Plastic film stretching detection equipment

Abstract

The utility model relates to the technical field of plastic film processing, and in particular relates to plastic film stretching detection equipment which comprises a bracket; a film extruder; a cooling roller; the first driving mechanism is connected with the cooling roller; the negative pressure box is arranged between the film extruder and the cooling roller, an outlet for a film to pass through is formed between the first side face of the negative pressure box and the cooling roller, and a negative pressure opening is formed in the second side face of the negative pressure box; the negative pressure mechanism is communicated with the negative pressure opening; wherein the negative pressure box comprises at least two inner cavities, the inner cavities are distributed in the axial direction of the cooling roller, a first partition plate is arranged between every two adjacent inner cavities, and a negative pressure opening is formed in the second side face of each inner cavity; the negative pressure mechanism comprises at least two fans, and each fan is communicated with the corresponding negative pressure port of the inner cavity; and the controller is electrically connected with each fan. The utility model discloses plastic film stretching detection equipment, and aims to solve the problem that transverse mechanical properties are easy to be different during film production in the prior art.

Description

A plastic film tensile testing device Technical Field

[0001] This utility model relates to the field of plastic film processing technology, and more specifically, to a plastic film tensile testing device. Background Technology

[0002] Plastic film tensile testing equipment typically consists of an extruder, cooling rollers, and a thickness measurement device. After molten plastic is extruded into a film, it is rapidly cooled and solidified by the cooling rollers, and its mechanical properties are finally evaluated using tensile testing equipment. In existing technologies, the film forming quality is controlled by adjusting the cooling roller speed, extrusion speed, or negative pressure adsorption force.

[0003] In traditional equipment, the overall negative pressure adsorption design makes it impossible to independently control the pressure in different areas of the film. When the film suffers from poor adhesion in some areas due to uneven temperature distribution on the surface of the cooling roller or differences in material flowability, existing technologies can only adjust the power of the negative pressure fan or compensate for the temperature of the cooling roller globally, failing to accurately address differences in transverse solidification rates. This leads to inconsistent transverse mechanical properties of the film (such as tensile strength and thickness uniformity), especially in the production of wide-width films, where the performance differences between the edge and center areas are significant, increasing the scrap rate. Summary of the Invention

[0004] The main purpose of this invention is to provide a plastic film tensile testing device, which aims to solve the problem that the transverse mechanical properties of films are easily inconsistent during the production of films in the prior art.

[0005] To address the aforementioned technical problems, a plastic film tensile testing device is proposed, comprising: a support frame, horizontally positioned;

[0006] A film extruder is fixed on the support.

[0007] A cooling roller is rotatably mounted on the support and located on the lower side of the film extruder;

[0008] A first drive mechanism is connected to the cooling roller;

[0009] A negative pressure box is disposed between the film extruder and the cooling roller. The extrusion outlet of the film extruder is located inside the negative pressure box. An outlet for film to pass through is provided between the first side of the negative pressure box and the cooling roller. A negative pressure port is provided on the second side of the negative pressure box. The first side and the second side are located on both sides of the film.

[0010] A negative pressure mechanism, connected to the negative pressure port, is used to act on the side of the film that contacts the cooling roller;

[0011] The negative pressure box includes at least two inner cavities, each inner cavity being distributed along the axial direction of the cooling roller, with a first partition plate between adjacent inner cavities, and the negative pressure port being provided on the second side of each inner cavity;

[0012] The negative pressure mechanism includes at least two fans, and the number of fans is equal to the number of inner cavities. Each fan is connected to a negative pressure port corresponding to the inner cavity.

[0013] A controller is electrically connected to each of the aforementioned wind turbines, and the controller is used to individually control the power of each of the aforementioned wind turbines.

[0014] In any of the above technical solutions, further comprising:

[0015] Two or more thickness detection mechanisms, each corresponding to a thin film setting in each of the aforementioned inner cavities, are electrically connected to the controller.

[0016] In any of the above technical solutions, further comprising:

[0017] The second partition plate is disposed inside the negative pressure box and located on the side closer to the second side than the base outlet of the film extruder. It is arranged parallel to the axial direction of the cooling roller, with its top attached to the inner side of the negative pressure box and its bottom separated from the cooling roller.

[0018] In any of the above technical solutions, further comprising:

[0019] A temperature detection mechanism is provided on the outer surface of the film after it is separated from the cooling roller, and is used to detect the roller surface temperature after the cooling roller is separated from the film.

[0020] The second drive mechanism is arranged parallel to the axial direction of the cooling roller, and the temperature detection mechanism is mounted on the second drive mechanism. The second drive mechanism is used to drive the temperature detection mechanism to reciprocate.

[0021] In any of the above technical solutions, further comprising:

[0022] A low-temperature component is disposed on the side of the second side away from the first side and is attached to the surface of the cooling roller to reduce the surface temperature of the cooling roller.

[0023] In any of the above technical solutions, the cryogenic component further includes:

[0024] A cold water pipe is installed on the bracket, with one end connected to a cold water source and the other end connected to a drain pipe;

[0025] The conductive element is sleeved on the outside of the cold water pipe and abuts against the cooling roller.

[0026] The beneficial effects are:

[0027] 1. The plastic film tensile testing equipment of this utility model has multiple independent inner cavities in the negative pressure box. Each inner cavity is isolated by a first partition plate and equipped with an independent fan, which can adjust the negative pressure intensity of different areas individually.

[0028] 2. Each inner cavity is equipped with an independent thickness detection mechanism to provide real-time feedback on the transverse thickness distribution data of the film. The control unit dynamically adjusts the corresponding fan power accordingly to form a closed-loop control and reduce the scrap rate.

[0029] 3. A second, axially parallel partition plate is installed on the side of the negative pressure chamber near the film extrusion outlet to limit airflow turbulence and ensure that the negative pressure is applied evenly to the film surface.

[0030] 4. By connecting the cold water pipe to the cooling roller surface, residual heat is quickly dissipated, which improves the surface temperature uniformity when the extruded film first contacts the cooling roller, and reduces the difference in film crystallinity.

[0031] 5. The temperature detection mechanism is driven by the second drive mechanism to scan back and forth along the cooling roller axis, and monitors the residual temperature on the surface of the cooling roller after the film is removed in real time. Combined with the thickness data, the control unit can automatically adjust the fan power and cooling parameters, and can also quickly detect abnormal temperature data and shorten the fault response time. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 is a three-dimensional structural schematic diagram of a plastic film tensile testing device according to an embodiment of the present invention;

[0034] Figure 2 is a cross-sectional structural schematic diagram of a plastic film tensile testing device according to an embodiment of the present invention.

[0035] Figure 3 is a partial structural schematic diagram of a plastic film tensile testing device according to an embodiment of the present invention.

[0036] The annotations in the attached figures are explained as follows:

[0037] 1. Bracket;

[0038] 2. Film extruder; 201. Extruder outlet;

[0039] 3. Cooling rollers;

[0040] 4. First drive mechanism;

[0041] 5. Negative pressure box; 501. Inner cavity;

[0042] 6. Negative pressure mechanism; 601. Fan;

[0043] 7. First partition plate;

[0044] 8. Thickness testing equipment;

[0045] 9. Second partition plate;

[0046] 10. Temperature detection equipment;

[0047] 11. Second drive mechanism;

[0048] 12. Low-temperature components; 1201. Cold water pipes; 1202. Conductive components. Detailed Implementation

[0049] Hereinafter, exemplary embodiments according to this application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0050] It should be noted that, as shown in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list; the method or apparatus may also include other steps or elements.

[0051] If the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0052] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0053] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0054] The following embodiments will provide a detailed description of a plastic film tensile testing device according to this application.

[0055] In this embodiment, as shown in Figures 1 to 3, the plastic film tensile testing device includes: a support 1, which is horizontally arranged;

[0056] Film extruder 2 is fixed on bracket 1;

[0057] Cooling roller 3 is rotatably mounted on support 1 and located below film extruder 2;

[0058] The first drive mechanism 4 is connected to the cooling roller 3;

[0059] A negative pressure box 5 is set between the film extruder 2 and the cooling roller 3. The extrusion outlet of the film extruder 2 is located inside the negative pressure box 5. An outlet for film to pass through is provided between the first side of the negative pressure box 5 and the cooling roller 3. A negative pressure port is provided on the second side of the negative pressure box 5. The first side and the second side are located on both sides of the film.

[0060] The negative pressure mechanism 6 is connected to the negative pressure port and is used to generate an effect on the side of the film that contacts the cooling roller 3;

[0061] The negative pressure box 5 includes at least two inner cavities 501, each inner cavity 501 is distributed along the axial direction of the cooling roller 3, a first partition plate 7 is provided between adjacent inner cavities 501, and a negative pressure port is provided on the second side of each inner cavity 501.

[0062] The negative pressure mechanism 6 includes at least two fans 601, and the number of fans 601 is equal to the number of inner cavities 501. Each fan 601 is connected to the corresponding negative pressure port of the inner cavity 501.

[0063] The controller (not shown in the figure) is electrically connected to each fan 601 and is used to control the power of each fan 601 individually.

[0064] In this technical solution, the support frame 1 is horizontally installed on the ground, using a steel structure frame with shock-absorbing pads on the surface. The film extruder 2 is fixed to the upper left side of the support frame 1, with the extrusion outlet tilted downwards at 15°-55° and an outlet width of 2m; it is commercially available. The cooling roller 3 has a diameter of 800mm, a chrome-plated and polished surface, and is rotatably mounted in the lower middle part of the support frame 1 via bearings, located below the extruder. The first drive mechanism 4 includes a servo motor and a reducer, driving the cooling roller 3 to rotate clockwise at an adjustable speed of 0.5-5m / min.

[0065] The negative pressure chamber 5 is made of stainless steel with a hollow bottom. It has an outlet for the film to pass through on the right side (first side) and a negative pressure port on the left side (second side). The interior of the negative pressure chamber 5 is divided into three independent inner cavities 501 along the axial direction of the cooling roller 3 (i.e., the film width direction). Specifically, adjacent inner cavities 501 are separated by a vertical first partition plate 7. The bottom surface of the first partition plate 7 is an arc surface coaxial with the cooling roller 3, and there is a 5-15mm gap between the bottom surface of the first partition plate 7 and the cooling roller 3. The upper end of the negative pressure chamber 5 has a strip-shaped notch, through which the extruder outlet 201 extends into the interior of the negative pressure chamber 5. The lower end of the negative pressure chamber 5 is 10mm away from the surface of the cooling roller 3. The right side of the negative pressure chamber 5 has an opening 30-50mm high to form a film movement channel. Three Φ200mm circular negative pressure ports are located on the left side of the negative pressure chamber 5.

[0066] The negative pressure mechanism 6 includes three centrifugal fans 601, which are connected to the negative pressure ports of the three inner cavities 501 via flanges. The power range of each fan 601 is 0.5-3kW, and they are independently controlled by frequency converters. The controller (not shown in the figure) is a PLC, which communicates with the frequency converter and drive mechanism of the fan 601 via an RS485 interface.

[0067] In this embodiment, it also includes:

[0068] Two or more thickness detection mechanisms 8, each corresponding to the thin film setting of each inner cavity 501, are electrically connected to the controller.

[0069] In this technical solution, the thickness detection mechanism 8 includes three laser thickness gauges, each installed corresponding to a film conveying area in one of the three inner cavities 501, 50mm from the surface of the cooling roller 3. The laser thickness gauges transmit thickness data to the controller in real time via a 4-20mA signal.

[0070] During use, molten plastic flows out from the extruder outlet 201 and enters the negative pressure box 5 area.

[0071] The controller starts three fans 601 according to the preset program, generating negative pressure in the three inner cavities 501 respectively (for example: negative pressure of -500Pa in the inner cavities on both sides and negative pressure of -400Pa in the inner cavity in the middle), so that the film adheres tightly to the surface of the cooling roller 3 and is cured.

[0072] If the thickness gauge detects that the thickness of the central film is too thin, the controller will increase the power of the central fan 601 from 2kW to 2.5kW to enhance the negative pressure adsorption force and restore the thickness of the central film to the target value.

[0073] Specifically, the controller is set to a target thickness of 0.1mm ± 5%.

[0074] When the thickness gauge on one side detects a thickness of 0.12mm (i.e., exceeding the tolerance by +20%), the controller reduces the power of the fan 601 on that side to 1.8kW (originally 2kW), reducing the suction force and allowing the molten plastic on that side to stretch more fully, thus reducing the thickness. Simultaneously, if the thickness on one side is 0.09mm (less than -10%), the power of the fan 601 on that side is increased to 2.2kW, causing the thickness to recover.

[0075] In some technical solutions, when the thickness of a certain area exceeds the tolerance three times consecutively, the controller triggers an alarm and suspends production.

[0076] In this embodiment, it also includes:

[0077] The second partition plate 9 is disposed inside the negative pressure box 5 and is located on the side closer to the second side than the base outlet of the film extruder 2. It is arranged parallel to the axial direction of the cooling roller 3, with its top attached to the inner side of the negative pressure box 5 and a gap left between its bottom and the cooling roller 3.

[0078] In this technical solution, the second spacer 9 is made of aluminum alloy, with a thickness of 10mm and a height of 300mm. It is vertically fixed in the negative pressure box 5 in the front-to-back direction, located to the left of the extruder outlet 201, at a distance of 20-50mm from the extruder outlet 201, parallel to the axial direction of the cooling roller 3, and with its bottom 2-20mm away from the surface of the cooling roller 3. It can prevent airflow from flowing back to the extruder outlet 201, ensuring that the negative pressure is concentrated on the film surface.

[0079] In this embodiment, it also includes:

[0080] Temperature detection mechanism 10 is set on the outer surface of the film after it is separated from the cooling roller 3, and is used to detect the roller surface temperature of the cooling roller 3 after it is separated from the film.

[0081] The second drive mechanism 11 is arranged parallel to the axial direction of the cooling roller 3. The temperature detection mechanism 10 is arranged on the second drive mechanism 11. The second drive mechanism 11 is used to drive the temperature detection mechanism 10 to reciprocate.

[0082] In this technical solution, the temperature detection mechanism 10 is an infrared thermal imager, mounted on a linear guide rail parallel to the axial direction of the cooling roller 3. The second drive mechanism 11 is a stepper motor, driving the thermal imager to reciprocate at a speed of 0.5 m / s.

[0083] After the film detaches from the cooling roller 3, the thermal imager scans its surface temperature along the guide rail. For example, the temperatures of the front / middle / rear areas are 23℃ / 25℃ / 23℃. The controller compares this temperature with the target temperature (24℃±1℃) and detects that the middle section is overheating. It then increases the power of the middle fan 601 to 2.3kW and activates the low-temperature component 12 to increase cooling output. After 5 minutes, the middle temperature drops to 23.5℃, and the system enters a stable state.

[0084] In some technical solutions, the second drive mechanism 11 is a lead screw and slider moving mechanism, and the temperature detection mechanism 10 is set on the slider of the second drive mechanism 11.

[0085] In this embodiment, it also includes:

[0086] The low-temperature component 12 is disposed on the side of the second side away from the first side and is attached to the surface of the cooling roller 3 to reduce the surface temperature of the cooling roller 3.

[0087] In this technical solution, it is located on the left side of the negative pressure box 5.

[0088] In this embodiment, the cryogenic component 12 includes:

[0089] Cold water pipe 1201 is installed on bracket 1, with one end connected to the cold water source and the other end connected to the drain pipe;

[0090] The conductive element 1202 is sleeved on the outside of the cold water pipe 1201 and abuts against the cooling roller 3.

[0091] In this technical solution, the cold water pipe 1201 is a copper water pipe with an inner diameter of 20mm, through which 5℃ cold water is introduced at a flow rate of 10L / min. The conductive component 1202 is a graphite block, which is horizontally mounted on the periphery of the cold water pipe 1201 and has its bottom surface in close contact with the surface of the cooling roller 3, so as to efficiently conduct the cooling energy to the roller surface.

[0092] When the temperature detection mechanism 10 detects that the surface temperature of the cooling roller 3 exceeds 25°C, the controller starts the cold water pump to inject low-temperature water into the cold water pipe 1201, so that the roller surface temperature drops below 20°C. At the same time, if the temperature in a certain inner cavity 501 area is still too high, the power of the corresponding fan 601 is increased separately to enhance local adsorption and heat dissipation.

[0093] In some technical solutions, the cold water pipe 1201 is coiled in a serpentine shape to increase the coverage area.

[0094] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A plastic film tensile testing device, characterized in that, include: A support (1) is horizontally positioned; a film extruder (2) is fixed on the support (1); a cooling roller (3) is rotatably mounted on the support (1) and located below the film extruder (2); a first drive mechanism (4) is connected to the cooling roller (3); a negative pressure box (5) is located between the film extruder (2) and the cooling roller (3), with the extrusion outlet of the film extruder (2) located inside the negative pressure box (5), an outlet for film passage is provided between the first side of the negative pressure box (5) and the cooling roller (3), and a negative pressure port is provided on the second side of the negative pressure box (5), with the first side and the second side located on both sides of the film; a negative pressure mechanism (6) communicates with the negative pressure port and is used to connect the film and the negative pressure port. The cooling roller (3) acts on the side it contacts; wherein, the negative pressure box (5) includes at least two inner cavities (501), each inner cavity (501) is distributed along the axial direction of the cooling roller (3), a first partition plate (7) is provided between adjacent inner cavities (501), and the negative pressure port is provided on the second side of each inner cavity (501); the negative pressure mechanism (6) includes at least two fans (601), and the number of fans (601) is equal to the number of inner cavities (501), each fan (601) is connected to the corresponding negative pressure port of the inner cavity (501); a controller is electrically connected to each fan (601), and the controller is used to individually control the power of each fan (601).

2. The plastic film tensile testing equipment according to claim 1, characterized in that, Also includes: Two or more thickness detection mechanisms (8) are respectively corresponding to the thin film settings of each inner cavity (501), and are all electrically connected to the controller.

3. The plastic film tensile testing equipment according to claim 1, characterized in that, Also includes: The second partition plate (9) is disposed inside the negative pressure box (5) and located on the side closer to the second side than the base outlet of the film extruder (2). It is arranged parallel to the axial direction of the cooling roller (3), with its top attached to the inner side of the negative pressure box (5) and its bottom separated from the cooling roller (3).

4. The plastic film tensile testing equipment according to claim 1, characterized in that, Also includes: A temperature detection mechanism (10) is provided on the outer surface of the film after it is separated from the cooling roller (3), and is used to detect the roller surface temperature of the cooling roller (3) after it is separated from the film; a second drive mechanism (11) is provided parallel to the axial direction of the cooling roller (3), and the temperature detection mechanism (10) is provided on the second drive mechanism (11), which is used to drive the temperature detection mechanism (10) to reciprocate.

5. The plastic film tensile testing equipment according to claim 1, characterized in that, Also includes: A low-temperature component (12) is disposed on the side of the second side away from the first side and is attached to the surface of the cooling roller (3) to reduce the surface temperature of the cooling roller (3).

6. The plastic film tensile testing equipment according to claim 5, characterized in that, The low-temperature component (12) includes: a cold water pipe (1201), which is mounted on the bracket (1), with one end connected to a cold water source and the other end connected to a drain pipe; and a conductive element (1202), which is sleeved on the outside of the cold water pipe (1201) and abuts against the cooling roller (3).

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