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CN-122016177-A - Method for verifying packaging sealing effect of paper box

CN122016177ACN 122016177 ACN122016177 ACN 122016177ACN-122016177-A

Abstract

A method for verifying the packaging sealing effect of a paper box belongs to the field of packaging detection. The method comprises four steps of sample preparation, outer layer stripping, chemical layering treatment, sealing detection and judgment. Firstly, shearing and cleaning the package, trimming the package into an I shape, stripping the outer layer, then sequentially soaking and rubbing the package with nitric acid solution and sodium hydroxide solution to thoroughly strip the paper layer, the adhesive layer and the aluminum foil layer, only keeping the inner polyethylene film, then precisely injecting the longitudinal seal by using a specially prepared red dye solution, checking the longitudinal seal by combining an ultraviolet lamp, observing the transverse seal by using a 40-time scale magnifying glass after injecting the transverse seal, and finally, judging whether the package is qualified according to quantitative standards of no leakage and no fluorescence of the longitudinal seal, the length of the transverse seal bubble and the effective sealing width. The problems of large detection error, high missing judgment rate of micro defects and poor repeatability of results caused by incomplete interlayer stripping and non-uniform operation parameters in the prior art are solved, and the accurate, reliable and standardized detection of the sealing quality of the multi-layer composite package is realized.

Inventors

  • ZHANG YINHUI
  • LI JIE
  • XIN YUEZHEN
  • LI WEI

Assignees

  • 北大荒完达山乳业股份有限公司
  • 黑龙江完达山阳光乳业有限公司

Dates

Publication Date
20260512
Application Date
20260213

Claims (8)

  1. 1. The method for verifying the packaging sealing effect of the paper box is characterized by comprising the following steps of: s1, preparing an I-shaped sample, namely packaging a paper box to be detected, cutting the package along a direction parallel to the longitudinal seal direction of the paper box to be detected, cleaning all substances contained in the paper box, reserving the complete structures of the transverse seal and the longitudinal seal areas, and trimming the package into an I shape; s2, peeling the outer layer, namely manually peeling and removing the printing layer and the polyethylene protective layer on the outer surface of the I-shaped sample; s3, chemical layering treatment: S31, acid soaking and stripping, namely completely soaking the sample treated by the S2 into 30% nitric acid solution at room temperature for 30 to 40 minutes, taking out, and slightly rubbing under flowing water until the paper layer and the first adhesive layer adhered with the paper layer completely fall off to expose an aluminum foil layer in the middle of the I-shaped sample; s32, alkaline soaking and stripping, namely completely soaking the I-shaped sample treated by S31 into a sodium hydroxide solution with the concentration of 2.0-2.5%, soaking for 10-15 minutes at about 35 ℃, and stripping an aluminum foil layer to obtain a sample to be detected, wherein the sample is only the innermost layer of food which contacts the polyethylene film; S4, detecting and judging the sealing position: S41, longitudinal sealing detection, namely extracting red dye liquor by using an injector, penetrating a polyethylene film at an angle of 45 degrees at the position of about 1 millimeter at the edge of a longitudinal sealing line, injecting 0.5 milliliter of the red dye liquor at a speed of 0.5 milliliter/second, and after waiting for 1 minute, firstly using an ultraviolet lamp with a wavelength of 365 nanometers to irradiate and check; S42, detecting the transverse seal, namely slowly injecting 0.5 milliliter of red dye liquid into an interlayer of the transverse seal by using the same injector, and then observing and measuring the maximum length of bubbles at the transverse seal by using a 40-time magnifying glass with a graduated scale; S43, judging that the package sealing effect is qualified if no red dye liquor exudes or fluoresces under naked eyes and ultraviolet lamps at the longitudinal sealing position and the maximum length of bubbles at the transverse sealing position is less than 2.0 mm, and otherwise, judging that the package sealing effect is unqualified.
  2. 2. A method of verifying the closure of a carton package as in claim 1 wherein in step S1 the transverse seal area is trimmed to a straight edge of width 1.0 to 1.5 cm.
  3. 3. The method of verifying the closure of a carton package according to claim 1, wherein the red dye solution used in steps S41 and S42 is prepared by dissolving 1.5 g of erythrosin dye in 1 liter of isopropanol.
  4. 4. The method of claim 1, wherein in step S32, after peeling off the aluminum foil layer, if the food contacts the polyethylene film, the glue is left, and the glue is gently brushed off by a soft brush.
  5. 5. The method of verifying the closing effect of a paper cassette package according to claim 1, wherein in the step S42, the width of the bubble-free continuous area at the transverse seal is measured using the 40-fold magnifying glass, and the width is not less than 1.0 mm.
  6. 6. A method for verifying the sealing effect of a carton package according to claim 1, wherein the nitric acid solution and the sodium hydroxide solution used in the method are stored separately in a polytetrafluoroethylene container.
  7. 7. The method for verifying the sealing effect of the paper box package according to claim 1, further comprising a waste liquid treatment step of neutralizing the used acidic waste liquid and the alkaline waste liquid to a pH value of 6-8 respectively and then uniformly treating the acidic waste liquid and the alkaline waste liquid.
  8. 8. The method for verifying the sealing effect of the paper box package according to claim 1, wherein the paper box package is a 6-layer composite packaging material for liquid foods, and comprises a polyethylene layer, a printed paper layer, a first adhesive layer, an aluminum foil layer, a second adhesive layer and a food contact polyethylene layer in sequence from outside to inside.

Description

Method for verifying packaging sealing effect of paper box Technical Field The invention relates to a verification method for the packaging sealing effect of a paper box, and belongs to the field of packaging detection. Background In the modern food and beverage industry, carton packages employing multiple layers of composite materials (e.g., 6 layers of conventional aseptic packages) are widely used for filling and preserving liquid products such as milk, juice, and the like. The sealing integrity of the package, especially the sealing quality of the longitudinal sealing and the transverse sealing, is directly related to the sterility, the quality guarantee period and the edible safety of the content, so that the accurate verification of the sealing effect is a core link of quality control. Currently, the industry generally relies on traditional "peeling test" and visual inspection methods. In operation, the package sealing edge is usually peeled off manually, and then whether defects such as bubbles and gaps exist or not is observed through naked eyes or a low power magnifying glass. However, such conventional methods have several significant limitations in practical applications. Firstly, the general stripping process is difficult to realize thorough and clean separation between layers due to different bonding characteristics among materials of the packaging layers, such as firm bonding of the aluminum foil layer and the adhesive layer and relatively easy separation of the adhesive layer and the polyethylene layer. Residual aluminum foil or adhesive can interfere with the observation of a true sealing interface and even cause pseudo defects, resulting in larger errors in the detection results. Secondly, the whole detection process lacks unified operation standard, for example, the concentration, injection speed and dosage of red dye liquor depend on personnel experience, and the observation of transverse sealing is also stopped at naked eyes or a 10-time magnifying glass, so that the repeatability of detection results of different personnel and different batches is poor, and the deviation rate can exceed 25%. More importantly, the prior method is limited by the observation precision, and the identification capability of micro bubbles (0.5-2 mm), hidden micro slits (0.05 mm) and micro leakage is seriously insufficient, the missed judgment rate is up to more than 30%, and the undiscovered defects form the potential quality risk of the product in the storage and transportation process. In addition, the determination of whether to pass or not often depends on subjective experience, lacks unified criteria based on objective measurement data (e.g., bubble size, effective seal width), and further increases the uncertainty of the results. Therefore, it is needed to provide a method for verifying the sealing effect of the paper box package, so as to solve the above-mentioned technical problems. Disclosure of Invention The invention realizes thorough and clean separation of a multilayer packaging structure through acid-base step treatment and standardized reagent configuration, eliminates interference of interlayer material residues on detection, and establishes objective and quantitative judgment standards by precisely controlling red dye liquor injection parameters and combining ultraviolet light and high-power magnifier observation, thereby improving the identification accuracy of sealing defects and solving the problem of inconsistent detection results caused by difference of experience of operators. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. The technical scheme of the invention is as follows: The method for verifying the packaging sealing effect of the paper box comprises the following steps of: s1, preparing an I-shaped sample, namely packaging a paper box to be detected, cutting the package along a direction parallel to the longitudinal seal direction of the paper box to be detected, cleaning all substances contained in the paper box, reserving the complete structures of the transverse seal and the longitudinal seal areas, and trimming the package into an I shape; s2, peeling the outer layer, namely manually peeling and removing the printing layer and the polyethylene protective layer on the outer surface of the I-shaped sample; s3, chemical layering treatment: S31, acid soaking and stripping, namely completely soaking the sample treated by the S2 into 30% nitric acid solution at room temperature for 30 to 40 minutes, taking out, and slightly rubbing under flowing water until the paper layer and the first adhesive layer adhered with the paper layer completely fall off to expose an aluminum foil layer in the middle of the I-shaped sample; s32, alkaline soaking and stripping, namely completely soaking the I-shaped sample treated by S31 into a sodi