Patent Application
20060130435
Many tissue products, such as toilet paper and paper towels, are typically formed into large supply rolls after being manufactured. After the supply rolls are formed, the rolls are rewound into smaller sized rolls, which are generally more useful for commercial purposes. For example, in many conventional processes, the tissue is wound onto a hollow cylindrical core made of paper stock during a winding and converting operation.
Once formed into smaller rolls, the rolls of material are typically fed to a packaging line and wrapped in groups such as by being encased in a plastic film. The wrapped groups are then placed in boxes and shipped to customers.
Current wrapping machines are of two primary styles, reciprocating single sheet feeding wrappers and continuous flow wrappers. Reciprocating wrappers cut individual sheets of plastic film, feed the film into a machine, and push the product through the sheet to cover three sides of the product. The package is first sealed into a tube and the sides of the package are then sealed by heated belts. Reciprocating wrappers are capable of automatically adjusting to rolled products that may vary in size and in firmness because it is the contents of the package that determine the tightness of the wrap. Reciprocating wrappers, however, are prone to mechanical wear from the constant traversing load that is placed on key components and because of the reciprocating motion, generally run at lower operating speeds.
Continuous motion wrappers, on the other hand, may include an in-feed conveyor and a sorter for placing the rolls of material into groups of a desired size. The groups are then fed to a forming shoulder where the groups are placed in a tube formed from a plastic packaging film. The forming shoulder is configured to change a flat sheet of continuous film into a continuous tube sized to the product. The forming shoulder, however, is typically sized for only one combination of roll diameter and firmness. Products that have a lower firmness value may result in a loose pack while products that have high firmness values can cause machine jam-ups. Continuous flow wrappers, in comparison to reciprocating wrappers, are mechanically simpler, are less prone to wear, and, in some embodiments, may run at higher speeds. More recently, continuous flow wrappers that can handle more than one layer of product has further increased their versatility. One embodiment of a continuous motion wrapper, for example, is described in U.S. Pat. No. 5,195,300, which is incorporated herein by reference.
In view of the above, however, a need remains for an improved wrapping apparatus that combines the advantages of reciprocating wrappers with the advantages of continuous motion wrappers. Specifically, a need exists for a wrapping apparatus capable of operating at high speeds that is mechanically simple and does not place a tremendous amount of stress on the packaging material as the material is wrapped around the product and does not require a fixed forming shoulder to form the wrapping material around the package. Also, an added advantage is a wrapper with these features that permits the use of recycled, low caliper wrapping material or paper as the wrapping medium.
In general, the present disclosure is directed to an improved system and process for packaging products, such as rolls of material. In accordance with the present invention, a continuous wrapping material is unwound, severed along opposing edges, and perforated in a center region. The cut edges allow wrapping of the product without strain on the wrapping material. The system of the present invention is particularly well suited to replacing the forming shoulder in conventional continuous motion wrappers.
In one particular embodiment, for instance, the system for packaging products includes a conveyor for conveying a product separated into groups. An unwind device unwinds a wrapping material adjacent to a first surface of the product groups that are being conveyed on the conveyor. The wrapping material includes first flaps that are positioned along a first edge region and second flaps that are positioned along a second edge region. The wrapping material optionally further comprises perforation lines located in a middle region of the wrapping material. In one particular embodiment, for instance, a cutting and perforating device severs the edges of the material as the material is being unwound while simultaneously perforating the middle region of the material.
A pair of opposing folding devices, such as a plurality of folding dies, are positioned adjacent each side of the product groups. The folding devices are configured to engage the first and second flaps and fold them over the sides of the groups. The flaps are further folded over a second surface of the groups that is opposite the first surface. Once the wrapping material is completely surrounding the package a heating device is used to seal the product around the package. If paper is used as the wrapping medium, glue is applied or activated to complete the sealing process. Note that it is possible to pre-apply a hot melt adhesive to the paper film and activate it using the same heating mechanism as that used for polyethylene film.
After the first and second flaps have been folded, a perforation breaking device severs the wrapping material along the perforation lines thus separating the groups into individual packages. The direction of movement is altered by ninety degrees to the initial wrapping direction to allow a second and third sealing device to seal a front end and a back end of the package where the perforation lines have been severed.
In one embodiment, the wrapping material is unwound above a top surface of the product groups. In this embodiment, the first and second flaps are folded around the side surfaces and over a bottom surface of the groups. Prior to being folded, the first and second flaps may be held above the groups by at least one suction device. The at least one suction device, for instance, may comprise a plurality of vacuum belts.
The folding devices that are used to fold the flaps may comprise a plurality of folding dies. For example, in one embodiment, a pair of opposing folding dies may initially engage the flaps and fold them over the side surfaces of the groups. Next, a third folding die positioned adjacent to a bottom surface of the groups may engage the flaps for folding the flaps over the bottom surface. In this embodiment, the groups may be supported by a pair of opposing side conveyors while the flaps are being folded and sealed together. The folding dies may also include vacuum belts to continue to pull the wrapping material tightly around the product groups. A feature of the wrapping section is the ability to adjust to the width of the package either with feed forward sensing of the width of the packages, adjustment to a set pressure or to a static width which is kept constant for all packages.
In addition to a system for packaging products, the present invention is also directed to a process for packaging product groups in a wrapping material. The process may include the steps of conveying a product separated into groups down a process line while unwinding a continuous wrapping material. The wrapping material may include opposing flaps and a plurality of perpendicular perforation lines spaced along the length of the material.
While the product groups are being conveyed down the process line, a first surface, such as the top surface, of each group may be placed adjacent to the wrapping material in between the perforation lines. The first flaps and the second flaps are then folded over the groups. Specifically, the flaps are folded over the sides of the groups and over a bottom surface of the groups and sealed together. The wrapping material is then severed along the perforation lines in order to separate the groups into individual packages. The packages are then sealed along a front end and along a back end where the perforation lines have been severed. Usually this final sealing step requires that the package direction be changed by ninety degrees to expose the unsealed ends of the packages to the heat sealing mechanism.
The system and process of the present invention are particularly well suited to packaging rolled materials. Of particular advantage, a relatively low amount of strain and stress is placed on the wrapping material as the material is placed around the groups. Thus, weaker wrapping materials may be used to construct the packages. The wrapping material may comprise, for instance, a relatively thin plastic film, a paper product, or a film that contains recycled materials.
Other features and aspects of the present invention are discussed in greater detail below.
A full and enabling disclosure of the present invention, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
In general, the present invention is directed to a process and system for packaging products. For instance, the system and process of the present invention are particularly well suited to packaging rolls of material, such as spirally wound paper products. The wound products may include, for example, bath tissues, paper towels, wet wipes, industrial wipers, and the like. It is to be understood that this method of wrapping can also be used for the wrapping of a multitude of goods where plastic or paper wrapping is required.
In one embodiment, the products are fed to a processing line and separated into groups. Each group may contain a single product or may contain a plurality of products. As the groups are conveyed down a conveyor, a continuous supply of wrapping material is placed on a first surface of the product groups. The packaging material contains flaps which are then folded around the sides and over a second surface of the groups. The first surface, for example, may be a top surface while the second surface may be a bottom surface. After the flaps are folded and sealed, a perforation line formed into the wrapping material is broken in order to separate the groups into individual packages. Finally, the front and back ends of the packages where the perforation lines have been severed are sealed.
The process and system of the present invention provide various advantages and benefits. For example, since the groups of products are packaged from a continuous supply of wrapping material instead of from individual sheets, the packaging apparatus is capable of operating at relatively high speeds. Further, due to the formation of the flaps and the perforation lines, the wrapping material may form around each group of products without being subjected to any significant stress or strain. Thus, there is less likelihood that the wrapping material will break during formation of the packages. Further, since less strain is placed on the packaging material, the process and system is capable of using lower strength materials to package the products. For instance, the products may be packaged in a paper wrapper, in a plastic film having a relatively low caliper and/or in a plastic film containing recycled materials.
Another advantage to the process and system of the present invention is that the wrapping material is wrapped around the groups of product by, in one embodiment, a plurality of stationary folding dies. Since the folding dies are stationary, the system is not prone to mechanical wear. It is recognized that some assistance may be required to ensure that the flaps are completely folded around the product groups before heat sealing the film.
Still another benefit of the present invention is that the system is capable of accommodating product groups that may vary in size and firmness. Specifically, since the wrapping material is wrapped around the product groups without being subjected to relatively high amounts of stress and strain, the wrapping material is less likely to break or tear and product jam-ups are less likely to occur even if the size and/or firmness of the products vary over time.
Although the principles of the present invention may be incorporated into any suitable packaging or bundling process line, one exemplary illustration of a packaging line is shown in
As illustrated, the process line includes an in-feed section 12 that is used to meter the rolls 24 into the wrapping machine. Next, the processing line includes an optional roll turning section 14 where the rolls are rotated 90 degrees about their longitudinal axis to a vertical orientation in order to reduce the width of the columns of rolled product as the product is further conveyed down the line. Once oriented, the rolled products then enter a roll alignment and grouping section 16. Here, the columns of product are separated into the desired groupings. Not shown is the ability to stack the groups into two layers for packages with a higher count of roll. As used herein, a group may refer to only a single product or to a plurality of products.
After being grouped, the rolls of material 24 are then fed to a packaging apparatus 18 in accordance with the present invention where the groups of rolls are wrapped in a packaging material, such as a flexible plastic film or a paper. Once packaged, the groups are then conveyed to a sealing section 22 where the ends of the packages are sealed. Once sealed, the packages may then be loaded into boxes for shipping to a desired site.
Describing each section in more detail, as shown in
In one embodiment, as the rolls of material 24 are fed to the process line, the conveyors 44 and 46 apply compression to the rolls so as to at least partially collapse the hollow core contained with the rolls. In other embodiments, however, it may be desirable not to compress the rolls of material but simply to use the in-feed section as a means for feeding the rolled products into the processing line in an organized manner.
From the in-feed section 12, the rolls of material 24 are optionally rotated 90 degrees in the roll turning section 14 and then fed to the roll alignment and grouping section 16. In the roll turning section 14, as shown in
The roll alignment and grouping section 16 includes a pair of opposing side conveyors 54 and 56. The side conveyors 54 and 56 may further compact the rolls prior to being placed in a wrapping material. In an alternative embodiment, instead of using side conveyors, the system may include side rails for guiding the products.
In order to separate the rolls of material 24 into groups, the system may further include a flight bar device 28. The flight bar device 28, for example, may be positioned above the product groups and may include a plurality of flight bars 30 that are selectively placed in between adjacent rows of products for separating the products into groups and to take up the air gap between individual rolls of product. For example, as shown in
Once exiting the roll alignment and grouping section 16, the rolls of material now in groups enter the packaging apparatus 18 of the present invention, which is also shown in
As the wrapping material 32 is unwound, the material is engaged by a cutting and perforation device 36. As shown in
By periodically severing the wrapping material 32, lateral flaps are formed in the wrapping material. For example, as shown in
In the embodiments shown in the figures, the cutting and perforation device 36 forms the slits 38 and 40 into the wrapping material 32 as the material is unwound. In other embodiments, however, the wrapping material 32 may already contain the slits 38 and 40 and the perforation line 42. For example, the slits 38 and 40 and the perforation line 42 may be formed into the wrapping material as the wrapping material is formed and wound into a roll.
After the first flaps 48 and the second flaps 52 are formed, in order to keep the flaps above the product groups, the flaps are engaged by a suction device such as by a plurality of vacuum belts 58. While the flaps are being held above the product groups, the product groups being conveyed on the conveyor 34 merge with the wrapping material 32. Specifically, the process is controlled such that each product group becomes positioned in between adjacent perforation lines 42. Further, if various graphics are contained on the wrapping material 32, the cut and perforation step is registered with the graphics on the material and the location of the groups in order to maintain the graphics in alignment with the product.
The slits 38 and 40 formed into the wrapping material may, in one embodiment, include uncut portions to assist the vacuum belts 58 in holding the flaps above the product groups. For instance, the slits may have a single uncut portion or the slits may comprise perforation lines. The uncut portions or perforations may later be severed as the flaps are folded around the product groups by the strain put on the wrapping material during the wrapping process.
As a product group on conveyor 34 merges with the wrapping material 32, the flaps 48 and 52 are wrapped around the groups. In particular, in the embodiments shown in the figures, a retaining belt 60 places and holds the wrapping material 32 on a top surface of the product groups. At least one folding device generally 62 is then used to wrap the flaps 48 and 52 over the sides of the product groups and around the bottom surface of the groups. The folding device 62 may comprise, for instance, any suitable device capable of engaging the flaps and folding them in the desired manner. For example, in one embodiment, the folding device 62 may comprise one or more stationary folding dies that are positioned to receive the flaps 48 and 52.
In one embodiment, as shown particularly in
As shown in
At this point in the process, the wrapping material 32 is in the form of a tube wrapped around each of the product groups. In order to separate the tube formed from the wrapping material into individual packages, the system further includes a separating section generally 20 as shown in
The perforation breaking device 84, in one embodiment, may comprise a rotating plate that strikes the perforation lines in order to initiate the breaking process. It should be understood, however, that any suitable device capable of weakening the wrapping material along the perforation line may be used. Perforating breaking devices can operate singly or in pairs, or be phased such that one perforating device contact the perforation before another one.
In still another embodiment of the present invention, however, the wrapping material may not include the perforation lines 42. Instead, a cutting device may be used to cut the wrapping material where the perforation breaking device 84 is located. The cutting device may be used alone to sever the product groups into individual packages or may work in conjunction with the conveyor 66 and the conveyor 68. A suitable cutting device would be a rotating or sliding serrated blade.
As the packages exit the conveyor 68, the packages flow through an angled section 86. The purpose of the angled section is to change the direction of the packages and to rotate the packages 90 degrees so that the open ends of the packages are perpendicular to the direction of flow. Any suitable apparatus may be used in order to change the direction and rotate the packages.
Finally, the packages enter the sealing section 22. In the sealing section 22, the open ends of the packages are folded and sealed by a pair of sealing devices 88 and 90. The packages may be folded and heat sealed or alternatively an adhesive may be used in order to seal the ends.
Once the packages are sealed, the packages may be placed in boxes and shipped to a location as desired for further sale or consumer use.
Thus, as described above, the wrapping material 32 is cut and perforated to allow the material to form around the product groups without strain. Cutting the wrapping material in the edge regions also allows the use of a flat material without the need of a forming shoulder.
Since a relatively low amount of strain is placed on the wrapping material during formation of the packages, of particular advantage, weaker wrapping materials may be used in the process and system of the present invention. Such materials may include plastic wrapping materials that have a lower caliper and/or plastic materials containing recycled plastics. For example, the wrapping materials may have a caliper or thickness of less than about 5 mils, such as less than about 2 mils and, in one embodiment, less than about 1 mil. In still other embodiments, paper wrappers, such as coated paper products, may be used in order to wrap the rolls of material.
In addition to using weaker wrapping materials, the wrapping materials used in the process of the present invention may contain various other perforations in addition to the perforation lines 42 without the material breaking during processing. Additional perforation lines may be incorporated into the wrapping material, for instance, to allow for later easy opening of the packages. Perforations used for opening the package may be parallel to the slit forming the first and second flaps or may be in line with the direction of the package. Perforation used to open the package may also be tied to graphics on the package indicating the location of these easy opening regions.
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.
