Paper mould killing method and application

Abstract

The invention belongs to the technical field of cultural relic protection, and relates to a paper mould killing method and application, the paper mould killing method comprises the following steps: putting borate in a non-woven fabric bag, and clamping paper to be killed in the non-woven fabric bag; then the non-woven fabric bag is placed in a vacuum tank; and discontinuous vacuum treatment is carried out in an environment with the humidity of 50%-90%, and mold killing of the paper is completed. Under the humidity environment, the borate is combined with discontinuous vacuum to sterilize the mould on the paper. The method is efficient in sterilization and good in safety, and paper can be prevented from being damaged and stored for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of cultural relics protection and relates to a method for disinfecting mold on paper and an application thereof. Background Art

[0002] Paper materials (including paintings and calligraphy, ancient books and documents, archival documents, newspapers and magazines) are one of the important media for the recording and dissemination of information in the world, and are of great significance for historical and cultural research. However, as time goes by, paper is inevitably damaged by aging, acidification, mold contamination and other damages. Mold can produce a variety of hydrolases to decompose paper cellulose, which is one of the most important reasons for the damage of paper cultural relics in libraries, archives and museums. In addition, mold in the environment can cause a series of symptoms such as human allergies, respiratory symptoms (especially rhinitis), aggravated asthma, and even allergic pneumonia. At the same time, the mycotoxins produced by mold can suppress the human immune system and aggravate the condition. These factors lead to the risk of high occupational exposure levels for library and archive staff almost higher than any other office workers. Therefore, it is necessary to disinfect the mold on paper.

[0003] At present, there are many methods for sterilizing mold, such as disinfectants, high pressure sterilization, ultraviolet sterilization and microwave sterilization. However, these methods will cause changes in the structural characteristics of paper as a biological material, and are not suitable for paper materials. Some researchers have proposed the use of gaseous ethylene oxide and gamma rays to sterilize paper materials. However, ethylene oxide is carcinogenic, harmful to human health, and has poor safety. Gamma rays will damage the paper if the irradiation dose is too high, making it difficult to preserve the paper material for a long time. If the irradiation dose is strictly controlled to avoid damage to the paper, the operation will be complicated, the sterilization efficiency will be low, and the cost will be high. In addition, existing sterilization materials or antibacterial agents often exist in liquid form, and paper materials are easy to absorb water, which can easily cause damage to paper cultural relics, which is inconsistent with the sterilization conditions of paper cultural relics.

[0004] Therefore, it is an urgent problem to find a safe and efficient sterilization method that can avoid paper damage and preserve it for a long time. Summary of the invention

[0005] The invention provides a method for disinfecting mold in paper, which solves the technical problems of poor safety, easy damage and difficulty in long-term preservation of paper and low sterilization efficiency in the existing disinfecting of paper cultural relics.

[0006] The invention uses borate combined with discontinuous vacuum in a humid environment to achieve sterilization of paper mold. The method of the invention has high sterilization efficiency and good safety, and can avoid paper damage and enable long-term storage.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for disinfecting mold on paper comprises the following steps:

[0009] Put borate in a non-woven bag and sandwich the paper to be disinfected between two non-woven bags; then put the non-woven bag in a vacuum tank; perform discontinuous vacuum treatment at 90% humidity to complete the disinfection of paper mold.

[0010] It is further defined that the mass ratio of the borate to paper is at most 2000:1.

[0011] Further defined, the borate is a water-soluble borate; the water-soluble borate is Na 2 B 8 O 13 ·4H 2 O、Na 2 B 4 O 7 、Na 2 B 4 O 7 10H 2 O or borax.

[0012] It is further defined that the discontinuous vacuum treatment is: first evacuate until the pressure is maintained at not less than 0.4 MPa; then release the pressure every 2 hours; the time of the discontinuous vacuum treatment is 1 to 5 days.

[0013] It is further specified that the paper after mold disinfection has obvious fiber morphology, the horizontal / vertical double fold error is within 2, ΔE<3; and the pH value of the paper is alkaline.

[0014] An application of borate combined with discontinuous vacuum treatment in the disinfection of paper cultural relics with mold in a humid environment.

[0015] It is further limited that the humidity is 50% to 90%, the maximum mass ratio of borate to paper cultural relics is 2000:1, and the time of discontinuous vacuum treatment is 1 to 5 days.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention utilizes borate combined with discontinuous vacuum treatment in a humidity environment of 50% to 90%, wherein the discontinuous vacuum can promote the penetration of borate to achieve sterilization of paper mold. The method of the present invention is efficient in sterilization and safe, and can avoid damage to paper, thereby enabling the paper to be stored for a long time.

[0018] 2. The present invention has been found through comparison that the present invention has 1 O 2 The production of boron will synergize with borate to promote the improvement of bactericidal effect. The boron content in the paper after disinfection treatment is high and the bactericidal effect is good.

[0019] 3. The present invention found through comparison that the paper has obvious fiber morphology, the horizontal / vertical double fold error is within 2, and ΔE<3; this shows that the disinfection treatment will not change the original fiber characteristics of the paper, nor will it cause obvious color difference to the color of the paper, and will have little impact on the performance of the paper, and will not cause damage to the paper, making it more suitable for the disinfection of mold on paper cultural relics. At the same time, the pH value of the paper after treatment is more alkaline, which can prevent the acidification of the paper to a certain extent and extend the shelf life of the paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The flat plate image and SEM image of mold on paper after being treated by the mold disinfecting method of the present invention;

[0021] Figure 2 Characterization of paper performance after being treated by the mold disinfecting method of the present invention;

[0022] Figure 3 Different treatment methods for disinfecting mold on paper;

[0023] Figure 4 This is the growth plate diagram of Aspergillus flavus under different treatment methods;

[0024] Figure 5 The SEM results of paper surface after treatment in Control group, BDV group and ZnDV group;

[0025] Figure 6 The chemical composition and chemical valence of the intermediate paper surface after BDV treatment;

[0026] Figure 7 The surface structures of paper samples after disinfection at different humidity in Examples 1 to 3 are shown. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0028] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0029] Technologies, methods, and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0030] It should also be understood that the specific embodiments described above are only used to explain the present invention, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0031] A method for disinfecting mold on paper comprises the following steps:

[0032] Put borate in a non-woven bag and clamp the paper to be disinfected between two non-woven bags; then put the non-woven bag in a vacuum tank; perform discontinuous vacuum treatment at a humidity of 50% to 90% to complete the disinfection of paper mold.

[0033] It is further specified that the maximum mass ratio of borate to paper is 2000:1.

[0034] It is further defined that the borate is a water-soluble borate; preferably, the water-soluble borate is Na 2 B 8 O 13 ·4H 2 O、Na 2 B 4 O 7 、Na 2 B 4 O 7 10H 2 O or borax Na 2 [B 4 O 5 (OH) 4 ]·8H 2 O.

[0035] It is further defined that the discontinuous vacuum treatment is: first evacuate until the pressure is maintained at not less than 0.4 MPa; then release the pressure every 2 hours; the time of the discontinuous vacuum treatment is 1 to 5 days.

[0036] After the mold is sterilized by the method of the present invention, the paper has an obvious fiber morphology, the error of the horizontal / vertical double fold number is within 2, ΔE<3; and the pH value of the paper is alkaline.

[0037] The specific implementation of the paper mold disinfection method of the present invention is described below with reference to embodiments.

[0038] Example 1

[0039] The paper mold disinfecting method provided in this embodiment comprises the following steps:

[0040] Place 200g Na in a non-woven bag. 2 B 8 O 13 ·4H 2 O; then 10 sheets of paper to be sterilized (0.1 g) were sandwiched between the 2 B 8 O 13 ·4H 2O in the middle of the non-woven bag; then put the non-woven bag into a vacuum tank and perform discontinuous vacuum treatment at 90% humidity; specifically, first evacuate the air and maintain the pressure at 0.4Mpa, and after releasing the pressure every 2 hours, the pressure is still maintained at 0.4Mpa, and the discontinuous vacuum treatment is performed for a total of 3 days to complete the mold elimination.

[0041] Example 2

[0042] The paper mold disinfecting method provided in this embodiment comprises the following steps:

[0043] Place 200g Na in a non-woven bag. 2 B 8 O 13 ·4H 2 O; then 10 sheets of paper to be sterilized (0.1 g) were sandwiched between the 2 B 8 O 13 ·4H 2 O in the middle of the non-woven bag; then put the non-woven bag into a vacuum tank and perform discontinuous vacuum treatment at 80% humidity; specifically, first evacuate the air and maintain the pressure at 0.4Mpa, and after releasing the pressure every 2 hours, the pressure is still maintained at 0.4Mpa. A total of 3 days of discontinuous vacuum treatment are performed to complete the mold elimination.

[0044] Example 3

[0045] The paper mold disinfecting method provided in this embodiment comprises the following steps:

[0046] Place 200g Na in a non-woven bag. 2 B 8 O 13 ·4H 2 O; then 10 sheets of paper to be sterilized (0.1 g) were sandwiched between the 2 B 8 O 13 ·4H 2 O in the middle of the non-woven bag; then put the non-woven bag into a vacuum tank and perform discontinuous vacuum treatment at 50% humidity; specifically, first evacuate the air and maintain the pressure at 0.4Mpa, and after releasing the pressure every 2 hours, the pressure is still maintained at 0.4Mpa. A total of 3 days of discontinuous vacuum treatment are performed to complete the mold elimination.

[0047] In order to illustrate the advantages of the paper mold disinfection method of the present invention, the disinfected paper placed in the middle of the non-woven bag was selected as the experimental group (BDV group), and the undisinfected paper was used as the control group (Control group) to carry out the following performance test.

[0048] Test 1

[0049] The common fungi on the BDV group paper and the Control group paper were observed by flat plate and SEM. The results are as follows: Figure 1 As shown in the figure, A: Talaromyces variabilis; B: Aspergillus niger; C: Aspergillus flavus; D: Trichoderma harzianum; E: Talaromyces purpureogenus.

[0050] See also Figure 1 The mold on the surface of the papers in the Control group grew vigorously, covered with a large number of spores and hyphae; no obvious mold growth was observed on the surface of the papers in the BDV group, and no obvious spores were attached to the paper fibers. This shows that the paper mold disinfecting method of this embodiment has a good antibacterial effect on the five fungi after three days of treatment.

[0051] Test 2

[0052] The BDV group paper and the Control group paper were subjected to SEM micromorphology characterization test, folding resistance test, tensile strength test and colorimetric test. The results are as follows: Figure 2 As shown, among which: (A) micromorphology characterization; (B) folding resistance; (C) tensile strength; (D) colorimetry.

[0053] See also Figure 2 , SEM results showed that after treatment with the BDV group, the paper fibers were continuous without breaks, randomly arranged and interwoven into a complex network, with no significant difference compared with the Control. Compared with the Control group, the transverse / longitudinal double fold error of the paper sample in the BDV group was within 2, and P>0.05. At the same time, the transverse / longitudinal tensile strength of the treated paper samples was 0.6366MPa / 0.3939MPa, which was not significantly different from that of the Control group (P>0.05). When ΔE<3, it is considered that there is no significant difference in color. After 1 day, 3 days and 5 days of treatment, the ΔE values ​​were all less than 3, and the color of the paper did not change significantly. These results show that the paper mold disinfection method of this embodiment will not change the characteristics of the paper fibers after treatment, nor will it cause obvious color difference in the color of the paper, and has little effect on the performance of the paper.

[0054] Test 3

[0055] In this experiment, Aspergillus flavus was isolated from mold-contaminated archives in Shaanxi Provincial Archives as a representative of mold, and the performance superiority of the paper mold disinfection method of the present invention was further explored.

[0056] The samples uniformly sprayed with Aspergillus flavus spores were treated in different groups (see Figure 3 ).

[0057] The mice were divided into 8 groups: Control group, DV group, BDV group, BCV group, BAP group, BDV-15 group, ZnDV group, and ZnCV group. The treatment conditions of each group were as follows:

[0058] Control group: paper samples were placed in a room temperature and pressure without Na 2 B 8 O 13 ·4H 2 O humidity 90% in a vacuum tank;

[0059] BAP group: paper samples were placed in a room temperature and pressure atmosphere with Na 2 B 8 O 13 ·4H 2 O humidity 90% in a vacuum tank;

[0060] DV group: paper samples were placed in a Na-free 2 B 8 O 13 ·4H 2 O humidity 90% vacuum tank discontinuous vacuum treatment;

[0061] BDV group: paper samples were placed in 2 B 8 O 13 ·4H 2 Humidity of O 90% Vacuum tank discontinuous vacuum;

[0062] BDV-15 group: paper samples were placed in 2 B 8 O 13 ·4H 2 O humidity 15% vacuum tank discontinuous vacuum;

[0063] BCV group: paper samples were placed in Na 2 B 8 O 13 ·4H 2 O humidity 90% continuous vacuum in vacuum tank;

[0064] ZnDV group: paper samples were placed in a vacuum tank with Nano ZnO at a humidity of 90% and subjected to discontinuous vacuum;

[0065] ZnCV group: The paper samples were placed in a vacuum tank with a humidity of 90% and continuously vacuumed.

[0066] Each of the above groups uses 10 paper samples, which are numbered from 1, 2, ..., 5, ..., 10 and stacked in order. After each group is treated under the above conditions for 3 days, the paper sample numbered 5 in each group is taken out for cultivation, and the growth plate of Aspergillus flavus on the paper is observed. Figure 4 shown.

[0067] See also Figure 4 The surface of the paper samples in the control group had dense and compact mycelium and obvious yellow spores; in the BAP group, DV group, BDV-15 group, ZnDV group and ZnCV group, although the surface of the paper samples was covered with dense mycelium, the spore formation was moderately reduced. The surface of the BCV group was covered with a little mycelium, but the spore formation was significantly reduced; after treatment under the BDV group, the surface of the paper was smooth and there were no obvious Aspergillus flavus spores. The results showed that 90% humidity, Na 2 B 8 O 13 ·4H 2 O and discontinuous vacuuming, the single condition had a poor inhibitory effect on Aspergillus flavus. 2 B 8 O 13 ·4H 2 When the paper samples were treated with the three conditions of humidity, borate and discontinuous vacuuming, the inhibition effect on aflatoxin was better. This shows that the combined treatment of humidity, borate and discontinuous vacuuming can greatly improve the disinfecting effect of paper mold.

[0068] After each group of treatments was completed, paper samples from the Control group, BDV group, and ZnDV group were taken to further observe the surface structures of the three groups of paper samples using TFSEM. Figure 5 shown.

[0069] See also Figure 5 The surface of the paper samples in the Control group was covered with a large number of hyphae and spores, and no obvious paper fiber structure was observed; after the ZnDV group was treated, although the surface hyphae and spores of the paper samples were less than those in the Control group, it was still difficult to observe the paper fiber structure; after the BDV group was treated, it was observed that the paper samples had obvious fiber morphology, and no obvious spores were attached to the fiber surface when the ambient humidity was 90%, which was consistent with the plate results. This further illustrates that the combined treatment of humidity, borate and discontinuous vacuuming not only improves the fungus disinfecting effect, but also does not damage the paper.

[0070] Test 4

[0071] Referring to the method of Experiment 3, paper sample numbered 5 (i.e., the paper sample in the middle position) was taken from the Control group, BAP group, and BDV group after treatment.

[0072] Test process: (1) The composition, valence and boron content of paper samples in the control group, BAP group and BDV group were tested by XPS and ICPMS, and the pH value of the paper was tested. (2) Since the half-life of oxygen is short, it is difficult to detect it directly; therefore, a spin trap was used to detect the pH value of the paper. 1 O 2 The ESR spectrum in the vacuum tank after BDV treatment was detected using the capture agent TEMP. Figure 6 As shown in the figure: (A) The composition and valence of the paper surface after treatment in the Control group; (B) The composition and valence of the paper surface after treatment in the BAP group (i.e., Na 2 B 8 O 13 ·4H 2 (O) Composition and valence of the paper surface after treatment; (C) Composition and valence of the paper surface after treatment with the BDV group; (D) Boron content of paper after treatment with different groups; (E) pH value of paper after treatment with different groups; (F) ESR spectrum of the paper after treatment with the BDV group using TEMP as a spin trap.

[0073] See also Figure 6 , and found that the boron valence on the paper surface ( Figure 6 C)With Na 2 B 8 O 13 ·4H 2 O( Figure 6 B) has similar valence. This indicates that Na 2 B 8 O 13 ·4H 2 O. Inductively coupled plasma-Mass Spectrometry (ICP-MS) was used to detect the boron element in paper. The boron content of paper in the BDV group was higher, reaching 2138 mg / kg; and was significantly higher than that in the BAP group ( Figure 6 D) XPS spectrum and ICPMS results confirmed that BDV group treatment can increase the Na 2 B 8 O 13 ·4H 2 O. At the same time, the pH test results showed that the pH value of the paper in the BDV group was more alkaline than that in the BAP group, which could prevent the acidification of the paper and prolong the storage time of the paper. The ESR spectrum showed that after the BDV group was treated, TEMP had obvious ESR signals, indicating that there was 1 O 2 (Active oxygen) production. 1 O2 (Reactive oxygen species) have an oxidative potential and can effectively react with cell components such as nucleic acids, unsaturated membrane lipids and protein components, playing an important role in the inactivation of fungi. Therefore, the improvement of the inhibitory effect of the BDV group on mold is due to Na 2 B 8 O 13 ·4H 2 O and 1 O 2 (Active oxygen) The result of the combined action.

[0074] Test 5

[0075] The paper samples disinfected at different humidity in Examples 1 to 3 were taken respectively, and the paper at the same position in 10 sheets were taken, which were respectively recorded as BDV-90, BDV-80 and BDV-50; then the surface structures of the three groups of paper samples were further observed by TFSEM. The results are as follows Figure 7 shown.

[0076] See also Figure 7 Compared with the Control group and BDV-15 group in Experiment 3, the area of ​​spores attached to the fiber surface of the paper treated with BDV-50 was reduced to a greater extent; while observing BDV-80 and BDV-90, it can be seen that with the increase of environmental humidity, the spores attached to the fiber surface continued to decrease, but the reduction was not large, and finally when the environmental humidity was 90%, no obvious spores were attached to the fiber surface. The above results show that when the environmental humidity is between 50% and 90%, the paper sample treated with the disinfection method of the present invention has obvious fiber morphology and has a better disinfection effect on mold; and the environmental humidity of 90% is the best preferred humidity.

[0077] Through the above experimental research, it can be seen that discontinuous vacuum treatment of paper in a humid environment can promote the penetration of the sterilization material solid borate, thereby enhancing the mold killing effect of moldy paper. Not only can it improve the sterilization effect, but it will not damage the paper, allowing the paper to be preserved for a long time. Therefore, solid borate combined with discontinuous vacuum treatment in a humid environment can be used to disinfect mold on paper cultural relics.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the present invention, although the present invention has been described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the technical solutions of the present invention can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for disinfecting mold on paper, characterized in that: The following steps are involved: Put borate in a non-woven bag and clamp the paper to be disinfected in the non-woven bag; then place the non-woven bag in a vacuum tank; perform discontinuous vacuum treatment in a humidity environment of 50% to 90% to complete the disinfection of paper mold.

2. The method for disinfecting mold on paper according to claim 1, characterized in that: The mass ratio of the borate to paper is at most 2000:

1.

3. The method for disinfecting mold on paper according to claim 1, characterized in that: The borate is a water-soluble borate; the water-soluble borate is Na2B8O 13 ·4H2O, Na2B4O7, Na2B4O7·10H2O or borax.

4. The method for disinfecting mold on paper according to claim 1, characterized in that: The discontinuous vacuum treatment is: firstly vacuuming until the pressure is maintained at not less than 0.4 MPa; then releasing the pressure every 2 hours; the time of the discontinuous vacuum treatment is 1 to 5 days.

5. The method for disinfecting mold on paper according to claim 1, characterized in that: After mold disinfection, the paper has obvious fiber morphology, the horizontal / vertical double fold error is within 2, ΔE<3; and the pH value of the paper is alkaline.

6. An application of borate combined with discontinuous vacuum treatment in the disinfection of mold on paper cultural relics in a humid environment.

7. The use according to claim 6, characterized in that: The humidity is 50% to 90%, the maximum mass ratio of borate to paper cultural relics is 2000:1, and the time of discontinuous vacuum treatment is 1 to 5 days.

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