Device and method for improving weighing accuracy of a membrane
By improving the tray structure, the accuracy error problem of film weighing equipment was solved, achieving higher weighing accuracy and coating weight precision, thus ensuring the quality of film products and the stability of the processing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING SINSTAR PACKAGING MACHINERY CO LTD
- Filing Date
- 2023-09-26
- Publication Date
- 2026-06-19
Smart Images
Figure CN117309111B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thin film weighing technology, and specifically to a device and method for improving the accuracy of thin film weighing. Background Technology
[0002] A thin film is a thin, soft, transparent sheet made of plastics, adhesives, rubber, or other materials. Scientifically, a thin film is a two-dimensional material formed by the deposition of atoms, molecules, or ions on a substrate surface. Examples include optical thin films, composite thin films, superconducting thin films, polyester films, nylon films, and plastic films. Thin films are widely used in electronics, machinery, printing, and other industries. A coating is a solid, continuous film obtained by applying a paint in a single application. It is a thin layer of plastic applied to a substrate such as metal, fabric, or plastic for purposes such as protection, insulation, and decoration. Paints can be gaseous, liquid, or solid, and their type and state are usually determined by the substrate to be sprayed. The coating weight of thin film products plays a crucial role in the product's performance, cost, and energy consumption control.
[0003] Current methods for measuring coating weight mostly involve subtracting the initial weight of the substrate from the final weight of the coated product. The weighing of the film and substrate is typically done using a high-precision balance, such as an electronic balance with an accuracy of 0.01%. To ensure accuracy, multiple sets of film samples of equal area are usually selected, weighed using a balance, and their average weight is calculated. This average is then subtracted from the average weight of the substrate before coating to obtain the final coating weight. However, in actual production, the inventors have found that film-based products consistently exhibit precision errors, hindering product performance and cost control. The inventors have investigated various factors related to film processing and coating processes, ultimately discovering that industry professionals have long overlooked the errors introduced by high-precision balances in weighing film substrates. Therefore, there is an urgent need to develop a device and method to improve the accuracy of film weighing. Summary of the Invention
[0004] The present invention aims to provide a device for improving the accuracy of membrane weighing, so as to solve the technical problem of inaccurate weighing of existing membrane weighing balances, thereby improving the precision and performance of finished membrane products.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A device for improving the accuracy of membrane weighing includes a tray, the outer periphery of which is provided with an upwardly protruding limiting flange, and the inner diameter of the tray is consistent with the outer diameter of the membrane to be measured; the upper surface of the tray is recessed downward to form a plurality of flow guide grooves, which are used to discharge the airflow between the bottom of the membrane and the tray when the membrane is placed.
[0007] The principles and advantages of this scheme are:
[0008] When calculating the average value of thin film test samples, multiple sets of thin film test samples with equal areas are usually selected for weighing, and the weight of each thin film test sample is recorded. This can eliminate errors caused by the thin film test sample itself. However, in an accidental test, the inventor repeatedly weighed the same thin film test sample and found that the weight data was different each time, and there were large fluctuations between multiple sets of data. That is, the single data values obtained from the previous weighing of multiple sets of thin film test samples with equal areas were inaccurate. Each single measurement data is not the true weight of the thin film test sample. The coating weight obtained by subtracting the average value of the thin film substrate before coating from the data obtained after calculating the average value includes various errors, but these error values are all calculated as the weight of the coating, thus leading to a series of inaccurate problems in subsequent processing.
[0009] After discovering that multiple measurements of a single thin-film test sample were inaccurate, the inventors initially considered finding a more precise balance, such as an electronic balance with an accuracy of one ten-thousandth. However, multiple measurements still failed to yield a stable weighing value, indicating that the inaccuracy was not due to insufficient precision, but rather influenced by multiple factors. Based on this, the inventors conducted further research and ultimately identified several factors affecting the accuracy of thin-film weighing, including: the effect of air buoyancy on the thin film, the contact area between the thin film and the tray, the deviation of the center of gravity of the thin film placed on the tray, the effect of airflow on the thin film when the balance's windproof door is closed, and the inherent linearity error of the electronic balance itself.
[0010] The inventors conducted research and analysis on the first four controllable errors and modified the structure of the balance tray. Specifically, they added a flow guide groove to the upper surface of the tray. When the film is placed on the tray, the flow guide groove allows airflow between the film and the tray to be discharged, resulting in better adhesion between the film and the tray surface. This reduces the impact of air buoyancy, airflow on the film, and incomplete contact between the film and the tray. In addition, a limiting flange is set on the outer periphery of the tray, and the inner diameter of the tray is consistent with the outer diameter of the film sample to be tested. When the film is placed, its edge is completely within the limiting flange, reducing the center of gravity deviation of the film placed on the tray. Furthermore, the limiting flange also prevents the influence of airflow on the edge of the film, improving the weighing accuracy.
[0011] In summary, this application addresses the impact of placement center of gravity deviation, contact area, buoyancy, and airflow on the accuracy of film weighing by modifying the tray structure, thereby improving the accuracy of film weighing and consequently enhancing the accuracy of coating weight, ensuring the amount of adhesive applied in subsequent processing and the quality of the product.
[0012] Preferably, as an improvement, the guide channel includes a plurality of concentric annular grooves arranged outward from the center of the tray, each annular groove having at least one vent hole, and the vent hole vertically penetrating the tray.
[0013] Beneficial effects: When the film is placed on the tray, it exerts downward pressure, which causes the airflow on the tray surface to flow quickly from the annular groove to the vent hole, and then to be discharged from the bottom of the vent hole. This reduces the airflow between the film and the tray, reduces the effect of gas buoyancy, and allows the film to adhere completely to the tray, improving the accuracy of weighing.
[0014] Preferably, as an improvement, the center of the tray is also provided with an exhaust hole, and the width of the annular groove located on the inner side of the tray is smaller than the width of the annular groove located on the outer side.
[0015] Intentional effects: The study found that when placing film samples, the gas around the film and the outside of the tray is easy to expel, while the gas in the center of the tray is not easy to expel. Setting an exhaust hole in the center of the tray facilitates the expulsion of the gas in the center. In addition, the closer the annular groove is to the center of the tray, the smaller the width of the annular groove will be, and the less air will be in the annular groove. This can greatly reduce the residual air in the center of the tray, and further reduce the impact of the buoyancy of the residual air in the middle on the film sample.
[0016] Preferably, as an improvement, each annular groove is provided with two vent holes arranged opposite each other, the vent holes on adjacent annular grooves are staggered, and the line connecting all the vent holes on the annular grooves to the center of the tray is cross-shaped.
[0017] Beneficial effects:
[0018] 1. Two oppositely arranged exhaust holes are set on each annular groove to facilitate air flow along both sides of the annular groove, which helps to improve airflow discharge efficiency. When there are more exhaust holes on the annular groove, although the air discharge efficiency is higher, when the film is placed on the tray, it will also be affected by the reverse air buoyancy from the exhaust holes, which cannot completely ensure that the film adheres to the tray surface. During the weighing process, it will also be affected by the reverse air buoyancy, resulting in unstable weighing data.
[0019] 2. The staggered arrangement of the vent holes on adjacent annular grooves, compared to their corresponding arrangement along the same direction, can further disperse the influence of reverse air buoyancy. When all vent holes are arranged in a cross shape, the influence of reverse air buoyancy on the film can be minimized, allowing the film to be placed stably on the tray surface.
[0020] Preferably, as an improvement, the bottom of the tray is provided with a limiting groove, and the top of the limiting groove is a downwardly convex spherical shape.
[0021] Beneficial effects: The limiting groove at the bottom of the tray facilitates the accurate placement of the tray on the weighing part of the balance body. The top of the limiting groove is a downward-convex spherical surface, which helps to expel air between the tray and the balance body when placing the tray. It also helps to quickly expel air from the center of the tray along the vent hole into the arc-shaped groove and out along the spherical surface when the diaphragm is placed on the tray. At the same time, the arc-shaped spherical surface can further reduce the impact of the reverse buoyancy of the bottom air on the diaphragm.
[0022] Preferably, as an improvement, the diameter of the vent hole is 3.5-4.5 mm.
[0023] Beneficial effects: When the diameter of the exhaust port is greater than 4.5mm, although it is more conducive to the rapid exhaust of air, it is also more susceptible to the reverse air buoyancy from the bottom up. When the diameter of the exhaust port is less than 3.5mm, the efficiency of air exhaust will be reduced.
[0024] Preferably, as an improvement, the width of the annular groove is 0.5-1mm, and the radial distance between adjacent annular grooves is 5.3-5.7mm; the edge of the tray is provided with a notch for easy clamping of the film, and the width of the notch is 8-12mm.
[0025] Beneficial effects:
[0026] 1. The more annular grooves there are, the smaller the contact area between the film and the tray surface will be, and the more exhaust holes will be required, which is not conducive to the film being placed stably on the tray. The width of the annular grooves and the radial dimension between adjacent annular grooves in this application can ensure rapid airflow discharge while minimizing the impact of reverse airflow, and at the same time ensure a large contact area and good adhesion between the film and the tray.
[0027] 2. Generally, tweezers are used to pick up the film and place it on the tray. A notch is provided to facilitate the tweezers to reach into the notch to pick up the film and to fine-tune the placement of the film, so that the edge of the film is completely within the limiting flange. Compared with the tray area being larger than the film area, this application can ensure that the center of gravity of the film is basically consistent after multiple placements. Compared with the tray area being smaller than the film area, it can also avoid the film edge being repeatedly affected by air buoyancy.
[0028] 3. The width of the notch should be 8-12mm to facilitate the placement of tweezers to fine-tune the position of the film. When the notch is less than 8mm, the size is too small to operate. When the notch is wider than 12mm, the film at the notch is easily affected by air buoyancy, and the stability after placement is not easy to guarantee.
[0029] Preferably, as an improvement, the balance is also included, with the tray used to place the balance.
[0030] This invention also provides a method for improving the accuracy of membrane weighing, which uses a device to measure the weight of a thin film product, including the following steps:
[0031] S1: Use a sampler to take several composite film samples at different test machine speeds, and weigh the film samples in a constant temperature and humidity environment.
[0032] S2: Place each film sample on the tray and weigh it repeatedly N times to obtain several sets of sample data at different test machine speeds;
[0033] S3: Place the same film sample from S2 on the pan provided with the balance and weigh it N times to obtain several sets of film sample weighing data.
[0034] S4: Calculate the average value of the same thin film samples in S2 and S3 after N repeated weighings.
[0035] Preferably, as an improvement, the maximum and minimum values in the data obtained from N repeated measurements of the same thin film sample in S4 are removed, and the average value of the remaining data is calculated to obtain the weight of the thin film sample. Attached Figure Description
[0036] Figure 1 This is a top view of a tray in the prior art;
[0037] Figure 2 This is a top view of the tray of the present invention;
[0038] Figure 3 for Figure 2 Sectional view in;
[0039] Figure 4 A line graph showing the weight of film samples repeatedly weighed using existing trays;
[0040] Figure 5 A line graph showing the weight of film samples repeatedly weighed using the tray of this invention;
[0041] Figure 6 This is a top view of the first-generation improved tray of the present invention. Detailed Implementation
[0042] The following detailed description illustrates the specific implementation method:
[0043] The reference numerals in the accompanying drawings include: tray 1, limiting flange 11, annular groove 2, strip groove 22, edge annular groove 21, vent 3, limiting groove 4, spherical 41, inclined surface 42, and notch 5.
[0044] Example 1
[0045] A device for improving the accuracy of membrane weighing includes a balance body and a tray 1. In this embodiment, the balance body is an electronic balance of model FA2004 sold by Shanghai Puchun Metrology Instrument Co., Ltd., and the tray 1 of this balance has the following structure. Figure 1 As shown, this application improves the structure of the tray 1 that carries the film, and applies the improved tray 1 to the above-mentioned model of electronic balance according to the film product being weighed; it is worth noting that the tray 1 structure of this application can be applied to any electronic balance for weighing different products, and is not limited to film products.
[0046] The structure of tray 1 in this application is as follows: Figure 2-3 As shown, the outer periphery of tray 1 is provided with an upwardly protruding limiting flange 11, and the inner diameter of tray 1 is consistent with the outer diameter of the film sample to be tested. Specifically, in this embodiment, the height of the limiting flange 11 is 1 mm and the thickness is 1.4 mm. The upper surface of tray 1 is recessed downward to form several sets of guide grooves, which are used to discharge the airflow between the bottom of the film and tray 1 when the film is placed; specifically as shown... Figure 2 As shown, the guide channel includes several concentric annular grooves 2 arranged outward from the center of the tray 1. The bottom of the annular groove 2 is arc-shaped. Each annular groove 2 is provided with at least one exhaust hole 3. The center of the exhaust hole 3 is on the center line of the annular groove 2, and the exhaust hole 3 vertically penetrates the tray 1 to form a through hole. The diameter of the exhaust hole 3 is 3.5-4.5mm. In this embodiment, any one of 3.5mm, 4mm, and 4.5mm is preferred.
[0047] like Figure 2 As shown, to facilitate the expulsion of air from the center of tray 1, this embodiment also provides an exhaust hole 3 at the center of tray 1. The width of the annular groove 2 located on the inner side of tray 1 is smaller than the width of the annular groove 2 located on the outer side, and the width of the annular groove 2 is 0.5-1mm. Specifically, this embodiment provides seven sets of annular grooves 2 on tray 1, with widths of 0.7mm, 0.7mm, 0.8mm, 0.9mm, 0.9mm, 0.9mm, and 1mm respectively. The distance between the innermost annular groove 2 and the center of tray 1 is 15.3mm. Compared to uniformly providing several annular grooves 2 in the center of tray 1, this application does not provide annular grooves 2 in the center of tray 1, which facilitates air expulsion. The radial distance between the remaining adjacent annular grooves 2 is the same or slightly increases from the inside to the outside, specifically, the radial distance between adjacent annular grooves 2 is 5.3-5.7mm. To facilitate the expulsion of air from the edge of tray 1, this embodiment also provides a set of annular grooves 2 on the edge of tray 1. For easy distinction, this annular groove 2 is referred to as the edge annular groove 21.
[0048] To improve air exhaust efficiency and reduce the impact of upward air buoyancy from the bottom of exhaust port 3 on the membrane, such as Figure 2As shown, in this embodiment, two oppositely arranged exhaust holes 3 are provided on each annular groove 2 to facilitate air flow along both sides of the annular groove 2, which is beneficial to improving airflow discharge efficiency. While a higher air discharge efficiency is achieved with more exhaust holes 3 on the annular groove 2, the film placed on the tray 1 is also affected by the upward reverse air buoyancy from the exhaust holes 3, making it impossible to completely ensure the film adheres to the surface of the tray 1. This reverse air buoyancy also affects the weighing process, leading to unstable weighing data. The exhaust holes 3 on adjacent annular grooves 2 are staggered, specifically as shown... Figure 2 As shown, the line connecting all the vent holes 3 on the annular groove 2 to the center of the tray 1 is cross-shaped. The staggered arrangement can further disperse the influence of the reverse buoyancy of the air. When all the vent holes 3 are arranged in a cross shape, the influence of the reverse buoyancy of the air on the film can be minimized, so that the film is placed stably on the surface of the tray 1.
[0049] like Figure 3 As shown, a limiting groove 4 is provided at the bottom of the tray 1 to facilitate the accurate placement of the tray 1 on the weighing part of the balance body. In order to further expel the air in the middle of the tray 1, the top of the limiting groove 4 is set as a downward convex spherical surface 41, and the distance between the lowest point of the spherical surface and the bottom horizontal line of the tray 1 is 1.1mm. The side wall of the limiting groove 4 is an inclined slope 42, and the inclined direction is downward. The slope 42 has a guiding function to facilitate the rapid expulsion of air. Specifically, the inner diameter of the limiting groove 4 is 75.6mm and the outer diameter is 76.6mm.
[0050] like Figure 2 As shown, to facilitate the clamping and placement of the film on the tray 1, this embodiment provides a notch 5 on the edge of the tray 1 for easy clamping of the film. The width of the notch 5 is 8-12mm, and this embodiment preferably uses any one of 8mm, 10mm, and 12mm. Generally, tweezers are used to clamp the film and place it on the tray 1. The notch 5 facilitates the insertion of tweezers into the notch 5 to clamp the film and fine-tune its placement, ensuring that the edge of the film is completely within the limiting flange 11. Compared to a tray 1 area larger than the film area, this application can ensure that the center of gravity remains basically consistent after multiple film placements. Compared to a tray 1 area smaller than the film area, it avoids the film edge being repeatedly affected by air buoyancy. The width of the notch 5 is 10mm, which facilitates the placement of tweezers to fine-tune the film's position. When the notch 5 is less than 10mm, the size is too small for easy operation; when the notch 5 is greater than 10mm, the film located at the notch 5 is easily affected by air buoyancy, making it difficult to guarantee stability after placement.
[0051] like Figure 4-5 As shown, the pallet using this application and existing pallets (such as...) Figure 1As shown, the same thin film test sample was weighed repeatedly 10 times. The test data values of this application fluctuated little, and the accuracy of thin film weighing was significantly improved.
[0052] It is worth noting that the inventors made several attempts regarding the structure and layout of the guide channel, such as... Figure 6 The diagram shows the structure of the first-generation improved tray. The guide channel structure includes an annular groove 2 and a cross-shaped strip groove 22 for cutting off the annular groove 2. The four ends of the cross-shaped strip groove 22 extend to the limiting flange 11, and exhaust holes 3 are provided at the four ends that penetrate the tray 1. When the film is placed, the airflow quickly flows from both sides of the annular groove 2 to the strip groove 22, and then flows along the strip groove 22 to the exhaust hole 3 and is then discharged. The exhaust hole 3 is set at the edge of the tray 1, which can minimize the impact of air buoyancy on the film after the air enters the tray 1 from the bottom of the exhaust hole 3.
[0053] However, during actual use, the inventors discovered that the guide channel structure still could not effectively remove the air between the membrane and tray 1, especially the air in the middle of tray 1, which was even more difficult to expel, and the exhaust efficiency was low; only after numerous studies was the following solution obtained. Figure 2-3 The technical solution shown allows the tray 1 structure to simultaneously achieve both exhaust efficiency and effectiveness, particularly solving the problem of ineffective gas removal from the middle of the tray 1.
[0054] Example 2
[0055] A method for improving the accuracy of film weighing is to weigh the film product using the tray structure disclosed in Example 1. The film sample measurement is subject to strict regulations on environmental factors, testing methods, and experimental equipment. In particular, different temperatures and humidity in the experimental environment have a great influence on the material. Therefore, the coating amount is measured under constant temperature and humidity conditions in this application. Specifically, the temperature is 18-26°C and the humidity is 45%-65%.
[0056] Specifically, the steps include the following:
[0057] S1: Using a sampler, collect 10 composite film samples produced at different testing speeds. Specifically, select film samples with testing speeds of 50m / min, 100m / min, 200m / min, 300m / min, and 400m / min. Selecting film samples at different testing speeds can avoid errors caused by different adhesive application speeds. In this embodiment, the film sample is circular with an area of 0.01m². 2 .
[0058] S2: Place each film sample on the tray disclosed in Example 1 and weigh it 10 times to obtain several sets of sample data at different test speeds; specifically, first open the windproof door of the electronic balance, use tweezers to pick up the film sample, place it on the tray, so that the edge of the film sample is inside the limiting flange and just flat on the inside of the limiting flange, then close the windproof door, and after the reading on the electronic balance stabilizes, record the value; then take out the film sample and repeat the above steps 10 times, and 10 sets of measurement data can be obtained for each film sample.
[0059] S3: Using the method in step 2, place the same thin film sample on the tray of the electronic balance and weigh it 10 times to obtain 10 sets of test data corresponding to those in S2.
[0060] S4: Calculate the average value of the same film sample weighed 10 times in S2 and S3 respectively. This average value is the weight of the film sample, which is the weight of the film substrate plus the weight of the coating. To calculate the weight of the coating, the weight of the film substrate also needs to be measured. Then, the weight of the film substrate is subtracted from the average value of the film sample in this application. This calculation method is existing technology and will not be described in detail here. The focus of this embodiment is how to accurately weigh the film sample using the tray in Example 1. After ensuring the accuracy of film weighing, the weight of the coating can also be calculated more accurately. In order to further eliminate operational errors and improve the accuracy of the calculated average value, the maximum and minimum values in the data obtained from the 10 repeated measurements of the same film sample in S4 can also be removed before calculating the average value of the remaining data. In this embodiment, for the sake of ease of calculation, the maximum and minimum values are not removed.
[0061] Specifically, this embodiment uses the same thin film sample with a test speed of 50 m / min as an example to illustrate the test data in detail, mainly calculating the average value and standard deviation. The calculation formula is as follows:
[0062] Formula for calculating the average:
[0063] M = (A1 + ... + A10) / 10
[0064] Where M is the average value, and A1…A10 represent the measurements of the same thin film sample weighed 10 times.
[0065] The formula for calculating standard deviation is:
[0066] σ = sqrt(((A1-M)^2 +(A2-M)^2 +...(A10-M)^2) / n)
[0067] Table 1: Using the method in Example 1 Figure 1 The existing tray is shown as the test data for 10 repeated weighings of the film sample:
[0068]
[0069] Table 2: Using the method in Example 1 Figure 2 The improved tray shown represents the test data from 10 repeated weighings of the same film sample:
[0070]
[0071] In summary, based on the average values in Tables 1 and 2, the average value of repeatedly weighing the same film sample using the existing tray is M1 = 0.35462, while the average value of repeatedly weighing the same film sample using the improved tray is M2 = 0.35508. Since M2 > M1, it can be seen that the influence of air buoyancy on the film sample has been eliminated during the weighing process, and the calculated average value is closer to the true value, thus improving the weighing accuracy.
[0072] Based on the standard deviation data, σ1=0.0004996 and σ2=0.00035157, and σ1>σ2. This indicates that when using existing weighing tools to repeatedly measure the film sample 10 times, the resulting data sets have a large degree of dispersion. In other words, each weighing is greatly affected by various factors, resulting in unstable weighing data and low accuracy. However, when using the weighing tool of this application to repeatedly measure multiple times, the dispersion between multiple data sets is small, and the stability and accuracy of each weighing data set are high.
[0073] It is worth noting that after determining the weight of the adhesive layer in the composite film, the amount of adhesive applied during the actual adhesive application process will be affected by a variety of factors. For example, the viscosity of the adhesive will vary greatly under different temperatures and speeds. Therefore, accurately measuring the film weight and the amount of adhesive applied has a significant impact on the subsequent processing of the product.
[0074] Example 3
[0075] This embodiment also provides an application of the film processed using the above-described weighing device and process. The film product can be used for flexible packaging in the fields of medicine, agriculture, machinery, and electronics, and in particular, it can also be used as chip film, as an electrostatic film, lithium battery packaging film, etc.
[0076] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A device for improving the weighing accuracy of a membrane, comprising a tray, characterized in that, The tray has an upwardly protruding limiting flange on its outer periphery, and the inner diameter of the tray is the same as the outer diameter of the film to be tested. The upper surface of the tray is recessed downward to form several sets of guide grooves, which are used to discharge the airflow between the bottom of the film and the tray when the film is placed. The guide grooves include several concentric annular grooves arranged outward from the center of the tray. Each annular groove has at least one exhaust hole, and the exhaust hole vertically penetrates the tray. The center of the tray also has an exhaust hole. The width of the annular groove on the inner side of the tray is smaller than the width of the annular groove on the outer side. Each annular groove has two oppositely arranged exhaust holes. The exhaust holes on adjacent annular grooves are staggered, and the line connecting all the exhaust holes on the annular grooves to the center of the tray is cross-shaped. The bottom of the tray has a limiting groove, and the top of the limiting groove is a downwardly protruding spherical surface.
2. The device for improving the accuracy of membrane weighing according to claim 1, characterized in that: The diameter of the vent hole is 3.5-4.5 mm.
3. The device for improving the accuracy of membrane weighing according to claim 2, characterized in that: The width of the annular groove is 0.5-1mm, and the radial distance between adjacent annular grooves is 5.3-5.7mm; the edge of the tray is provided with a notch for easy clamping of the film, and the width of the notch is 8-12mm.
4. The device for improving the accuracy of membrane weighing according to claim 3, characterized in that: It also includes a balance, and the tray is used to place the balance on the balance.
5. A method for improving the accuracy of membrane weighing, comprising weighing a thin film sample using the apparatus for improving the accuracy of membrane weighing as described in any one of claims 1-4, characterized in that, Includes the following steps: S1: Use a sampler to take several composite film samples at different test machine speeds, and weigh the film samples in a constant temperature and humidity environment. S2: Place each group of thin film samples on the tray as described in any one of claims 1-4 and weigh them N times to obtain several groups of sample data at different test machine speeds. S3: Place the same thin film sample from S2 on the pan of the existing balance and weigh it N times to obtain several sets of weighing data for the thin film sample. S4: Calculate the average value of the same thin film samples in S2 and S3 after N repeated weighings.
6. The method for improving membrane weighing accuracy according to claim 5, characterized in that: Remove the maximum and minimum values from the data obtained from N repeated measurements of the same thin film sample in S4, and then calculate the average value of the remaining data to obtain the weight of the thin film sample.