A device for quantitatively detecting the liquid and moisture resistance properties of paper-based packaging materials

Abstract

The present invention provides a device for quantitatively detecting the liquid resistance and moisture resistance of paper-based packaging materials. The device includes a control module, a measuring cylinder, a support base, left / right support columns, left / right fixing nuts, a tensioning plate, a peristaltic pump, a liquid storage tank, upper / lower sealing rubber pads, an indicator material, a display material, a high-speed camera, and an image processing system. The device of the present invention can detect circular paper-based packaging material samples of different sizes. The control module controls the liquid inlet of the peristaltic pump to determine the water pressure for detection, the tensioning plate seals the base and the measuring cylinder, different color development reagents react to liquid water / water vapor, and the image processing system determines the liquid resistance time / moisture resistance time, thereby achieving quantitative and separate measurement of the time it takes for the paper-based packaging material to block the transmission of liquid water and the time it takes for the paper-based packaging material to block the transmission of water vapor. Therefore, the present invention has the characteristics of simple operation, wide measurement range, high accuracy, and good repeatability and reproducibility.

Description

Technical Field

[0001] The present invention relates to a device for measuring the liquid and moisture barrier properties of paper-based packaging materials. Specifically, it relates to a device for measuring the liquid and moisture barrier properties of paper-based packaging materials based on color reaction. This belongs to the field of barrier property measurement. Background Art

[0002] While plastic products bring countless conveniences to our lives, they also create pollution that is unbearable for the planet. Disposable plastic tableware and packaging are increasingly putting increasing pressure on the environment. Paper-based packaging, due to its wide availability, recyclability, and biodegradability, is recognized as the most promising green and sustainable packaging material throughout its life cycle, and its application in the packaging industry is growing.

[0003] As the application of paper-based materials in the packaging field gradually expands, the requirements for their liquid and moisture resistance are also becoming increasingly stringent. Currently, devices for measuring the liquid or water barrier properties of paper-based packaging materials are mainly based on the national standard GB / T 1540-2002, "Determination of Water Absorption of Paper and Paperboard (Cobble Method)." This type of device can only measure the amount of water absorbed by a paper-based packaging material under a single water pressure over a certain period of time, thereby evaluating the barrier properties of the paper-based packaging material. However, in the actual application scenarios of paper-based packaging materials, it is necessary to test their ability to withstand different water pressures and to evaluate the time required for the paper-based packaging material to block liquid water penetration. Furthermore, devices for measuring the moisture barrier properties of paper-based packaging materials are primarily based on national and international standards, including GB / T 1037-2021, GB / T 16928, ASTM E96, ASTM D1653, TAPPI T464, and ISO 2528. These devices measure the water vapor transmission rate of paper-based packaging materials, evaluating their ability to block water vapor transmission based on the water vapor transmission rate. However, they cannot directly measure the duration of water vapor transmission. Furthermore, because water vapor is in gaseous form, it will permeate paper-based packaging materials with certain barrier properties before liquid water. However, current testing equipment lacks the ability to distinguish between liquid and moisture barrier properties. Therefore, for paper-based packaging materials with different barrier grade requirements, how to quantitatively measure their liquid and moisture barrier properties under varying water pressures, evaluate their ability to withstand varying water pressures, and, based on this, refine the packaging scenarios suitable for paper-based packaging materials with different barrier performance grades, is a key technical challenge that existing equipment needs to address. Summary of the Invention

[0004] To address the shortcomings and drawbacks of existing testing equipment, the present invention provides a device for testing the liquid and moisture barrier properties of paper-based packaging materials. This device can test circular paper-based packaging material samples of varying sizes. By controlling the peristaltic pump's liquid inlet via a control module to determine the testing water pressure, a tensioning plate to seal the base and measuring cylinder, and the color reaction of different colorimetric reagents to identify liquid water / water vapor, and an image processing system to determine the liquid / moisture barrier time, the device achieves a quantitative and intuitive evaluation of the paper-based packaging material's barrier properties and improves testing accuracy, addressing the shortcomings of conventional barrier performance testing devices for paper-based packaging materials.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0006] A device for detecting the liquid resistance and moisture resistance of paper-based packaging materials, comprising a control module, a measuring cylinder (1), a support base (2), a left support column (3), a right support column (4), a left fixing nut (5), a right fixing nut (6), a tensioning plate (7), a peristaltic pump (8), a liquid storage tank (9), an upper sealing rubber pad (10), a lower sealing rubber pad (11), an indicating material (13), a display material (12), a high-speed camera (14) and an image processing system; two support columns (3 and 4) are respectively mounted on the left and right fixing holes (21 and 22) of the support base (2) through their bottom threads (33 and 43); the tensioning plate (7) is provided with a plurality of screw threads. Three through holes (71, 72 and 73) are opened, a hose is fixed on the middle through hole (72), the other end of the hose is connected to the peristaltic pump (8), and the other end of the peristaltic pump (8) is connected to the liquid storage tank (9) through the hose; three left, middle and right through holes (111, 112 and 113) are opened on the lower sealing rubber pad (11), and the lower sealing rubber pad (11) is installed on the support base (2) through the left and right through holes (111 and 113) respectively through the left support column (3) and the right support column (4); a high-speed camera (14) is connected to the bottom of the support base (2) through a fixing device, so as to realize high-speed continuous shooting of the bottom of the support base (2).

[0007] The measuring cylinder (1) is a hollow transparent cylindrical body with a scale, a certain wall thickness and a through-hole. The absolute values ​​of the inner and outer diameters are determined according to the size of the test sample. The absolute difference between the inner and outer diameters is 10-20 mm. The inner diameter is more than 10 mm smaller than the diameter of the test sample. The measuring cylinder (1) is fixed on the support base (2) and between the left / right support columns (3 and 4) by a tensioning plate (7), a left support column (3), a left fixing nut (5), a right support column (4), a right fixing nut (6) and an upper sealing rubber pad (10), and a seal is formed on the bottom of the measuring cylinder (1).

[0008] The support base (2) is made of a light-transmissive colorless transparent material and has threaded left and right fixing holes (21 and 22) corresponding to the left support column (3) and the right support column (4), respectively. The thickness of the support base is not more than 30 mm.

[0009] The upper and lower parts of the left support column (3) are respectively provided with fixing threads (31 and 33), and the upper and lower parts of the right support column (4) are respectively provided with fixing threads (41 and 43). The diameters of the left and right support columns (3 and 4) are adapted to the left and right through holes (111 and 113) of the lower sealing rubber pad (11), ensuring that the lower sealing rubber pad (11) can be fixed to the support base (2) through the left and right support columns. The diameters of the left and right support columns (3 and 4) are not greater than 100 mm.

[0010] The left fixing nut (5) is used in conjunction with the upper thread (31) of the support column (3); the right fixing nut (6) is used in conjunction with the upper thread (41) of the support column (4).

[0011] The diameter of the middle through hole (72) on the tensioning plate (7) is more than 10 mm smaller than the inner diameter of the measuring cylinder (1), the diameters of the left and right through holes (71 and 73) are more than 0.5 mm larger than the diameter of the support column, and more than 1 mm smaller than the outer diameter of the fixing nuts (5 and 6).

[0012] The peristaltic pump (8) controls the height of the measuring liquid in the measuring cylinder (1) through the middle through hole (72) by using the injection time and injection speed, thereby determining the water pressure borne by the sample to be measured.

[0013] The upper sealing rubber pad (10) is provided with three through holes (101, 102 and 103) on the left, middle and right sides. The diameters of the left and right through holes (101 and 103) of the upper sealing rubber pad (10) are adapted to the diameters of the left and right support columns (3 and 4), ensuring that the upper sealing rubber pad (10) can be fixed on the lower sealing rubber pad (11) through the left and right support columns. The diameters of the middle through hole (102) of the upper sealing rubber pad (10) and the middle through hole (112) of the lower sealing rubber pad (11) are the same, and their sizes are determined according to the diameter of the sample to be tested and are at least 5 mm smaller than the diameter of the sample to be tested.

[0014] The indicating material (13) is adsorbed with two color developing reagents with different properties for identifying liquid water and water vapor. The indicating material (13) and the display material (12) are made of absorbent paper.

[0015] The control module controls the peristaltic pump (8) to inject and absorb liquid.

[0016] The image processing system analyzes the pictures taken by the high-speed camera (14), and determines the liquid-blocking time and moisture-blocking time of the paper-based packaging material by comparing and analyzing the color changes of the pictures and the shooting time.

[0017] Compared with the existing technology, the advantages of the present invention are as follows: the present invention uses a control module, a measuring cylinder (1), a tensioning plate (7), and a peristaltic pump (8) and other devices to realize automatic simulation of different packaging scenarios, control and quantify the water pressure on the paper-based packaging material sample to be tested; by selecting colorimetric reagents with different response capabilities to liquid water and water vapor, independent quantitative detection of liquid water and water vapor barrier properties is realized; at the same time, through the colorimetric reaction, a graphical representation of the water vapor and liquid water permeation process is realized. Therefore, the device has the characteristics of simple operation, wide measurement range, high accuracy, good repeatability and reproducibility, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which constitute a part of the specification of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 Schematic diagram of a device for testing the liquid resistance and liquid absorption properties of paper-based packaging materials;

[0020] Figure 2 Schematic diagram of the top structure of the device.

[0021] Among them: 1-measuring cylinder, 2-support base, 21-left fixing hole on the support base, 22-right fixing hole on the support base, 3-left support column, 31-upper thread of the left support column, 32-middle thread of the left support column, 33-bottom thread of the left support column, 4-right support column, 41-upper thread of the right support column, 42-middle thread of the right support column, 43-bottom thread of the right support column, 5-left fixing nut, 51-lower left fixing nut, 6-right fixing nut, 61-lower right fixing nut, 7-tensioning plate, 71-left Through hole, 72-middle through hole, 73-right through hole, 8-peristaltic pump, 9-liquid storage tank, 10-upper sealing rubber pad, 101-upper sealing rubber pad left through hole, 102-upper sealing rubber pad middle through hole, 103-upper sealing rubber pad right through hole, 11-lower sealing rubber pad, 111-lower sealing rubber pad left through hole, 112-lower sealing rubber pad middle through hole, 113-lower sealing rubber pad right through hole, 13-indicating material, 12-display material, 14-high-speed camera, 15-sample to be tested (schematic position). DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments and drawings. However, it should be noted that the following embodiments are only used to illustrate the present invention and do not limit the scope of the present invention. After reviewing the detailed contents of the present invention, various modifications or changes made to the present invention by those skilled in the art should fall within the scope of the present invention.

[0023] The present invention is a paper-based packaging material liquid resistance and moisture resistance detection device embodiment: Figure 1 As shown, the present invention comprises a control module, a measuring cylinder (1), a support base (2), a left support column (3), a right support column (4), a left fixing nut (5), a right fixing nut (6), a tensioning plate (7), a peristaltic pump (8), a liquid storage tank (9), an upper sealing rubber pad (10), a lower sealing rubber pad (11), an indicating material (13), a display material (12), a high-speed camera (14) and an image processing system; the left and right support columns (3 and 4) are mounted on the support base (2) through positioning holes; three through holes (71, 72 and 73) are opened on the tensioning plate (7), a hose is fixed to the middle through hole (72), the other end of the hose is connected to the peristaltic pump (8), and the other end of the peristaltic pump (8) is connected through a positioning hole. The hose is connected to the liquid storage tank (9); three left, middle and right through holes (111, 112 and 113) are opened on the lower sealing rubber pad (11); the lower sealing rubber pad (11) is installed on the support base (2) through the left and right through holes (111 and 113) respectively through the left support column (3) and the right support column (4); the indicating material (13) and the display material (12) are placed on the middle through hole (112) of the lower sealing rubber pad (11) and below the middle through hole (102) of the upper sealing rubber pad (10) in a stacked manner; the high-speed camera (14) is connected to the bottom of the support base (2) through a fixing device to realize high-speed continuous shooting of the bottom of the support base (2).

[0024] The measuring cylinder (1) is a hollow transparent cylindrical body with a certain wall thickness and a scale, which is continuous from top to bottom. The diameter of the sample to be measured is 100 mm. The inner diameter of the measuring cylinder (1) is 80 mm and the outer diameter is 95 mm. The measuring cylinder (1) can be fixed on the support base (2) and between the left and right support columns (3 and 4) by a tensioning plate (7), a left support column (3), a left fixing nut (5), a right support column (4), a right fixing nut (6) and an upper sealing rubber pad (10), thereby forming a seal on the bottom of the measuring cylinder (1).

[0025] The support base (2) is made of a light-transmissive colorless transparent material (such as polyethylene terephthalate (PET) material), and has threaded left and right fixing holes (21 and 22) corresponding to the left support column (3) and the right support column (4), respectively. The thickness is 25 mm.

[0026] The upper and lower parts of the left support column (3) are respectively provided with fixing threads (31 and 33), and the upper and lower parts of the right support column (4) are respectively provided with fixing threads (41 and 43). The diameters of the left and right support columns (3 and 4) are both 30 mm, and the diameters of the left and right through holes (111 and 113) of the lower sealing rubber pad (11) are both 31 mm.

[0027] The diameter of the middle through hole (72) on the tensioning plate (7) is 65 mm, the diameters of the left and right through holes (71 and 73) are 31 mm, and the outer diameters of the left and right fixing nuts (5 and 6) are both 33 mm.

[0028] The left and right through holes (71 and 73) of the tensioning plate are respectively sleeved on the left and right support columns (3 and 4), and the tensioning plate is fixed on the measuring cylinder through the left fixing nut (5) and the right fixing nut (6), and the middle through hole (72) of the tensioning plate and the opening of the measuring cylinder are communicated.

[0029] The peristaltic pump (8) is controlled by the control module to add liquid to the measuring cylinder (1) and remove liquid through the middle through hole (72); the liquid height is 100mm, and the water pressure on the sample to be tested is calculated according to the formula P = ρgh (P is the water pressure; ρ is the density of water, 1000kg / m 3 ; g is the gravitational acceleration constant, 9.8N / kg; h is the height of the water column, 0.1m). After calculation, P = 980Pa.

[0030] The upper sealing rubber pad (10) is provided with three through holes (101, 102 and 103) on the left, middle and right sides. The diameters of the left and right through holes (101 and 103) of the upper sealing rubber pad (10) are both 31 mm. The diameters of the middle through hole (102) of the upper sealing rubber pad (10) and the middle through hole (112) of the lower sealing rubber pad (11) are both 90 mm.

[0031] Two colorimetric reagents with different properties for identifying liquid water and water vapor are adsorbed on the indicator material (13). Since water vapor permeates the paper-based packaging material before liquid water, a colorimetric reagent that responds to both liquid water and water vapor, such as Brilliant Blue R, can be used. A colorimetric reagent that responds only to liquid water, such as phenol, should be selected. Phenol is colorless under acidic conditions, but it reacts with hydroxyl groups in alkaline aqueous solutions (pH ≥ 8.2) to produce a pink color. Therefore, the liquid selected in this embodiment is a NaHCO3 solution with a pH of 8.62. The indicator material (13) and the display material (12) are made of absorbent paper.

[0032] The image processing system processes the pictures taken by the high-speed camera (14), and determines the liquid blocking time and liquid absorbing time of the paper-based packaging material by comparing and analyzing the color changes of the pictures and the shooting time.

[0033] The specific measurement steps are as follows:

[0034] (a) The left support column (3) is fixed to the left fixing hole (21) of the support base (2) through the thread (33) at the bottom of the left support column, and the right support column (4) is fixed to the right fixing hole (22) of the support base (2) through the thread (43) at the bottom of the right support column; the lower sealing rubber pad (11) is passed through the left and right through holes (111 and 113) and the left and right support columns (3 and 4) and then fixed to the support base (2). The sample to be tested, the indicating material (13) and the display material (12) are sequentially stacked on the middle through hole (112) of the lower sealing rubber pad (11).

[0035] (b) The upper sealing rubber pad (10) is placed on the sample to be tested through the left and right through holes (101 and 103) and the left and right support columns (3 and 4); the measuring cylinder (1) is placed on the middle through hole (102) of the upper sealing rubber pad (10); the measuring cylinder (1) is then fixed to the upper sealing rubber pad (10) by the tensioning plate (7) through the left and right fixing nuts (5 and 6); and the peristaltic pump (8) is connected to the measuring cylinder (1) through the middle through hole (72) on the tensioning plate (7).

[0036] (c) Turn on the high-speed camera (14) and start taking high-speed continuous pictures of the bottom of the support base (2); start the peristaltic pump (8), control the injection amount by the injection time and injection speed, and when the liquid height in the measuring tube reaches 100 mm, turn off the peristaltic pump (8) and record the time t0.

[0037] (d) The image captured by the high-speed camera (14) is observed in real time through the image processing system. When blue spots and pink spots appear on the image, the high-speed camera (14) is turned off. The peristaltic pump (8) is started in reverse to quickly discharge the liquid in the measuring cylinder (1) into the liquid storage tank (9), thereby ending the test.

[0038] (e) Analyze the images taken by the high-speed camera (14) through the image processing system to find the time t1 when the blue spot image first appears and the time t2 when the pink spot image first appears. Calculate the moisture blocking time T according to the following formula v (T v =t1-t0, min) and liquid blocking time T L (T L =t2-t0,min).

Claims

1. A device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials, characterized by: It includes a control module, a measuring cylinder, a support base, left / right support columns, left / right fixing nuts, a tensioning plate, a peristaltic pump, a liquid storage tank, an upper / lower sealing rubber pad, an indicator material, a display material, a high-speed camera and an image processing system; two support columns are installed on the support base; three through holes are opened on the tensioning plate, a hose is fixed on the middle through hole, the other end of the hose is connected to the peristaltic pump, and the other end of the peristaltic pump is connected to the liquid storage tank through the hose; three left, middle and right through holes are opened on the lower sealing rubber pad, and the lower sealing rubber pad is installed on the support base through the left and right through holes respectively; the sample to be tested, the indicator material and the display material are stacked on the middle through hole of the lower sealing rubber pad in sequence; the high-speed camera is connected to the bottom of the support base through a fixing device to realize high-speed continuous shooting of the bottom of the support base; the image processing system analyzes the pictures taken by the high-speed camera, and determines the liquid resistance time and moisture resistance time of the paper-based packaging material by comparing and analyzing the color changes of the pictures and the shooting time; The peristaltic pump controls the height of the measuring liquid in the measuring cylinder by using the injection time and injection speed through the middle through hole on the tensioning plate, thereby determining the water pressure on the sample to be tested; The indicator material is adsorbed with two color developing reagents with different properties for identifying liquid water and water vapor, and the indicator material and the display material are absorbent paper; The control module controls the peristaltic pump to inject and aspirate liquid.

2. The device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials according to claim 1, characterized in that: The measuring cylinder is a hollow transparent cylindrical cylinder with a scale, a certain wall thickness, and a through-hole from top to bottom. The absolute values ​​of the inner and outer diameters are determined according to the size of the test sample. The absolute difference between the inner and outer diameters is 10-20mm, and the inner diameter is more than 10mm smaller than the diameter of the sample to be tested. The measuring cylinder is fixed on the support base and between the left / right support columns by a tensioning plate, left / right support columns, left / right fixing nuts and an upper sealing rubber pad, and a seal is formed on the bottom of the measuring cylinder.

3. The device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials according to claim 1, characterized in that: The support base is made of a light-transmissive colorless transparent material, and its thickness is no more than 30 mm.

4. The device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials according to claim 1, characterized in that: The upper and bottom parts of the left / right support columns are respectively provided with fixing threads. The diameters of the left and right support columns are adapted to the left and right through holes of the lower sealing rubber pad, ensuring that the lower sealing rubber pad can be fixed to the support base through the left and right support columns. The diameters of the left and right support columns are not greater than 100 mm.

5. The device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials according to claim 1, characterized in that: The diameter of the middle through hole on the tensioning plate is more than 10mm smaller than the inner diameter of the measuring cylinder, the diameters of the left and right through holes are more than 0.5mm larger than the diameter of the support column, and more than 1mm smaller than the outer diameter of the fixing nut.

6. The device for quantitatively detecting the liquid and moisture barrier properties of paper-based packaging materials according to claim 1, characterized in that: The upper sealing rubber pad is provided with three through holes on the left, middle and right sides. The diameters of the left and right through holes of the upper sealing rubber pad are adapted to the diameters of the left and right support columns, ensuring that the upper sealing rubber pad can be fixed to the lower sealing rubber pad through the left and right support columns. The diameters of the middle through holes of the upper / lower sealing rubber pads are consistent, and their size is determined according to the diameter of the sample to be tested, which is at least 5mm smaller than the diameter of the sample to be tested.

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