Patent Application
20230034891
The present disclosure generally relates to dispensable plastic sheets and more particularly to packages of discrete plastic sheets and methods of making plastic sheets that facilitate dispensing of the discrete plastic sheets one-at-a-time.
Dispensable sheet products such as tissue paper, deli paper, and wet wipes are in wide use. Dispensable plastic sheet products comprise discrete sheets of material that are stacked in an interfolded stack, wherein the stack is placed into a package enclosure, such as a box or film enclosure, with an opening through which individual stacks may be dispensed, one-at-a-time. Dispensable sheet products may be formed of various materials, including paper and plastic.
The present disclosure discloses a sheet product package. The sheet product package comprises a package enclosure including a dispensing opening structure and a plurality of discrete plastic sheets arranged in a stack. The plurality of discrete plastic sheets are disposed within the package enclosure, and each of the plurality of discrete plastic sheets is electrostatically charged.
In another aspect of the present disclosure, a method of making the dispensable plastic sheets comprises forming electrostatically charged discrete plastic sheets and arranging the electrostatically charged discrete plastic sheets in a stack. The method further includes forming a continuous plastic film, cutting the continuous plastic film into discrete plastic sheets, and, after cutting, electrostatically charging the discrete plastic sheets.
Other objects and features of the present disclosure will be in part apparent and in part pointed out herein.
Corresponding reference numbers indicate corresponding parts throughout the drawings.
The present inventors have recognized that existing sheets made of plastic, such as deli scale sheets, do not dispense as well as paper sheets. In comparison with plastic deli scale sheets, dispensable paper sheets generally have a higher friction coefficient (COF) and lower density. Because of this, for paper sheets, packages have been devised with very small dispensing openings. The first sheet in the stack is partially pulled through the opening and is substantially compressed by the package in the opening. To dispense the sheet from the package, the first sheet is pulled fully out of the dispensing opening. As the first sheet comes out of the dispensing opening, it clings to the second sheet immediately below it in the stack and pulls the second sheet partially through the opening. The package constricts the second sheet within the opening sufficiently to cause the first sheet to release from the second sheet. Thus, after the first sheet is fully dispensed, the second sheet is held in the package in a ready-to-dispense configuration. Because plastic deli scale sheets have lower COF, higher density, filler content, and higher weight per unit area, they will not draw through the dispensing opening and release to consistently dispense one-sheet-at-a-time in the same way that paper dispensable sheets do.
In general, the inventors have recognized that discrete plastic sheets (e.g., deli scale sheets) can be made to reliably dispense one-at-a-time through a dispensing opening in a housing by imparting electrostatic charge to plastic sheets and, optionally, by designing the dispensing opening to have a particular size and shape that promotes the electrostatically charged sheets dispensing one-at-a-time through the dispensing opening. Various types of dispensable discrete plastic sheets can be used without departing from the scope of this disclosure. In an exemplary embodiment, the discrete plastic sheets are ‘deli paper’ sheets. In one or more embodiments, the electrostatically charged discrete plastic sheets are comprised of a polyolefin material. Sheets in accordance with this disclosure may have a density of greater than 0.9 g/cm3 (preferably greater than 1.0 g/cm3, further greater than 1.2 g/cm3, further greater than 1.4 g/cm3), a weight per unit area in a range of from about 50 to 200 g/m2 (preferably, a range from 100 to 150 g/m2), and/or a filler content of 5-80%.
Referring now to
The term “dispensing opening structure” is used in this disclosure to define pre-formed openings in the package enclosure 103 or other structures formed in the package enclosure for defining a dispensing opening at the time of use. For instance, in one or more embodiments, the dispensing opening structure 107 comprises a tear-out panel defined by a line of perforations or other tear line structure formed in a wall of the package enclosure. In the illustrated embodiment, the dispensing opening structure 107 is configured to define an elongate opening having a length L1 extending along a longitudinal axis LA. In this disclosure, “dispensing opening” refers to the smallest opening through which the pre-formed sheets pass when being dispensed. So if the package enclosure were constructed like a conventional tissue body (not shown) with a tear-out cardboard pocket that revels a film gland with a narrower slit than the cardboard tear-out, the slit in the film gland would define the dispensing opening, rather than the cardboard tear-out, because the film gland defines the smallest opening through which the pre-formed sheet must pass to be dispensed through the dispensing opening. In the illustrated embodiment, the cardboard tear-out defines the dispensing opening because there is not film gland that defines a smaller opening, and moreover, the hole provided by the cardboard tear-out is the smallest opening through which the sheet passes as it is dispensed.
Each of the plurality of discrete plastic sheets 105 has a length L2 along the longitudinal axis LA, and the sheets are packaged in the package enclosure 103 such that the lengths L1, L2 are parallel. In an exemplary embodiment, the length L1 of the dispensing opening is less than the length L2 of the discrete plastic sheets but greater than one-half of the length L2 of the discrete plastic sheets (e.g., the length L1 is 70-98% of the length L2). As will be explained in further detail below, the inventors have discovered that openings of this length can reliably facilitate one-at-a-time dispensing of the discrete plastic sheets. In the illustrated embodiment, the dispensing opening structure 107 defines a dispensing opening with an elongate rectangular portion that defines the length L1 and a widened (e.g., rounded) central portion connected to the middle of the elongate rectangular portion. Other dispensing opening structures can define dispensing openings of other shapes without departing from the scope of the disclosure.
The plurality of discrete plastic sheets 105 are arranged in a stack and disposed within the package enclosure 103. As shown in
In certain embodiments, each discrete plastic sheet 105A, 105B includes a charged side and an opposite side opposite the charged side. For instance, in one or more embodiments, only the inward facing side of each of the discrete plastic sheets 105A, 105B has a greater electrostatic charge than the outward facing side. The effect of this configuration is that the inward facing sides of adjacent sheets 105A, 105B are (relatively) strongly bonded together by electrostatic charge, whereas the outward facing sides are loosely stacked. In an exemplary embodiment, the sheets 105A, 105B have electrostatic charge in an inclusive range of from 3 KV to 20 KV, for example, in an inclusive range of from 5 KV to 15 KV or in an inclusive range of from 7 KV to 10 KV.
In use, the sheet product package 101 allows for a first discrete plastic sheet 105A to be drawn out of package enclosure 103 without a second discrete plastic sheet falling back into the enclosure or creating a long chain of (e.g. three or more) clinging-together sheets. When the sheet product package 101 is new, the user reaches into the package enclosure 103 through the dispensing opening structure 107 for a first time to retrieve the first discrete plastic sheet 105A in the package enclosure. The user pulls the first discrete plastic sheet 105A through the dispensing opening structure 107. As the discrete plastic sheet 105A is drawn through the dispensing opening structure, the edges of the package enclosure 103 defining the opening structure constrict and deform the discrete plastic sheet. In order to successfully remove the first discrete plastic sheet 105A from the package enclosure 103, the user must apply a force greater than the resistance being applied by the package enclosure. As the first discrete plastic sheet 105A is pulled through the dispensing opening 107, it clings to the second sheet 105B immediately below it in the stack due to the electrostatic force of attraction between the inward facing sides of sheets. This pulls the second discrete plastic sheet 105B partially through the dispensing opening structure 107. The dispensing opening structure 107 sufficiently constricts the second discrete plastic sheet 105B within the opening to cause the first sheet 105A to release from the second sheet. Thus, after the first discrete plastic sheet 105A is fully dispensed, the second discrete plastic sheet 105B is held in the dispensable opening structure 107 in a ready-to-dispense configuration.
An exemplary method of making the above-described dispensable plastic sheets and packages will now be briefly described. In general, the process involves steps of (i) forming electrostatically charged discrete plastic sheets and (ii) arranging the electrostatically charged discrete plastic sheets in a stack inside a package enclosure.
Referring to
A set of output rollers outputs parallel first and second series of electrostatically charged discrete plastic sheets 120, 121 to an interfolding stacking process 130, shown in
It can be seen that the interfolding stacking process 130 creates a stack of interfolded electrostatically charged discrete plastic sheets. The interfolded stack can be packaged into a package enclosure in accordance with any suitable packaging process. In an exemplary embodiment, the package enclosure is formed with a dispensing opening structure having a length running parallel to the length of each of the interfolded sheets, wherein the length of the dispensing opening is less than the length of the interfolded sheets but greater than one-half of the length of the sheets.
A series of tests were conducted in which stacks of discrete plastic sheets with varying characteristics were placed into cardstock packages with dispensing openings of different lengths. The sheets were then pulled through the dispensing opening as one would conventionally pull a tissue from a tissue box. The conditions of each experiment and results are described below.
In a first test labeled C1 in Table 1 below, a package enclosure design was used wherein the dispensing opening structure length L1 was 100% of the length L2 of the discrete plastic sheets. The discrete plastic sheets in test C1 were not electrostatically charged. The discrete plastic sheets were folded in half along lengthwise creases and placed in the package enclosure as an interfolded stack.
In a second test labeled C2 in Table 1 below, a package enclosure was used wherein the dispensing opening structure length L1 was 100% of the length L2 of the discrete plastic sheets. The discrete plastic sheets were not electrostatically charged. The discrete plastic sheets were folded into three sections along lengthwise creases and placed in the package enclosure in an interfolded stack.
In a third test labeled C3 in Table 1 below, a package enclosure was used wherein the dispensing opening structure length L1 was less than 70% of the length of the discrete plastic sheets L2. The discrete plastic sheets in test C3 were electrostatically charged. The discrete plastic sheets were folded in half along lengthwise creases and placed in the package enclosure as an interfolded stack.
In a fourth test labeled C4 in Table 1 below, a package enclosure was used wherein the dispensing opening structure length L1 was 100% of the length L2 of the discrete plastic sheets. The discrete plastic sheets in test C3 were electrostatically charged. The discrete plastic sheets were folded in half along lengthwise creases and placed in the package enclosure as an interfolded stack.
In a fifth test labeled C5 in Table 1 below, a package enclosure was used wherein the dispensing opening structure length L1 is between 70% and 98% of the length of the discrete plastic sheets L2. The discrete plastic sheets in L3 were electrostatically charged. The discrete plastic sheets were folded in half along lengthwise creases and placed in the package enclosure as an interfolded stack.
The results from tests C1, C2, C3, C4, C5 are summarized in Table 1. In test C1, after drawing between one and four dispensable plastic sheets, the following dispensable plastic sheet remained within or fell back within the package enclosure. In test C2, the following dispensable plastic sheet remained or fell back within the package enclosure after nearly every prior sheet was drawn out of the package enclosure. The inventors believe that this is due to the lack of electrostatic charging in the discrete plastic sheets. Without the electrostatic charging, the force used to pull a following sheet into the dispensing opening structure is only friction, which, due to the low COF of plastic sheets, is insufficient to pull the following sheet (which is relatively dense in comparison with tissue paper) through the opening. Because the dispensable plastic sheets frequently and unpredictably continued to stay within the package enclosure, users were required to reach their hand into the package enclosure via the dispensing opening structure to retrieve the next dispensable plastic sheet. This could result in the contamination of the remaining dispensable plastic sheets in the package enclosure.
In test C3, the results showed that after drawing between four and eight dispensable plastic sheets, the following dispensable plastic sheet remained within or fell back within the package enclosure. The inventors believe this is due to the dispensing opening being overly narrow. In addition, the following dispensable plastic sheet would occasionally be disconnected from the prior dispensable plastic sheet due to the increased resistance of the narrower dispensing opening structure when compared to the electrostatic force and friction between dispensable plastic sheets. This may create the contamination problem as mentioned with the results of tests C1 and C2. Additionally, the entire package enclosure was observed as being lifted and tilted by as the dispensable plastic sheet was drawn. This is an undesirable occurrence and becomes more significant and frequent when the package enclosure is close to being emptied of dispensable plastic sheets.
In test C4, the results showed that when drawing on the first dispensable plastic sheet, the electrostatic force between the dispensable plastic sheets caused multiple sheets to be drawn out of the package enclosure in a continuous chain. This is due to the fact that the wider opening does not apply any resistance to the dispensable plastic sheets as they exit the package enclosure via the dispensing opening. In order to separate a prior dispensable plastic sheet from the following dispensable plastic sheet, the user must grip both the prior dispensable plastic sheet with one hand and the following dispensable plastic sheets with the other hand and manually draw the dispensable plastic sheets apart. This results in a waste of dispensable plastic sheets and a messier workspace.
In C5, the results showed that after each dispensable plastic sheet was removed from the package enclosure, the following dispensable plastic sheet was positioned in a ready-to-dispense configuration. This was due to the fact that the length of the dispensing opening structure provides resistance sufficient to overcome the electrostatic charge force between the dispensable plastic sheets as the following dispensable plastic sheet enters the dispensing opening structure. However, the resistance is not so large as to prevent the electrostatic force between the prior dispensable plastic sheet and the following dispensable plastic sheet from drawing the following dispensable plastic sheet partially out of the package enclosure via the dispensing opening structure. This results in the following dispensable plastic sheet being easily accessible to the user without the user having to reach into the package enclosure and potentially contaminating the remaining dispensable plastic sheets. In addition, it prevents extended chains of three or more dispensable plastic sheets from being drawn out of the package enclosure.
When introducing elements of aspects of the invention or the embodiments thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Not all of the depicted components illustrated or described may be required. In addition, some implementations and embodiments may include additional components. Variations in the arrangement and type of the components may be made without departing from the spirit or scope of the claims as set forth herein. Additional, different or fewer components may be provided and components may be combined. Alternatively, or in addition, a component may be implemented by several components.
The above description illustrates the aspects of the invention by way of example and not by way of limitation. This description enables one skilled in the art to make and use the aspects of the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the aspects of the invention, including what is presently believed to be the best mode of carrying out the aspects of the invention. Additionally, it is to be understood that the aspects of the invention are not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The aspects of the invention are capable of other embodiments and of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
It will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
In view of the above, it will be seen that several advantages of the aspects of the invention are achieved and other advantageous results attained.
The Abstract and Summary are provided to help the reader quickly ascertain the nature of the technical disclosure. They are submitted with the understanding that they will not be used to interpret or limit the scope or meaning of the claims. The Summary is provided to introduce a selection of concepts in simplified form that are further described in the Detailed Description. The Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the claimed subject matter.
