Method and apparatus for packing glass sheets with interleaf paper

Abstract

A packaging apparatus and method includes: positioning two or more glass sheets in the packaging apparatus; and disposing a paper interlayer between adjacent glass sheets in the two or more glass sheets. The paper interlayer has a total lignin content of at least about 5% by weight.

Description

Technical Field

[0001] Cross-referencing of related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 190,501, filed May 19, 2021, the contents of which are the basis of this application and are incorporated herein by reference in their entirety.

[0003] This disclosure relates to a method and apparatus for packaging glass sheets with interlayer paper. Prior Technology

[0004] In the packaging and transportation of glass sheets (such as those used in display applications), interlayer materials (such as interlayer paper) are often inserted between the glass sheets to help protect them from damage. In addition to providing physical protection, interlayer materials are designed to minimize the transfer of contaminants to the glass surface. Furthermore, such interlayer materials should not impart undesirable electrostatic charge levels to the glass or undesirably adhere to the glass surface. Moreover, such materials should perform well over time in a variety of different environments, such as under varying temperature and / or humidity conditions. There remains a continuous need for interlayer materials that meet these and other requirements in a cost-effective manner. Summary of the Invention

[0005] The embodiments disclosed herein include a method for packaging glass sheets. The method includes positioning two or more glass sheets in a packaging apparatus. The method also includes disposing a paper interlayer between adjacent glass sheets of the two or more glass sheets. The paper interlayer contains at least about 5% by weight of total lignin.

[0006] The embodiments disclosed herein also include a packaging apparatus. The packaging apparatus includes two or more glass sheets positioned within the packaging apparatus. The packaging apparatus also includes a paper interlayer disposed between adjacent glass sheets among the two or more glass sheets. The paper interlayer contains at least about 5% by weight of total lignin.

[0007] Further features and advantages disclosed herein will be set forth in the following detailed description, and those skilled in the art will readily understand them by means of the description or by practicing the disclosed embodiments as described herein (including the following detailed description, the claims and accompanying drawings).

[0008] It should be understood that the above overview and the following detailed description of this embodiment are intended to provide an overview or framework for understanding the nature and features of the claimed embodiments. The accompanying drawings are included to provide further understanding, and these drawings are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of this disclosure, and the description is used to explain their principles and operation. Simple Explanation of the Diagram

[0009] Figure 1 is a side perspective view of an exemplary packaging device according to an embodiment disclosed herein;

[0010] Figure 2 is a side perspective view of a plurality of glass sheets and a paper interlayer disposed between adjacent glass sheets in an exemplary packaging device according to an embodiment disclosed herein;

[0011] Figure 3 is a perspective view of an exemplary glass sheet according to an embodiment disclosed herein;

[0012] Figure 4 is a perspective view of an exemplary paper interlayer according to an embodiment disclosed herein;

[0013] Figure 5 is a graph showing the water contact angle of the glass slide's main surface after contact aging and after contact aging and subsequent washing for various paper interlayers;

[0014] Figure 6 is a graph showing the particle density on the main surface of the glass slide after contact and after contact and subsequent washing for various paper interlayers;

[0015] Figure 7 is a graph showing the zeta potential of a glass slide after contact with various paper interlayers; and

[0016] Figures 8A and AB show the surface concentrations of magnesium and aluminum ions for various paper interlayers, respectively. Implementation

[0017] Reference will now be made in detail to the present preferred embodiments of this disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element symbols in all the accompanying drawings will be used to refer to the same or similar parts. However, this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0018] A range may be expressed herein as from "about" a specific value and / or to "about" another specific value. When expressing such a range, another embodiment includes from the one specific value and / or to the other specific value. Similarly, for example, when expressing a value as an approximation by using the antecedent "about," it should be understood that the specific value forms another embodiment. It should further be understood that each endpoint of the range is meaningful both relative to and independent of the other endpoint.

[0019] The directional terms used in this article—for example, up, down, right, left, front, back, top, bottom—are used only with reference to the diagrams drawn and are not intended to imply absolute orientation.

[0020] Unless otherwise expressly stated, it is not intended to interpret any method described herein as requiring its steps to be performed in a particular order, nor is it intended to require a particular orientation of any device. Therefore, it is not intended to infer any order or orientation unless a method claim actually describes the order in which its steps are followed, or any device claim does not actually describe the order or orientation of individual components, or unless it is otherwise specifically stated in the claims or description that the steps will be limited to a particular order, or a particular order or orientation of the components of the device is not described. This applies to any possible non-representational basis for interpretation, including: logical questions regarding the arrangement of steps, procedures, the order of components, or the orientation of components; explicit meaning derived from grammatical organization or punctuation; and the number or type of embodiments described in this specification.

[0021] As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include a plural referent. Thus, for example, unless the context clearly indicates otherwise, a reference to “a” component includes a state having two or more such components.

[0022] As used herein, the term lignin refers to a cross-linked phenolic biopolymer having a weight-average molecular weight of at least about 5,000 g / mole.

[0023] As used herein, the term polysaccharide refers to a polymeric carbohydrate having monosaccharide units linked by glycosidic bonds. Examples include cellulose, amylose, dextran, xylan, mannan, arabinogalactan, and galactan.

[0024] As used herein, the term "two-month aging process with paper interlayer" refers to the test method described herein, in which the paper interlayer is placed in a heavy stack between adjacent glass slides at approximately 54% relative humidity and approximately 20°C for a period of two months. After this period, the glass slides are separated from the paper interlayer and the glass slides are then washed with an aqueous solution containing approximately 1% Semiclean KG for approximately one minute, followed by rinsing in deionized water for approximately one minute, and this process is repeated twice.

[0025] As used herein, the term "vibration process with paper interlayer" refers to the test method described herein, in which a paper interlayer is placed between adjacent glass slides and vibration is performed using the Telecordia standard. After this, the glass slides are separated from the paper interlayer and the glass slides are subsequently washed with an aqueous solution containing approximately 4% Semiclean KG at approximately 70°C and ultrasonically for approximately twelve minutes, followed by rinsing in deionized water at approximately 70°C and ultrasonically for approximately 12 minutes.

[0026] As used herein, the term "paper-intercalated current potential process" refers to the test method described herein, in which the paper intercalation is placed on a glass slide at approximately 20°C and approximately 54% relative humidity for approximately 24 hours, after which the glass slide and paper intercalation are separated.

[0027] As used herein, the term "atomization process with paper interlayer" refers to the test method described herein, in which a perforated paper interlayer is placed on a glass slide at approximately 20°C and approximately 54% relative humidity for approximately 24 to 48 hours, after which the paper interlayer is removed and the glass slide is exposed to vapor. The glass slide is then washed with an aqueous solution containing approximately 1% Semiclean KG for approximately one minute, followed by rinsing in deionized water for approximately one minute, and then the glass slide is further exposed to vapor.

[0028] As used herein, the term "wooden defect" refers to a surface-perceptible non-uniformity, as known to a person skilled in the art and described, for example, in U.S. Patent No. 5,917,935.

[0029] Figure 1 shows a side perspective view of an exemplary packaging apparatus 100 according to an embodiment disclosed herein. The packaging apparatus 100 includes a cover 102, a support member 104, a base 106, a tray 108, and at least one support column 110. The packaging apparatus 100 is assembled to encapsulate a plurality of glass sheets positioned therein.

[0030] In some exemplary embodiments, the cover 102 may comprise metal, polymer, polymer composition, and / or metal / polymer laminate. In some exemplary embodiments, the support member 104, base 106, tray 108, and / or support column 110 may comprise metal (such as aluminum or stainless steel) or polymer composition.

[0031] Figure 2 shows a side perspective view of a plurality of glass sheets 10 and paper interlayers 20 disposed between adjacent glass sheets 10 in an exemplary packaging apparatus 100 according to embodiments disclosed herein. The glass sheets 10 and paper interlayers 20 are positioned on a cushioning member 112, which in turn is positioned on a base 106, wherein the cushioning member 112 can be attached to the base 106 using a suitable adhesive. The cushioning member 112 may, for example, comprise an elastic polymer material, such as a material comprising an ethylene-propylene-diene terpolymer.

[0032] Figure 3 shows a perspective view of an exemplary glass sheet 10 according to an embodiment disclosed herein. The glass sheet 10 has a first main surface 12; a second main surface 14 opposite to the first main surface 12 extending in a direction generally parallel to the first main surface 12 (on the side of the glass sheet 10 opposite to the first main surface 12); and an edge surface 16 extending between the first main surface 12 and the second main surface 14 and extending in a direction generally perpendicular to the first main surface 12 and the second main surface 14.

[0033] Figure 4 shows a perspective view of an exemplary paper interlayer 20 according to an embodiment disclosed herein. The paper interlayer 20 has a first main surface 22 and a second main surface 24 opposite to it, which extends in a direction generally parallel to the first main surface 22 (on the side of the paper interlayer 20 opposite to the first main surface 22).

[0034] The embodiments disclosed herein include the following embodiments in which the total lignin content of the paper interlayer 20 is at least about 5% by weight, such as at least about 10% by weight, and further such as at least about 15% by weight, and even further such as at least about 20% by weight, including from about 5% by weight to about 40% by weight, and further including from about 10% by weight to about 35% by weight, and even further including from about 20% by weight to about 30% by weight.

[0035] The embodiments disclosed herein include the following embodiments in which the total polysaccharide content contained in the paper interlayer 20 does not exceed about 80% by weight, such as not exceeding about 75% by weight, and further such as not exceeding about 70% by weight, and even further such as not exceeding about 65% by weight, including from about 40% by weight to about 80% by weight, and further including from about 45% by weight to about 75% by weight, and even further including from about 50% by weight to about 70% by weight.

[0036] Table 1 summarizes the contents of five paper interlayers, the first two of which are comparative paper interlayers and the last three of which are exemplary paper interlayers according to the embodiments disclosed herein. The comparative interlayers are illustrated in Table 1 as "Paper 1" and "Paper 2," and specifically, are commercially available polysaccharide-based paper interlayers. The exemplary paper interlayers are illustrated in Table 1 as "Paper 3," "Paper 4," and "Paper 5," and specifically, are commercially available recycled newsprint (in the case of "Paper 3") and commercially available natural newsprint (in the case of "Paper 4" and "Paper 5"). The composition of the paper was determined by submitting approximately 30 grams of each paper to a large-volume lignocellulose analysis laboratory according to the Celignis Biomass Analysis Laboratory P10 protocol.

[0037] Table 1: Paper type: Paper 1 Paper 2 Paper 3 Paper 4 Paper 5 Total polysaccharides (wt%) 86.56 95.13 60.1 59.9 59.4 Glucan (wt%) 76.95 80.6 42.8 42.6 42.5 Xylan (wt%) 4.68 8.33 4.5 4.4 4.1 Mannan (wt%) 4.37 5.46 10 9.9 9.7 Arabica polysaccharides (wt%) 0.35 0.52 1 0.9 1 Galactan (wt%) 0.21 0.21 - - - Klason lignin (wt%) 1.66 0.56 28.9 35.5 27.5 Acid-soluble lignin (wt%) 0.73 0.71 0.6 0.7 0.8 Extract (wt%) 9.76 1.69 4.2 3.7 3.3 Starch (wt%) 0.07 0.03 0.04 0.05 0.16 Ash content (wt%) 0.25 0.19 0.3 0.8 0.6

[0038] The glass sheet 10 may comprise a variety of glass compositions. For example, the embodiments disclosed herein include the following embodiments in which the glass sheet 10 comprises an alkali-free glass composition comprising 58-65 wt% SiO2, 14-20 wt% Al2O3, 8-12 wt% B2O3, 1-3 wt% MgO, 5-10 wt% CaO, and 0.5-2 wt% SrO. The glass sheet 10 may also comprise an alkali-free glass composition comprising 58-65 wt% SiO2, 16-22 wt% Al2O3, 1-5 wt% B2O3, 1-4 wt% MgO, 2-6 wt% CaO, 1-4 wt% SrO, and 5-10 wt% BaO. In addition, the glass sheet 10 may contain an alkali-free glass composition comprising 57-61 wt% SiO2, 17-21 wt% Al2O3, 5-8 wt% B2O3, 1-5 wt% MgO, 3-9 wt% CaO, 0-6 wt% SrO, and 0-7 wt% BaO. The glass sheet 10 may also contain an alkali-containing glass composition comprising 55-72 wt% SiO2, 12-24 wt% Al2O3, 10-18 wt% Na2O, 0-10 wt% B2O3, 0-5 wt% K2O, 0-5 wt% MgO, and 0-5 wt% CaO. In some embodiments, this alkali-containing glass composition may also contain 1-5 wt% K2O and 1-5 wt% MgO.

[0039] In some exemplary embodiments, the glass sheet 10 has a thickness of less than about 1 millimeter, such as ranging from about 0.1 millimeter to about 1 millimeter, including from about 0.2 millimeter to about 0.8 millimeter, and further including from about 0.3 millimeter to about 0.7 millimeter, including a thickness of about 0.5 millimeter.

[0040] Example

[0041] The embodiments disclosed herein are further illustrated by the following non-limiting examples.

[0042] Example 1:

[0043] A two-month aging process was performed on paper interlayers, in which the paper interlayers were stacked at approximately 5 kg weight between clean Corning® Eagle XG® glass plates (with a main surface area of ​​approximately 4 inches by 4 inches) at approximately 20°C and approximately 54% relative humidity for two months. The glass plates were then separated from the paper interlayers, and the glass plates were subsequently washed for approximately one minute with an aqueous solution containing approximately 1% Semiclean KG (produced by Yokohama Oils and Fats Industry Co., Ltd.), followed by rinsing in deionized water for approximately one minute, repeated twice. Specifically, this process was performed on the following five types of paper interlayers: Paper 1, Paper 3, Paper 4, and Paper 5 as described above with reference to Table 1, and another commercially available natural newsprint (“Paper 6”). Before and after the washing and rinsing steps, the water contact angle of the main surface of the glass slides in contact with each paper interlayer was obtained by measuring the angle formed by approximately 2 μL of water droplets with the glass surface, as determined using a Kruss DSA 100E droplet shape analyzer (five measurements per sample), and the results are shown in Figure 5. As can be seen from Figure 5, a water contact angle of less than approximately 10 degrees was observed for all glass slides after the washing and rinsing steps. A water contact angle of less than approximately 10 degrees indicates that the main surface of the glass slide has acceptable hydrophilicity.

[0044] Example 2:

[0045] A vibration process was performed with paper interlayers positioned between adjacent Corning® Eagle XG® glass plates (20 plates in total, each with a main surface area of ​​approximately 4 inches by 4 inches) and vibrated using the Telecordia standard (GR63 transport vibration, Chapter 4.4.5). The glass plates and paper interlayers were then separated, and the glass plates were subsequently washed for approximately twelve minutes at approximately 70°C and ultrasonically with an aqueous solution containing approximately 4% Semiclean KG, followed by rinsing in deionized water for twelve minutes at approximately 70°C and ultrasonically. Specifically, this process was performed for the following four types of paper interlayers (each interlayer was tested twice): Paper 1, Paper 3, Paper 4, and Paper 5 as described above in Table 1. Furthermore, for each paper interlayer, vibration processes were performed at approximately 20°C at approximately 20%, approximately 50%, and approximately 80% relative humidity. After each experimental run, before and after the washing and rinsing steps, particles with a diameter greater than approximately 0.3 micrometers were counted on the main surface of each glass slide using a Toray Engineering HS830 particle counter, and the results are shown in Figure 6. As can be seen from Figure 6, after washing, the main surface of each glass slide had fewer than approximately 30 particles per square centimeter with a diameter greater than approximately 0.3 micrometers.

[0046] Example 3:

[0047] A zeta potential process with paper interlayers was performed, wherein the paper interlayers were placed on a clean Corning® Eagle XG® glass slide (with a main surface area of ​​approximately 2 inches by 2 inches) at approximately 54% relative humidity and approximately 20°C for approximately 24 hours. Specifically, this process was performed on the following four types of paper interlayers: paper 1, paper 3, paper 4, and paper 5 as described above in Table 1. The glass slides and paper interlayers were then separated, and the glass surface was analyzed for zeta potential using an Anton Paar SurPass system for electrokinetic analysis, and the results are shown in Figure 7. This system measures the zeta potential of the glass surface as a function of pH via zeta potential and zeta current methods. As can be seen from Figure 7, the main surfaces of each glass slide have a zeta potential ranging from about -40 mV to about -80 mV at a pH of about 3, a zeta potential ranging from about -70 mV to about -110 mV at a pH of about 7, and a zeta potential ranging from about -80 mV to about -120 mV at a pH of about 11, which is not different from the control values. These zeta potentials indicate an acceptable level of electrostatic repulsion between the glass slide and the paper interlayer.

[0048] Example 4:

[0049] A paper-interlayer atomization process was performed, in which paper with a main surface area of ​​approximately 4 inches by 4 inches and perforations of approximately 0.25 inches in diameter was placed on a Corning® Eagle XG® glass plate (with a main surface area of ​​approximately 4 inches by 4 inches) at approximately 20°C and approximately 54% relative humidity for approximately 24 to 48 hours. The glass plate was then separated from the paper and exposed to a brief vapor. The glass plate was then washed at approximately 50°C with an aqueous solution containing approximately 1% Semiclean KG for approximately one minute, followed by rinsing in deionized water for approximately one minute, repeated twice. This step was followed by further exposure of the glass plate to a brief vapor. Specifically, this process was performed on two types of paper interlayers: paper 1 and paper 3 as described above with reference to Table 1. In the case of paper 3 interlayer, although visible wood-like defects were observed on the main surface of the glass plate after exposure to the first vapor, these visible defects did not exist after exposure to the second vapor for both paper 1 and paper 3 interlayers.

[0050] Example 5:

[0051] Layers 1, 3, 4, 5, and 6 of paper (each with a main surface area of ​​approximately 1 inch by 1 inch) were analyzed using time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the results of normalized magnesium and aluminum ion intensities are shown in Figures 8A and 8B, respectively. Specifically, an IONTOF ToF-SIMS NCS with an M6 analyzer (ion beam characterization as follows: Bi3+, mass spectrometry mode, 400 μm beam-defined aperture, 200 μm by 200 μm random rasterization area with a density of 128 x 128 pixels, 350 μs cycle time, and approximately 0.7–0.8 pA pulse current) was used, with a low-energy diffuse electron gun used for charge compensation during analysis. The analysis time was approximately 3 minutes, comprising 31 beam scans and a total ion dose of approximately 1.94 x 10¹¹ ions / cm². Peak areas were normalized by the sum of all detected ions, with each interlayer analyzed four times (positive mode). The graphs shown represent the average of the four analyses, and the error bars represent the standard deviation. As can be seen from Figures 8A and 8B, the main surfaces of each of the paper 3-6 interlayers have normalized magnesium ion intensities of less than approximately 2 and normalized aluminum ion intensities of less than approximately 2. Magnesium and aluminum indicate the presence of talc and aluminum silicate.

[0052] In some exemplary embodiments, after a two-month aging process and washing with a paper interlayer, the main surface of the glass sheet has a water contact angle of less than about 10 degrees, such as less than about 8 degrees, and further such as less than about 6 degrees, and even further such as less than about 4 degrees, such as from about 1 degree to about 10 degrees, and further such as from about 2 degrees to about 8 degrees, and even further such as less than about 3 degrees to about 6 degrees.

[0053] In some exemplary embodiments, after the vibration process with the paper interlayer, the main surface of the glass slide after washing has fewer than about 30 particles per square centimeter having a diameter greater than about 0.3 micrometers, such as fewer than about 25 particles per square centimeter, and further such as fewer than about 20 particles per square centimeter, and even further such as fewer than about 15 particles per square centimeter, including from about 5 particles per square centimeter to about 30 particles per square centimeter, and further including from about 10 particles per square centimeter to about 25 particles per square centimeter.

[0054] In some exemplary embodiments, after analyzing the surge potential of the glass surface before and after contact with the paper interlayer, the main surface of the glass sheet has a zeta potential ranging from about -40 mV to about -80 mV, such as from about -45 mV to about -75 mV, at a pH of about 3; a zeta potential ranging from about -70 mV to about -110 mV, such as from about -75 mV to about -105 mV, at a pH of about 7; and a zeta potential ranging from about -80 mV to about -120 mV, such as from about -85 mV to about -115 mV, at a pH of about 11.

[0055] In some exemplary embodiments, after the atomization process with paper interlayer, the main surface of the glass sheet shows no visible wood-like defects.

[0056] In some exemplary embodiments, the main surface of the paper interlayer has a normalized magnesium ion intensity of less than about 2, such as less than about 1.5, including from about 0.5 to about 2, and further including from about 1 to about 1.5, and a normalized aluminum ion intensity of less than about 2, such as less than about 1.5, including from about 0.5 to about 2, and further including from about 1 to about 1.5, as determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

[0057] The embodiments disclosed herein enable cost-effective packaging and transportation of glass sheets (such as those for display applications) including a main surface having, for example, acceptable hydrophilicity, reduced submicron particle density, acceptable surge potential, absence of visible wood pull defects, and reduced talc contamination.

[0058] It will be apparent to those skilled in the art that various modifications and alterations can be made to the embodiments disclosed herein without departing from the spirit and scope of this disclosure. Therefore, this disclosure is intended to cover such modifications and alterations, provided that they fall within the scope of the appended claims and their equivalents.

[0059] 10: Glass plate 12, 22: First primary surface 14, 24: Second primary surface 16: Edge Surface 20: Paper interlayer 100: Packaging Equipment 102: Cover piece 104: Supporting components 106: Base 106: Base 108: Pallet 110: Support column 112: Pad component

[0060] Domestic storage information (please note in order of storage institution, date, and number) none Overseas storage information (please note in the order of storage country, institution, date, and number) none

Claims

1. A method for packaging glass sheets, comprising the steps of: positioning two or more glass sheets in a packaging apparatus; and disposing a paper interlayer between adjacent glass sheets among the two or more glass sheets; wherein: The paper interlayer contains at least about 5% by weight of total lignin.

2. The method as described in claim 1, wherein the paper interlayer contains a total lignin content ranging from about 5% by weight to about 40% by weight.

3. The method as described in claim 1, wherein the paper interlayer contains a total polysaccharide content of no more than about 80% by weight.

4. The method as described in claim 3, wherein the paper interlayer contains a total polysaccharide content ranging from about 40% by weight to about 80% by weight.

5. The method as described in claim 1, wherein after one or two months of aging and washing processes with the paper interlayer, one of the main surfaces of any one of the two or more glass plates has a water contact angle of less than about 10 degrees.

6. The method as described in claim 1, wherein after a vibration and washing process with the paper interlayer, the main surface of any one of the two or more glass plates has fewer than about 30 particles per square centimeter having a diameter greater than about 0.3 micrometers.

7. The method as claimed in claim 1, wherein after a surge potential process with the paper interlayer, one of the main surfaces of any one of the two or more glass plates has a zeta potential ranging from about -40 mV to about -80 mV at a pH of about 3, a zeta potential ranging from about -70 mV to about -110 mV at a pH of about 7, and a zeta potential ranging from about -80 mV to about -120 mV at a pH of about 11.

8. The method as described in claim 1, wherein after a fogging process with the paper interlayer, the main surface of any one of the two or more glass plates shows no visible wood-like defects after washing.

9. The method as described in claim 1, wherein one of the main surfaces of the paper interlayer has a normalized magnesium ion strength of less than about 2 and a normalized aluminum ion strength of less than about 2, as determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

10. A packaging apparatus comprising: two or more glass sheets positioned within the packaging apparatus; and a paper interlayer disposed between adjacent glass sheets among the two or more glass sheets; wherein: The paper interlayer contains at least about 5% by weight of total lignin.

11. The packaging equipment as claimed in claim 10, wherein the paper interlayer contains a total lignin content ranging from about 5% by weight to about 40% by weight.

12. The packaging equipment as claimed in claim 10, wherein the paper interlayer contains a total polysaccharide content of no more than about 80% by weight.

13. The packaging apparatus as claimed in claim 12, wherein the paper interlayer contains a total polysaccharide content ranging from about 40% by weight to about 80% by weight.

14. The packaging equipment as claimed in claim 10, wherein after one or two months of aging and washing processes with the paper interlayer, the main surface of any one of the two or more glass sheets has a water contact angle of less than about 10 degrees.

15. The packaging equipment as claimed in claim 10, wherein after a vibration and washing process with the paper interlayer, the main surface of any one of the two or more glass sheets has fewer than about 30 particles per square centimeter having a diameter greater than about 0.3 micrometers.

16. The packaging apparatus as claimed in claim 10, wherein after a surge potential process with the paper interlayer, one of the main surfaces of any one of the two or more glass plates has a zeta potential ranging from about -40 mV to about -80 mV at a pH of about 3, a zeta potential ranging from about -70 mV to about -110 mV at a pH of about 7, and a zeta potential ranging from about -80 mV to about -120 mV at a pH of about 11.

17. The packaging apparatus as claimed in claim 10, wherein after a frosting process with the paper interlayer, the main surface of any one of the two or more glass sheets shows no visible wood pull defects after washing.

18. The packaging apparatus as claimed in claim 10, wherein one of the main surfaces of the paper interlayer has a normalized magnesium ion strength of less than about 2 and a normalized aluminum ion strength of less than about 2, as determined by time-of-flight secondary ion mass spectrometry (TOF-SIMS).

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