Roller device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- JOA CURT G INC
- Filing Date
- 2023-05-19
- Publication Date
- 2026-04-28
AI Technical Summary
Elasticity in absorbent articles, such as adult incontinence products and diapers, causes the absorbent members to bunch up, leading to poor fit and increased likelihood of leakage due to clumping, which is undesirable.
A roller device with pattern and anvil rollers that apply pressure and heat to elastic webs, using cartridge heaters with controlled temperature zones to reduce the resiliency of discrete areas, ensuring consistent temperature and pressure distribution.
The roller device effectively reduces the resiliency of elastic webs, preventing clumping and ensuring a snug fit, thereby reducing the risk of leakage and improving the appearance of absorbent articles.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a roller device for processing at least one web passing through the device, and a method for processing a web. More specifically, the present invention relates to a roller device and an associated method for processing a stretchable web to reduce the elasticity of the web.
Background Art
[0002] For example, wearable absorbent articles including adult incontinence products, night-time pants, training pants, and diapers generally incorporate stretchable portions across the front and / or back sides of the article to keep the article snug against the wearer during use. Some articles use a number of elastic strands within the front and back waist panels to provide the required elasticity. Other articles may use an elastomeric web that may be provided alone or attached to one or more woven or non-woven layers, such as a meltblown elastomeric fiber web, a co-extruded elastomeric film, an elastic scrim, or an elastomeric film. Also, certain feminine hygiene products include stretchable regions manufactured from the aforementioned elastomeric materials.
[0003] Such absorbent articles include an absorbent member formed from wood pulp fluff, superabsorbent polymers, and / or other absorbent materials for absorbing urine or other body fluids. The absorbent member is generally located in the crotch region, but may extend towards the front and back of the article. If there is an overlap between the absorbent member and the stretchable region of the article, the tension created by the elastic strands or elastomeric web incorporated in the waist panel may cause clustering of the absorbent member.
[0004] Such clumping is undesirable because it affects the fit of absorbent materials. Absorbent materials that clump in the front or back area do not fit snugly to the wearer during use, resulting in increased leakage. Furthermore, clumped absorbent materials are bulkier and more easily visible through outer clothing. This is particularly problematic for people wearing adult incontinence products and bedwetting pants.
[0005] To reduce the clumping of absorbent materials across the front and rear regions, the elasticity of the web used to form the front and rear waist sections is often compromised. The reduction in the elasticity of the web in the region overlapping with the absorbent material eliminates tension that could otherwise cause clumping of the absorbent material, thereby reducing the bulk of the absorbent material. [Overview of the project]
[0006] According to one aspect of the present invention, a roller device is provided which processes at least one web passing through the device and comprises a pattern roller in the form of a first cylindrical body and mounted to rotate around the long axis of the first cylindrical body, and an anvil roller in the form of a second cylindrical body and mounted to rotate around the long axis of the second cylindrical body, wherein the pattern roller and the anvil roller are positioned adjacent to each other so as to define a nip between the outer cylindrical surfaces of the first and second cylindrical bodies, and the first and second cylindrical bodies are configured to rotate in opposite directions to each other in use so as to pull in at least one web through the nip defined between the outer cylindrical surfaces of the first and second cylindrical bodies. The outer cylindrical surface of the first cylindrical body defines a raised contour portion having a predetermined shape that extends in both the width direction and the circumferential direction of the first cylindrical body. The pattern roller incorporates a long cartridge heater extending in the width direction of the first cylindrical body along or near the long axis of the first cylindrical body, the cartridge heater defining at least two outer zones located in the width direction on either side of a centrally located intermediate zone, and the cartridge heater is configured to generate more heat in the outer zones than in the intermediate zone when in use.
[0007] The roller apparatus includes a mechanism for reducing the elasticity of a stretchable web, for example, for use in the manufacture of absorbent articles. A nip defined between the pattern roller and the anvil roller applies pressure to the stretchable web being drawn between the rollers, and in this case, a raised contour defined by the circumferential surface of the first cylindrical body increases the pressure applied to separate areas of the web.
[0008] When increased pressure is applied to distinct areas of the web, combined with the application of heat resulting from a cartridge heater integrated into the pattern roller, the elasticity of those distinct areas of the web decreases.
[0009] A cartridge heater is provided that extends in the width direction of the first cylindrical body along or near the longitudinal axis of the first cylindrical body and defines at least two outer zones located in the width direction on both sides of the intermediate zone, wherein the cartridge heater is configured to generate more heat in the outer zones than in the intermediate zone, which is particularly advantageous because it provides a more consistent temperature along the width of the first cylindrical body.
[0010] Otherwise, if the temperature differs along the width of the cylinder, different regions of the cylinder will expand more than other regions. In the roller apparatus described above, temperature inconsistency along the width of the first cylinder results in nip size inconsistency along the lengths of the first and second cylinders.
[0011] Maintaining a consistent temperature along the width of the first cylinder helps ensure that the nip size remains consistent along the width of the first cylinder, and that the amount of heat applied to the web as it passes through the nip is also consistent along the width of the roller.
[0012] Furthermore, the anvil roller of the roller device also incorporates a long cartridge heater that extends along or near the long axis of the second cylindrical body in the width direction of the second cylindrical body, the cartridge heater defining at least two outer zones located in the width direction on either side of a centrally located intermediate zone, and the cartridge heater is configured to generate more heat in the outer zones than in the intermediate zone when in use.
[0013] Similar to pattern rollers, the cartridge heater configuration provides a more consistent temperature along the width of the second cylindrical body.
[0014] By heating both rollers, the roller apparatus can heat the elastic web drawn in through the nip from both sides, thereby improving the performance of the roller apparatus by reducing the elasticity of the elastic web over areas of the web that receive greater pressure as a result of the raised contour defined by the outer circumferential surface of the first cylindrical body of the pattern roller.
[0015] In embodiments of the present invention, the pattern roller and optionally the anvil roller may include a single heated cartridge extending along the elongated axis of each cylindrical body. This ensures a uniform distribution of heat throughout the cylindrical body.
[0016] In other embodiments, the pattern roller incorporates a plurality of elongated cartridge heaters extending in the width direction of the first cylindrical body, the elongated heaters being arranged at equal intervals around the elongated axis of the first cylindrical body so as to extend in the width direction substantially parallel to the elongated axis of the first cylindrical body. This arrangement similarly ensures a uniform heat distribution throughout the cylindrical body, especially when a cylindrical body with a relatively large diameter is used.
[0017] Preferably, the cartridge heaters of the pattern roller and anvil roller are selectively controllable during use to independently control the temperature of the outer cylindrical surfaces of the first and second cylindrical bodies. This makes it possible to achieve different operating temperatures on the outer cylindrical surfaces of the first and second cylindrical bodies to accommodate the different nonwoven layers used on both sides of the web.
[0018] This is advantageous when the elastomer film is bonded to one or more nonwoven layers that require different amounts of thermal energy to penetrate the outer layer and heat the elastomer film, resulting in a reduction in the required elasticity of the elastomer film.
[0019] By independently controlling the operating temperatures of the pattern roller and the anvil roller, it is possible to heat the anvil roller to a higher temperature than the pattern roller when a stretchable web is pulled through a nip that includes a relatively thicker nonwoven layer on the web side that contacts the anvil roller compared to a thinner nonwoven layer on the web side that contacts the pattern roller.
[0020] In a particularly preferred embodiment, the cartridge heater or each cartridge heater is configured not to generate heat in its intermediate zone.
[0021] Unexpectedly, the applicant discovered that by forming a so-called "low-temperature zone" in the cartridge heater or at the center of each cartridge heater in the width direction, a more consistent flow of thermal energy from the cartridge heater through the cylindrical body can be obtained, resulting in a more consistent temperature along the width of the outer cylindrical surface.
[0022] Preferably, the heat generated in the cartridge heater or the outer zone of each cartridge heater can be controlled to maintain a consistent temperature along the width of the outer cylindrical surface of each cylindrical body during use.
[0023] For example, in a particularly preferred embodiment of the present invention, the controller can control the operation of the outer zone of the cartridge heater according to the measured values received from temperature sensors incorporated in one or both of the cylindrical bodies to measure the temperature of the outer cylindrical surface or near it.
[0024] By controlling the cartridge heater or the outer zone of each cartridge heater to generate more or less heat, the variation in the operating temperature of the outer cylindrical surface of each cylindrical body can be adjusted to ensure a consistent temperature along the width of the outer cylindrical surface.
[0025] In an embodiment of the present invention, the raised contour portion defines a smooth treatment surface that protrudes equidistantly from the remaining portion of the outer cylindrical surface of the first cylindrical body.
[0026] By providing a smooth treatment surface, in combination with the heat from the pattern roller and optionally the anvil roller, a consistent application of pressure is ensured to reduce the elasticity of the stretchable web supplied between the nips of the first and second cylindrical bodies.
[0027] The use of a continuous treatment surface, in contrast to a patterned surface, enables a consistent temperature along the width of the outer cylindrical surfaces of the pattern roller and optionally the anvil roller. This allows for greater control over the application of pressure and heat to separate regions of the stretchable web to carefully control the degree of elasticity reduction. The pressure and heat may be controlled, for example, to reduce the elasticity by a specific percentage, or may be controlled, for example, to attenuate the elasticity according to the performance required from the web in the final product.
[0028] To further adjust the amount of pressure applied to the web through the nip between the first and second cylindrical bodies, the pattern roller and the anvil roller may be movable relative to each other to adjust the nip defined between the outer cylindrical surfaces of the first and second cylindrical bodies.
[0029] This enables adjustment of the nip, for example, to adjust the amount of pressure applied by the raised profile to separate regions of the web according to the thickness of at least one web and / or to adjust the degree to which the elasticity of the web is reduced.
[0030] According to a second aspect of the present invention, there is provided a method of processing a web, the method comprising: feeding the web to a roller apparatus for processing the web, the apparatus comprising a pattern roller in the form of a first cylinder and mounted for rotation about the longitudinal axis of the first cylinder, and an anvil roller in the form of a second cylinder and mounted for rotation about the longitudinal axis of the second cylinder, the pattern roller and the anvil roller being positioned adjacent to each other so as to define a nip between the outer cylindrical surfaces of the first and second cylinders; rotating the pattern roller in a first direction and rotating the anvil roller in a second opposite direction to draw the web through the nip; applying pressure to separate regions of the web by a raised profile defined by the outer cylindrical surface of the first cylinder, the raised profile having a predetermined shape extending in both the width direction and the circumferential direction of the first cylinder; heating the first cylinder and operating a cartridge heater incorporated in the pattern roller to heat the outer surface of the web in contact with the outer cylindrical surface of the first cylinder when the web is drawn through the nip, the cartridge heater extending in the width direction of the first cylinder along or near the longitudinal axis of the first cylinder and defining at least two outer zones positioned in the width direction on both sides of a centrally located intermediate zone, the cartridge heater generating more heat in the outer zones than in the intermediate zone; including.
[0031] Other preferred features of the present invention are set forth in claims 10 to 16 of the appended claims. Herein, preferred embodiments of the present invention will be described as non-limiting examples with reference to the attached drawings. [Brief explanation of the drawing]
[0032] [Figure 1] A side view of a roller device according to one embodiment of the present invention is shown. [Figure 2] Figure 1 shows a perspective view of the roller device. [Figure 3] Figure 1 shows a cross-sectional view of the roller device. [Figure 4a] Figure 1 shows the cartridge heater of the roller device. [Figure 4b] Figure 1 shows the cartridge heater of the roller device. [Figure 5a] Figure 1 shows a perspective view of the pattern roller of the roller device. [Figure 5b] Figure 1 shows a side view of the pattern roller of the roller device. [Figure 5c] Figure 1 shows a cross-sectional view of the pattern roller of the roller device. [Figure 6a] Figures 5a to 5c show perspective views of the bonder roller of the pattern roller. [Figure 6b] Figures 5a to 5c show side views of the bonder roller of the pattern roller. [Figure 6c] Figures 5a to 5c show cross-sectional views of the bonder roller of the pattern roller. [Figure 7a] Figures 5a to 5c show perspective views of the pattern sleeve of the pattern roller. [Figure 7b] Figures 5a to 5c show side views of the pattern sleeve of the pattern roller. [Figure 7c] Figures 5a to 5c show cross-sectional views of the pattern sleeve of the pattern roller. [Figure 8a] Figure 1 shows a perspective view of the anvil roller of the roller device. [Figure 8b] Figure 1 shows a cross-sectional view of the anvil roller of the roller device. [Figure 9] Figure 1 shows the stretchable web portion after being processed by the roller device. [Modes for carrying out the invention]
[0033] A roller device 10 according to one embodiment of the present invention is shown in Figures 1 and 2.
[0034] The roller device 10 includes a pattern roller 12 that takes the form of a first cylindrical body 14 and is mounted to rotate around the long axis A of the first cylindrical body 14, and an anvil roller 16 that takes the form of a second cylindrical body 18 and is mounted to rotate around the long axis B of the second cylindrical body 18.
[0035] The pattern roller and anvil rollers 12 and 16 are mounted within the frame 20 so as to be adjacent to each other in order to define a nip 22 between the outer cylindrical surfaces 14a and 18a of the first and second cylindrical bodies 14 and 18. The relative positions of the pattern roller 12 and anvil roller 16 can be adjusted by sliding one or both of the rollers 12 and 16 within the frame to bring the outer cylindrical surfaces 14a and 18a of the first and second cylindrical bodies 14 and 18 closer together or further apart. This facilitates adjustment of the size of the nip 22 between the outer cylindrical surfaces 14a and 18a.
[0036] A motor (not shown) is coupled to the pattern roller and the anvil rollers 12 and 16 to drive the rollers 12 and 16 to rotate in opposite directions.
[0037] The cylindrical surface 14a of the first cylindrical body 14 defines a raised contour portion 24 having a predetermined shape that extends in both the width direction and the circumferential direction of the first cylindrical body 14.
[0038] In relation to the present invention, the "widths" of the first and second cylindrical bodies 14 and 18 are identified as C in Figure 1 and are elongated dimensions that are aligned with the elongated axes of the cylindrical bodies 14 and 18.
[0039] Referring to Figure 3, it can be seen that the pattern roller 12 includes a long cartridge heater 26 that extends in the width direction along the long axis A of the first cylindrical body 14. As shown in Figures 3, 4a and 4b, the cartridge heater 26 defines at least two outer zones 26a, 26c located in the width direction on either side of a centrally located intermediate zone 26b.
[0040] In the embodiment shown in Figure 1, the anvil roller 16 also includes an elongated cartridge heater 18 (Figure 3) extending in the width direction along the elongated axis B of the second cylindrical body 28. Similar to the pattern roller 12, the cartridge heater of the anvil roller 16 defines at least two outer zones 28a, 28c located in the width direction on either side of a centrally located intermediate zone 28b.
[0041] In other embodiments, one or both of the pattern and anvil rollers 16, 18 include a plurality of elongated cartridge heaters 26, 28 extending in the width direction of the respective cylindrical bodies 14, 18. In such embodiments, the elongated heaters 16, 18 are arranged equidistantly around the elongated axes A, B of the cylindrical bodies 14, 18 so as to extend in the width direction substantially parallel to the elongated axes A, B of the cylindrical bodies 14, 18. This arrangement is particularly useful when cylindrical bodies 14, 18 with relatively large diameters are used to ensure a uniform heat distribution throughout the cylindrical bodies 14, 18.
[0042] The cartridge heaters 26 and 28 are connected to a controller (not shown) that controls the operation of the cartridge heaters 26 and 28. Zones 26a to 26c are configured to be controlled independently so that one zone can generate more or less heat than one or more of the other zones.
[0043] In the embodiment shown in Figure 1, the outer zones 26a, 26c and 28a, 28c of the two cartridge heaters 26, 28 are configured to generate heat, while the intermediate zones 26b and 28b of the cartridge heaters 26, 28 do not generate heat and are configured to form a so-called "low temperature zone".
[0044] Referring to the cartridge heater 26, it can be seen that the intermediate or low-temperature zone 26b is twice as wide as each of the outer zones 26a and 26c. This configuration results in a particularly beneficial heating mode in that it allows for a consistent flow of heat from the heated outer zones 26a and 26c through the body of the cylindrical body 14, and thus a consistent temperature on the outer cylindrical surface 14a. This is a surprising result, as it would be expected that thermal energy would be lost through the ends of the cylindrical body 14 to the surrounding air and flame 20, and therefore not enough heat would flow into the central part of the cylindrical body 14 around the intermediate or low-temperature zone 26b of the cartridge heater 26, and that heating from the intermediate zone 26b would also be necessary. However, the applicant has found that this is not the case.
[0045] In the embodiment shown in Figure 1, intended for use in the manufacture of a typical adult pants unit, a cartridge heater 26 having a width in the range of 550mm to 650mm and a diameter in the range of 15mm to 25mm is incorporated into a pattern roller 12 having a width in the range of 550mm to 650mm and a diameter in the range of 200mm to 250mm. The outer zones 26a and 26c each have a width in the range of 15 to 35% of the total width of the pattern roller 12, and the intermediate zone 26b has a width in the range of 30 to 70% of the total width of the pattern roller 12. In this configuration, the ends of the cartridge heater 26 are not heated.
[0046] Depending on the size of each cylindrical body 14, 18, cartridge heaters 26, 28 of different widths may be used in other embodiments. Generally, cartridge heaters 26, 28 having widths in the range of 40 mm to 950 mm and diameters in the range of 15 mm to 55 mm are used.
[0047] In relation to the present invention, it can be understood that the "width" of the cartridge heaters 26 and 28 is the elongated dimension aligned with the elongated axis of the respective cylindrical bodies 14 and 18. The cartridge heaters 28 incorporated into the anvil roller 16 have the same dimensions, but the anvil roller 16 has a width in the range of 550 mm to 650 mm and a diameter in the range of 200 mm to 250 mm.
[0048] The cylindrical bodies 14 and 18 of different sizes in the pattern roller and anvil roller 12 and 16 are used for manufacturing different absorbent products. Naturally, the size required for adult-sized products is significantly larger than the size required for infant-sized products or feminine hygiene products. Generally, the cylindrical bodies 14 and 18 can have widths ranging from 50 mm to 1 m and diameters ranging from 150 mm to 510 mm. Smaller dimensions within this range are suitable for smaller products such as infant products and feminine hygiene products. Larger dimensions within this range are applicable to adult panty products where the pattern roller 12 is utilized in a multi-up configuration where multiple raised pattern areas are spaced apart around the pattern roller 12.
[0049] In the embodiment shown in Figure 1, the power of each cartridge heater 26, 28 is 5500W. In other embodiments, cartridge heaters with different power levels can be used depending on the size of the cylindrical bodies 14, 18, the material from which the cylindrical bodies 14, 18 are made, and / or the heating characteristics required by each of the rollers 12, 16. Generally, the power level can range from 100W to 10,000W.
[0050] The pattern roller 12 and the anvil roller 16 include temperature sensors located on or near the outer cylindrical surfaces 14a, 18a of the cylindrical bodies 14, 18. This allows the controller to effectively monitor the temperature of the outer cylindrical surfaces 14a, 18a to maintain a consistent temperature along the width of the outer cylindrical surfaces 14a, 18a of the cylindrical bodies 14, 18, and to control the outer zones 26a, 26c and 28a, 28c of the two cartridge heaters 26, 28.
[0051] The pattern roller 12 is shown in detail in Figures 5a to 5c. The pattern roller 12 includes a bonder roller 30 incorporating a cartridge heater 26 that extends in the width direction along the long axis A of the bonder roller 30. A hollow cylindrical pattern shell 32 slides over the outer cylindrical surface 30a of the bonder roller 30. The bonder roller 30 and the pattern shell 32 together define the first cylindrical body 14 of the pattern roller 12, and the outer cylindrical surface of the pattern shell 32 defines the outer cylindrical surface 14a.
[0052] A raised contour 24 defined by the outer cylindrical surface 14a of the first cylindrical body 14 is shown in Figures 5c and 7c. The raised contour 24 has a predetermined shape and protrudes equidistant from the rest of the outer cylindrical surface of the first cylindrical body 14.
[0053] As shown in Figures 5a and 7a, the raised contours 24 define a smooth processed surface 24a. The shape of the raised contours 24 is determined by the final use of the processed web. It can therefore be understood that the shape and size of the raised contours 24, and therefore the shape and size of the smooth processed surface 24a, may differ from those shown in Figures 5a and 7a. Furthermore, the first cylindrical body 14 may have two or more raised contours 24 spaced apart from each other across the outer circumference of the first cylindrical body 14. Such a multi-up configuration of the pattern roll can be used for smaller sized products, including infant diapers, light incontinence products, and feminine hygiene products, which are manufactured with a relatively small product pitch. The first cylindrical body 14 may also include a plurality of raised contours 24 spaced apart in the width direction of the first cylindrical body 14 to form discontinuous weak areas in the machine transverse direction.
[0054] The anvil roller 16 is shown in more detail in Figures 8a and 8b. The anvil roller 16, like the pattern roller 12, includes a bonder roller 30 incorporating a cartridge heater 28 that extends in the width direction along the long axis B of the bonder roller 30. A hollow cylindrical anvil shell 38 slides over the cylindrical surface 30a of the bonder roller 30. Together, the bonder roller 30 and the anvil shell 38 define a second cylindrical body 18 of the anvil roller 16, and the outer cylindrical surface of the anvil shell 38 defines an outer cylindrical surface 18a.
[0055] A temperature sensor (not shown) can be received in an opening 40 (Figure 8b) formed in the anvil shell 38 to measure the temperature of the outer cylindrical surface 18a of the second cylindrical body 18 of the anvil roller 16 or its vicinity.
[0056] Similarly, a temperature sensor is housed in a corresponding opening (not shown) formed in the pattern shell 32 of the pattern roller 12 to measure the temperature of the outer cylindrical surface 14a of the first cylindrical body of the pattern roller 12 or its vicinity.
[0057] The roller device 10 may also be used to process the stretchable web 34 in order to reduce the elasticity in separate areas of the web 34, and the operation of the roller device 10 is described here in relation to the processing of the stretchable web 34 in the form of an elastomer web sandwiched between nonwoven outer layers.
[0058] During use, the pattern roller 12 and the anvil roller 16 are driven by motors to rotate in opposite directions, so that when the web 34 is fed into the nip 22 of the roller device 10, the web is pulled through the nip 22 by the rotation of the rollers 12 and 16.
[0059] The cartridge heaters 26, 28 of the pattern roller and anvil rollers 12, 16 are operated to heat two outer zones 26a, 26c and 28a, 28c in order to heat the web 34 as the web is pulled through the nip 22 by heating the outer cylindrical surfaces 14a, 18a.
[0060] In addition to applying heat, the outer cylindrical surfaces 14a and 18a of the pattern roller and anvil rollers 12 and 16 apply pressure to the web 34. This pressure increases as the processing surface contacts the web 34, across separate regions of the web 34 that contact the smooth processing surface 24a of the raised contour 24 defined by the outer cylindrical surface 12a of the pattern roller 14.
[0061] The increased pressure applied to separate regions of the web 34, combined with the heat applied by the outer cylindrical surfaces 14a and 18a of the pattern roller and anvil roller, acts to reduce the elasticity of the web 34 across these separate regions.
[0062] During operation, the temperature of the outer cylindrical surfaces 14a and 18a of the pattern roller and anvil roller is measured by sensors mounted on the pattern shell 32 and anvil shell 38. These temperatures are used to control the operation of the cartridge heaters 26 and 28 in order to maintain a consistent temperature along the width of the outer cylindrical surfaces 14a and 18 of both the pattern roller 12 and the anvil roller 16. As previously mentioned, the controllers provided to control the operation of the cartridge heaters 26 and 28 maintain the temperature of the outer cylindrical surfaces 14a and 18a by increasing or decreasing the heat generated in the outer zones 26a, 26c and 28a, 28c of the cartridge heaters 26 and 28 as needed. No heat is generated in the intermediate zones 26b and 28b of the cartridge heaters 26 and 28.
[0063] In other less preferred embodiments, depending on the properties of the material used to form the web 34, it is assumed that one or both of the cartridge heaters 26, 28 can be operated to generate heat in the intermediate zones 26b, 28b. However, in all circumstances, the outer zones 26a, 26c and 28a, 28c will generate more heat than the intermediate zones 26b, 26c in order to maintain a consistent temperature along the length of the outer cylindrical surfaces 14a, 18a of the pattern rollers and anvil rollers 12, 16.
[0064] Inconsistent temperatures along the width of either the outer cylindrical surfaces 14a and 18a of the pattern roller and anvil rollers 12 and 16 cause areas of the cylindrical body at higher temperatures to expand more than areas at lower temperatures. This results in inconsistency in the size of the nip 22 between the outer cylindrical surfaces 14a and 18a of the pattern roller and anvil rollers 12 and 16, and therefore, uneven pressure is applied to the web 34 as it is pulled through the nip 22. This is undesirable because it can result in an inconsistent decrease in the elasticity of the web 34 in separate areas processed by the processed surface 24a of the raised contour portion 24 of the pattern roller 12.
[0065] The ability to maintain a consistent temperature along the length of the outer cylindrical surfaces 14a and 18a allows for the use of a smooth processing surface 24a on the raised contour 24. This enables greater uniformity of the pressure applied to individual areas of the web 34 that are in contact with the processing surface 24. The consistent application of heat along the length of the outer cylindrical surfaces 14a and 18a of the pattern rollers and anvil rollers 12 and 16, along with the uniform pressure application by the smooth processing surface 24a, significantly improves the performance of the roller device 10 in reducing elasticity in separate areas of the web 34.
[0066] The degree to which the elasticity of a given web 34 is reduced can be adjusted by adjusting the relative positions of the rollers 12 and 16 within the frame 20, thereby adjusting the size of the nip 22 between the outer surfaces 14a and 18a of the pattern roller and anvil roller 12 and 16.
[0067] In the embodiment shown in Figure 1, the size of the nip 22 is in the range of 0 mm to 0.254 mm. The raised contour 24 has a radial height in the range of 1 mm to 10 mm compared to the non-relieved portion of the outer peripheral surface 14a of the pattern roller 12. In other embodiments, the size of the nip 22 and / or the radial height of the raised contour 24 may vary depending on the thickness of the individual material layers of the elastic web 34 supplied to the nip 22.
[0068] The degree of elasticity reduction can also be adjusted by adjusting the temperature of the outer surfaces 14a, 18a of the pattern rollers and anvil rollers 12, 16 by adjusting the heat generated in the outer zones 26a, 26c and 28a, 28c of the cartridge heaters 26, 28. The cartridge heaters 26, 28 may be controlled, for example, to heat the pattern rollers and anvil rollers 12, 16 so that the outer surfaces 14a, 18a operate at different temperatures.
[0069] In the embodiment shown in Figure 1, the operating temperature of the outer circumferential surfaces 14a and 18a of the pattern roller and anvil roller is in the range of 50°C to 180°C, more preferably in the range of 80°C to 100°C. In other embodiments, the operating temperature of the outer circumferential surfaces 14a and 18a may vary based on the material properties of the stretchable web 34.
[0070] In a particularly preferred embodiment, the stretchable web 34 is processed by being pulled through a roller device 10 in order to reduce the elasticity of separate areas of the stretchable web 34 to 25% or more of the elasticity indicated by the stretchable web 34 before processing. In an alternative embodiment, the elasticity of the stretchable web may be reduced to less than 25% of the elasticity indicated by the stretchable web 34 before processing, or completely eliminated.
[0071] This may be particularly advantageous when the nonwoven outer layer of the web 34 that comes into contact with the anvil roller 16 and is drawn in through the nip 22 is thicker or denser than the nonwoven layer of the web 34 that comes into contact with the pattern roller 12 and is drawn in through the nip 22. In such a situation, the operating temperature of the outer circumferential surface 18a of the anvil roller 16 may be higher than the operating temperature of the outer circumferential surface 14a of the pattern roller 12.
[0072] As a result, the roller device 10 can be used to process the web 34, creating separate areas in the elastic web 34 where the elasticity is reduced to varying degrees or completely eliminated.
[0073] Furthermore, the nip 22 may be adjusted to allow webs 34 of different thicknesses to be supplied to the nip 22 and pulled through the nip.
[0074] Furthermore, the operating temperatures of the outer peripheral surfaces 14a and 18a of the pattern roller and anvil roller may be adjusted when one or both of the nonwoven outer layers of the web 34 are formed from a heat-sensitive material.
[0075] To allow for variations in the outer surface of the web 34, the rotational speeds of the pattern roller and the anvil rollers 12 and 16 may be varied relative to each other. This is desirable, for example, when the friction between the nonwoven outer layers of the web 34 in contact with the anvil roller 16 is greater than the friction between the nonwoven outer layers of the opposite surface of the web 34 in contact with the pattern roller 12. In such situations, the rotational speed of the anvil roller 16 can be increased to ensure that the web 34 is pulled through the nip 22 with minimal strain.
[0076] As the continuous length of the web 34 is drawn in through the nip 22 defined between the outer circumferential surfaces 14a and 18a of the pattern roller and anvil rollers 12 and 16, the smooth processing surface 24a of the raised contour 24 defined by the outer circumferential surface 12a of the pattern roller 14 repeatedly contacts equally spaced regions of the web 34. As a result, the web 34 emerging from the nip 22 has a series of equally spaced regions in which the elasticity of the web 34 is reduced, and the shape and size of each of these regions corresponds to the shape and size of the processing surface 24a of the raised contour 24.
[0077] The distance between adjacent regions where elasticity is reduced is determined by the circumferential distance of the non-raised portions of the outer peripheral surface 14a between the edges of the raised contour portions 24 on the pattern roller 12.
[0078] If the web is intended to be used to form the front and rear waistbands of adult incontinence pants, the raised contour 24 may be molded to correspond in shape and size to the absorbent material used in the pants, so as to align with a portion of the web where the elasticity is reduced in order to prevent the absorbent material from clumping together when the absorbent material is aligned with the front and rear waistbands.
[0079] The circumferential size of the outer surface of the pattern roller 12 can be varied by using different pattern shells 32. A pattern shell 32 with a larger circumferential size may be desirable, for example, to accommodate a larger processing surface 24a and allow for sufficient distance between the non-relieved portions of the outer surface 14a between the edges of the raised contours 24. Separate areas of the processed web 34 with reduced elasticity may otherwise not be sufficiently spaced apart from one another. The rotational speed of the pattern roller 12 can also be varied using mechanical elements such as cams or linkages to control the spacing between separate areas of the processed web with reduced elasticity.
[0080] From the perspective of the structure of the web 34, when the elastomer film is bonded to one or more nonwoven outer layers, it is preferable that the nonwoven layers be bonded to the elastomer film in such a way as to prevent slippage between different layers. The elastomer film and the outer nonwoven layer may be bonded to each other, for example, via an adhesive, or supplied via a mechanical bonding unit, a thermal bonding unit, or an ultrasonic bonding unit before being supplied to the roller device 10, thereby forming the entire bonding pattern between the outer nonwoven layer and the elastomer film.
Claims
1. A roller device for processing at least one web passing through the device, comprising a pattern roller in the form of a first cylindrical body and mounted to rotate around the long axis of the first cylindrical body, and an anvil roller in the form of a second cylindrical body and mounted to rotate around the long axis of the second cylindrical body, wherein the pattern roller and the anvil roller are positioned adjacent to each other so as to define a nip between the outer cylindrical surfaces of the first and second cylindrical bodies, and the first and second cylindrical bodies are configured to rotate in opposite directions to each other in use so as to pull the at least one web through the nip defined between the outer cylindrical surfaces of the first and second cylindrical bodies, The outer cylindrical surface of the first cylindrical body defines a raised contour portion having a predetermined shape that extends in both the width direction and the circumferential direction of the first cylindrical body. A roller device comprising a pattern roller incorporating a long cartridge heater extending in the width direction of the first cylindrical body along or near the long axis of the first cylindrical body, wherein the cartridge heater defines at least two outer zones located in the width direction on both sides of a centrally located intermediate zone, and the cartridge heater is configured to generate more heat in the outer zones than in the intermediate zone when in use.
2. The roller device according to claim 1, wherein the anvil roller incorporates a long cartridge heater extending in the width direction of the second cylindrical body along or near the long axis of the second cylindrical body, the cartridge heater defining at least two outer zones located in the width direction on both sides of a centrally located intermediate zone, and the cartridge heater is configured to generate more heat in the outer zones than in the intermediate zone when in use.
3. The roller device according to claim 1 or 2, wherein the pattern roller incorporates a plurality of elongated cartridge heaters extending in the width direction of the first cylindrical body, and the elongated cartridge heaters are arranged to be equally spaced around the elongated axis of the first cylindrical body so as to extend in the width direction substantially parallel to the elongated axis of the first cylindrical body.
4. The roller device according to claim 1 or 2, wherein the anvil roller incorporates a plurality of elongated cartridge heaters extending in the width direction of the second cylindrical body, and the elongated cartridge heaters are arranged to be equally spaced around the elongated axis of the second cylindrical body so as to extend in the width direction substantially parallel to the elongated axis of the second cylindrical body.
5. The roller apparatus according to claim 1 or 2, wherein the cartridge heaters of the pattern roller and the anvil roller can be selectively controlled to independently control the temperature of the outer cylindrical surfaces of the first and second cylindrical bodies during use.
6. The roller device according to claim 1 or 2, wherein the cartridge heater or each cartridge heater is configured not to generate heat in its intermediate zone.
7. The roller device according to claim 1 or 2, wherein the heat generated in the cartridge heater or the outer zone of each cartridge heater can be controlled to maintain a consistent temperature along the width of the outer cylindrical surface of each cylindrical body during use.
8. The roller device according to claim 1 or 2, wherein the raised contour defines a smooth processing surface that protrudes at an equidistant distance from the remaining portion of the outer cylindrical surface of the first cylindrical body.
9. The roller apparatus according to claim 1 or 2, wherein the pattern roller and the anvil roller are movable relative to each other to adjust the nip defined between the outer cylindrical surfaces of the first and second cylindrical bodies.
10. The roller device according to claim 1 or 2, wherein the rotation of the first and second cylindrical bodies can be selectively controlled to independently control the rotational speeds of the first and second cylindrical bodies during use.
11. In methods of processing the web, A step of supplying a web to a roller device for processing the web, wherein the device comprises a pattern roller having the form of a first cylindrical body and mounted to rotate around the long axis of the first cylindrical body, and an anvil roller having the form of a second cylindrical body and mounted to rotate around the long axis of the second cylindrical body, wherein the pattern roller and the anvil roller are positioned adjacent to each other so as to define a nip between the outer cylindrical surfaces of the first and second cylindrical bodies, The steps include rotating the pattern roller in a first direction and rotating the anvil roller in a second opposite direction to pull the web through the nip, A step of applying pressure to a separate region of the web by a raised contour defined by the outer cylindrical surface of the first cylindrical body, wherein the raised contour has a predetermined shape that extends in both the width direction and the circumferential direction of the first cylindrical body, A step of operating a cartridge heater incorporated in the pattern roller to heat the first cylindrical body and the outer surface of the web in contact with the outer cylindrical surface of the first cylindrical body when the web is drawn through the nip, wherein the cartridge heater extends in the width direction of the first cylindrical body along or near the elongated axis of the first cylindrical body and defines at least two outer zones located in the width direction on both sides of a centrally located intermediate zone, and the cartridge heater generates more heat in the outer zones than in the intermediate zone, A method that includes this.
12. A method for processing a web according to claim 11, further comprising the steps of heating the second cylindrical body and operating a cartridge heater incorporated in the anvil roller to heat the outer surface of the web which is in contact with the outer cylindrical surface of the second cylindrical body and is drawn in through the nip, wherein the cartridge heater extends in the width direction of the second cylindrical body along or near the elongated axis of the second cylindrical body and defines at least two outer zones located in the width direction on either side of a centrally located intermediate zone, and the cartridge heater generates more heat in the outer zones than in the intermediate zone.
13. A method for processing a web according to claim 11 or 12, wherein the pattern roller incorporates a plurality of elongated cartridge heaters extending in the width direction of the first cylindrical body, and the elongated cartridge heaters are arranged to be equally spaced around the elongated axis of the first cylindrical body so as to extend in the width direction substantially parallel to the elongated axis of the first cylindrical body.
14. A method for processing a web according to claim 11 or 12, wherein the anvil roller incorporates a plurality of elongated cartridge heaters extending in the width direction of the second cylindrical body, and the elongated cartridge heaters are arranged to be equally spaced around the elongated axis of the second cylindrical body so as to extend in the width direction substantially parallel to the elongated axis of the second cylindrical body.
15. The method for processing a web according to claim 12, wherein the cartridge heaters of the pattern roller and the anvil roller are selectively and independently controlled to independently control the temperature of the outer cylindrical surfaces of the first and second cylindrical bodies.
16. The method for processing a web according to claim 11 or 12, wherein the cartridge heater or each cartridge heater is operated so as not to generate heat in its intermediate zone.
17. The method for processing a web according to claim 11 or 12, wherein the heat generated in the cartridge heater or the outer zone of each cartridge heater is controlled to maintain a consistent temperature along the width of the outer cylindrical surface of each cylindrical body.
18. The method for processing a web according to claim 11 or 12, wherein the raised contour defines a smooth processed surface that protrudes equidistant from the rest of the outer cylindrical surface of the first cylindrical body.
19. The method for processing a web according to claim 11 or 12, wherein the positions of the pattern roller and the anvil roller are moved relative to each other to adjust the nip defined between the outer cylindrical surfaces of the first and second cylindrical bodies according to the thickness of the web.
20. The method for processing a web according to claim 11 or 12, wherein the rotation of each of the first and second cylindrical bodies is selectively and independently controlled to independently control the rotational speeds of the first and second cylindrical bodies.