Automatic control system for transverse thickness of calendered film and calender

Abstract

The present invention discloses an automatic control system for the transverse thickness of calendered films and a calender, which includes: a heating device capable of heating the raw materials on the calender rolls, having a plurality of individually heat-generating parts distributed along the width direction of the film; a thickness detection device arranged at the cooling and shaping mechanism, including a detection member that can reciprocate along the width direction of the film; a control unit having an input part electrically connected to the detection member and a plurality of output parts, and the plurality of output parts are electrically connected to the heat-generating parts one by one. The control unit can control the heat generated by the heat-generating parts at the corresponding positions according to the detected thickness of the film. Through the cooperative action of the detection member, the control unit and the heat-generating parts, the thickness in the width direction of the film is automatically detected and controlled, and a film with a similar or even the same thickness in the width direction can be produced fully automatically. Therefore, it has the advantages of high production quality, low production difficulty, and time and labor saving.

Description

Technical Field

[0001] The invention relates to the field of film production, and in particular to an automatic control system for the transverse thickness of a calendered film and a calender. Background Art

[0002] As is known to all, in the production process of films, especially plastic films such as PVC films, a calender is required to shape the raw materials. Existing calenders usually include a pressing roller and a cooling and shaping mechanism, which press the heated raw materials into shape through the pressing roller, and then cool and shape them through the cooling and shaping mechanism. However, due to the large width of the films produced by the existing calenders, the pressure on the raw materials in the width direction of the films is difficult to be exactly the same, so after cooling and shaping, there is generally a problem of uneven thickness in the width direction of the same film.

[0003] At present, the main method to solve this problem is to have experienced workers intervene manually, and blow cold air to the thinner parts in time during the hot pressing to make them firm, so as to avoid the thin parts from becoming thinner again. However, this processing method undoubtedly has the disadvantages of being time-consuming and labor-intensive. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an automatic control system for the transverse thickness of a calendered film, which can automatically control the thickness of the film in the width direction of the film.

[0005] The present invention also provides a calender having the above-mentioned automatic control system for the transverse thickness of the calendered film.

[0006] According to the first aspect of the present invention, the automatic control system for the transverse thickness of the calendered film includes: a heating device, which is arranged beside the pressure roller and can heat the raw material on the pressure roller, and the heating device has a plurality of heating parts that can generate heat independently, and the plurality of heating parts are distributed along the width direction of the film; a thickness detection device, which is arranged at the cooling and shaping mechanism, and the thickness detection device includes a detection member that can reciprocate along the width direction of the film; a control unit, including an input part and a plurality of output parts, the input part is electrically connected to the detection member, and the plurality of output parts are electrically connected to the heating part one by one, and the control unit can control the heat emitted by the heating part at the corresponding position according to the thickness detected by the detection member.

[0007] The automatic control system for the transverse thickness of the calendered film according to the embodiment of the present invention has at least the following beneficial effects: when the detection member moves in the width direction of the film, it will reciprocate in the width direction of the film and detect the thickness of the formed material. When the detection member detects that the thickness of the material in the width direction of the film is too high or too low, it will send a signal to the control unit, so that the control unit controls the heating device to increase or decrease the amount of heating for the too thick or too thin parts. When the amount of heating increases, the material will be more easily deformed, so it will be pressed thinner by the pressure roller; when the heat decreases, the material will not be easily deformed, so it can still retain a high thickness after being pressed by the pressure roller.

[0008] Through the cooperation of the detection part, the control unit and the heating part, the thickness of the film in the width direction can be automatically detected and controlled, and films with similar or even the same thickness in the width direction can be produced fully automatically. Therefore, it has the advantages of high production quality, low production difficulty and time and labor saving.

[0009] According to some embodiments of the present invention, a safe current interval is set in the control unit, and the detection element can send detection currents of different sizes to the control unit according to the thickness it detects; when the current value of the detection current is higher than the safe current interval, the control unit will control the heating part corresponding to the position of the detection element to further heat. After the detection element detects the thickness, it can convert the thickness into the current, so as to facilitate the transmission of the thickness change information to the control unit, and compare it with the safe current interval in the control unit, so as to determine whether it is necessary to further heat the width direction of the film where the detection element is located. The safe current interval can provide an allowable value for the thickness change, thereby avoiding excessive control of the thickness change.

[0010] According to some embodiments of the present invention, the safe current interval is 0 to 20 mA, and 20 mA is a reasonable upper limit of the current value corresponding to the upper limit of the reasonable value of the thickness change.

[0011] According to some embodiments of the present invention, a comparison module is provided in the detection member, a preset thickness is set in the comparison module, and the comparison module can compare the thickness detected by the detection member with the preset thickness; when the thickness of the detection member is inconsistent with the preset thickness, the detection member will send a detection current to the control unit. The preset thickness is the most reasonable thickness value. By comparing the difference between the detected thickness and the preset thickness, the amount of thickness fluctuation at different positions in the width direction of the same film can be intuitively known, so that it is easier to adjust the thickness of the same film in the width direction to the preset thickness.

[0012] According to some embodiments of the present invention, when the thickness detected by the detection member is greater than the preset thickness, the detection member will send a current to the control unit, and the current value of the current changes with the difference between the detected thickness and the preset thickness. By controlling the difference between the detected thickness and the preset thickness to increase or decrease the amount of heat generated by the heating portion, the amount of thickness that needs to be adjusted can be determined more directly and accurately.

[0013] According to some embodiments of the present invention, a prejudgment module is provided in the control unit, and the prejudgment module can judge whether the detection current will rise to exceed the safe current range according to the change trend of the detection current, and control the heat emitted by the heating part according to the judgment result. By judging the detection current and the change trend, the change trend of the thickness detected by the detection member can be understood, and then it can be judged whether the thickness of the undetected position exceeds or falls below the reasonable range, so as to control the heating device to further heat the place, reduce the heating amount or keep the heating amount unchanged. By judging the thickness change by the prejudgment module, the thickness of the film after molding can be effectively adjusted when the pressure roller is performing compression molding, thereby avoiding the processing of too thick or too thin films.

[0014] According to some embodiments of the present invention, the heating part is an arc-shaped infrared heating rod, and the heating part is bent toward the pressure roller. The heating part is rod-shaped and bent toward the pressure roller, so it can effectively transfer the heat it emits to the pressure roller, thereby improving the heating effect.

[0015] According to some embodiments of the present invention, the heating device further comprises a heat collecting cover, wherein a reflective surface for concentrating heat on the pressure roller is provided in the heat collecting cover. The heat collecting cover and the reflective surface can further concentrate the heat emitted by the heating part on the pressure roller, thereby improving the heating effect.

[0016] According to some embodiments of the present invention, the heat collecting cover is an arc-shaped structure, the bending direction of the heat collecting cover is the same as the bending direction of the heating part, and the reflecting surface is an 8K stainless steel mirror. The heat collecting cover is bent toward the pressure roller, so that the heat emitted by the heating part can be effectively concentrated to the pressure roller, and the 8K stainless steel mirror can effectively reflect the heat emitted by the heating part to the pressure roller, thereby improving the heating effect.

[0017] The calender according to the second embodiment of the present invention comprises the automatic control system for the transverse thickness of the calendered film according to the first embodiment of the present invention.

[0018] The calender according to the embodiment of the present invention has at least the following beneficial effects: through the cooperation of the detection part, the control unit and the heating part, the thickness of the film in the width direction of the film is automatically detected and controlled, and films with similar or even the same thickness in the width direction of the film can be produced fully automatically, thus having the advantages of high production quality, low production difficulty and time and labor saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 A schematic diagram of a calender according to an embodiment of the present invention;

[0021] Figure 2 for Figure 1 The schematic diagram of the safe current area and the detection current change of the automatic control system of the lateral thickness of the calendered film is shown;

[0022] Figure 3 A schematic diagram of a calendering mechanism of a calender according to an embodiment of the present invention;

[0023] Figure 4 for Figure 1 A schematic diagram of the heating device of the system for automatically controlling the transverse thickness of a calendered film is shown.

[0024] Reference numerals: 100 is a calendering mechanism, 110 is a pressing roller, 111 is a uniform speed roller, and 112 is a discharge roller;

[0025] 200 is a cooling and shaping mechanism.

[0026] 300 is a thickness detection device,

[0027] 400 is a heating device, 410 is a heat collecting cover, 420 is a heating part,

[0028] 500 is the safe current range, and 550 is the detection current. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0030] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0033] Reference Figure 1 A system for automatically controlling the transverse thickness of a calendered film comprises: a heating device 400, which is arranged beside a pressing roller 110 and can heat the raw material on the pressing roller 110, and the heating device 400 has a plurality of heating parts 420 that can generate heat independently, and the plurality of heating parts 420 are distributed along the width direction of the film; a thickness detection device 300, which is arranged at a cooling and shaping mechanism 200, and the thickness detection device 300 comprises a detection member that can reciprocate along the width direction of the film; a control unit, which comprises an input part and a plurality of output parts, the input part is electrically connected to the detection member, and the plurality of output parts are electrically connected to the heating part 420 one by one, and the control unit can control the heat emitted by the heating part 420 at the corresponding position according to the thickness detected by the detection member.

[0034] When the detection part moves in the width direction of the film, it will reciprocate in the width direction of the film and detect the thickness of the formed material. When the detection part detects that the thickness of the material in the width direction of the film is too high or too low, it will send a signal to the control unit, so that the control unit controls the heating device 400 to increase or decrease the amount of heating for the too thick or too thin part. When the amount of heating increases, the material will be more easily deformed, so it will be pressed thinner by the pressure roller 110; when the heat is reduced, the material will not be easy to deform, so it can still retain a high thickness after being pressed by the pressure roller 110. Through the cooperation of the detection part, the control unit and the heating part 420, the thickness of the film in the width direction of the film is automatically detected and controlled, and a film with a similar or even the same thickness in the width direction of the film can be produced fully automatically, so it has the advantages of high production quality, low production difficulty and time and labor saving.

[0035] In certain embodiments, reference Figure 2 , a safe current interval 500 is set in the control unit, and the detection element can send different sizes of detection current 550 to the control unit according to the thickness it detects; when the current value of the detection current 550 is higher than the safe current interval 500, the control unit will control the heating part 420 corresponding to the position of the detection element to further heat. After the detection element detects the thickness, it can convert the thickness into the current, so as to facilitate the transmission of the thickness change information to the control unit, and compare it with the safe current interval 500 in the control unit, so as to determine whether it is necessary to further heat the width direction position of the film where the detection element is located. The safe current interval 500 can provide an allowable value for the thickness change, thereby avoiding excessive control of the thickness change.

[0036] In certain embodiments, reference Figure 2 , the safe current range 500 is 0 to 20mA. 20mA is the reasonable upper limit of the current value corresponding to the upper limit of the reasonable value of thickness change. Of course, the value of 20mA is not absolute, but can be adjusted according to the different circuit components, which can be 10mA, 30mA or other values, and is not limited here.

[0037] In some embodiments, a comparison module is provided in the detection member, and a preset thickness is set in the comparison module. The comparison module can compare the thickness detected by the detection member with the preset thickness; when the thickness of the detection member is inconsistent with the preset thickness, the detection member will send a detection current 550 to the control unit. The preset thickness is the most reasonable thickness value. By comparing the difference between the detected thickness and the preset thickness, the amount of thickness fluctuation at different positions in the width direction of the same film can be intuitively known, so that it is easier to adjust the thickness of the same film in the width direction to the preset thickness.

[0038] It is conceivable that the comparison module can be a combination of a resistor circuit (not shown in the figure) and a voltage comparator (not shown in the figure). After the resistor circuit converts the current into a voltage, the voltage comparator can determine the difference between the detected thickness and the preset thickness by comparing the voltage. Of course, the comparison module can also be a differential amplifier circuit or other settings. The actual setting method can be adjusted accordingly according to the actual use situation, and is not limited here.

[0039] In some embodiments, when the thickness detected by the detection member is greater than the preset thickness, the detection member will send a current to the control unit, and the current value of the current changes with the difference between the detected thickness and the preset thickness. By controlling the difference between the detected thickness and the preset thickness to increase or decrease the amount of heat generated by the heating portion 420, the amount of thickness that needs to be adjusted can be determined more directly and accurately.

[0040] In some embodiments, a pre-judgment module is provided in the control unit, and the pre-judgment module can judge whether the detection current 550 will rise to exceed the safe current interval 500 according to the change trend of the detection current 550, and control the heat emitted by the heating part 420 according to the judgment result. By judging the detection current 550 and the change trend, the change trend of the thickness detected by the detection member can be understood, and then it can be judged whether the thickness of the undetected position exceeds or falls below the reasonable interval, so as to control the heating device 400 to further heat the position, reduce the heating amount or keep the heating amount unchanged. By judging the thickness change by the pre-judgment module, the thickness of the formed film can be effectively adjusted when the pressing roller 110 is pressed and formed, so as to avoid processing a film that is too thick or too thin.

[0041] In certain embodiments, reference Figure 4 The heating portion 420 is an arc-shaped infrared heating rod, and the heating portion 420 is bent toward the pressure roller 110. The heating portion 420 is rod-shaped and bent toward the pressure roller 110, so that the heat emitted by itself can be effectively transferred to the pressure roller 110, thereby improving the heating effect.

[0042] Specifically, there are five heating parts 420. Of course, there may be four, six or other numbers of heating parts 420. The specific arrangement may vary according to actual needs and is not limited here.

[0043] In certain embodiments, reference Figure 4 The plurality of heating parts 420 are evenly spaced along the width direction of the film. The evenly spaced distribution can ensure that the heat distribution between every two adjacent heating parts 420 is the same, thereby ensuring that the thickness of the film in the width direction is uniform.

[0044] In certain embodiments, reference Figure 4The heating device 400 further includes a heat collecting cover 410, and a reflective surface for concentrating heat on the pressure roller 110 is provided in the heat collecting cover 410. The heat collecting cover 410 and the reflective surface can further concentrate the heat emitted by the heating part 420 on the pressure roller 110, thereby improving the heating effect.

[0045] In some embodiments, the reflective surface and the pressure roller 110 are located on opposite sides of the heating portion 420 .

[0046] In some embodiments, the reflective surface is an arc-shaped surface that is curved toward the pressure roller 110, and the arc length of the reflective surface is greater than the arc length of the heating portion 420. Since the arc length of the reflective surface is greater than the arc length of the heating portion 420, the reflective surface can cover the heating portion 420, thereby concentrating all the heat generated by the heating portion 420 to the pressure roller 110.

[0047] In certain embodiments, reference Figure 4 The heat collecting cover 410 is in an arc-shaped structure, and the bending direction of the heat collecting cover 410 is the same as the bending direction of the heating part 420, and the reflecting surface is an 8K stainless steel mirror. The heat collecting cover 410 is bent toward the pressure roller 110, so that the heat emitted by the heating part 420 can be effectively concentrated to the pressure roller 110, and the 8K stainless steel mirror can effectively reflect the heat emitted by the heating part 420 to the pressure roller 110, thereby improving the heating effect.

[0048] It is conceivable that the thickness detection device 300 may also include a plurality of immovable detection members, and the plurality of detection members operate simultaneously to form a monitoring area sufficient to cover the width direction of the thin film.

[0049] According to an embodiment of the present invention, a calender is also provided, including an automatic control system for the transverse thickness of a calendered film according to the above embodiment of the present invention. Through the cooperation of the detection element, the control unit and the heating unit 420, the thickness of the film in the width direction of the film is automatically detected and controlled, and films with similar or even identical thickness in the width direction of the film can be fully automatically produced, thus having the advantages of high production quality, low production difficulty, and time and labor saving.

[0050] In certain embodiments, reference Figure 1 The calendering machine includes: a calendering mechanism 100 and a cooling and shaping mechanism 200.

[0051] The calendering mechanism 100 includes: a frame 105, on which five pressing rollers 110 are pivotally connected. Among the multiple pressing rollers 110, four pressing rollers 110 are uniform speed rollers 111, and the four uniform speed rollers 111 are pivotally connected to the frame 105 in the up-down direction at equal intervals. Another pressing roller 110 is a discharge roller 112, which is pivotally connected to the frame 105 and has the same height as the highest uniform speed roller 111 among the four uniform speed rollers 111. The four uniform speed rollers 111 are used to fit the material and make the material rotate with the uniform speed rollers 111, and the discharge roller 112 is used to cooperate with the uniform speed rollers 111 to press the material into a film, and export the formed film to the outside of the pressing rollers 110 for the next step of processing.

[0052] The cooling and shaping mechanism 200 includes: a frame 230, on which a small conveyor belt 220 is provided, the small conveyor belt 220 is adjacent to the calendering mechanism 100 and can support the film extending from the discharge roller 112; the cooling and shaping mechanism 200 also includes a rotating roller 210, which is pivotally connected to the frame 230. There are multiple rotating rollers 210, and the distance between every two adjacent rotating rollers 210 is equal. The small conveyor belt 220 is folded with multiple connecting parts, and the connecting parts and the rotating rollers 210 are arranged at intervals.

[0053] In certain embodiments, reference Figure 1 The heating device 400 is disposed on the frame 105 and is adjacent to the uniform speed roller 111. Specifically, the heating device 400 is adjacent to the lowest uniform speed roller among the four uniform speed rollers 111.

[0054] In certain embodiments, reference Figure 1 The thickness detection device 300 is disposed beside the frame 230. Specifically, the thickness detection device 300 is disposed on a side of the frame 230 away from the frame 105.

[0055] In some embodiments, the detection member is an eddy current thickness sensor, a magnetic thickness sensor, a capacitive thickness sensor, an ultrasonic thickness sensor, a nuclear radiation thickness sensor, an X-ray thickness sensor, or a microwave thickness sensor. The thickness detection device 300 includes a slide rail (not shown) and a slider (not shown) that cooperate with each other. The slide rail is arranged above the cooling and shaping mechanism 200 along the width direction of the film, and the detection member is fixed on the slider.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0057] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A system for automatically controlling the transverse thickness of calendered films. It is characterized in that include: A heating device (400) is arranged beside the pressing roller (110) and is capable of heating the raw material on the pressing roller (110). The heating device (400) has a plurality of heating parts (420) that can generate heat independently. The plurality of heating parts (420) are distributed along the width direction of the film. A thickness detection device (300) is arranged at the cooling and shaping mechanism (200), wherein the thickness detection device (300) comprises a detection member that can reciprocate along the width direction of the film; A control unit, comprising an input portion and a plurality of output portions, wherein the input portion is electrically connected to the detection element, and the plurality of output portions are electrically connected to the heating portion (420) in a one-to-one correspondence, and the control unit can control the amount of heat emitted by the heating portion (420) at a corresponding position according to the thickness detected by the detection element; A safe current range (500) is set in the control unit, and the detection element can send detection currents (550) of different magnitudes to the control unit according to the thickness detected by it; When the current value of the detection current (550) is higher than the safe current range (500), the control unit will control the heating portion (420) corresponding to the position of the detection element to perform further heating; The control unit is provided with a prejudgment module, which can judge whether the detection current (550) will rise to exceed the safe current range (500) according to the change trend of the detection current (550), and control the heat generated by the heating part (420) according to the judgment result.

2. The automatic control system for the transverse thickness of a calendered film according to claim 1, Features: The safe current range (500) is 0 to 20 mA.

3. The automatic control system for the transverse thickness of a calendered film according to claim 1, Features: A comparison module is provided in the detection member, and a preset thickness is set in the comparison module. The comparison module can compare the thickness detected by the detection member with the preset thickness; when the thickness of the detection member is inconsistent with the preset thickness, the detection member will send a detection current (550) to the control unit.

4. The automatic control system for the transverse thickness of a calendered film as claimed in claim 3, Features: When the thickness detected by the detection member is greater than the preset thickness, the detection member will send a current to the control unit, and the current value of the current changes with the difference between the detected thickness and the preset thickness.

5. The automatic control system for the transverse thickness of a calendered film according to claim 1, Features: The heating portion (420) is an arc-shaped infrared heating rod, and the heating portion (420) is bent toward the pressure roller (110).

6. The automatic control system for the transverse thickness of a calendered film as claimed in claim 5, Features: The heating device (400) further comprises a heat collecting cover (410), wherein a reflective surface for concentrating heat on the pressure roller (110) is provided in the heat collecting cover (410).

7. The automatic control system for the transverse thickness of a calendered film as claimed in claim 6, Features: The heat collecting cover (410) has an arc-shaped structure, the bending direction of the heat collecting cover (410) is the same as the bending direction of the heating portion (420), and the reflecting surface is an 8K stainless steel mirror surface.

8. A calender, It is characterized in that A system for automatically controlling the transverse thickness of a calendered film comprising the system described in any one of claims 1 to 7.

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