CN1029110C - Selectively weakened cores for core wound paper products - Google Patents

Abstract

A core for core-wound paper products such as toilet paper and paper towels is provided with a plurality of axially extending joining scores, cuts or holes. These continuous score lines, cuts or holes weaken the core so that when crushed they form peaks. When the core is rounded, each score line, slit or hole forms a peak, thus forming a predetermined polygonal cross-section which is closer to a circle.

Description

The present invention relates to a core for a product wound on a core (hereinafter referred to as a core-wound paper product), in particular to a core to be flattened or compressed to minimize its useless space, more specifically It relates to a crushed core having means for rounding the core closer to its original state.

Corewound paper products, such as toilet paper and paper towels, are well known in the industry and are widely used consumer products. Such products comprise a core around which multiple layers of the paper product are wound. The core can be, and often is, fitted over a mandrel to facilitate temporary storage of the paper product and to facilitate removal of the paper product from the roll when required. The mandrel passes through the center of the core, thus requiring the core to be open so that the mandrel can pass therethrough without excessive friction and without causing difficulty in later access to the paper product.

A preferred core shape is a cylinder having a circular cross-section to allow free rotation of the core with the paper product wound thereon about the axis of the mandrel and to allow the paper product to be easily removed from the roll. Take it out. An improvement to rolls of paper wound on a core is to compress the press in a direction perpendicular to the axis of the core to reduce dead space within the core. Such a construction facilitates storage, handling and shipping of core wound paper products, since such products can be stored and shipped more economically and at a higher density.

Various schemes have been proposed in the art to take advantage of the benefits of compressed core wound paper products. For example, U.S. Patent 4,762,061 issued to Watanabe et al. on August 9, 1988 and U.S. Patent 4,909,388 issued to Watanabe on March 20, 1990 disclose compression to one-half to the original diameter of the article. One-fifth roll of paper products. The cores of these articles are slightly elastic, allowing them to return to their original cylinders from their compressed, flattened shape shape. According to these patents, it is generally desirable that a crushed paper roll can easily return to its original shape.

U.S. Patent 1,005,787 issued to Sibley in October 1911 discloses a flattened toilet paper package wrapped around a hollow core formed from a flexible, axially corrugated paper blank. The corrugated core catches the toilet paper, causing chatter when it is pulled from the roll. European Patent 709,363, issued May 19, 1954 to Samson, discloses a paper web or flexible sheet wound on a core which is diametrically flattened and said to be very fast after unpacking. regain its tubular shape. The core consists of a helically wound strip of kraft paper and is flexible. Its flexibility is said to enable the core to be crushed without cracking and to return to its cylindrical shape after crushing.

U.S. Patent 4,886,167 issued to Dearwater on December 12, 1989 discloses a flattened core with little to no dead space between diametrically opposed faces of the flattened core cross-section. One-way compressed toilet paper. The Dearwater patent is incorporated by reference into this application for the purpose of showing a particularly preferred compact, compressed toilet paper or paper towel roll.

The above-mentioned patents all suffer from the disadvantage that, during recirculation, diametrically opposed corrugations often occur throughout the core and prevent it from returning to the desired cylindrical shape. These wrinkles often cause the core to not fit properly on the mandrel, causing inconvenience to the user each time the core is placed on the mandrel, each time it is used on the mandrel, or each time it is removed from the mandrel. Furthermore, the out-of-round cross-section of such cores would prevent the paper product from being easily removed from the roll, making it inconvenient for the user to remove one or more paper products each time. Cores with non-circular cross-sections are generally noisy in use.

One solution to overcome the problems associated with core flattening is to avoid such flattening, as disclosed in U.S. Patent 2,659,543 issued to Guyer on November 17, 1953, which proposes a A method of maintaining the original core shape. This patent introduces a core for strip-shaped products, such core has at least one groove or groove extending axially along the outside of the core, Or have a plurality of such grooves or grooves uniformly distributed along the circumferential direction. When the material is tightly wound around the core, the grooves collapse slightly, relieving the compressive clamping stress caused by the tape being tightly wound around the core. However, this solution has the disadvantage of maintaining the circular cross-section of the core while losing the above-mentioned advantages of crushing the core.

What is needed, therefore, is a core that can be collapsed as well as the prior art but that can be more easily and accurately re-rounded after the compressive stress applied to the paper product is removed.

It is therefore an object of the present invention to provide a core having means for flattening and rounding the core in a more convenient manner for the user and capable of precisely and repeatedly returning the core to a shape closer to its original shape. .

The invention comprises a flattened core around which a paper product is wound to form a roll. The collapsed core has an inner perimeter, an outer perimeter, and two opposed ends defining a longitudinal axis. The crushed core can be restored to a nearly circular cross-section when rounded. The core also comprises at least one means for weakening the resistance of the core against the compressive force applied by unloading, the weakening means being arranged on at least one of the inner and outer peripheries, or may penetrate the entire thickness of the core through the inner and outer peripheries of the core.

In one embodiment, the weakening means is a plurality of axially extending continuous score lines. In a second embodiment, the weakening means is a plurality of axially extending cuts. In a third embodiment, the weakening means is a plurality of axially oriented holes. The score lines, cuts or holes may be impervious so that only one peripheral surface of the core is affected by the weakening means, or the weakening means may penetrate the entire thickness of the core through the inner and outer circumferences of the core.

Although the claims of the present application specifically and clearly set forth the protection scope of the present invention, it is believed that the present invention will be better understood through the following description in conjunction with the accompanying drawings. In the drawings, like parts are given the same reference numerals.

Figure 1 is a perspective view of a flattened core and paper product of the present invention;

Figure 2 is a perspective view of the core of the present invention before flattening, with a plurality of different types of score lines oriented axially on its inner and outer circumferences;

Fig. 3 is the expanded schematic plan view of a kind of core of the present invention, has 5 on it Holes spaced upwards and axially staggered;

Fig. 4 is an expanded schematic plan view of a core of the present invention having five circumferentially spaced holes arranged inwardly from each end;

Figure 5 is an expanded schematic plan view of a core of the present invention having five intermittent cuts extending approximately 2.54 cm (1 inch) from each end of the core with cut and uncut zones of equal length Wire;

Fig. 6 is a schematic plan view of the development of a core of the present invention, on which there are five intermittent incision lines whose lengths of the cutting zone and the non-cutting zone are equal, and the depth of cut is only about half of the thickness of the core;

Fig. 7 is a schematic plan view of the expansion of a core of the present invention, on which there are 5 intermittent incision lines whose cutting zone length is one-third of the uncut zone length;

Fig. 8 is a schematic plan view of the expansion of a core of the present invention, on which there are five tangent lines set at a distance from the end face of the core and composed of two tangent lines;

Fig. 9 is an expanded schematic plan view of a core of the present invention, on which there are five intermittent incision lines whose lengths of the cutting zone and the non-cutting zone are larger than those shown in Figs. 6 and 7;

Fig. 10 is a schematic plan view of the development of a core of the present invention, on which there are 5 intermittent cut lines whose lengths of the cut zone and the uncut zone are equal and less than the length shown in the above figures;

Fig. 11 is a schematic plan view of the development of a core of the present invention, on which there are 5 intermittent incision lines whose length of the cutting zone is 3 times of the length of the non-cutting zone.

A "core" as used in this document refers to a hollow cylindrical member on which is wound another helically wound product for later use and removal. "Paper product" as used herein refers to a cellulosic product that is wound around a core 20, typically taken one or more sheets at a time, and discarded after use. The paper product 24 is not returned to the core 20 after it has been taken out for use. The "paper roll" mentioned herein refers to a combination of a "core" and a "paper product" wound thereon. The paper roll 28 may also have a wrapper 32 to maintain it in the shape shown in FIG. 1 .

The core 20 of the present invention can be advantageously used on toilet paper or tissue products. The core 20 has a generally cylindrical shape before flattening, the axial length of which is defined by its two oppositely disposed ends. The ends of the core 20 are circular in cross-section before being flattened. The line connecting the centers of the two ends is called the "longitudinal axis" of the core 20 . As used herein, "axial" refers to the direction of the longitudinal axis.

When the toilet paper is wound on the core 20, the diameter of the toilet paper roll 28 is generally from about 10.2 cm to about 12.7 cm (i.e., 4.00 to 5.00 inches), and the length between its ends is generally about 11.4 cm (4.5 inches). . If the core 20 of the present invention is used in a tissue product, according to the embodiments described herein, the diameter of the roll 28 is generally from about 10.2 centimeters to about 15.2 centimeters (4.00 to 6.00 inches), and its length is generally about 27.9 centimeters ( 11.0 inches).

A typical core 20 may be constructed of two plies of paper which may be any suitable combination of bleached kraft, sulfite, hardwood, softwood, and recycled paper. The core should be of uniform strength with no weak spots. The core 20 is preferably not calendered so that it is relatively hard and tends to hold the adhesive applied thereto. Core 20 should have a burst strength of at least 60, preferably at least 70, when measured in accordance with ASTM test method D2529. Core 20 may have a thickness of about 0.5 millimeters (0.020 inches). The core 20 should be free of unpleasant odors and skin irritating impurities or contaminants.

The core 20 can be used with a basis weight of about 0.16 kg/ ^m (0.032 lb/ft2) and a ring crush strength of at least 6.79 kg/cm (38 lb/in), preferably at least 8.93 kg/cm (50 lbs/in) paper, the ring crush strength is measured in accordance with TAPPI Standard T818 OM-87.

The core 20 of the present invention is provided with means 36 for selectively weakening the resistance of the core 20 against compressive forces, in particular against diametrically applied compressive forces. The diametrically applied compressive force may be applied at any point along the axis of the core 20 or across its entire axis.

As used herein, "diametrically applied compressive force" refers to an opposing compressive force exerted on any diameter of any cross-section of the core 20 . Of course, it will be appreciated that compressive forces may Can be applied along a chord of the section and not coincident with a diameter. However, the principles involved in such cases are essentially the same as for diametrically applied compressive forces and thus will not be differentiated or repeated here.

Upon application of a compressive force, core 20 will collapse into the collapsed state shown in FIG. 1 . The cross-section of the collapsed core 20 shown in Figure 1 has a major axis a-a and a minor axis i-i perpendicular thereto. The major axis a-a and the minor axis i-i of the cross-section are transverse to and perpendicular to the longitudinal axis of the core 20 . After flattening, the major axis a-a is aligned with the longest dimension of the cross-section of the paper product 24 and the minor axis i-i is the perpendicular bisector of the major axis.

It has been found that at least one circumferentially disposed means 36 for attenuating the resistance of the core 20 against an applied compressive force is desirable, preferably - but not necessarily required - equally spaced from adjacent equally functioning means 36 , so that the cross-section of the core 20 is closer to a circle than an irregular polygon when compounding a circle.

The azimuthal orientation of the major axis a-a and minor axis i-i of the crushed core 20 may be predetermined by the circumferential arrangement and spacing of the means 36 for weakening the resistance of the core 20 against the applied compressive force. If the core 20 is provided with two diametrically opposite means 36 for weakening the resistance of the core 20 against an applied compressive force, and if the diameter on which the compressive force is applied is relative to the two weakening means 36 At about 90°, the core 20 will be crushed approximately at the location of the two weakening means 36 .

The collapsed core 20 has a major axis a-a with two peaks at its ends corresponding to the weakening means 36, respectively. Therefore, it is preferable to provide an even number of weakening means 36 such that each weakening means 36 is diametrically opposite the other weakening means 36 .

However, the core 20 cannot return to a nearly original cylindrical shape when it is rounded, because the two peaks maintain the cross-section of the core 20 in an almost double-sided convex shape. To provide more peak points, more weakening devices 36 need to be arranged in the circumferential direction, so that when the circle is rounded, the core 20 will be a polygonal cross-section, and its number of sides is equivalent to the number of peak points, and each peak point is equivalent to the number of peak points. to a specific means 36 for weakening the resistance of the core 20 against the applied compressive force.

As mentioned above, since the core 20 has a double-sided convex shape after compounding, it is not suitable for the core 20 to be provided with an even number of weakening devices 36 , and one or more pairs are not suitable. If four weakening means 36 are provided, the core 20 has a substantially square cross-section after rounding and has the shape of a hollow hexahedron. When the core 20 is put on the mandrel after being rounded, there will be too much shaking and too much noise, so it is generally not recommended.

A six attenuation means 36 equally spaced around the circumference works well. When the core 20 is flattened, a weakening device 36 appears at each end of its end face long axis a-a, and the crushed core 20 has two weakening devices 36 on each flattened face, and these two weakening devices 36 span the The minor axis i-i is juxtaposed with the two weakening means 36 on the opposite flattened face. This kind of core 20 has a hexagonal cross-section after being rounded, and the shaking and noise are relatively small during use.

Cores having 8, 10 or 12 equally spaced weakening means 36 are undesirable because such cores have a natural tendency to form a quadrangular cross-section when rounded. This structure also needs two segments of complex circles, which is more inconvenient for users.

As shown in FIG. 2, a particularly preferred means 36 for reducing the resistance of the core 20 against an applied compressive force is a continuous axially extending score line. The score lines are preferably parallel to the axis of the core 20, but may also spiral around the core 20 if desired. A weakening means 36 is said to be "axially extended" if a line extending along the weakening means 36 forms an angle with the longitudinal axis of the core 20 of less than 45°.

The score lines may be provided on the inner circumference or the outer circumference of the core 20 . Obviously, if multiple scoring lines are provided, these scoring lines can be separately provided on the inner and outer circumferences of the core 20 .

As used herein, "score lines" include indentation lines, and preferably include lines formed by removal of material from core 20 . The score lines can be made with a scribe ruler or a rotary die, and the score lines are preferably pressed into about 25% to 100% of the thickness of the core 20. The score lines preferably extend between and onto the ends of the core 20.

If desired, such as a score line for weakening the core 20 against applied compression The force resisting means 36 may be continuous, discontinuous or intermittent and may correspond to a plurality of discrete holes or cuts. These discrete holes or slits can - but need not - extend to each end of the core 20 and can be axially staggered from the end of the core 20 .

For example, FIGS. 3-10 illustrate eight non-limiting examples in sequence, illustrating various means 36 for attenuating the resistance of the core 20 against an applied compressive force. Table 1 lists a sample of each example so that the effect of core 20 on recirculation can be easily compared by the parameters listed in Table 1.

Each row in Table 1 represents a sample prepared from commercially available Charmin brand toilet paper manufactured and sold by Proget Gamble Company of Cincinnati, Ohio. The cores 20 are removed from the paper roll 28 of the paper product 24, on which said means 36 for weakening the resistance of the core 20 against the applied compressive force are made, and these cores 20 are inserted back into the paper product 24 to form a complete roll 28. The roll 28 of paper product 24 is then compressed diametrically along its minor axis i-i with a force of about 36 kg (80 lb).

The rolled paper product 24 was then aged for about four weeks at a relative humidity of about 50% and a temperature of 72°F. An aging period of at least two weeks is considered necessary to allow any memory or elasticity of the core 20 to evolve, thereby approximating storage and shipping conditions and obtaining accurate data on subsequent re-rounding of the sample. A aging period of less than two weeks is considered undesirable because the results obtained do not approximate the reality in which paper products are manufactured, stored in warehouses, transported to points of sale, sold, taken to the consumer's home and finally loaded onto a mandrel for use.

Each core 20 is made of the material described above and has a length of approximately 11.43 cm (4.5 inches). The sample shown in Figures 3 to 10 is provided with 6 equally spaced devices 36 for weakening the resistance of the core 20 against the applied compressive force, one for opening the through slit of the core 20, and 5 for weakening the core 20. The resistance of the core 20 against applied compressive forces will be described below.

Column 1 of Table 1 represents the resistance depicted to weaken the core 20 against the applied compressive force. Figure number of the plan view of the force device 36. Column 2 of Table 1 describes the characteristics of the five attenuating devices 36 . However, the core 20 of these samples had to be cut and opened as shown in the plan views of FIGS. resistance to compressive forces.

When five of said weakening devices 36 are used together with one continuous through-slit, the through-slit is re-sealed with tape and then the core 20 is compressed such that the major axis a-a, when flattened, is aligned with the taped The slot intersects one of said weakening means 36 . In practice, the aforementioned through-slit can be replaced by a weakening device 36 identical to the other 5 said weakening devices, so that all 6 devices for weakening the resistance of the core 20 against the applied compressive force are identical of.

The perforations or cuts listed in column 3 of Table 1 as a percentage of the axial dimension are the percentages of the axial linear dimension of the core 20 that are affected by the weakening means 36 . The overall linear dimension of the attenuating means 36 of each core 20 is 68.6 cm (6 x 4.5 = 27 inches). List the axial distribution of each weakening device 36 on the core 20 in the 4th column of Table 1, for example: from end to end and extending through the full length of core 20, located in the middle and not Extended to the ends, or set at both ends from the ends and discontinuous in the middle.

The peak point formation effect of each weakening device 36 is listed in the fifth column of Table 1, which is determined according to the main performance judgment when the core 20 is rounded back to its original cylindrical state, and is divided into three types: low, medium and high. grade. If no sharp peaks were seen on the core after rounding, the sample was judged to have low peak formation effect. A sample is judged to have moderate peaking effects if a significant change in direction of curvature occurs at one or more peak locations. If the peaking knuckles are formed at the attenuating means 36, the peaking effect of this sample is judged to be high.

The core sample shown in Figure 3 has five holes approximately 6.4 mm (0.25 in) in diameter. Each hole is axially offset from its circumferentially adjacent holes by a distance of about one-fifth of the length of core 20 .

The core sample shown in Fig. 4 is provided with 10 holes arranged at intervals along the circumferential direction, and its diameter is about 6.4 mm (0.25 in), 5 per end. Every five holes are arranged on the same plane, and are arranged on the position about 2.54 centimeters inward from the end of the core 20 . The five holes on one end of the core 20 are axially aligned with the corresponding five holes on the other end of the core 20 .

The core sample shown in Fig. 5 is cut from each end of the core 20 towards the center, the cut is about 2.54 cm (1 inch) long, and consists of alternating 1 mm (0.04 inch) long cutting zones and 1 mm long cutting zones. mm (0.04 inches) of uncut zone.

The core sample shown in Figure 6 had cut lanes consisting of alternately 1 mm (0.04 inch) cut zones 40 and 1 mm (0.04 inch) uncut zones 44 . The cutting area 40 is formed on the inner periphery of the core 20 with a cutting depth half the thickness of the core 20 . The effective percentage of the cut area for the sample of FIG. 6 is halved because the cut affects only half of the total core 20 thickness.

The core sample shown in Figure 7 had cut lanes consisting of alternating cut zones 40 of 2 mm (0.08 inches) in length and non-cut zones 44 of 6 mm (0.24 inches) in length. The cut zone 40 and the uncut zone 44 extend the full length of the core 20 .

The core sample shown in FIG. 8 was provided with dual cut regions 40 each approximately 2.54 cm (1 inch) in length and one end approximately 1.27 cm (0.5 inch) from the end of the core 20.

The core sample shown in Figure 9 had cut lanes consisting of alternating cut zones 40 of 9.6 mm (0.38 inches) in length and uncut zones 44 of 9.6 mm (0.38 inches) in length. The cuts extend from one end of the core 20 to the other.

The core sample shown in Figure 10 had cut lanes consisting of alternately 1 mm (0.04 inch) cut zones 40 and 1 mm (0.04 inch) uncut zones 44 . The cuts extend from one end of the core 20 to the other.

The core sample shown in Figure 11 had alternating cut zones 40 of 3 mm (0.12 inches) in length and uncut zones 44 of 1 mm (0.04 inches) in length. The cuts extend from one end of the core 20 to the other.

It can be seen from Table 1 that, in general, the peak forming effect of the core samples was judged to be low when the attenuating means 36 accounted for less than about 20% of the axial dimension of the core. when attenuation device 36 Between 20% and 45% of the axial dimension of the core, the peak formation effect was judged to be moderate relative to the other samples. The peak forming effect of the attenuating means 36 is judged to be high when it occupies more than 50% of the axial dimension of the core. All samples were placed on mandrels and then used. However, all samples proved to be superior to the reference sample without attenuation means 36 in terms of noise and smooth use without interruption.

Table 1

Figure Description Axis of perforation or cut Axis of attenuation device Peak point shape

Percentage of number direction size direction distribution effect

3 axially staggered holes, 6 end-to-end low

Aperture is 6.4mm

4 5 diameter 6.4 11 ends low

mm hole, from

2.54 cm at each end

5 1 mm cutting zone, 22 in both ends

1 mm no-cut zone,

inward from each end

Exhibition 2.54 cm

6 1 mm cutting zone, 25 end-to-end

1 mm no-cut zone,

core thickness

half of the degree

7 2 mm cutting zone, 25 end-to-end

6 mm no-cut zone

8 double cutting areas, each 44 central

A length of 2.54 cm,

respectively from the end

1.27 cm

9 9.6 mm cut 50 end-to-end height

area, 9.6mm

Not cut area

10 1 mm cutting area, 50 end-to-end height

1 mm no-cut zone

11 3 mm cutting area, 75 end-to-end height

1 mm no-cut zone

Claims (9)

1, a kind of fuse that can be wound with paper products thereon, the compressive force that this fuse can be applied in flattens to make things convenient for storage, loading and unloading and the transportation of core around paper products, the fuse of this flattening has interior week, periphery and two opposed ends that limit longitudinal axis, the fuse of this flattening can form the cross-sectional plane near tubulose, it is characterized in that having the device of the drag that is used to weaken the compressive force that this fuse resists to apply, this reducer is provided in a side of a plurality of incisor paths that stretch vertically in this fuse.

2, a kind of fuse that can be wound with paper products thereon, the compressive force that this fuse can be applied in flattens to make things convenient for storage, loading and unloading and the transportation of core around paper products, the fuse of this flattening has interior wealth, periphery and two opposed ends that limit longitudinal axis, the fuse of this flattening can form the cross-sectional plane near tubulose, it is characterized in that having the device of the drag that is used to weaken the compressive force that this fuse resists to apply, this reducer be at least one on the interior week of this fuse and in the periphery at least one groove that be provided with, that stretch vertically.

3, a kind of fuse that can be wound with paper products thereon, the compressive force that this fuse can be applied in flattens to make things convenient for storage, loading and unloading and the transportation of core around paper products, the fuse of this flattening has interior wealth, periphery and two opposed ends that limit longitudinal axis, the fuse of this flattening can form the cross-sectional plane near tubulose, it is characterized in that having the device of the drag that is used to weaken the compressive force that this fuse resists to apply, this reducer is a plurality of many holes on the line that stretches vertically that are distributed in.

4,, it is characterized in that described groove is continuous basically and along the periphery setting of fuse by the described fuse of claim 2.

5, by a described fuse one of in the claim 1 to 3, it is characterized in that the orientation of described reducer becomes one from about 0 ° to 45 ° angle with described longitudinal axis.

6, by the described fuse of claim 5, it is characterized in that described reducer is arranged essentially parallel to described longitudinal axis.

7,, it is characterized in that described reducer is arranged between the described opposite end and does not intersect with any described end by a described fuse one of in the claim 1 to 3.

8, by a described fuse one of in the claim 1 to 3, it is characterized in that reducer that each described multiple tracks stretches vertically round described longitudinal axis along circumferentially uniformly-spaced being provided with basically.

9, by the described fuse of claim 8, it is characterized in that the road number of the reducer that described multiple tracks stretches vertically is 6.

Images