Hook-and-loop fastener

Abstract

Provided is a fastening tape that can stably secure appropriate peel strength with respect to a ring member and that can improve the texture of the skin compared to conventional fastening tapes. This fastening tape (1) is a synthetic resin fastening tape (1) having a base section (10) and a plurality of engaging elements (20), each engaging element (20) having a rod section (22), an engaging head section (23), and at least one engaging section (24) protruding from the outer peripheral section of the engaging head section (23), the total area of the engaging head section (23) per 1 cm2 of the fastening tape (1) being 10,000 in a plan view in which the fastening tape (1) is viewed from the top, and the total area of the engaging head section (23) per 1 cm2 of the fastening tape (1) being 10,000 in a plan view in which the fastening tape (1) is viewed from the top. The synthetic resin has a tensile modulus of elasticity of 700 MPa or more and 2300 MPa or less.

Description

Technical Field

[0001] The invention relates to a hook and loop fastener. Background Art

[0002] In the past, there have been known products with hook and loop fasteners that are used by combining a pair of ring members (also called female hook and loop fasteners) having multiple rings and a male hook and loop fastener (hereinafter referred to as hook and loop fasteners) that can be detached from the ring members. The hook and loop fastener generally has: a flat base; and a plurality of male engaging elements that are arranged on the upper surface of the base and have a hook or mushroom shape, and are sometimes referred to as hook members.

[0003] Such fasteners are currently widely used in a variety of products, for example, disposable diapers, diaper pants for infants, protective devices for protecting the joints of the hands and feet, tights (back pain belts), gloves and other products that can be attached or detached from the body.

[0004] Velcro for disposable diapers and the like has been developed in large numbers so far, for example, as disclosed in International Publication No. 2017 / 109902 (Patent Document 1). The Velcro described in Patent Document 1 has a base and a plurality of engaging elements protruding from the base. Each engaging element of Patent Document 1 has a rod portion rising from the base and a disc-shaped engaging head portion integrally formed at the upper end of the rod portion. The engaging head portion is provided with a plurality of tiny claw portions protruding from the outer peripheral edge portion of the engaging head portion.

[0005] In the Velcro of such patent documentation 1, by being provided with tiny claw portion at the engaging head of engaging element, the ring of ring member can be made to be easy to be hooked on each engaging element, in addition, the ring that is hooked can be made to be difficult to disengage from the engaging element.Thus, the peel strength (sometimes also referred to as engaging strength) of Velcro with respect to ring member can be improved.In addition, in patent documentation 1, the claw portion that helps to increase peel strength is formed on the outer peripheral edge portion of the engaging head with tiny size, therefore, the impact that the claw portion brings to the sense of touch of Velcro can be reduced.Thereby, the Velcro with higher engaging strength, good skin touch on the surface can be provided.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2017 / 109902 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] For the Velcro used in disposable diapers, diaper trousers and other products such as body, even if the body is moved under the state that Velcro is engaged with the ring member, the Velcro is stably provided with such appropriate peeling strength (also sometimes referred to as engagement strength) that the Velcro is not easily separated from the ring member. In addition, due to the difference of the products used, Velcro is also sometimes in direct contact with the skin, therefore, it is desirable to improve the skin feel of the surface side of the Velcro configuration with the engagement element, so as to obtain soft touch.

[0011] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a hook and loop fastener that can stably ensure appropriate peel strength with respect to a ring member and can improve the touch to the skin compared with the conventional hook and loop fastener.

[0012] Solutions for solving problems

[0013] In order to achieve the above-mentioned purpose, the Velcro provided by the present invention is a Velcro made of synthetic resin, comprising: a flat base portion, which is formed longitudinally in the mechanical direction; and a plurality of engaging elements, which are arranged on the upper surface of the base portion, in the Velcro, each of the engaging elements has: a rod portion, which stands up from the base portion; a engaging head portion, which is arranged at the top end of the engaging element and extends outward relative to the boundary portion between the engaging head portion and the rod portion; and at least one engaging portion, which protrudes from the outer peripheral portion of the engaging head portion, and when the Velcro is viewed from above, every 1 cm of the Velcro 2 The total area of ​​the engaging head is 10,000,000 μm 2 In the above, the tensile elastic modulus of the synthetic resin is 700 MPa or more and 2300 MPa or less.

[0014] In the hook and loop fastener of the present invention, preferably, the formation density of the engaging elements is 300 pieces / cm 2 above.

[0015] In addition, in the present invention, it is preferred that the base end portion of the locking portion is formed with a width smaller than 1 / 2 of the dimension of the boundary portion of the locking element in the direction orthogonal to the mechanical direction, the locking portion protrudes obliquely downward from the outer peripheral portion of the locking head toward the base portion, and the back side of the locking portion is inclined at an angle of less than 70° relative to the up and down direction of the Velcro.

[0016] Effects of the Invention

[0017] The hook and loop fastener of the present invention can stably ensure appropriate peel strength with respect to the loop member and can improve the touch to the skin compared to the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view showing a hook and loop fastener according to an embodiment of the present invention.

[0019] Figure 2 From the mechanical perspective Figure 1 A front view of the snap fastener elements shown.

[0020] Figure 3 It is used to manufacture Figure 1 Schematic diagram of a manufacturing device for Velcro shown.

[0021] Figure 4 It is schematically indicated Figure 3 The manufacturing apparatus shown is a perspective view of an outer cylindrical body and an inner cylindrical body arranged in a primary molding device.

[0022] Figure 5 It is a perspective view schematically showing a primary molded body molded in the primary molding step.

[0023] Figure 6 This is an explanatory diagram for explaining a friction test of a hook and loop fastener.

[0024] Figure 7 This is a diagram schematically showing a test piece used for a peel strength test of a hook and loop fastener.

[0025] Figure 8 This is an explanatory diagram for explaining a peel strength test.

[0026] Description of Reference Numerals

[0027] 1. Velcro; 10. Base; 20. Engagement element; 21. Engagement element array; 22. Rod; 23. Engagement head; 23a. Top end face of head; 23b. Side face of outer periphery of head; 23c. Back face of head; 24. Engagement claw (engagement part); 25. Boundary; 26. Imaginary vertical line; 30. Primary molded body; 31. Primary element; 32. Primary rod; 33. Rib; 34. Protrusion (primary engagement claw); 40. Manufacturing device; 50. Primary molding device; 51. Die wheel; 52. Outer cylindrical body (outer sleeve); 52a. Through hole; 53 , inner cylindrical body (inner sleeve); 53a, groove portion (recessed portion); 54, rotating drive roller; 55, supply nozzle portion; 56, pick-up roller; 57, upper clamping roller; 58, lower clamping roller; 60, heating and pressing device (secondary forming device); 61, upper pressing roller (calendering roller); 62, lower pressing roller (calendering roller), 70, friction test device; 71, workbench; 72, contact; 73, resin arm; 74, foam silicon plug; 75, detector; 81, first test piece; 82, second test piece; 83, cut piece; 84, supporting member; 85, non-woven fabric. DETAILED DESCRIPTION

[0028] Below, while referring to the attached Figure 1 Preferred embodiments of the present invention will be described.

[0029] Figure 1 It is a perspective view showing the hook and loop fastener according to the present embodiment. Figure 2 From the mechanical perspective Figure 1 A front view of the engaging element of the hook and loop fastener shown in FIG. Figure 1 and Figure 2 In order to clearly show the shape of the engaging element of the present embodiment, the hook and loop fastener is schematically shown. Therefore, when compared with the hook and loop fastener actually manufactured, there are cases where the dimensions and size are different.

[0030] In the following description, the front-back direction is the length direction of the hook and loop fastener formed in a longitudinal direction. In addition, the front-back direction is the direction along the machine direction MD in which the hook and loop fastener or the primary molded body is conveyed in the manufacturing process of the hook and loop fastener.

[0031] The left-right direction is a width direction perpendicular to the longitudinal direction and along the flat upper and lower surfaces of the base portion of the hook and loop fastener. In addition, the left-right direction and the width direction are directions along the orthogonal direction CD perpendicular to the machine direction MD.

[0032] The up-down direction is a height direction along a direction perpendicular to the upper surface and the lower surface of the base, or a thickness direction of the base, and is also a direction perpendicular to the front-back direction and the left-right direction. In the up-down direction, the direction of the side of the engaging element protruding relative to the base is set as the upper side, and the opposite direction is set as the lower side.

[0033] The hook and loop fastener 1 of this embodiment uses a hook and loop fastener having a Figure 3 The manufacturing device 40 of the primary forming device 50 and the heating pressing device (secondary forming device) 60 shown in the figure is manufactured lengthwise along the machine direction MD of the manufacturing device 40 when the hook and loop fastener 1 is viewed from above. In addition, the length dimension (the dimension on the machine direction MD) and the width dimension (the dimension on the orthogonal direction CD) of the hook and loop fastener 1 are not particularly limited and can be arbitrarily changed by cutting the hook and loop fastener 1, etc.

[0034] The hook and loop fastener 1 of the present embodiment is formed by a thermoplastic resin having a tensile modulus of more than 700MPa and less than 2300MPa. In this case, as the synthetic resin forming the hook and loop fastener 1, thermoplastic resins such as polyolefin resin, polyamide resin, polyester resin, PVC resin, ABS resin or their copolymers can be adopted. In addition, in the present invention, the synthetic resin forming the hook and loop fastener 1 is not particularly limited as long as it possesses the tensile modulus of the above-mentioned scope.

[0035] Velcro 1 has a thinner flat plate-like base 10 and a plurality of mushroom-shaped engaging elements 20 arranged on the upper surface of the base 10. The base 10 is formed longer along the machine direction MD when manufacturing Velcro 1. In addition, the base 10 has a predetermined thickness that can obtain appropriate intensity. The base 10 has a flat upper surface (the 1st face) and is configured at the flat lower surface (the 2nd face) on the opposite side of the upper surface. The upper surface of the base 10 is formed parallel to the lower surface.

[0036] A plurality of engaging elements 20 are regularly arranged in a sawtooth configuration pattern and are arranged on the upper surface of the base 10. Specifically, the engaging elements 20 are arranged at a certain spacing (interval) along the front-to-back direction to form a row of engaging elements 20. A plurality of engaging element 20 rows are arranged at a certain interval in the left-right direction. A plurality of engaging elements 20 are arranged alternately or arranged in a sawtooth configuration pattern in a sawtooth shape between the rows of engaging elements 20 adjacent to each other along the left-to-right direction, with the positions of the engaging elements 20 being staggered by 1 / 2 spacing in the front-to-back direction. In addition, in the present invention, the configuration of the engaging elements 20 is not particularly limited. For example, a plurality of engaging elements 20 may also be arranged in a lattice configuration pattern arranged in the front-to-back direction and the left-to-right direction, or may be arranged randomly.

[0037] Each engaging element 20 includes a rod portion 22 rising from the base portion 10 , an engaging head portion 23 provided on the rod portion 22 , and two engaging claw portions (engaging portions) 24 protruding outward from the outer periphery of the engaging head portion 23 .

[0038] The rod portion 22 is formed so as to extend in a direction perpendicular to the upper surface of the base portion 10. The rod portion 22 has a truncated cone or a substantially truncated cone shape in which the area of ​​the cross section perpendicular to the up-down direction increases as it approaches the base portion 10. Here, the substantially truncated cone refers to a shape close to a truncated cone. In addition, in the present invention, the shape of the rod portion 22 is not limited, and it can also be formed into a prism such as a quadrangular pyramid, a cylinder, or a prism such as a quadrangular prism, or a shape close to them.

[0039] The engaging head 23 is formed integrally with the rod 22 by means of the boundary 25 on the rod 22. In this case, the boundary 25 between the rod 22 and the engaging head 23 can also be referred to as the upper end of the rod 22. The engaging head 23 forms the top end of the engaging element 20, and has a shape extending from the entire circumference of the boundary 25 toward the outer side in the radial direction of the engaging head 23. The engaging head 23 has a disc-like or dish-like shape. Specifically, the thickness dimension (dimension in the up-down direction) of the engaging head 23 is relatively small, and it is circular when the engaging element 20 is viewed from the top.

[0040] like Figure 2 As shown, the engaging head 23 has: a top end surface 23a of the head, which faces upward; a back end 23c of the head, which extends from the boundary portion 25 between the engaging head 23 and the rod portion 22 toward the outside in the radial direction; and a peripheral side surface 23b of the head, which is continuously formed from the peripheral portion of the top end surface 23a of the head to the peripheral portion of the back end 23c of the head.

[0041] The head top surface 23a of the engaging head 23 includes a flat surface arranged parallel to the upper surface of the base portion 10. The head back surface 23c is arranged on the opposite side of the head top surface 23a in the vertical direction so as to face the base portion 10. The head peripheral side surface 23b is formed in a curved surface shape that curves from the head top surface 23a toward the head back surface 23c toward the radial outer side of the engaging head 23 except for the portion where the engaging claw portion 24 is formed.

[0042] Each engaging element 20 is provided with a pair of left and right tiny engaging claws 24 protruding outward from the outer peripheral portion of the engaging head 23. The left and right engaging claws 24 are arranged in a point-symmetrical positional relationship with each other when the engaging element 20 is viewed from above, and protrude from the engaging head 23 toward the outer side in the radial direction of the engaging head 23. In particular, in the case of the present embodiment, the left and right engaging claws 24 protrude in opposite directions from the central portion of the engaging head 23 in the machine direction MD along the left-right direction (diameter direction CD) to each other.

[0043] like Figure 2 As shown, each of the left and right engaging claws 24 has a shape that protrudes obliquely downward from the outer periphery of the engaging head 23 so as to approach the base portion 10. The engaging claw 24 has a base end portion connected to the engaging head 23 and a top end portion arranged on the side opposite to the base end portion in the protruding direction of the engaging claw 24. The engaging claw 24 is formed with a small size that is smaller than 1 / 2 of the size of the boundary 25 in the orthogonal direction CD when the engaging element 20 is viewed from the machine direction MD, preferably smaller than 1 / 3, and more preferably smaller than 1 / 5. In addition, the claw width size at the base end portion of the engaging claw 24 refers to the maximum value of the size of the base end portion of the engaging claw 24 in the circumferential direction of the engaging head 23.

[0044] In the front view ( Figure 2 ), the engaging claw portion 24 has a claw upper surface facing upward and a claw back surface facing the base portion 10. The claw back surface is arranged on the opposite side of the claw upper surface in the vertical direction in the engaging claw portion 24. The claw back surface of the engaging claw portion 24 is formed in such a way that the inclination angle θ of the claw back surface relative to the imaginary vertical line 26 along the vertical direction when viewed from above becomes less than 70°. In addition, at this time, the claw upper surface is located at a position lower than the upper surface of the engaging head portion 23.

[0045] The inclination angle θ of the claw back is less than 70°, so that when the hook of the ring member (not shown) is hooked on the engaging element 20 of the hook and loop fastener 1 and the hook and loop member are engaged, the ring of the ring member can be stably held on the engaging claw portion 24. Moreover, the hooked ring can be difficult to be disengaged from the engaging claw portion 24.

[0046] In addition, the angle of inclination θ of the claw back side is below 70 °, thus can suppress the skin feel of Velcro 1 caused by the setting of the engaging claw portion 24 and reduce. If specifically described, then newly confirm that the skin feel when people's skin contacts the upper surface of Velcro 1 (the face of one side of the Velcro 1 that is configured with the engaging element 20) and the friction coefficient of the upper surface of Velcro 1 have a correlation as discussed later. For such a correlation, the angle of inclination θ of the claw back side is below 70 ° as mentioned above, thus the claw upper surface is located at a position lower than the upper surface of the engaging head 23, and the friction coefficient of the upper surface of Velcro 1 can be suppressed to increase due to the setting of the engaging claw portion 24. Therefore, Velcro 1 can be easy to possess smooth and good skin feel.

[0047] On the other hand, the inclination angle θ of the claw back of the engaging claw 24 is preferably 10° or more. When the inclination angle θ is 10° or more, the ring of the ring member can easily enter the back side of the engaging claw 24 and the ring can be easily hooked on the engaging claw 24.

[0048] The hook and loop fastener 1 of the present embodiment is formed so that when the hook and loop fastener 1 is viewed from above, the hook and loop fastener 1 has a thickness of 1 cm. 2 The total area of ​​the engaging head 23 is 10,000,000 μm 2 Above, preferably 16,000,000 μm 2 That is, in this embodiment, the hook and loop fastener 1 is arranged at every 1 cm 2 The total area of ​​the engaging head 23 of each engaging element 20 confirmed when the hook and loop fastener 1 is viewed from above is 10,000,000 μm 2 above.

[0049] The total value of the area of ​​the engaging head 23 of the engaging element 20 includes the value of the area of ​​the engaging head 23 disposed per 1 cm. 2 The area of ​​the engaging head 23 of each engaging element 20 is calculated and the value obtained by summing up the areas of each engaging element 20. In addition, the sum value also includes, for example, a value obtained by calculating the average area of ​​the engaging head 23 for a plurality of engaging elements 20 and summing the average area with the area of ​​the engaging head 23 arranged every 1 cm. 2The number of the engaging elements 20 (that is, the formation density of the engaging elements 20) multiplied each other and the value obtained.The area of ​​the engaging head 23 of each engaging element 20 for example can be obtained according to the image data that obtains by shooting the hook and loop fastener 1 from the upper side.In addition, when the engaging head 23 of the engaging element 20 is circular or oval when looking down on the hook and loop fastener 1, the area of ​​each engaging head 23 also can be calculated according to the diameter of each engaging head 23.

[0050] Furthermore, in the present invention, in order to make every 1 cm of the hook and loop fastener 1 2 The total area of ​​the engaging head 23 is set to 10,000,000 μm 2 The above may also be, for example, a method in which the Velcro 1 is formed by reducing the area of ​​the engaging head 23 in one engaging element 20 but increasing the formation density of the engaging element 20, or a method in which the Velcro 1 is formed by reducing the formation density of the engaging element 20 but increasing the area of ​​the engaging head 23 in one engaging element 20.

[0051] In this embodiment, by configuring every 1 cm 2 The total area of ​​the engagement head 23 of the engagement element 20 is increased to 10,000,000 μm as described above. 2 For example, when measuring the friction coefficient of the upper surface of the hook and loop fastener 1 using such a friction test device discussed later, it is easy to smoothly move the contact of the friction test device relative to the upper surface of the hook and loop fastener 1. Thus, the variation of the friction coefficient of the hook and loop fastener 1 measured by the friction test device can be reduced.

[0052] Wherein, the relation between the skin feel of Velcro and the friction coefficient is described.For the skin feel of the upper surface side of the configuration with a plurality of engaging elements in Velcro and the friction coefficient of the upper surface side of Velcro, various experiments, investigations and researches etc. have been carried out, and as a result, there is a correlation between the variation of the friction coefficient when the skin feel obtained by rubbing the upper surface side of Velcro relative to the skin of the subject and the friction coefficient of the upper surface of Velcro 1 when the subject cannot see the position and the friction coefficient of the upper surface is measured and becomes clear. That is, for various Velcro, the quality of the skin feel felt by the subject and the friction coefficient measured in each Velcro are compared, and the result confirms that there is following tendency: the Velcro that makes a lot of subjects feel good skin feel more, the variation of the friction coefficient measured is less (specifically, the variation of the friction coefficient becomes below 0.06), the Velcro that feels the poorer skin feel more, the variation of the friction coefficient measured is greater.

[0053] Therefore, in the hook and loop fastener 1 of the present embodiment, 2 The total area of ​​the engagement head 23 of the engagement element 20 is 10,000,000 μm as described above.2 As described above, the variation in the friction coefficient of the surface fastening tape 1 can be suppressed to be small, and therefore, the user who touches the surface fastening tape 1 can easily feel a good skin touch.

[0054] On the other hand, in the hook and loop fastener 1 of the present embodiment, the 2 The total area of ​​the engagement head 23 of the engagement element 20 is preferably 50,000,000 μm 2 Less than, and more preferably 35,000,000 μm 2 By making every 1cm 2 The total area of ​​the engaging head 23 is 50,000,000 μm 2 Next, an appropriate gap into which the loop of the ring member can be inserted can be easily ensured between two adjacent engagement elements 20. Thus, when the hook and loop fastener 1 and the loop member are superimposed, the loop of the ring member and the engagement elements 20 of the hook and loop fastener 1 can be stably engaged.

[0055] In this embodiment, the formation density of the engaging elements 20 in the hook and loop fastener 1 is 300 pieces / cm 2 More than 400 pieces / cm 2 The density of the engagement elements 20 is 300 pieces / cm 2 As described above, it is possible to easily arrange the 2 The total area of ​​the engagement head 23 of the engagement element 20 is set to 10,000,000 μm 2 Thereby, the touch feeling of the hook and loop fastener 1 on the skin can be easily improved.

[0056] Furthermore, in the present embodiment, as described above, the synthetic resin forming the hook and loop fastener 1 has a tensile elastic modulus of 700 MPa or more and 2300 MPa or less.

[0057] The tensile elastic modulus of synthetic resin is more than 700MPa, and thus the engaging element 20 can properly possess rigidity (strength).Therefore, the peel strength of Velcro 1 relative to the ring member can be improved.In addition, in the manufacturing process of Velcro 1, when heating and pressing the primary element 31 in the secondary forming process discussed subsequently, it is possible to suppress the rapid deformation produced in the primary element 31 due to pressing, making the shape of the engaging element 20 stable.

[0058] The tensile elastic modulus of the synthetic resin is below 2300 MPa, so that the primary element 31 can be deformed appropriately and quickly in the secondary molding process. As a result, a relatively thin disc-shaped engaging head 23 can be stably formed, and the engaging claw portion 24 with an inclination angle θ of the claw back being below 70° can be stably arranged on the engaging head 23. Therefore, the hook and loop fastener 1 can easily have a higher peel strength relative to the ring member, and can also easily have a good skin touch.

[0059] Next, a method for producing the hook and loop fastener 1 of the above-described embodiment will be described.

[0060] use Figure 3 The manufacturing device 40 shown is used to manufacture Figure 1 and Figure 2 The manufacturing device 40 includes a primary molding device 50 that performs a primary molding step and a heating and pressing device (secondary molding device) 60 that performs a secondary molding step of pressing and molding the primary molded body 30 molded in the primary molding step.

[0061] The primary molding device 50 comprises: a mold wheel 51 driven to rotate in one direction (counterclockwise in the accompanying drawing); a supply nozzle portion 55, which is arranged opposite to the circumferential surface of the mold wheel 51 and continuously supplies molten synthetic resin material; and a pick-up roller 56, which is arranged at a position downstream of the supply nozzle portion 55 in the rotation direction of the mold wheel 51.

[0062] The mold wheel 51 includes: a cylindrical outer cylindrical body (outer sleeve) 52 that serves as a mold; a cylindrical inner cylindrical body (inner sleeve) 53 that is disposed inside the outer cylindrical body 52 in a manner that is in close contact with the outer cylindrical body 52; and a rotating drive roller 54 that rotates the outer cylindrical body 52 and the inner cylindrical body 53 in one direction. A cooling jacket (not shown) that allows a coolant to flow is provided inside the rotating drive roller 54.

[0063] The outer cylindrical body 52 has a plurality of through holes 52a extending from the outer circumferential surface to the inner circumferential surface thereof, which are formed as cavities for forming the primary rod portion 32, which will be discussed later, of the primary molded body 30. Each through hole 52a has a truncated cone or substantially truncated cone shape in which the circular shape of the outer circumferential surface of the outer cylindrical body 52 is formed larger than the circular shape of the inner circumferential surface of the outer cylindrical body 52.

[0064] A plurality of grooves (recesses) 53a are formed on the outer circumferential surface of the inner cylindrical body 53. Each groove 53a is provided in a straight line along a direction (orthogonal direction CD) parallel to the central axis of the inner cylindrical body 53, and is provided in a size that allows the melted synthetic resin to flow in. The grooves 53a are formed at regular intervals along the circumferential direction (machine direction MD) of the inner cylindrical body 53. In addition, at least a portion of the grooves 53a of the inner cylindrical body 53 is provided so as to intersect with the outer circumferential edge of the through hole 52a formed on the inner circumferential surface of the outer cylindrical body 52 when the die wheel 51 is attached.

[0065] In addition, in the present invention, the material and size of the outer cylindrical body 52 and the inner cylindrical body 53, as well as the method of forming them, are not particularly limited. In addition, a plurality of recessed portions having shapes and sizes different from those of the recessed groove portion 53a may be provided on the outer peripheral surface of the inner cylindrical body 53. Furthermore, the mold wheel 51 may not include the inner cylindrical body 53, and the outer cylindrical body 52 may be directly attached to the rotating drive roller 54. In this case, it is preferred that a recessed portion connected to the outer peripheral edge of the through hole 52a is provided on the inner peripheral surface of the outer cylindrical body 52 or on the surface of the rotating drive roller 54 in contact with the outer cylindrical body 52.

[0066] The pickup roller 56 includes a pair of upper clamping rollers 57 and lower clamping rollers 58 that clamp and pull the primary molded body 30 formed by the outer peripheral surface of the mold wheel 51 from above and below. The outer peripheral surface of each of the upper clamping roller 57 and the lower clamping roller 58 is provided with a surface layer (not shown) formed of an elastic body such as a polyurethane elastomer.

[0067] The heating and pressing device 60 includes a pair of upper and lower pressing rollers (calendering rollers) 61 and 62 arranged downstream of the pickup roller 56. The upper pressing roller 61 and the lower pressing roller 62 are arranged opposite to each other with a predetermined interval therebetween. The interval between the upper pressing roller 61 and the lower pressing roller 62 can be adjusted by a height adjustment member (not shown).

[0068] The upper pressing roller 61 is provided with a heat source (not shown) inside, and is formed so that the surface temperature (heating temperature) of the upper pressing roller 61 can be controlled, that is, the heating temperature of the upper pressing roller 61 can be set to a desired temperature. In addition, in the present invention, the structure of the heating pressing device 60 is not particularly limited as long as it has the upper pressing roller 61 that contacts the primary element 31 discussed later of the primary molded body 30 and heats and presses at least a part of the primary element 31.

[0069] When the hook and loop fastener 1 is manufactured using the manufacturing device 40 having the above-mentioned primary molding device 50 and the heating and pressing device 60, first, the primary molding process of molding the primary molded body 30 is performed using the primary molding device 50. In this primary molding process, the molten thermoplastic resin is continuously supplied from the supply nozzle portion 55 toward the outer peripheral surface of the rotating mold wheel 51. At this time, as the thermoplastic resin supplied from the supply nozzle portion 55 to the mold wheel 51, as described above, a synthetic resin with a tensile elastic modulus of more than 700MPa and less than 2300MPa is used.

[0070] The base portion 10 is continuously formed along the machine direction MD between the supply nozzle portion 55 and the die wheel 51 by supplying the molten synthetic resin from the supply nozzle portion 55 to the die wheel 51. In addition, the base portion 10 is molded, and the plurality of primary elements 31 are integrally molded on the base portion 10 by the outer cylindrical body 52 and the inner cylindrical body 53 of the die wheel 51.

[0071] In addition, the primary molding device can also be formed by, for example, supplying molten synthetic resin material from a supply nozzle portion toward the gap between two opposing die wheels. In this case, the base portion 10 is formed between a pair of die wheels, and the primary element 31 is formed in a cavity provided in one of the die wheels.

[0072] The primary molded body 30 formed by the primary molding device 50 has a base 10 and a plurality of primary elements 31 protruding from the upper surface of the base 10. The base 10 of the primary molded body 30 directly becomes the base 10 of the Velcro 1. The primary element 31 is deformed into the engaging element 20 by pressing and molding in the secondary molding process. Each primary element 31 has: a truncated cone or roughly truncated cone-shaped primary rod portion 32, which stands up from the base 10; a rod-shaped rib 33, which bulges upward from the upper surface of the primary rod portion 32; and two protrusions (primary engaging claws) 34, which are formed integrally with the rib 33 and protrude to the outside of the primary rod portion 32.

[0073] The primary element 31 may not include the rod-shaped rib 33 bulging upward from the upper surface of the primary rod 32. In this case, the primary element 31 includes two protrusions (primary engagement claws) 34 protruding outward from the outer peripheral edge of the primary rod 32 at the upper end of the primary rod 32.

[0074] In the primary molding process, the synthetic resin flows from the through hole 52a of the outer cylindrical body 52 into the groove 53a provided in the inner cylindrical body 53, and enters the portion beyond the through hole 52a along the groove 53a, thereby molding the rib 33 and the protrusion 34 of the primary element 31. In this case, the rib 33 is partially formed along the orthogonal direction CD on the upper surface of the primary rod part 32. The two protrusions 34 protrude from both ends of the rib 33 toward the outside in the left-right direction.

[0075] In the primary molding process, the molten synthetic resin is solidified by half-rotation while being cooled by the outer peripheral surface of the die wheel 51. Thus, the primary molded body 30 is formed. Thereafter, the primary molded body 30 is continuously torn off from the outer peripheral surface of the die wheel 51 by the pickup roller 56. At this time, the protrusion 34 of the primary molded body 30 is smoothly pulled out from the groove 53a of the inner cylindrical body 53 and the through hole 52a of the outer cylindrical body 52 while being elastically deformed.

[0076] Next, the primary molded body 30 torn off from the die wheel 51 is conveyed toward the heating and pressing device 60 for performing the secondary molding process, and introduced between the upper pressing roller 61 and the lower pressing roller 62 of the heating and pressing device 60. In this secondary molding process, the base portion 10 of the primary molded body 30 is supported from below by the lower pressing roller 62. In addition, by rotating the upper pressing roller 61 while bringing the upper pressing roller 61 into contact with the upper end of each primary element 31, at least the upper end of each primary element 31 is heated to a desired temperature by the upper pressing roller 61 to soften it, and the primary element 31 is pressed from above.

[0077] At this time, the synthetic resin forming the primary molded body 30 has a tensile elastic modulus of 700 MPa or more and 2300 MPa or less. Therefore, by heating and pressing each primary element 31 in the secondary molding process, the upper end of the primary rod portion 32, the rib 33, and the protrusion 34 in the primary element 31 can be appropriately thermally deformed in a short time. As a result, the engagement head 23 with a thin thickness and a flat surface formed on the upper surface and the tiny engagement claw 24 protruding obliquely downward from the engagement head 23 can be stably formed, thereby manufacturing Figure 1 and Figure 2 The hook and loop fastener 1 of the present embodiment is shown.

[0078] Afterwards, the manufactured hook and loop fastener 1 which is long in the machine direction is conveyed to a cutting portion (not shown) and cut into a predetermined length at the cutting portion for recycling. Alternatively, the hook and loop fastener 1 is directly rolled up on a recycling roll or the like while maintaining its long state for recycling.

[0079] In addition, in the present invention, the method and the manufacturing apparatus of the surface fastener 1 are not particularly limited.

[0080] In the hook and loop fastener 1 of the present embodiment manufactured as described above, the plurality of engaging elements 20 are arranged at 300 pieces / cm 2 In addition, the formation density is set at 10,000,000 μm. 2 The above size ensures that the configuration is within 1cm 2 The total area of ​​the engaging head 23 in more than 300 engaging elements 20. Thus, the change of the friction coefficient on the upper surface side of the hook and loop fastener 1 can be suppressed to be small, so when the hook and loop fastener 1 is contacted from the side where the engaging elements 20 are configured, it is easy to feel good skin touch.

[0081] Moreover, as described above, the Velcro 1 of the present embodiment is formed of a synthetic resin having a tensile elastic modulus of greater than 700 MPa and less than 2300 MPa, and therefore, two tiny engaging claws 24 protruding obliquely downward at an inclination angle of less than 70° toward the base 10 can be appropriately arranged on the outer periphery of the thinner and larger engaging head 23.

[0082] For example, in previous Velcro, when the total area of ​​the engaging head per unit area was increased, it was difficult to insert the engaging elements with larger engaging heads or the engaging elements arranged with a higher formation density deeply between the rings of the ring member when the Velcro was pressed against the ring member and engaged. As a result, there was a possibility that the peel strength (engagement strength) of the Velcro relative to the ring member was reduced.

[0083] In contrast, in the Velcro 1 of the present embodiment, the tensile elastic modulus of synthetic resin is in the predetermined range as described above, so that tiny engaging claws 24 can be properly arranged on the engaging head 23. Thus, the ring of the ring member can be hooked on the engaging claws 24 of each engaging element 20. In addition, the ring hooked on the engaging claws 24 can be difficult to disengage. Therefore, even if the total of the area of ​​the engaging head 23 per unit area in the Velcro 1 is increased as described above, the peel strength of the Velcro 1 suitable for use in disposable diapers, diaper pants, etc. can be easily ensured.

[0084] [Example]

[0085] Hereinafter, the present invention will be described in more detail with reference to Examples.

[0086] (Manufacture of Velcro)

[0087] As Examples 1 to 6 and Comparative Examples 1 to 4, the hook and loop fasteners 1 were each manufactured using the manufacturing apparatus 40 described in the above-mentioned embodiment.

[0088] Specifically, in Examples 1 to 6 and Comparative Examples 1 to 4, as the synthetic resin forming the hook and loop fastener 1, a primary molded body 30 was produced by performing a primary molding process performed by a primary molding device 50 using polypropylene having a tensile elastic modulus shown in Tables 1 and 2 below. Afterwards, the obtained primary molded body 30 was subjected to a secondary molding process performed by a heating and pressing device 60 to manufacture each of the hook and loop fasteners 1 of Examples 1 to 3. In addition, the polypropylene contains a homopolymer, a random copolymer, and a block copolymer.

[0089] In Examples 1 to 6 and Comparative Examples 1 to 4, each hook and loop fastener 1 was manufactured so that at least one of the area of ​​the engaging head 23 of each engaging element 20 and the formation density of the engaging elements 20 was different from each other.

[0090] (per 1cm 2 Determination of the total value of the area of ​​the engaging head)

[0091] For each Velcro 1 of the manufactured embodiments 1 to 6 and comparative examples 1 to 4, each Velcro 1 is photographed from the upper side to obtain image data, and the area of ​​the engaging head 23 of the Velcro 1 when viewed from above is obtained using the obtained image data. Specifically, the area of ​​the engaging head 23 of each engaging element 20 (for example, more than 10 engaging elements 20) of the Velcro 1 is measured by image analysis using the image data of the Velcro 1, and the average value of the area of ​​the engaging head 23 of one engaging element 20 is calculated.

[0092] Next, the image data described above is used to measure the thickness of each of the plurality of portions of each hook and loop fastener 1 per cm. 2 The formation density of the engaging elements 20 in the embodiment 1 to 6 and the formation density of the engaging elements 20 are calculated, and the average formation density is calculated. Furthermore, based on the product of the calculated average area of ​​the engaging head 23 and the average formation density of the engaging elements 20, the number of hook and loop fasteners 1 arranged per 1 cm is calculated for the embodiments 1 to 6 and the comparative examples 1 to 4. 2 The total value of the area of ​​the engaging head 23 of the engaging element 20. The calculation results are shown in Tables 1 and 2 below.

[0093] (Inclination angle θ of the back surface of the engaging claw portion)

[0094] For each Velcro 1 of the manufactured Examples 1 to 6 and Comparative Examples 1 to 4, the respective engaging elements 20 were photographed from one side (front side) of the machine direction MD. Furthermore, the inclination angle θ of the claw back of the engaging claw portion 24 was measured from the image of the photographed engaging element 20. For each Velcro 1, the values ​​of the measured inclination angle θ are superimposed on the following Tables 1 and 2 for representation.

[0095] (Measurement of Friction Coefficient Change)

[0096] use Figure 6 A friction test for measuring the friction coefficient was performed on each of the hook and loop fasteners 1 of Examples 1 to 6 and Comparative Examples 1 to 4 using a friction tester 70 shown in FIG.

[0097] The friction test device 70 has: a workbench 71, which is used to fix the hook and loop fastener 1 and is movable; a contact 72, which contacts the upper surface of the hook and loop fastener 1 provided with the engaging element 20; and a detector 75, which measures the friction between the hook and loop fastener 1 and the contact 72. The contact 72 has: a resin arm 73, which extends from the detector 75; and a foam silicon plug 74, which simulates human skin and is mounted on the resin arm 73. The foam silicon plug 74 is formed in a cylindrical shape, and the contact surface of the foam silicon plug 74 relative to the hook and loop fastener 1 is formed in a circular shape. The foam silicon plug 74 has a weight of more than 10g and less than 15g.

[0098] In the friction test, each Velcro 1 of Examples 1 to 6 and Comparative Examples 1 to 4 was cut into a size of 25 mm in the machine direction MD×45 mm in the orthogonal direction CD, and the cut pieces of the Velcro 1 were fixed to the workbench 71 of the friction tester using double-sided tape. At this time, the Velcro 1 was fixed to the workbench 71 in the direction in which the contact 72 of the friction tester moved on the Velcro 1 along the orthogonal direction CD. In addition, the contact 72 of the friction test device 70 was set on the Velcro 1 fixed on the workbench 71 in a well-balanced manner. At this time, the weight of the foam silicone plug 74 was applied to the Velcro 1 from the foam silicone plug 74.

[0099] The friction test device 70 moves the workbench 71 along the orthogonal direction CD of the hook and loop fastener 1 at a speed of 1 mm / sec under the state that the hook and loop fastener 1 and the contact 72 are set as described above, and the friction force when the workbench 71 moves is measured by the detector 75. In the measurement of the friction force this time, the moving distance of the workbench 71 is set to 30 mm. In the analysis, the moving distance is 5 mm to 25 mm. The data and the dynamic friction coefficient are obtained according to the measured friction force, and the change of the dynamic friction coefficient in the analysis interval is calculated.

[0100] The changes in the dynamic friction coefficient calculated for each Velcro 1 of Examples 1 to 6 and Comparative Examples 1 to 4 are shown in the following Tables 1 and 2. In this friction test, based on the results of investigation and research on the correlation between the skin feel of Velcro 1 and the change in the friction coefficient of Velcro 1, Velcro 1 with a change in the friction coefficient of 0.06 or less was evaluated as Velcro 1 that can obtain good skin feel.

[0101] (Determination of peel strength)

[0102] In the peel strength test, Figure 7As shown, each hook and loop fastener 1 of Examples 1 to 6 and Comparative Examples 1 to 4 was cut into a size of 25 mm in the machine direction MD×25 mm in the orthogonal direction CD, and the cut pieces 83 of the hook and loop fastener 1 were bonded to a supporting member 84 formed of a nonwoven fabric 85, thereby producing a first test piece 81 on the hook and loop fastener 1 side. In addition, a nonwoven fabric 85 having a larger size in the machine direction MD than the size in the machine direction MD of the cut piece 83 of the hook and loop fastener 1 was bonded to a supporting member 84, thereby producing a second test piece 82 on the ring member side.

[0103] Then, if Figure 8 As shown, the cut piece 83 of the hook and loop fastener 1 in the first test piece 81 is engaged with the second test piece 82. Moreover, the second test piece 82 is folded back into a U shape. Next, the first test piece 81 and the second test piece 82 are respectively held by a pair of unillustrated clamps, and then the pair of clamps holding the first test piece 81 and the second test piece 82 are moved away from each other at a certain speed. Thus, a load is gradually applied to the first test piece 81 and the second test piece 82 in the engaged state.

[0104] And, the integral average peeling force (N) is calculated from the force from the beginning of applying the load to the peeling of the first test piece 81 and the second test piece 82, and the value obtained by dividing the value of the integral average peeling force by the effective width (cm) of the hook and loop fastener 1 is set as the peeling strength (N / cm) of the hook and loop fastener 1. For each hook and loop fastener 1 of Examples 1 to 6 and Comparative Examples 1 to 4, such a peeling strength test is carried out for each plurality of hook and loop fasteners 1, and the average value of the measured peeling strength is calculated. The average value of the peeling strength calculated for each hook and loop fastener 1 is shown in the following Tables 1 and 2. In this peeling strength test, when the average value of the calculated peeling strength is more than 0.25N / cm, it is evaluated that the hook and loop fastener 1 has a higher peeling strength.

[0105]

Table 1

[0106]

[0107]

Table 2

[0108]

[0109] As shown in Table 1, in the configuration of every 1cm 2 The total area of ​​the engaging head 23 of the engaging element 20 is 10,000,000 μm 2 In the surface fasteners 1 of Examples 1 to 6 described above, the fluctuation of the dynamic friction coefficient in the friction test was a small value of 0.06 or less. Therefore, it was confirmed that the surface fastener 1 had a good feel to the skin.

[0110] In the Velcro 1 of Examples 1 to 6 formed of polypropylene having a tensile elastic modulus of 700 MPa or more and 2300 MPa or less, it was confirmed that the engaging element 20 was stably formed with the inclination angle θ of the back side of the engaging claw portion 24 being 70° or less. In addition, the Velcro 1 of Examples 1 to 6 had a relatively high peel strength with an average value of more than 0.25 N / cm. In particular, in the Velcro 1 of Example 1, although the average area of ​​the engaging head 23 of each engaging element 20 was as large as 80,000 μm 2 , but it was confirmed that a higher peel strength could be obtained.

[0111] On the other hand, in the hook and loop fasteners of Comparative Examples 1 to 3, the formation density of the engaging elements was 300 pieces / cm 2 Small, configured in every 1cm 2 The total area of ​​the engaging head of the engaging element is greater than 10,000,000 μm 2 Therefore, in each of the hook and loop fasteners of Comparative Examples 1 to 3, the variation of the dynamic friction coefficient in the friction test was larger than 0.06, and a good skin feel could not be obtained.

[0112] The hook and loop fastener of Comparative Example 4 is formed of polypropylene having a tensile elastic modulus of less than 700 MPa. Therefore, the hook and loop fastener of Comparative Example 4 has a hook and loop fastener having a hook back surface with an inclination angle θ greater than 70°. Thus, in Comparative Example 4, the hook and loop fastener is arranged at every 1 cm 2 Although the total area of ​​the engaging head of the engaging element is 10,000,000 μm 2 However, the variation of the dynamic friction coefficient in the friction test was larger than 0.06, and a good skin touch could not be obtained. This is believed to be because the engaging claw portion having an inclination angle θ larger than 70° affected the skin touch of the hook and loop fastener.

[0113] In the fastener of Comparative Example 4, the inclination angle θ was larger than 70°, and therefore the average value of the peel strength was extremely small at 0.16 N / cm, indicating that a peel strength suitable for use in disposable diapers, diaper pants, etc. could not be obtained.

[0114] The present invention is not limited to the above-described embodiments and examples, and various modifications are possible as long as the present invention has substantially the same configuration and exhibits the same functions and effects.

[0115] For example, in the above-mentioned embodiment, Figure 2As shown, a pair of left and right tiny engagement claws 24 are provided on the engagement head 23 of the engagement element 20. However, in the present invention, the shape of the engagement element is not particularly limited as long as the engagement element has an engagement portion such as a rod portion, an engagement head portion, and at least one engagement claw portion protruding from the outer periphery of the engagement head portion.

[0116] For example, in the present invention, the small left and right engaging claws of the engaging element 20 may also be arranged at positions different from those in the above-mentioned embodiment. That is, the engaging element of the present invention includes, for example, an engaging element in which the left and right engaging claws are arranged at positions deviated forward or backward from the central part of the mechanical direction MD in the engaging head, or an engaging element in which four engaging claws are arranged in one engaging head.

[0117] In addition, in the manufacturing device 40 of the Velcro 1 of the present embodiment, due to the influence of the processing accuracy when making the outer cylindrical body 52 and the inner cylindrical body 53 of the primary forming device 50, the setting position of the through hole 52a arranged at the outer cylindrical body 52 and the setting position of the groove portion 53a arranged at the inner cylindrical body 53 are sometimes deviated in the mechanical direction. If considering this point, in the Velcro 1 of the present embodiment, the engaging element 20 with two tiny engaging claws 24 on the left and right is included in at least one part of the multiple engaging elements 20 provided in one base 10, preferably included in more than 10%, and further preferably included in more than 20%.

[0118] In this case, the engaging element 20 provided on one base portion 10 includes, in addition to the Figure 2 In addition to the locking element 20 of the shape shown, for example, the following locking elements may also be included: a locking element in which the left and right locking claws are arranged at a position deviated forward or backward from the central part of the mechanical direction MD in the locking head; a locking element in which four tiny locking claws are arranged in one locking head; a locking element in which the formation of the locking claws cannot be clearly determined; and a locking element in which no locking claws are arranged on the locking head.

Claims

1. A hook and loop fastener, which is a hook and loop fastener (1) made of synthetic resin, comprising: a flat base portion (10) formed longitudinally in a machine direction (MD); and a plurality of engaging elements (20) arranged on the upper surface of the base portion (10), wherein the hook and loop fastener (1) is characterized in that: Each of the engaging elements (20) comprises: a rod portion (22) which stands upright from the base portion (10); an engaging head portion (23) which is arranged at the top end of the engaging element (20) and protrudes outward relative to a boundary portion (25) between the engaging head portion (23) and the rod portion (22); and at least one engaging portion (24) which protrudes from the outer periphery of the engaging head portion (23). When the hook and loop fastener (1) is viewed from above, each 1 cm of the hook and loop fastener (1) 2 The total area of ​​the engaging head (23) is 10,000,000 μm 2 above, The synthetic resin has a tensile elastic modulus of 700 MPa or more and 2300 MPa or less.

2. The hook and loop fastener according to claim 1, characterized in that: The formation density of the engaging elements (20) is 300 pieces / cm 2 above.

3. The hook and loop fastener according to claim 1, characterized in that: The base end of the engaging portion (24) is formed to have a width smaller than half of the dimension of the boundary portion of the engaging element (20) in a direction perpendicular to the machine direction. The engaging portion (24) protrudes obliquely downward from the outer peripheral portion of the engaging head portion (23) toward the base portion (10). The back surface of the engaging portion (24) is inclined at an angle (θ) of 70° or less relative to the vertical direction of the hook and loop fastener (1).

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