Elastic knitted fabric pre-cutting and breaking device for disposable pant production

Abstract

The present application relates to the elastic knitted fabric pre-cutting breaking device of disposable pants production, to solve the technical problem that the elastic knitted fabric is easy to be stretched as a whole when being broken. The breaking roller includes the upper and lower pulling rollers arranged in parallel with the axis, and the upper and lower pulling rollers rotate at the same speed. The tensioning mechanism includes the fixed clamp and the movable clamp arranged protruding on the outer circumferential surface of the upper and lower pulling rollers, the fixed clamp and the movable clamp are respectively used for clamping on both sides of the point breaking line of the elastic knitted fabric, the fixed clamp is arranged in close contact with the movable clamp, the fixed clamp includes two fixed clamping strips and is respectively fixed on the upper and lower pulling rollers, the movable clamp includes two movable clamping strips, the movable clamping strips are respectively connected with the cylinder mechanism, the cylinder mechanism is respectively installed in the upper and lower pulling rollers, and the cylinder mechanism can drive the two movable clamping strips to displace towards the direction away from the fixed clamp, so as to break the elastic knitted fabric from the point breaking line.

Description

Technical Field

[0001] This invention relates to a device for tearing elastic knitted fabric after pre-cutting in the production of disposable underwear. Background Technology

[0002] In the automated production process of disposable underwear, the elastic knitted fabric needs to be pre-cut at the break points. Then, the upper and lower layers of non-woven elastic fabric are bonded to the elastic knitted fabric using hot melt adhesive. To facilitate the subsequent ultrasonic fusion of the two layers, the elastic knitted fabric needs to be pulled apart from the break points to prevent it from interfering with the fusion of the upper and lower layers. The pulled-out state is as follows... Figure 1 As shown, existing technologies generally involve stretching the elastic knitted fabric as a whole, which causes the elastic knitted fabric to stretch and deform in all parts. This leads to the following two problems: First, the overall stretching will reduce the stretch rate at the point of breakage of the elastic knitted fabric. If it is to be ensured that it breaks, the elastic knitted fabric will exceed the deformation limit, resulting in unevenness after shrinkage. Second, the non-woven elastic fabric and the elastic knitted fabric are bonded with hot melt adhesive, which may be torn by external force. Summary of the Invention

[0003] The purpose of this invention is to provide a tearing device for pre-cut elastic knitted fabric in the production of disposable underwear, so as to solve the technical problem that elastic knitted fabric is easily stretched as a whole when it is cut.

[0004] The technical solution of this invention is as follows: A tearing device for pre-cutting elastic knitted fabric used in the production of disposable underwear includes: The pull rollers are designed to break apart, including an upper pull roller and a lower pull roller with their axes parallel to each other, and the upper and lower pull rollers rotate at the same speed relative to each other. The tensioning mechanism includes a fixed clamp and a movable clamp protruding from the outer circumference of the upper and lower pull rollers. The fixed clamp and the movable clamp are used to clamp the elastic knitted fabric on both sides of the break line. The fixed clamp and the movable clamp are fitted together. The fixed clamp includes two fixed clamping strips and is symmetrically fixed on the upper and lower pull rollers respectively. The movable clamp includes two movable clamping strips. The movable clamping strips are symmetrically connected to a cylinder mechanism. The cylinder mechanism is installed inside the upper and lower pull rollers respectively. The cylinder mechanism can drive the two movable clamping strips to move away from the fixed clamp to pull the elastic knitted fabric off at the break line.

[0005] Based on the above scheme, further improvements are made as follows: the cylinder mechanism includes a cylinder and a slider mechanism. The cylinder body is hinged to the corresponding upper and lower pull rollers, and the cylinder telescopic rod is hinged to the corresponding movable clamping bar. The slider mechanism includes a slider and a slide rail. The slide rail is fixed on the corresponding upper and lower pull rollers respectively. The lower end of the slider is hinged to the corresponding movable clamping bar through a connecting rod. The two hinge points of the movable clamping bar with the telescopic rod and the connecting rod are located on both sides of the width direction of the movable clamping bar. After the cylinder is started, it can drive the movable clamping bar to achieve a composite motion of linear and rotational movement.

[0006] Based on the above scheme, further improvements are made as follows: Limiting pinions are rotatably mounted at the ends of the two movable clamping bars. Correspondingly, a cylindrical surface coaxial with the limiting pinions is provided on the outer surface of the movable clamping bars. The cylinder mechanism is activated simultaneously when the two limiting pinions disengage. Since the cylinder does not guarantee synchronized movement, the limiting pinions, by providing them, will still engage and transmit power as the movable clamping bars move, thus limiting their positions and ensuring that the movement of the movable clamping bars is as synchronized as possible.

[0007] Based on the above solution, the following further improvement is made: the outer surface of the fixed clamping bar and / or the movable clamping bar is made of an elastic material. This allows for a tighter clamping and also enables error compensation.

[0008] Based on the above scheme, the following improvements are made: the outer surface of the fixing clip is an arc-shaped surface, which is coaxial with the corresponding cylindrical upper or lower pull roller. Since the fixing clip rotates with the relatively rotating upper and lower pull rollers, the above arrangement ensures that the extrusion pressure is always the same when the two are in contact.

[0009] Based on the above scheme, the following improvement is made: the outer periphery of the movable clamping strip is an arc-shaped surface.

[0010] Based on the above scheme, the following improvements are made: two sets of synchronously moving cylinder mechanisms are respectively installed in the upper and lower pull rollers, and the two sets of cylinder mechanisms are arranged symmetrically along the axial direction of the upper and lower pull rollers.

[0011] Based on the above scheme, the following improvements are made: the upper and lower pull rollers are provided with radially penetrating V-shaped grooves, and the cylinder mechanism is installed in the V-shaped grooves.

[0012] Based on the above scheme, the following improvements are made: the ends of the upper and lower pull rollers are driven by meshing transmission gears.

[0013] Based on the above scheme, the following improvements are made: the movable clamping strip includes a metal plate and a rubber layer vulcanized on the outside of the metal plate. Bolt holes are provided at both ends of the metal plate for connecting to the corresponding upper and lower pull rollers by bolts.

[0014] The beneficial effects of this technical solution: When using the pre-cut elastic knitted fabric tearing equipment for disposable underwear production, the pre-cut elastic knitted fabric passes between the upper and lower pull rollers. As the elastic knitted fabric moves, the upper and lower pull rollers also rotate synchronously at the same speed. When the pre-cutting point is located between the axes of the upper and lower pull rollers, the fixed clamp and the movable clamp also move to this point along with the corresponding upper and lower pull rollers. The fixed clamp and the movable clamp are just clamped on the front and rear sides of the pre-cutting point. At this time, after the cylinder mechanism is started, it drives the movable clamp to move away from the fixed clamp. Since the movable clamp and the fixed clamp themselves rotate with the upper and lower pull rollers, and the movement displacement generated by the cylinder mechanism is a relative displacement relative to the fixed clamp, this relative displacement can drive the small area on both sides of the pre-cutting point to stretch, thereby causing it to break at the pre-cutting point. Therefore, it can be seen that, compared with the prior art, the solution of this application does not stretch the elastic knitted fabric as a whole from both ends, but only stretches it in a small area on both sides of the pre-cutting point. This ensures that most areas of the elastic knitted fabric will not be stretched and deformed, thereby avoiding problems such as reduced stretch rate at the cut point, uneven shrinkage of the elastic knitted fabric when it reaches the deformation limit, and cracking at the bonding joint between the non-woven elastic fabric and the elastic knitted fabric. Attached Figure Description

[0015] Figure 1 This is a longitudinal cross-sectional view of the combined structure of elastic knitted fabric and non-woven elastic fabric described in the background art of this invention after being broken. Figure 2 A three-dimensional structural schematic diagram of a specific embodiment of the tearing device for pre-cutting elastic knitted fabric in the production of disposable underwear according to the present invention; Figure 3 This is a schematic diagram illustrating the working principle of the pull-off device; Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 A three-dimensional view of the transverse section at the V-groove; Figure 6 A perspective view of the mating point between the fixed and movable clamps; Figure 7 This is a three-dimensional view of the end of the pull-down roller; In the diagram: 1-Non-woven elastic fabric, 2-Elastic knitted fabric, 21-Break point, 3-Frame, 4-Pressure roller, 5-Break roller pair, 51-Upper pull roller, 52-Lower pull roller, 53-Fixed clamp, 531-Upper fixed clamping bar, 532-Lower fixed clamping bar, 54-Modible clamp, 541-Upper movable clamping bar, 542-Lower movable clamping bar, 5421-Metal plate, 5422-Bolt hole, 5423-Rubber layer, 543-Upper limit pinion, 544-Lower limit pinion, 55-Cylinder mechanism, 551-Cylinder, 5511-Cylinder body, 5512-Telescopic rod, 552-Slider mechanism, 5521-Slider, 5522-Slide rail, 5523-Connecting rod, 553-Hinge shaft, 56-Transmission gear, 57-V-groove. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0018] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0020] A specific embodiment of the tearing device for pre-cutting elastic knitted fabric in the production of disposable underwear according to the present invention: as follows Figure 2-7 As shown, the tearing equipment for pre-cut elastic knitted fabric in disposable underwear production includes a frame 3, a pressing roller 4, tearing rollers 5, and a tensioning mechanism.

[0021] Specifically, the pull-off roller 5 includes an upper pull roller 51 and a lower pull roller 52 arranged parallel to each other on their axes, and the upper and lower pull rollers rotate at the same speed relative to each other; the ends of the upper and lower pull rollers are respectively driven by transmission gears 56 meshing together. Figure 3 As shown in the figure, the upper pull roller 51 rotates clockwise and the lower pull roller 52 rotates counterclockwise, and the pre-cut elastic knitted fabric 2 moves from right to left.

[0022] The tensioning mechanism includes a fixed clamp 53 and a movable clamp 54 protruding from the outer circumference of the upper and lower pull rollers. The fixed clamp 53 and the movable clamp 54 are respectively used to clamp on both sides of the break line of the elastic knitted fabric 2. The fixed clamp 53 and the movable clamp 54 are fitted together. The fixed clamp 53 includes two fixed clamping strips (i.e., upper fixed clamping strip 531 and lower fixed clamping strip 532) and are symmetrically fixed on the upper and lower pull rollers respectively. The movable clamp 54 includes two movable clamping strips (i.e., upper movable clamping strip 541 and lower movable clamping strip 542). The movable clamping strips are symmetrically connected to cylinder mechanisms 55. The cylinder mechanisms 55 are respectively installed inside the upper and lower pull rollers. The cylinder mechanisms 55 can drive the two movable clamping strips to move away from the fixed clamp 53 so as to pull the elastic knitted fabric 2 from the break line. The cylinder mechanism 55 includes a cylinder 551 and a slider mechanism 552. The cylinder body 5511 of the cylinder 551 is hinged to the corresponding upper and lower pull rollers, and the telescopic rod 5512 of the cylinder 551 is hinged to the corresponding movable clamping bar. The slider mechanism 552 includes a slider 5521 and a slide rail 5522. The slide rail 5522 is fixed on the corresponding upper and lower pull rollers respectively. The lower end of the slider 5521 is hinged to the corresponding movable clamping bar through a connecting rod 5523. The two hinge points of the movable clamping bar with the telescopic rod 5512 and the connecting rod 5523 are located on both sides of the width direction of the movable clamping bar. After the cylinder 551 is started, it can drive the movable clamping bar to achieve a composite motion of linear and rotational movement. The ends of the two movable clamping bars are respectively rotatably equipped with limit pinions (i.e., upper limit pinion 543 and lower limit pinion 544). The outer surface of the movable clamping bar is correspondingly provided with a partially cylindrical surface coaxial with the limit pinion. The cylinder mechanism 55 is started when the two limit pinions disengage. Since cylinder 551 does not guarantee synchronized movement, a limiting pinion is used. As the movable clamping bar moves, the limiting pinion will still mesh to limit its position, thus ensuring that the movement of the movable clamping bar is as synchronized as possible. The outer surfaces of both the fixed and movable clamping bars are made of elastic material. This allows for tighter clamping and error compensation. For example, a vulcanized rubber layer 5423 or an adhesive silicone layer can be applied to the metal substrate. The outer surface of the fixed clamping bar is arc-shaped, and this arc-shaped surface is coaxial with the corresponding cylindrical upper roller 51 or lower roller 52. Since the fixed clamping bar rotates with the relatively rotating upper and lower rollers, the above arrangement ensures that the squeezing pressure is always the same when the two are engaged. The outer circumferential surface of the movable clamping bar is arc-shaped. Two sets of synchronously moving cylinder mechanisms 55 are respectively installed inside the upper and lower rollers, and the two sets of cylinder mechanisms 55 are symmetrically arranged along the axial direction of the upper and lower rollers. The upper and lower rollers have radially penetrating V-shaped grooves 57 inside, and the cylinder mechanisms 55 are installed in the V-shaped grooves 57. The movable clamping bar includes a metal plate 5421 and a rubber layer 5423 vulcanized on the outside of the metal plate 5421. Bolt holes 5422 are provided at both ends of the metal plate 5421 for connecting to the corresponding upper and lower pull rollers by bolts.

[0023] When using the pre-cut elastic knitted fabric 2 for disposable underwear production, the pre-cut elastic knitted fabric 2 passes between the upper and lower pull rollers. As the elastic knitted fabric 2 moves, the upper and lower pull rollers also rotate synchronously at the same speed. When the pre-cutting point is located between the axes of the upper and lower pull rollers, the fixed clamp 53 and the movable clamp 54 also move to this point along with the corresponding upper and lower pull rollers. The fixed clamp 53 and the movable clamp 54 are just clamped on the front and rear sides of the pre-cutting point. At this time, after the cylinder mechanism 55 is started, it drives the movable clamp 54 to move away from the fixed clamp 53. Since the movable clamp 54 and the fixed clamp 53 themselves rotate with the upper and lower pull rollers, and the movement displacement generated by the cylinder mechanism 55 is a relative displacement relative to the fixed clamp 53, this relative displacement can drive the small area on both sides of the pre-cutting point to stretch, thereby causing it to break at the pre-cutting point. Therefore, it can be seen that, compared with the prior art, the solution of this application does not stretch the elastic knitted fabric 2 as a whole from both ends, but only stretches it in a small area on both sides of the pre-cutting point break line, ensuring that most of the area of ​​the elastic knitted fabric 2 will not be stretched and deformed, thereby avoiding problems such as reduced stretch rate at the break point, uneven shrinkage of the elastic knitted fabric 2 when it reaches the deformation limit, and cracking at the adhesive joint between the non-woven elastic fabric 1 and the elastic knitted fabric 2.

[0024] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A tearing device for pre-cutting elastic knitted fabric in the production of disposable underwear, characterized in that, include: The pull rollers are designed to break apart, including an upper pull roller and a lower pull roller with their axes parallel to each other, and the upper and lower pull rollers rotate at the same speed relative to each other. The tensioning mechanism includes fixed clamps and movable clamps protruding from the outer circumference of the upper and lower pull rollers. The fixed and movable clamps are respectively used to clamp the elastic knitted fabric at the point of breakage. The fixed and movable clamps are fitted together. The fixed clamp includes two fixed clamping strips symmetrically fixed to the upper and lower pull rollers. The movable clamp includes two movable clamping strips, each symmetrically connected to a cylinder mechanism. The cylinder mechanisms are installed inside the upper and lower pull rollers, and can drive the two movable clamping strips to move away from the fixed clamps, thereby pulling the elastic knitted fabric apart from the point of breakage. The cylinder mechanism includes a cylinder and a slider mechanism. The cylinder body is hinged to the corresponding upper and lower pull rollers, and the cylinder extension rod is hinged to the corresponding movable clamping bar. The slider mechanism includes a slider and a slide rail. The slide rail is fixed on the corresponding upper and lower pull rollers respectively. The lower end of the slider is hinged to the corresponding movable clamping bar through a connecting rod. The two hinge points of the movable clamping bar with the extension rod and the connecting rod are located on both sides of the width direction of the movable clamping bar. After the cylinder is started, it can drive the movable clamping bar to achieve a composite motion of linear and rotational movement.

2. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The ends of the two movable clamping bars are respectively equipped with limit pinions. The outer surface of the movable clamping bars is provided with a cylindrical surface coaxial with the limit pinions. The cylinder mechanism is activated when the two limit pinions disengage.

3. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The outer surface of the fixed clamping bar and / or the movable clamping bar is made of an elastic material.

4. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The outer surface of the fixing clip is an arc-shaped surface, which lies on a cylindrical surface coaxial with the corresponding upper or lower pull roller.

5. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The outer circumference of the movable clamping bar is an arc surface.

6. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, Two sets of synchronously moving cylinder mechanisms are respectively installed inside the upper and lower pull rollers, and the two sets of cylinder mechanisms are arranged symmetrically along the axial direction of the upper and lower pull rollers.

7. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The upper and lower rollers have radially penetrating V-shaped grooves inside, and the cylinder mechanism is installed inside the V-shaped grooves.

8. The tearing device for pre-cutting elastic knitted fabric in the production of disposable underwear according to claim 1, characterized in that, The ends of the upper and lower rollers are driven by meshing transmission gears.

9. The tearing device for pre-cutting elastic knitted fabric in disposable underwear production according to claim 1, characterized in that, The movable clamping bar includes a metal plate and a rubber layer vulcanized on the outside of the metal plate. Bolt holes are provided at both ends of the metal plate for connection with the corresponding upper and lower pull rollers by bolts.

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