Stretching detection device and method for stretching film

Abstract

The invention discloses a stretching detection device and method for a stretched film, and relates to the field of stretched film detection.The stretching detection device for the stretched film comprises a refrigerated cabinet and a placement assembly, a spraying assembly is arranged on the side of the placement assembly, and the spraying assembly is driven by a driving assembly to integrally move downwards till the stretched film is pulled downwards; the spraying assembly comprises two connecting boxes, and atomizing nozzles are fixedly mounted on the two connecting boxes; the blocking frame is arranged in the connecting box, the driving assembly supplies liquid into the connecting box and the atomizing spray head while enabling the connecting box and the atomizing spray head to move downwards, and the blocking frame is driven to rotate to change the shielding area of the atomizing spray head when the connecting box moves downwards; therefore, three areas of thick frost, thin frost and gradual frost are generated on the surface of the film in real time, and the stretched film is pulled in various frosting areas, so that the tensile property change of the stretched film in a cold storage low-temperature environment and under different frosting conditions can be better detected.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of tensile film detection, and particularly relates to a tensile detection device and method for tensile film. BACKGROUND

[0002] Tensile film is a kind of packaging material with high elasticity and self-adhesion, which is widely used in the fields of logistics transportation, storage and preservation, etc. Especially in the cold storage environment, it is often used for winding and packaging of frozen food, pharmaceutical products and other goods to achieve the purpose of fixation, dust prevention and reduction of temperature fluctuation. The tensile performance of tensile film in the cold storage low-temperature environment, including the breaking resistance, ductility and winding stability, is directly related to the packaging effect and the safety of goods.

[0003] However, the current tensile detection device and method for tensile film are mostly carried out in normal temperature environment, and only a single mechanical tensile test is used to evaluate the breaking strength, elongation and other parameters of the film, completely ignoring the influence of cold storage low-temperature environment on the physical properties of the film.

[0004] Specifically, the detection in normal temperature state cannot detect the material hardening and ductility attenuation of tensile film in low temperature, resulting in significant deviation between the detected tensile performance and the actual performance of the film in the cold storage, and the detected tensile performance data cannot reflect the reliability of the film in the real cold storage application. SUMMARY

[0005] The present application aims to provide a tensile detection device and method for tensile film, which can solve the technical problems that the normal temperature detection in the prior art cannot simulate the material hardening and ductility attenuation caused by low temperature, resulting in significant deviation between the detected data and the actual performance in the cold storage, and the influence of frost on the film surface during use is not considered.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The utility model provides a kind of tensile film tensile detection device, including refrigerator and the placement component for the both ends of tensile film fixed, the side of the placement component is equipped with spray component, spray component is driven by driving assembly and overall moves down, until the tensile film is pulled down;The spray component includes: two connection boxes are respectively arranged in the left and right sides of the tensile film, and a plurality of atomizing nozzles are fixedly installed on it;Shutoff frame is arranged in the connection box, for part atomizing nozzle is blocked;Wherein, in the stroke of the driving assembly driving two connection boxes synchronous moving down, the atomizing nozzle continuously sprays liquid to tensile film, while the shutoff frame is connected with first gear by rotating pipe, the first gear is engaged with the first pawl on the support frame in placement component, under this mechanical action, shutoff frame rotates with connection box moving down, to change the shielding area of atomizing nozzle, so that the coverage range of liquid on tensile film dynamically changes with moving down process.

[0007] Preferably, the placement component includes: a support frame is fixedly installed inside the refrigerator, a first clamp is fixedly installed on the support frame, and a second clamp is slidingly installed on the support frame.

[0008] Preferably, the spray component further includes: a rotating pipe is rotatably connected with the connection box and fixedly connected with the shutoff frame; and a first gear is fixedly installed on the rotating pipe.

[0009] Preferably, the spray component further includes: a storage box is fixedly installed on the refrigerator; an extrusion plate is slidingly installed inside the storage box and connected with the storage box by a plurality of first springs; a folding hose has one end fixedly connected with the storage box and the other end rotatably connected with the support frame.

[0010] Preferably, the utility model further includes a pulling component; the pulling component includes: a fixed pipe is fixedly installed inside the refrigerator; a moving column is slidingly installed inside the fixed pipe and connected with the fixed pipe by a second spring, and the top end of the moving column is fixedly connected with the second clamp.

[0011] Preferably, the driving assembly includes: a motor is fixedly installed on the top of the refrigerator, a first screw rod is fixedly installed on the power output shaft of the motor, a first threaded plate is slidingly installed inside the refrigerator and threadedly connected with the first screw rod, a plurality of bayonet slots are formed in the first threaded plate, one end of a tension rope is fixedly connected with the extrusion plate, and the other end of the tension rope is fixedly installed with a plug pin inserted into the bayonet slot.

[0012] Preferably, the adjusting assembly further comprises: an adjusting frame fixedly installed in the inside of the refrigerator cabinet, and a plurality of rows of second clamping teeth fixedly installed on the adjusting frame; a connecting frame fixedly installed on the first threaded plate, and a forward-reverse screw rotatably installed on the connecting frame, the forward-reverse screw being provided with threads of opposite directions at two ends; a second gear fixedly installed on the forward-reverse screw; and two second threaded plates threadedly connected with the forward-reverse screw, one end of each second threaded plate being slidably connected with the connecting frame, and the other end of each second threaded plate being fixedly connected with the connecting box.

[0013] Preferably, the adsorbing assembly further comprises: an installation frame allowing the stretch film to pass through, and a connecting rod fixedly connected with the supporting frame.

[0014] A stretch detection method for a stretch film, comprising the following steps: Step one, clamping and fixing both ends of the stretch film between a first clamp and a second clamp, allowing the film to pass through the installation frame, and closing the refrigerator cabinet; Step two, starting the motor, and lowering the first threaded plate and the connecting box through the first screw; in the process of lowering, the pressing plate is pulled by the elastic rope to deliver the liquid in the storage box to the atomizing nozzle for atomization and spraying on the film surface to form frost; Step three, when the connecting box is lowered, the blocking frame is driven to rotate to dynamically shield part of the atomizing nozzle, and sequentially form thick frost area, thin frost area and gradual frost area on the film surface; at the same time, the distance between the two connecting boxes is adjusted to change the atomization distance between the atomizing nozzle and the film to realize different frost thickness and distribution; Step four, the connecting box continuously lowered pushes the second clamp to move downward, and the moving column compresses the second spring to apply a constant tensile force to the film; Step five, repeating the opening and closing of the refrigerator cabinet door to simulate temperature fluctuations, and recording the tensile property data under dynamic frosting.

[0015] As described above, due to the adoption of the above technical solutions, the present application has the following advantages: 1. By setting the spraying assembly and the driving assembly, the driving assembly not only lowers the connecting box and the atomizing nozzle, but also supplies liquid to the inside of the connecting box and the atomizing nozzle, and the connecting box is further driven to rotate to change the shielding area of the atomizing nozzle when the connecting box is lowered; thereby, three areas of thick frost, thin frost and gradual frost are generated on the film surface in real time, and the stretch film is pulled in multiple frost areas, which can better detect the tensile property change of the stretch film under different frosting conditions in the low-temperature environment of the cold storage.

[0016] 2、The adjusting assembly and the adsorbing assembly in the application are connected through setting positive and negative screw rods, a second gear, a second clamping tooth and a mounting frame, when the positive and negative screw rods rotate with the second gear, the distance between the two connecting boxes is adjusted synchronously, and the atomization distance is accurately changed; at the same time, the mounting frame freezes and fixes the edge of the film, simulates the frozen and fixed difficult-to-release working condition when the tray is wound, realizes the double adjustment of frost thickness and boundary constraint, so that the basic thick frost, thin frost and gradual frost conditions can be further changed, more problems of the stretched film are exposed under the double actions of frost thickness gradient and freezing fixation, and the performance of the stretched film is further detected.

[0017] 3、The refrigeration cabinet in the application is connected with the circulating linkage of the refrigeration system through setting the cabinet door which can be frequently opened and closed, so that the external hot and humid air is periodically poured in and competes with the sprayed water vapor for condensation, the thick frost area is melted and refrozen, the thin frost area is partially shed, and the gradient of the gradual change area is intensified, so that the frost state on the stretched film is further changed, when the stretching detection is carried out, the effects of different frost conditions on the stretched film can be detected, and the performance of the stretched film is further detected. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0019] Figure 1 It is a perspective view of the stretching detection device for the stretched film of the application; Figure 2 It is a schematic view of the internal structure of the refrigeration cabinet in the application; Figure 3 It is a schematic view of the assembly structure of the placing assembly and the pulling assembly in the application; Figure 4 It is a schematic view of the A part of the application; Figure 3 Figure 5 It is a schematic view of the assembly structure of the spraying assembly in the application; Figure 6 It is a schematic view of the structure of the plugging frame in the application; Figure 7 It is a schematic view of the assembly structure of the adjusting assembly and the driving assembly in the application; Figure 8 It is a schematic view of the B part of the application; Figure 7 Figure 9 It is a schematic view of the structure of the first threaded plate in the application; Figure 10 ​​It is the internal structure diagram of the storage box in the application; Figure 11 It is the assembly structure diagram of the pulling assembly in the application; Figure 12 It is the assembly structure diagram of the adsorption assembly in the application.

[0020] The figure mark: 100, refrigerator; 111, motor; 112, elastic rope; 113, first screw rod; 114, bolt; 115, first threaded plate; 116, bayonet slot; 121, storage box; 122, folding hose; 123, connecting box; 124, first gear; 125, rotating pipe; 126, atomizing nozzle; 127, blocking frame; 128, extrusion plate; 129, first spring; 131, support frame; 132, first clamp; 133, second clamp; 134, first clamping tooth; 141, fixed pipe; 142, moving column; 143, second spring; 151, adjusting frame; 152, second clamping tooth; 153, second gear; 154, connecting frame; 155, second threaded plate; 156, positive and negative screw rod; 161, connecting rod; 162, mounting frame. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purpose, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0022] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from the description, and those skilled in the art can make similar generalizations without departing from the concept of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0023] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is separate or selectively excluded from other embodiments.

[0024] The present application is described in detail in conjunction with the drawings of the specification, and when the embodiments of the present application are described, the cross-sectional view of the device structure will be partially enlarged without the general proportion, and the drawings of the specification are only examples, which should not limit the scope of protection of the present application. In addition, three-dimensional spatial dimensions including length, width and depth should be included in actual manufacture.

[0025] Meanwhile, in the description of the present application, it should be noted that the terms "first", "second" or "third" are only used for descriptive purpose and cannot be understood as indicating or implying relative importance.

[0026] Unless otherwise defined, the terms "mounting, connecting, connecting" in the present application should be understood broadly, for example: it can be fixed connection, detachable connection or integral connection; it can also be mechanical connection, electrical connection or direct connection, it can also be indirectly connected through intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Embodiment 1: as shown in a kind of tensile film tensile detection device, including refrigerator 100 and the placement assembly for the both ends of tensile film fixed, the side of placement assembly is equipped with spray assembly, spray assembly is driven by driving assembly and is overall moved down, until the downward pull of tensile film is generated. Figures 1 to 12 Spray assembly includes two connecting boxes 123 and blocking frame 127, two connecting boxes 123 are respectively arranged on the left and right sides of tensile film, and a plurality of atomizing nozzles 126 are fixedly installed on two connecting boxes 123;Blocking frame 127 is arranged in connecting box 123, and blocking frame 127 is used to block part of atomizing nozzle 126.

[0028] Among them, in the stroke of driving assembly driving two connecting boxes 123 to move down synchronously, atomizing nozzle 126 continuously sprays liquid to tensile film, while blocking frame 127 is connected with first gear 124 through rotating pipe 125, first gear 124 is engaged with first tooth 134 on support frame 131 in placement assembly, under the mechanical action, blocking frame 127 rotates with the movement of connecting box 123, so as to change the shielding area of atomizing nozzle 126, so that the coverage range of liquid on tensile film changes dynamically in the process of moving down.

[0029]

[0030] ​It should be noted that the need to detect the stretch film is placed in the placement assembly, the placement assembly is used to clamp both ends of the stretch film, to achieve the effect of fixed, then, control the refrigerator 100, the temperature in the refrigerator 100 is adjusted to-20 degrees below, after these preparations are completed; start the drive assembly, the drive assembly drives the spray assembly to move down, in the process of moving down, it will make the multiple atomizing nozzles 126 on the spray assembly constantly spray atomized water, these water will adhere to the stretch film, until the stretch film frost, and in the process of constantly moving down of the spray assembly, the blocking frame 127 in the spray assembly will also rotate continuously, the blocking frame 127 will shield part of the atomizing nozzle 126, so that part of the atomizing nozzle 126 cannot spray atomized liquid, in this way, the frost situation of the stretch film at different positions will be different, including: Frosting area (thick frost): the atomizing nozzle 126 not shielded by the blocking frame 127 continuously sprays atomized water, and the water vapor quickly condenses in the low-temperature environment to form a thick frost layer with uniform thickness; Partial frost area (thin frost / local frost): the atomizing nozzle 126 intermittently shielded by the blocking frame 127 only sprays water for part of the time, and the water vapor supply is unstable, resulting in only partial condensation of the stretch film surface into thin frost; Uneven frost area (gradual frost layer): the edge of the blocking frame 127 changes continuously due to rotation, resulting in a gradient distribution of the spraying time of the atomizing nozzle 126, and finally forming a transition area with a gradual change in frost layer thickness from thick to thin.

[0031] When the spray assembly moves down to the bottom end of the stretch film, it will start to pull the stretch film.

[0032] The thick frost layer is formed by densely packed ice crystals, which has strong structural rigidity but high brittleness; during stretching, the ice crystals hinder the sliding of molecular chains, resulting in local stress concentration. Performance: fine cracks appear at the beginning of stretching, and with the increase of stretching ratio, the cracks rapidly expand and penetrate the frost layer, and finally break at the interface between the frost layer and the base film (the fracture surface can see obvious ice crystal residues).

[0033] The structure of the thin frost layer or discontinuous frost spot is loose, and the water vapor has not completely condensed into stable ice crystals, and the interlayer self-adhesion is significantly weakened. During stretching, the film layers are prone to relative sliding due to the lack of effective adhesion (such as layer misalignment after one turn around the tray); performance: the interlayer peeling strength drops sharply from the dry state, and the package can be easily separated by a light push, and cannot maintain close fitting.

[0034] The gradual frost layer has a gradient distribution of frost layer thickness, resulting in uneven stress distribution during stretching (stress concentration in thick areas and stress dispersion in thin areas). Performance: at the beginning of stretching, micro-cracks appear in the thick area (similar to the frosting area), but the thin area still maintains a certain toughness; with the increase of stretching ratio, the thin area is gradually pulled through due to stress accumulation, and finally forms a mixed failure mode of thick area fracture and thin area tearing.

[0035] The tension sensor can be installed at the connecting position of the moving column 142 of the pulling assembly and the second clamp 133, and the tension sensor is used to monitor the tension value in real time during the stretching process, record the maximum tension value when the thick frost area is broken, the critical tension value when the thin frost area is interlayer slipped, and the tension change curve when the gradual frost area is mixed failure; The high-speed camera can be installed on the refrigerated cabinet 100, and the high-speed camera is used to shoot the failure process of the three frost areas, and the image analysis system is used to quantify the crack propagation speed (thick frost area), the interlayer dislocation distance (thin frost area), and the tearing area (gradual frost area). In the process of pulling, the tension sensor is used to monitor the maximum tension value when the thick frost area is broken in real time, so as to measure the anti-breaking ability of the stretched film; The laser thickness gauge can be installed on the refrigerated cabinet 100, and the laser thickness gauge is used to measure the frost layer thickness and the film base film thickness of each frost area before and after stretching, and calculate the stretching ratio and thickness change rate of the film under different frost conditions; The temperature sensor can be installed on the refrigerated cabinet 100, and the temperature sensor is used to record the real-time temperature in the refrigerated cabinet and the temperature distribution of the frost area on the film surface, and the influence of temperature fluctuation on the stretching performance.

[0036] As shown in Figures 1 to 3 The placing assembly includes a support frame 131, a first clamp 132, a second clamp 133, and a first tooth 134.

[0037] The support frame 131 is fixedly installed inside the refrigerated cabinet 100, the first clamp 132 is fixedly installed on the support frame 131, and the second clamp 133 is slidingly installed on the support frame 131. A plurality of first teeth 134 are fixedly installed on the support frame 131.

[0038] It should be noted that in use, the selected stretched film can be placed in the support frame 131, and the first clamp 132 and the second clamp 133 are controlled to clamp the two ends of the stretched film for subsequent pulling test.

[0039] As shown in Figures 2 to 6 and Figure 10 The spraying assembly further includes a storage box 121, a folding hose 122, a connecting box 123, a first gear 124, a rotating pipe 125, an atomizing nozzle 126, a plugging frame 127, an extrusion plate 128, and a first spring 129. The outer surfaces of these components are provided with a heat preservation layer, which can resist the freezing effect of the low temperature environment in the refrigerated cabinet 100 on the liquid.

[0040] The rotating pipe 125 is rotatably connected with the connecting box 123, and the rotating pipe 125 is fixedly connected with the blocking frame 127; the first gear 124 is fixedly installed on the rotating pipe 125; the storage box 121 is fixedly installed on the refrigeration cabinet 100; the extrusion plate 128 is slidably installed in the storage box 121, and the extrusion plate 128 is connected with the storage box 121 through a plurality of first springs 129; one end of the folding hose 122 is fixedly connected with the storage box 121, and the other end of the folding hose 122 is rotatably connected with the supporting frame 131.

[0041] It should be noted that when the stretching film is fixed, the driving assembly will be started, and the driving assembly will control the two connecting boxes 123 to continuously move downward. Since the driving assembly controls the two connecting boxes 123 to move downward, the extrusion plate 128 is continuously pulled, so that the extrusion plate 128 transports the liquid in the storage box 121 to the inside of the connecting box 123 through the folding hose 122, and sprays out from the atomizing nozzle 126. The sprayed liquid is atomized and acts on the stretching film. Due to the refrigeration effect of the refrigeration cabinet 100, the atomized liquid will frost on the stretching film.

[0042] The storage box 121 is provided with a filling pipe at the top. When other stretching films need to be detected in the future, liquid can be continuously filled into the storage box 121 for continuous use.

[0043] The connecting box 123 will also drive the first gear 124 to move downward in the process of moving downward. The first gear 124 moves downward and interacts with a row of first clutches 134, thereby continuously rotating. When the first gear 124 rotates, the first gear 124 drives the blocking frame 127 to rotate. The blocking frame 127 rotates to block the atomizing nozzles 126 at different positions. In this way, the distribution of the atomizing nozzles 126 on the connecting box 123 that can spray out atomized liquid will be different. The corresponding area of the atomizing nozzle 126 that is not blocked by the blocking frame 127 forms a thick frost area (dense ice crystal accumulation) due to continuous water spraying. The corresponding area of the atomizing nozzle 126 that is intermittently blocked forms a partial frost area (thin frost or local frost spot) due to unstable water vapor supply. The edge of the blocking frame 127 forms a frost uneven area due to the change of the blocking frequency gradient caused by rotation. Finally, due to the dynamic difference in the distribution of the atomizing nozzles 126, the actual performance and shortcomings of the stretching film can be detected under various conditions during the stretching detection, so that the shortcomings can be further improved.

[0044] As shown in Figure 3 and Figure 11 , the stretching film uses a stretching detection device which further comprises a pulling assembly. The pulling assembly comprises a fixed tube 141, a moving column 142 and a second spring 143. The fixed tube 141 is fixedly installed inside the refrigerator cabinet 100; the moving column 142 is slidingly installed inside the fixed tube 141, and the moving column 142 is connected with the fixed tube 141 through the second spring 143, and the top end of the moving column 142 is fixedly connected with the second clamp 133.

[0045] It should be noted that when the connecting box 123 is lowered to the second clamp 133, as the connecting box 123 is continuously lowered, the connecting box 123 will extrude the second clamp 133 to drive the moving column 142 to move downward, thereby extruding the second spring 143, and the second clamp 133 moves downward to pull the stretch film, so as to detect the influence of different frosting conditions on the stretch film, so as to determine whether the quality of the stretch film meets the standard under different frosting conditions and whether it can be put into use.

[0046] As shown in Figures 7 to 9 , the driving assembly comprises a motor 111, a tension rope 112, a first screw rod 113, a plug 114, a first threaded plate 115 and a bayonet slot 116.

[0047] The motor 111 is fixedly installed at the top of the refrigerator cabinet 100, and the power output shaft of the motor 111 is fixedly installed with the first screw rod 113; the first threaded plate 115 is slidingly installed inside the refrigerator cabinet 100, and the first threaded plate 115 is threadedly connected with the first screw rod 113, and a plurality of bayonet slots 116 are formed in the first threaded plate 115; one end of the tension rope 112 is fixedly connected with the extrusion plate 128, and the other end of the tension rope 112 is fixedly installed with the plug 114 which is inserted into the bayonet slot 116.

[0048] The stretch film stretching detection device further comprises an adjusting assembly, and the adjusting assembly comprises an adjusting frame 151, a second clamping tooth 152, a second gear 153, a connecting frame 154, a second threaded plate 155 and a reversible screw rod 156.

[0049] The adjusting frame 151 is fixedly installed inside the refrigerator cabinet 100, and a plurality of rows of second clamping teeth 152 are fixedly installed on the adjusting frame 151; the connecting frame 154 is fixedly installed on the first threaded plate 115, and the reversible screw rod 156 is rotatably installed on the connecting frame 154; the second gear 153 is fixedly installed on the reversible screw rod 156; the two second threaded plates 155 are threadedly connected with the reversible screw rod 156, one end of the second threaded plate 155 is slidingly connected with the connecting frame 154, and the other end of the second threaded plate 155 is fixedly connected with the connecting box 123.

[0050] It needs to be explained that the starting motor 111, the motor 111 will control the first screw rod 113 to rotate, when the first screw rod 113 rotates, the first screw rod 113 will control the first screw plate 115 to move down, the first screw plate 115 moves down will drive the connecting box 123 to move down through the connecting frame 154 and the second screw plate 155, at the same time, it will also pull the elastic cord 112, so that the elastic cord 112 drives the extrusion plate 128 to move, so as to discharge the liquid in the storage box 121 into the folding hose 122, and finally sprayed from the atomizing nozzle 126, so as to act on the stretch film.

[0051] And in the process of driving the connecting frame 154 down by the first screw plate 115, the second gear 153 will also be driven down, the second gear 153 will interact with the second clamping tooth 152, so that the second gear 153 can rotate, the rotation of the second gear 153 will drive the positive and negative screw rod 156 to rotate, the rotation of the positive and negative screw rod 156 will change the distance between the two second screw plates 155, so that the distance between the two connecting boxes 123 connected thereto will also change, so that the distance between the atomizing nozzle 126 and the stretch film will change, the change of the distance will change the adhesion of the atomized liquid to the stretch film, so as to change the frost situation on the stretch film, so that in the subsequent pulling of the stretch film for detection, the performance of the stretch film under different frost conditions can be further analyzed.

[0052] And with the continuous pulling of the elastic cord 112, the extrusion plate 128 slides to the liquid inlet end position of the folding hose 122 in the storage box 121, at this time the extrusion plate 128 will block the liquid inlet end of the folding hose 122, so that the liquid cannot continue to be transported, and the extrusion plate 128 cannot move further, which completes the different atomizing injection of different areas, but the first screw plate 115 still needs to move down for stretch test, so that the pin 114 will be separated from the bayonet slot 116, avoiding the restriction of the elastic cord 112 on the downward movement of the first screw plate 115.

[0053] As shown in Figure 3 and Figure 12 The stretch film stretch detection device further comprises an adsorption assembly, and the adsorption assembly comprises a connecting rod 161 and a mounting frame 162. The mounting frame 162 is fixedly connected with the support frame 131 through the connecting rod 161.

[0054] It should be noted that when the first clamp 132 and the second clamp 133 are used to fix the stretch film, the stretch film needs to pass through the inside of the mounting frame 162, so that when the atomizing nozzle 126 on the connecting box 123 atomizes and sprays, the atomized liquid not only acts on the stretch film, but also acts on the gap between the stretch film and the mounting frame 162, so that the stretch film and the mounting frame 162 are connected together by means of freezing of the atomized liquid, so as to simulate the situation that when the stretch film roll is in an unreleased state in actual use, the release part is frozen and fixed due to low temperature environment, and the influence of the frozen part needs to be overcome before the release can continue, and in the case of overcoming the frozen part, there is still frost, which can be detected together.

[0055] Working principle: start the motor 111, the first screw rod 113 rotates, drives the first threaded plate 115 to move downward. The first threaded plate 115 drives the connecting box 123 to move downward synchronously through the connecting frame 154 and the second threaded plate 155, at the same time, the elastic rope 112 is tightened, pulling the extrusion plate 128 to slide in the storage box 121, the liquid is pressed into the folding hose 122, and finally sprayed out from the atomizing nozzle 126 in the atomized state, attached to the surface of the stretch film, and quickly frosted under the low temperature effect of the refrigeration cabinet 100.

[0056] During the downward movement of the connecting box 123, the first gear 124 is engaged with the first clamping tooth 134, driving the rotating pipe 125 to rotate, driving the plugging frame 127 to rotate, dynamically shielding part of the atomizing nozzle 126, so that the coverage range of the atomized liquid changes with the downward movement process, forming three different frosting states of thick frost area, thin frost area and gradual frost area, simulating the actual frosting situation of the film surface in the cold storage.

[0057] The second gear 153 is engaged with the second clamping tooth 152 during the downward movement of the connecting frame 154, driving the positive and negative screw rod 156 to rotate, so that the second threaded plate 155 synchronously adjusts the distance between the two connecting boxes 123, and then changes the distance between the atomizing nozzle 126 and the stretch film, adjusts the adhesion strength of the atomized liquid, realizes the frosting effect of different thickness and distribution, and improves the detection precision.

[0058] The liquid sprayed by the atomizing nozzle 126 acts on the contact surface of the stretch film and the mounting frame 162 at the same time, and the liquid freezes at low temperature, so that the film edge and the mounting frame 162 form frozen fixed.

[0059] When the connecting box 123 continues to move downward, it contacts and pushes the second clamp 133, the second clamp 133 drives the moving column 142 to slide in the fixed pipe 141 and compresses the second spring 143, so as to exert downward pulling force on the stretch film, and detect the anti-breaking capacity, ductility and winding stability of the film under different frosting states.

[0060] Example 2: as Figures 1 to 12In other parts are the same as example 1, the difference between this embodiment and example 1 is that: Because the refrigerator 100 is provided with a door, the heat flow from the outside will enter through the continuous opening and closing of the door.

[0061] In actual use, the actual stretch film is in a low-temperature environment. Due to personnel access, cargo storage and other operations, the door needs to be frequently opened, which causes the temperature in the warehouse to rise for a short time and then quickly fall back through the refrigeration system. After the external hot and humid air enters, it competes with the atomized liquid sprayed by the spraying assembly on the film surface to condense. The water vapor carried by the hot and humid air will dilute the existing water vapor concentration in the low-temperature environment, break the original water vapor balance, and cause the frosting process to change from continuous and stable to fluctuating and suppressed: the thick frost area temporarily melts due to temperature rise, but re-freezes after the refrigeration system restarts; part of the frosting area is disturbed by the hot and humid air, the frost thickness decreases and local shedding occurs; the gradient of the uneven frosting area is intensified due to temperature fluctuations. This cycle of freezing, melting and re-freezing is more similar to the actual unstable frosting problem of the film caused by frequent opening and closing of the door in the cold storage, avoiding the limitations of traditional static low-temperature tests. Example 3: as Figures 1 to 12 In other parts are the same as example 1, the difference between this embodiment and example 1 is that: A stretch film stretching detection method, comprising the following steps: Step one, low-temperature environment establishment and film clamping: clamp the two ends of the stretch film to be tested between the first clamp 132 and the second clamp 133, keep it horizontal and tensioned, and make the middle section of the film pass through the installation frame 162; then close the door of the refrigerator 100, start the refrigeration system, and make the temperature in the refrigerator 100 drop to below-20℃ to simulate a stable low-temperature environment in a cold storage; Step two, atomized frosting start: start the motor 111, the motor 111 drives the first screw rod 113 to rotate, and drives the first threaded plate 115 to move down at a constant speed; the first threaded plate 115 drives the second threaded plate 155 to move down synchronously through the connecting frame 154 and the second threaded plate 155; at the same time, the elastic rope 112 is pulled by the first threaded plate 115, driving the extrusion plate 128 to slide downward in the storage box 121, and the pre-filled pure water is pressed into the connecting box 123 through the folding hose 122, and is uniformly atomized and sprayed through the array type atomizing nozzle 126; the atomized droplets condense instantly at-20℃ low temperature, forming an initial frost layer on the film surface; Step three, dynamic frosting regulation: during the movement of the connecting box 123, the first gear 124 fixed on the rotating pipe 125 engages with the first clamping tooth 134 on the support frame 131, driving the rotating pipe 125 to rotate and driving the blocking frame 127 to periodically block the atomizing nozzles 126 at different positions, so that the film surface forms thick frost area, thin frost area and gradient frost area in turn; Meanwhile, the second gear 153 engages with the second clamping tooth 152 on the adjusting frame 151, drives the positive and negative screw rod 156 to rotate, and moves the connecting box 123 driven by the second threaded plate 155 on both sides, so as to change the vertical distance between the atomizing nozzle 126 and the film, change the droplet adhesion density, and realize the secondary precise control of the frost thickness. Step four, freeze boundary simulation: the atomized liquid is sprayed to the contact gap between the film and the mounting frame 162 at the same time, and is rapidly frozen at low temperature, so that the ice bridge is formed between the film edge and the mounting frame 162, and the working condition that the film roll end is frozen and cannot be smoothly released due to condensation in the actual cold storage is simulated; Step five, tensile test and data acquisition: the connecting box 123 continues to move downward, and when the bottom thereof contacts the second clamp 133, the second clamp 133 is driven to move downward at a constant speed, the moving column 142 slides in the fixed tube 141 and compresses the second spring 143, and a continuous tensile force is applied to the film; A high-precision tension sensor is used to record the tensile force and displacement curve in real time; A high-speed camera is used to synchronously shoot the crack propagation in the thick frost area, the interlayer slip in the thin frost area, and the tearing process in the gradual frost area; A laser displacement sensor is used to monitor the frost thickness change online.

[0062] The above is only a preferred embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

[0063] The preferred embodiments disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details, and the application is limited to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The embodiments are selected and described in detail in order to better explain the principles and practical applications of the present application, so that the skilled person in the art can well understand and use the present application. The present application is limited by the claims and the entire scope and equivalents thereof.

Claims

1. A tensile testing device for stretch film, comprising a refrigerator (100) and a placement assembly for fixing both ends of the stretch film, characterized in that: A spraying component is provided on the side of the placement component, which is driven by the drive component to move downward as a whole until the stretch film is pulled downward. The spray assembly includes: Two connecting boxes (123) are respectively located on the left and right sides of the stretch film, and multiple atomizing nozzles (126) are fixedly installed on them. A blocking frame (127) is disposed inside the connecting box (123) for blocking part of the atomizing nozzles (126); During the stroke in which the driving component drives the two connecting boxes (123) to move down synchronously, the atomizing nozzle (126) continuously sprays liquid onto the stretch film. At the same time, the sealing frame (127) is connected to the first gear (124) through the rotating tube (125). The first gear (124) meshes with the first locking tooth (134) on the support frame (131) in the placement component. Under the mechanical action of this meshing, the sealing frame (127) rotates as the connecting box (123) moves down, thereby changing the blocking area of ​​the atomizing nozzle (126) and making the coverage area of ​​the liquid on the stretch film dynamically change with the downward movement.

2. The tensile testing device for stretching films according to claim 1, characterized in that, The placement component includes: A support frame (131) is fixedly installed inside the refrigerator (100), on which a first clamp (132) is fixedly installed, and a second clamp (133) is slidably installed. Several first locking teeth (134) are fixedly installed on the support frame (131).

3. The tensile testing device for stretching films according to claim 2, characterized in that, The spray assembly also includes: The rotating tube (125) is rotatably connected to the connecting box (123) and fixedly connected to the sealing frame (127); The first gear (124) is fixedly installed on the rotating tube (125).

4. The tensile testing device for stretching films according to claim 3, characterized in that, The spray assembly also includes: Storage box (121) is fixedly installed on the refrigerator (100); The extrusion plate (128) is slidably installed inside the storage box (121) and connected to the storage box (121) by a plurality of first springs (129); The folded flexible tube (122) is fixedly connected at one end to the storage box (121) and rotatably connected at the other end to the support frame (131).

5. A tensile testing device for stretching films according to claim 2, characterized in that, It also includes a tensioning component; the tensioning component includes: A fixing pipe (141) is fixedly installed inside the refrigerator (100); The movable column (142) is slidably installed inside the fixed tube (141) and connected to the fixed tube (141) by the second spring (143). Its top end is fixedly connected to the second clamp (133).

6. The tensile testing device for stretching films according to claim 4, characterized in that, The driving component includes: The motor (111) is fixedly installed on the top of the refrigerator (100), and a first screw (113) is fixedly installed on its power output shaft. The first threaded plate (115) is slidably installed inside the refrigerator (100) and threadedly connected to the first screw (113), and has multiple bayonet slots (116) on it. The elastic cord (112) is fixedly connected at one end to the compression plate (128), and the other end is fixedly installed with a pin (114) that is inserted into the bayonet groove (116).

7. A tensile testing device for stretching films according to claim 6, characterized in that, It also includes an adjustment component, the adjustment component comprising: An adjustment bracket (151) is fixedly installed inside the refrigerator (100), and multiple rows of second locking teeth (152) are fixedly installed on it. A connecting bracket (154) is fixedly installed on the first threaded plate (115), and a positive and negative screw (156) is rotatably installed on it. The positive and negative screw (156) has threads with opposite directions at both ends. The second gear (153) is fixedly installed on the positive and negative screws (156); Two second threaded plates (155) are threadedly connected to the positive and negative screws (156), one end of which is slidably connected to the connecting frame (154), and the other end of which is fixedly connected to the connecting box (123).

8. A tensile testing device for stretching films according to claim 2, characterized in that, It also includes an adsorption component, which comprises: The mounting frame (162) allows the stretch film to pass through and is fixedly connected to the support frame (131) by the connecting rod (161).

9. A method for tensile testing of a stretched film, characterized in that, Includes the following steps: Step 1: Clamp and fix both ends of the stretch film between the first clamp (132) and the second clamp (133) respectively, so that the film passes through the mounting frame (162) and close the refrigerator (100). Step 2: Start the motor (111) and use the first screw (113) to lower the first threaded plate (115) and the connecting box (123); during the downward movement, the extrusion plate (128) is pulled by the tension rope (112) to transport the liquid in the storage box (121) to the atomizing nozzle (126) for atomization and spraying, which frosts on the film surface; Step 3: When the connecting box (123) moves down, the sealing frame (127) is driven to rotate, dynamically blocking part of the atomizing nozzle (126), forming a thick frost area, a thin frost area and a gradient frost area on the film surface in sequence; at the same time, the distance between the two connecting boxes (123) is adjusted to change the atomization distance between the atomizing nozzle (126) and the film, so as to achieve different frost thickness and distribution. Step 4: The connecting box (123) continues to move downward, pushing the second clamp (133) downward, and the moving column (142) compresses the second spring (143), applying a constant tensile force to the film; Step 5: Repeatedly open and close the refrigerator (100) door to simulate temperature fluctuations and record the tensile performance data under dynamic frost.

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