Dispenser with tear unit

Abstract

A dispenser for dispensing web of paper, the dispenser including a housing, a dispensing opening defined in the housing for dispensing paper. A tear unit is arranged at the dispensing opening for facilitating tear of the paper upon moving the tissue paper over the tear unit. The tear unit includes a tear unit body, and the tear unit body includes a friction surface provided with an elastomer. The elastomer includes rounded protrusions distributed along the friction surface such as to facilitate tearing during dispensing.

Claims

1. A tear unit for a dispenser for dispensing web of paper, the tear unit comprising a tear unit body, said tear unit body comprising a friction surface provided with an elastomer, and wherein said elastomer comprises rounded protrusions distributed along the friction surface such as to facilitate tearing during dispensing of paper, wherein said rounded protrusions are rounded in all directions.

2. The tear unit according to claim 1, wherein the rounded protrusions are evenly distributed along the friction surface.

3. The tear unit according to claim 1, wherein the rounded protrusions are arranged at a center-to-center distance from each other, the distance being larger than the maximum diameter of the rounded protrusions.

4. The tear unit according to claim 1, wherein said rounded protrusions have a height/diameter ratio of about 2/3.

5. The tear unit according to claim 1, wherein the height of said protrusions is less than 4 mm.

6. The tear unit according to claim 1, wherein the elastomer is a thermoplastic elastomer.

7. The tear unit according to claim 6, wherein said thermoplastic elastomer has a hardness of 70-90 Shore A.

8. The tear unit according to claim 7, wherein said thermoplastic elastomer is overmolded onto said tear unit body.

9. A dispenser for dispensing web of paper, the dispenser comprising: a housing, a dispensing opening defined in said housing for dispensing paper; and a tear unit according to claim 1, which unit is arranged at the dispensing opening for facilitating tear of the paper upon moving the tissue paper over the tear unit.

10. The dispenser according to claim 9, wherein said housing comprises a housing body and a cover, the cover allowing access into the housing for refilling the dispenser.

11. The dispenser according to claim 9, wherein the tear unit is arranged at least at one edge defining the dispensing opening.

12. The dispenser according to claim 9, wherein the dispenser is a roll dispenser.

13. The dispenser according to claim 12, the dispenser comprising a housing for accommodating at least one roll.

14. The dispenser according to claim 9, wherein the dispenser is a roll dispenser, and said tear unit is arranged to mainly extend in a direction parallel to the direction of the central axis of a paper roll when arranged in said dispenser, such that the outer cylindrical surface of said paper roll faces said tear unit during dispensing.

15. The dispenser according to claim 9, wherein the dispenser is a roll dispenser, and wherein said tear unit is arranged to mainly extend in a direction perpendicular to the direction of the central axis of said paper roll such that a side of said paper roll faces said tear unit during dispensing.

16. The dispenser according to claim 9, wherein said dispenser comprises at least one roll holder for rotatably supporting an axis of a roll of paper.

17. The dispenser according to claim 16, wherein said tear unit is arranged at a distance from said at least one roll holder, and wherein said distance between the central axis of said roll holder and the periphery of a full paper roll arranged on the roll holder is smaller than the distance between the central axis of the roll holder and the tear unit.

18. The dispenser according to claim 9, wherein said tear unit is arranged to mainly extend in a direction parallel to the direction of the width of a stack of paper when arranged in said dispenser, such that the unfolding surface of said stack of paper faces said tear unit during dispensing.

19. The dispenser according to claim 9, wherein the paper is tissue paper.

20. A method for manufacturing a tear unit for a dispenser for dispensing web of paper, wherein the method comprises providing a tear unit body comprising a friction surface, wherein the method further comprises the step of providing the friction surface with a thermoplastic elastomer comprising rounded protrusions by injection molding, and wherein the rounded protrusions are distributed along the friction surface, wherein the rounded protrusions are evenly distributed along the tear unit and are rounded in all directions such that the rounded protrusions are dome-shaped.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The disclosure herein is illustrated by way of examples and not limited to the accompanying figures, in which like references indicate similar elements:

(2) FIG. 1A is a perspective view of a dispenser with tear unit as disclosed herein,

(3) FIG. 1B is a perspective view of the dispenser of FIG. 1A with the lid of the dispenser being open,

(4) FIG. 2 is a perspective view of another dispenser with tear unit as disclosed herein,

(5) FIG. 3 is a perspective view of another dispenser with tear unit as disclosed herein,

(6) FIG. 4 is a front view of the lower part of the dispenser of FIG. 2,

(7) FIG. 5 is a perspective view of the tear unit as disclosed herein,

(8) FIG. 6A-6B is a cross sectional top view of the rounded protrusions as disclosed herein,

(9) FIG. 6C-6D is a cross sectional side view of the rounded protrusions as disclosed herein, and

(10) FIG. 7 is a perspective view of an alternative tear unit as disclosed herein.

DETAILED DESCRIPTION

(11) It is to be understood by one of ordinary skill in the art that the following is a description of example embodiments only, and is not intended as limiting the broader aspects of the present disclosure.

(12) FIG. 1A shows a wall-mounted dispenser 10 comprising a housing 11 enclosing two rolls of tissue paper, the housing 11 comprising a housing body 18 and a cover 19. The cover 19 is a hinged lid providing access to the interior of the dispenser 10 thereby allowing the roll of tissue paper to be replaced, as illustrated in FIG. 1B. Two roll holders 20 extend perpendicular from the back wall of the housing body 18, the roll holders 20 each being intended to hold a roll of continuous tissue paper in the housing 11.

(13) A dispensing opening 12 allowing access to the rolls for dispensing paper through the dispensing opening 12 is arranged at the bottom of the dispenser 10, the dispensing opening 12 facing downwards when the dispenser 10 is mounted on a wall, such that the tail of the roll of tissue paper is hanging freely down towards the dispensing opening 12. The dispensing opening 12 allows the user to readily access and grab the tail of the tissue paper roll. If the paper tail of the roll is not visible, the user can access the roll inside the dispenser 10 through the dispensing opening 12.

(14) The dispensing opening 12 is provided with a tear unit 13, the tear unit 13 delimiting the front and sides of the dispensing opening 12, as shown in FIG. 1a. The tear unit 13 is attached at its ends to the back wall of the housing body 18. The tear unit extends below the edge of the cover 19 when the cover 19 is closed, such as to delimit the dispensing opening 12 formed by the housing body 18 and the cover 19. The tear unit 13 comprises a tear unit body 14, the tear unit body 14 is provided, by overmolding, with a thermoplastic elastomer 16 which comprises rounded protrusions 17 evenly distributed along a friction surface 15 of the tear unit 13, the friction surface facing downwards away from the interior of the housing 11. The rounded protrusions 17 are uniformly rounded on all sides, forming raised hemispherical knobs.

(15) The tear unit 13 is not in contact with the outer cylindrical surface of the roll of paper. The tail of the tissue paper roll hangs freely downwards, not touching the tear unit 13, so the tear unit 13 comes into contact with the paper tail only when a user is pulling the tissue paper tail over the tear unit 13 during dispensing in order to separate a piece of paper from the paper roll.

(16) FIG. 2 shows a wall-mounted dispenser 10 comprising a housing 11 enclosing a roll of paper, the housing 11 comprising a housing body 18 and a cover 19. A roll holder 20 is arranged to extend perpendicular from the back wall of the dispenser 10, the roll holder 20 holding a roll of continuous paper in the housing 11. The cover 19 is a hinged lid providing access to the interior of the dispenser 10 thereby allowing the roll of tissue paper to be replaced. A tear unit 13, being an integral part of the hinged lid, is arranged so as to define the dispensing opening 12 through which paper can be dispensed. The tear unit 13 is arranged at the side edges as well as the front edge of the dispensing opening 12. The paper is pulled against a frictions surface on the tear unit 13 by the user when the user wishes to separate a piece of paper from the roll of paper. The friction surface 15 is provided with a thermoplastic elastomer 16, and rounded protrusions 17 made of thermoplastic elastomer 16, providing friction which allows the paper to separate at or close to the tear unit 13.

(17) FIG. 3 shows a wall-mounted dispenser 10 for two rolls of tissue paper. The dispenser 10 has a housing 11 comprising a housing body 18 and a cover 19, the cover 19 being a hinged lid allowing access to the interior of the dispenser 10 such that the user can replace the rolls. A dispensing opening 12 is arranged at the front of the dispenser 10, facing outwards when the dispenser 10 is mounted on the wall. The dispensing opening 12 provides access to the roll during dispensing, and the outer cylindrical surface of the roll is visible at the dispensing opening 12 when the roll is full. The rolls are arranged in the dispenser 10 such that the outer cylindrical surface of the roll faces the dispensing opening 12 and the tail of the tissue paper roll is hanging freely facing the dispensing opening 12. The dispensing opening 12 is partly covered by a slidable cover door allowing only one roll at a time to be accessed.

(18) The dispensing opening 12 is provided with a tear unit 13 at its upper outer edge. The tear unit 13 comprises a thermoplastic elastomer 16 comprising rounded protrusions 17 evenly distributed along a friction surface 15 of the tear unit 13. During dispensing the user pulls the free hanging tail downwards to achieve a paper length of desire, and then pulls the tissue paper over the tear unit 13 to separate it from the roll. The tissue paper comes into contact with the tear unit 13 once the user grabs the tail and pulls is towards and over the tear unit 13, and the friction exerted by the thermoplastic elastomer 16 protrusions 17 at the friction surface 15 facilitate the separation of the tissue paper.

(19) FIG. 4 shows the rounded protrusions 17 of thermoplastic elastomer 16 arranged at the outer edge of a dispensing opening 12 of a dispenser 10. The rounded protrusions 17 extend downwards away from the dispenser 10. A paper tail is present in the dispensing opening 12, hanging freely downwards. The paper tail may be grabbed, pulled downwards to unwind a desired length of web from the paper roll, and the pulled outwards in a perpendicular motion so that the web of paper comes into contact with the tear unit 13, thereby initiating a separation of a piece of tissue paper.

(20) With continued reference to FIGS. 1-4, FIG. 5 shows the rounded protrusions 17 of thermoplastic elastomer 16. The thermoplastic elastomer 16 covers the friction surface 15 of the tear unit body 14 and extends over the edges of the friction surface 15 such as to partly cover the inner surface and outer surface of the tear unit body 14. The tear unit body 14 comprises a recessed portion along its inner surface and a recessed portion along its outer surface, the recessed portions being covered by the thermoplastic elastomer 16. The recessed portion at the inner surface of the tear unit body 14 is larger than the recessed portion at the outer surface of the tear unit body 14, i.e. extends further up the height of the tear unit body 14. The thermoplastic elastomer 16 extends further up the inner surface of the tear unit body 14 than at the outer surface of the tear unit body 14 and hence provides more thermoplastic elastomer 16 material at the inner surface, facing the interior of the housing 11 from where the web of paper is drawn. The recessed portions provide improved molding of the thermoplastic elastomer 16 to the tear unit body 14 during the injection molding formation step.

(21) The rounded protrusions 17 are evenly distributed with a set distance (cc) between each protrusion. The rounded protrusions 17 are made of thermoplastic elastomer 16, and formed during injection molding the thermoplastic elastomer 16 to the tear unit 13. The surface between the rounded protrusions 17 is covered with thermoplastic elastomer 16 material, like a coating, having a set thickness (t).

(22) In a non-limiting example the rounded protrusions 17 are arranged at a distance 10 mm from each other centre-to-centre (cc), the height (h) of the protrusions 17 is 2 mm, the diameter (d) of the rounded protrusions 17 is 3 mm and the thickness (t) of the thermoplastic elastomer 16 is 4 mm in between the rounded protrusions 17.

(23) FIG. 6A shows the radius of a rounded protrusion with fixed radius (r). According to a non-limiting example shown in FIG. 6B the radius (r) of the rounded protrusions 17 may vary over the circumference of the rounded protrusions 17 such that for example the front of the protrusions have a larger radius (r) than the back of the protrusions 17 having a smaller radius (r). The front edge of the protrusions 17 is the side facing outwards from the dispensing opening 12, and the back edge is the side facing inwards towards the dispensing opening 12, the interior of the housing 11 and the web of paper.

(24) Moreover, the angle (a) between the plane of the intermediate surface between the rounded protrusions 17 and the slanted side of the rounded protrusions 17 may vary with the circumference of the rounded protrusions 17. In such a non-limiting example, shown in FIG. 6D, the angle (α1) at the front edge of the rounded protrusion is 90 degrees, and the angle (α2) at the back edge of the rounded protrusions 17 is less than 90 degrees so as to render more material at the back edge. The back edge is more prone to wear over time as the tissue paper is pulled from that direction over the tear unit 13. In FIG. 6C an example of rounded protrusions 17 with fixed angles (α0) throughout their circumference is shown.

(25) FIG. 7 shows an alternative embodiment, a tear unit with rounded protrusions of elastomer being wave-shaped.

Example

(26) The force required to break the tissue paper against the tear unit can be measured in the test method exemplified herein. The test results are used for comparative purposes.

(27) Procedure

(28) A tensile tester and a fixture are used to test the dispensability of the teeth of a dispenser. A clamp is attached to the tail of the paper, and the clamp is attached by a string to a tensile tester at the other end. The tail of the paper rests against the tear unit at the start of the test. The tensile tester pulls the paper for 300 mm with a speed of 10 000 mm/min and register the maximum load (N) and the extension (mm) before the tissue paper breaks. With this set up it is possible to measure how far the paper must be pulled before it breaks (extension at max load). Short distance (low extension at max load) represents a more effective tear, i.e. an effective tear unit.

(29) Tensile tester Zwick/Roell Z1.0 was used at speed 10 000 mm/min with load cell 200 N.

(30) The dispenser used was a roll dispenser with a vertically arranged roll, i.e. the side surface of the roll facing the tear unit. Such a dispenser type is shown in FIG. 1. The dispenser was equipped with a tear unit comprising conventional tear teeth of 30% glass fiber reinforced Polyamide 6 (SCHULAMID 66 GF30), a tear unit as disclosed herein, and a tear unit coated with TPE but without the rounded protrusions respectively. Conventional 2-ply toilet tissue paper was used (Tork Mini Jumbo Toilet Roll, available through www.tork.se).

(31) Results

(32) The test results for the max load and extension at max load are shown in Table 1.

(33) TABLE-US-00001 TABLE 1 Roll Extension Tear off diameter Max load at max load success rate (mm) (N) (mm) (%) Dispenser with Full 6.2 89 17 conventional roll tear teeth 60 mm 4.7 124 100 roll Dispenser with Full 6.5 30 100 tear unit as roll disclosed herein 60 mm 6.2 31 100 (rounded roll protrusions of TPE) Dispenser with Full 8.3 102 33 tear unit roll coated with TPE 60 mm 12.4 77 20 (without roll rounded protrusions)

(34) The dispenser with tear unit as disclosed herein provides reliable and precise tear off. The max load (N) needed to achieve tear in a web of paper is 6-7N which is comparable to the max load measured for a dispenser with a conventional tear teeth. However, the extension at maximum load is considerably less for a tear unit as disclosed herein than conventional tear teeth.

(35) As can be seen from the comparative result the dispenser according to the present disclosure displays a lower extension at max load than the other dispensers tested (with other tear units). The reduced extension at max load indicate that the tear is more precise and achieved faster with tear means as disclosed herein. Full rolls and rolls of 60 mm radius, which represent about 50% of the tissue paper left on the roll, has been tested. The effectiveness of the tear with a tear unit as disclosed herein is not affected by the amount of tissue paper left on the roll and hence the performance is reliable and consistent. Shredding or unsuccessful breaking is avoided, thereby providing a good tear off success rate. A tear unit coated with thermoplastic elastomer but without the rounded protrusions repeatedly failed to break the tissue paper, i.e. resulted in unsuccessful tear off. In summary, a combination of thermoplastic elastomer material and rounded protrusions of the same material achieve the optimal tear performance.