpose of this protocol all thickness measurements are performed at a load of 1 N with the use of a circular compression plate with a diameter of 150 mm. The sliding platform is installed to descend at a speed of 180 mm / mn to the starting position that is chosen near the height of the test piece. Then, the speed decreases to 12 mm / min and once the compression plate comes into contact with the test pieces, the resistance applied by the test piece to the sliding platform is measured permanently by the load cell connected to the test piece. the compression plate. Said low speed of 12 mm / min is necessary in order to be able to detect the precise moment in which the reaction force of 1 N is reached.

Clearly, the bags have to be properly placed in the measuring device (the stack height in the bag is always vertical). The level of temperature and relative humidity should be the same for the height measurement of the stack of free items and the height of the bag, for example, 21 ° C and 30% relative humidity.

The IBC is defined as the delta (in%) between the height of the stack of Free products and the stack height of the products in the primary bag, as calculated in the equation described below: IBC SHB = Height of the stack in the bag SHF &F = Height of the stack of free products (measured with 5 items) countingB = Counting in the bag The height of the stack in the bag can be measured directly as the height of the bag with the use of the test bench as indicated above. The thickness of the packaging material is, in general, insignificant, but it can be subtracted when this is not the case.

The stack height of the free products is measured with the use of a stack of 5 products with the use of a test bench, as indicated above.

For example, if the measured SHF &F (5 items) is 50 mm and the height of the stack in the SHB bag is 80 mm (bag containing 10 item), the IBC is 20% (= 100 * (1 -80 * 5 / (50 * 10))).

Claims (15)

1. CLAIMS 1 . A plastic bag (WB) containing stacked soft sanitary products (FCS), for example, sanitary napkins, pantiliners, diapers, or the like, characterized in that the plastic bag comprises a seal (35) in the machine direction throughout of a closing corner (46), and wherein the plastic bag does not have a fold line in the center of a side panel (42-45). 2. A plastic bag according to claim 1, further characterized in that the product stack (FCS) is contained in the closed plastic bag (WB) in a compressed state in the cross machine direction, preferably with a compression in the bag (IBC) of at least 15% as measured according to the compression measurement protocol in the bag described in the present invention. 3. A plastic bag according to claim 2, further characterized in that the compression in the bag (IBC) is at least 20% as measured in accordance with the compression measurement protocol in the bag described in the present invention. 4. A plastic bag according to claim 3, further characterized in that the compression in the bag (IBC) is at least 20% to 30% as measured in accordance with the compression measurement protocol in the bag described herein invention. 5. A plastic bag according to any of the preceding claims, further characterized in that the bag comprises a graphic that is continuous in the area of the seal (35) in the machine direction. 6. A plastic bag in accordance with any of the preceding claims, further characterized in that the bag comprises opening means (48). 7. A plastic bag according to claim 6, further characterized in that the opening means comprises a perforated line or segmented line (48) oriented in the machine direction (MD). 8. A plastic bag according to claim 6, further characterized in that the perforated line (48) extends continuously along the entire length of the plastic bag. 9. A plastic bag according to claim 6, further characterized in that the opening means comprises a perforated line (48) oriented transversely to the machine (CD). 10. A plastic bag according to claim 6, further characterized in that the opening means comprises a perforation (48) defining a two-dimensional surface area on the surface of the bag that can be used with a flap to open the bag and dispense the products contained in this one. eleven . A plastic bag according to claim 10, further characterized in that a tape (50) is placed on the flap to allow closing and re-opening of the flap. 12. A plastic bag according to any one of the preceding claims, further characterized in that the trimming on at least one of the seals (41) in the transverse direction to the machine is less than 2 mm in length along the length of the cutout . 13. A plastic bag according to any of the preceding claims, the plastic bag comprises a trimming area extended transverse seal (51) in one of the seals (41) in the direction transverse to the machine. 14. A plastic bag according to claim 13, further characterized in that the extended cutting area of transverse seal (51) comprises a means for hanging (52). 15. A plastic bag according to claim 13, further characterized in that the extended cut-out area of transverse seal (51) comprises opening and closing means such as zip-lock components, "hook and loop" fastening components or material components. of adjustable cord (53).