Test method for the fogging performance of protective film

Abstract

This application relates to the field of plastic protective film technology, and in particular to a method for testing the fogging performance of a protective film. In an embodiment of this application, a protective film is adhered to the surface of an object that meets a surface cleanliness standard. The object with the protective film is then placed under predetermined test conditions for a predetermined time, after which the protective film is removed. In a dark environment, the object is irradiated with strong light, and the surface is observed to determine whether fogging occurs. Therefore, this embodiment of the application can achieve the testing of the fogging performance of a protective film.

Description

Technical Field

[0001] This application relates to the field of protective film technology, and in particular to a method for detecting the fogging performance of a protective film. Background Technology

[0002] Protective films (such as PU protective films) offer advantages such as dust resistance, scratch resistance, rapid air release, easy application, easy tearing, and low tearing voltage. They are widely used in the electronics industry, on substrates such as mobile phones, smartwatches, tablets, automotive touchscreen glass panels, mobile phone cover glass, window glass, and acrylic panels. However, after application, protective films are prone to fogging; therefore, it is necessary to test their fogging performance. Summary of the Invention

[0003] This application provides a method for detecting the fogging performance of a protective film, which can detect whether the protective film exhibits fogging.

[0004] This application provides a method for testing the fogging performance of a protective film. The protective film includes a plastic substrate layer and a polyurethane adhesive layer. The method includes: obtaining a substrate and determining the cleanliness of the substrate surface; if the cleanliness meets the standard, pasting the protective film onto the surface of the substrate; placing the substrate with the protective film pasted on under predetermined test conditions for a predetermined time, and then peeling off the protective film from the surface of the substrate; in a dark environment, irradiating the substrate with strong light, and observing whether fogging occurs on the surface of the substrate under the strong light.

[0005] In the embodiments of this application, a protective film can be adhered to the surface of an object that meets the required cleanliness standard. The object with the protective film is then placed under predetermined test conditions for a predetermined time, after which the protective film is removed. In a dark environment, the object is irradiated with strong light, and the surface is observed to determine whether fogging occurs. Therefore, the embodiments of this application can detect the fogging performance of a protective film.

[0006] In some embodiments, when no fogging is observed on the surface of the object to be pasted under strong light, or when fogging is observed on the surface of the object to be pasted under strong light and the protective film is pasted on both sides of the object to be pasted, the method further includes: wiping at least one side of the object to be pasted with a wiping material soaked in solvent; if any surface of the at least one side increases in transparency after wiping or generates dirt during wiping, then it is determined that any surface with increased transparency after wiping or generating dirt during wiping exhibits fogging; or, drawing a pattern on at least one side of the object to be pasted with an object soaked in solvent; if the pattern can be observed on the at least one side of the object, then it is determined that any surface on which the pattern can be observed exhibits fogging.

[0007] In some embodiments, the step of illuminating the object with strong light in a dark environment and observing whether a fogging phenomenon occurs on the surface of the object under the strong light includes: placing the object in a dark environment; illuminating the object with strong light; adjusting the angle between the strong light and the surface of the object during the process of illuminating the object with strong light; and observing whether a fogging phenomenon occurs on the surface of the object under strong light illuminating at different angles.

[0008] In some embodiments, the object to be pasted is plain glass.

[0009] In some embodiments, the predetermined test conditions include room temperature test conditions and / or high temperature and high humidity test conditions.

[0010] In some embodiments, the temperature under the high temperature and high humidity test conditions is 60°C-85°C, and the relative humidity under the high temperature and high humidity test conditions is 85%-90%.

[0011] In some embodiments, the scheduled time is 3 to 15 days.

[0012] In some embodiments, before determining the cleanliness of the surface to be pasted, the method further includes: cleaning the surface to be pasted; the cleaning of the surface to be pasted includes: wiping the surface of the surface to be pasted with a wiping agent soaked in solvent; wherein the solvent includes at least one of anhydrous ethanol and ethyl acetate.

[0013] In some embodiments, determining the cleanliness of the surface of the object to be pasted includes: placing the object to be pasted in a dark environment and illuminating it with a strong light; and detecting the cleanliness of the surface of the object to be pasted under the irradiation of the strong light.

[0014] In some embodiments, if the cleanliness meets the standard, after the protective film is pasted onto the surface of the object to be covered, the method further includes: removing air bubbles between the protective film and the object to be covered.

[0015] It should be understood that the description in the Summary of the Invention section is not intended to limit the key or essential features of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0017] Figure 1 This is a flowchart of a method for testing the fogging performance of a protective film provided in some embodiments of this application. Detailed Implementation

[0018] The principles and spirit of this disclosure will be described below with reference to several exemplary embodiments illustrated in the accompanying drawings. It should be understood that these specific embodiments are described merely to enable those skilled in the art to better understand and implement this disclosure, and are not intended to limit the scope of this disclosure in any way. In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0019] As used herein, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "an embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects and are used only to distinguish the objects referred to, without implying a particular spatial order, temporal order, order of importance, etc., of the objects referred to.

[0020] Figure 1 This is a flowchart illustrating a method for identifying protective film fogging phenomena provided in some embodiments of this application, such as... Figure 1 As shown, the method includes the following steps:

[0021] Step 11: Obtain the object to be pasted and determine the cleanliness of the surface of the object to be pasted.

[0022] The protective film in this embodiment comprises a plastic substrate layer, a polyurethane adhesive layer, and a base film layer arranged sequentially. In use, the base film layer must be removed first, and then the protective film is bonded to the object using the polyurethane adhesive layer.

[0023] In some embodiments, the object to be bonded is plain glass, and the surface of the plain glass has not undergone surface treatment. If a protective film is applied to a surface-treated object, fogging will be less likely to occur; the surface treatment can be anti-fingerprint treatment, application of an explosion-proof film, or application of optically clear adhesive (OCA). In the embodiments of this application, if the protective film does not fog when bonded to plain glass, it will not fog when bonded to other objects. In practical applications, the protective film can be bonded to various substrate surfaces, and the surface treatment methods for various substrate surfaces can also be different. In the embodiments of this application, it is only necessary to bond the protective film to plain glass to detect whether the protective film will fog, rather than bonding the protective film to the surface of various objects to detect the fogging situation when the protective film is bonded to different object surfaces, thereby effectively improving the detection efficiency of the protective film's fogging performance.

[0024] In some embodiments, after obtaining the object to be attached, if the object has never been used, the surface of the object will be covered with a plastic film protective layer, such as polyethylene (PE) film; after removing the plastic film from the surface of the object, the cleanliness of the surface of the object is detected; if the cleanliness of the surface of the object meets the standard, the process proceeds directly to step 12; if the cleanliness of the surface of the object does not meet the standard, the surface of the object is cleaned.

[0025] In some embodiments, after obtaining the object to be affixed, if it is determined that the object has been used before, the surface of the object is cleaned directly after obtaining it, and then the cleanliness of the surface is tested. If the cleanliness of the surface meets the standard, proceed to step 12; if the cleanliness of the surface does not meet the standard, the surface of the object is cleaned again. For dirty areas, that is, areas where the cleanliness does not meet the standard, the area can be wiped in one direction with a solvent-based wiping material until the cleanliness of the dirty area meets the standard.

[0026] Specifically, in some embodiments, the surface of the object to be pasted is cleaned as follows: the surface of the object is wiped with a wiping material soaked in a solvent, such as ethanol (e.g., 99% anhydrous ethanol) or ethyl acetate. In this application embodiment, the wiping material can specifically be a lint-free cloth or lint-free paper.

[0027] In some embodiments, the method for detecting the cleanliness of the surface of the object to be pasted is as follows: placing the object to be pasted in a dark environment and illuminating it with a strong light; under the illumination of the strong light, detecting the cleanliness of the surface of the object to be pasted. For example, the object to be pasted can be placed in a darkroom, illuminated with a strong flashlight, and the cleanliness of the surface of the object to be pasted can be checked at the same time.

[0028] In some embodiments, after cleaning the object to be bonded, the method further includes drying the object. Specifically, the object to be bonded is placed on a rack and left to air dry; the time may be 20 minutes.

[0029] Step 12: If the cleanliness meets the standard, then affix the protective film to the surface of the object to be covered.

[0030] In this embodiment, the protective film is only bonded to the surface of the object when its surface cleanliness meets the standard; if the protective film is bonded to an object with insufficient cleanliness, it will affect the subsequent detection of fogging phenomena. Specifically, the bottom layer of the protective film can be peeled off first, and then the polyurethane adhesive layer can be bonded to the dried surface of the object. In other embodiments, after step 12, air bubbles between the protective film and the object can be removed. For example, a manual bonding roller can be used to reduce air bubbles between the protective film and the object.

[0031] The object to be adhered to includes a first surface and a second surface disposed opposite to the first surface. The first surface and the second surface can be the front and back of the object to be adhered to, respectively. Specifically, the protective film can be adhered to the first surface and / or the second surface of the object to be adhered to, thereby enabling the detection of fogging phenomena of the protective film on the first surface and / or the second surface.

[0032] Step 13: After placing the object with the protective film on it under predetermined test conditions for a predetermined time, remove the protective film from the surface of the object.

[0033] In this embodiment, after the protective film is pasted onto the surface of the object, the object with the protective film is placed under predetermined test conditions for a predetermined time. In some embodiments, the test conditions include room temperature test conditions; in this case, the object with the protective film can be placed on a rack at room temperature for a predetermined time. In other embodiments, the test conditions may also include high temperature and high humidity conditions; in this case, the object with the protective film can be placed under high temperature and high humidity conditions for a predetermined time, for example, the object with the protective film can be placed in a constant temperature and humidity chamber for a predetermined time. The temperature under the high temperature and high humidity test conditions is 60℃-85℃, and the relative humidity under the high temperature and high humidity test conditions is 85%-90%. Specifically, under the high temperature and high humidity conditions, the temperature can be 60℃ and the relative humidity can be 90%, or the temperature can be 85℃ and the relative humidity can be 85%. The predetermined time can be 3 days to 15 days, specifically 3 days, 7 days, or 15 days.

[0034] Step 14: In a dark environment, shine a strong light on the object to be pasted and observe whether the surface of the object to be pasted appears foggy under the strong light.

[0035] In this embodiment, after placing the object with the protective film on it under predetermined test conditions for a predetermined time, the protective film on the surface of the object is removed. Then, in a dark environment, the object is irradiated with strong light, and it is observed whether the surface of the object exhibits a fogging phenomenon under the strong light.

[0036] Specifically, a dark environment can be created; for example, by turning off the lights in a room. In this dark environment, peel off the protective film from the first and / or second surfaces of the object to be covered. Then, turn on a high-intensity flashlight and illuminate the object with its strong light. Observe the surface of the object under this light to see if fogging occurs. The angle between the flashlight and the object's surface can be adjusted to illuminate the surface with different angles of light, allowing for more accurate identification of fogging. In some embodiments, if snowflake-like substances are observed on the surface of the object, fogging is confirmed.

[0037] In some embodiments, when no fogging is observed on the surface of the object to be coated under strong light, or when fogging is observed on the surface of the object to be coated under strong light and the protective film is adhered to both sides of the object, the method further includes: wiping at least one side of the object to be coated with a solvent-soaked wiping material (such as a lint-free cloth or lint-free paper); if any surface on the at least one side increases in transparency after wiping or generates dirt during wiping, then it is determined that any surface on which the transparency increases after wiping or generates dirt during wiping exhibits fogging; or, drawing a pattern on at least one side of the object to be coated with a solvent-soaked object (such as a lint-free cloth or lint-free paper); if the pattern can be observed on at least one side of the object, then it is determined that any surface on which the pattern can be observed exhibits fogging. Therefore, embodiments of this application can determine which specific surface exhibits fogging when protective films are adhered to both sides of the object.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the fogging performance of a protective film, characterized in that, The protective film comprises a plastic substrate layer and a polyurethane adhesive layer, and the method includes: Obtain the object to be pasted and determine the cleanliness of the surface of the object to be pasted; If the cleanliness level meets the standard, the protective film is then pasted onto the surface of the object to be covered. After placing the object with the protective film on it under predetermined test conditions for a predetermined time, the protective film on the surface of the object is then removed. In a dark environment, the object to be pasted is illuminated with a strong light, and the surface of the object is observed to see if a fogging phenomenon occurs under the strong light.

2. The method according to claim 1, characterized in that, When no fogging is observed on the surface of the object to be adhered to under strong light, or when fogging is observed on the surface of the object to be adhered to under strong light, and the protective film is adhered to both sides of the object to be adhered to, the method further includes: By wiping at least one surface of the object being applied with a solvent-based wiping agent, if any surface on the at least one side of the object shows increased transparency after wiping or produces dirt during wiping, then it is determined that any surface showing increased transparency after wiping or producing dirt during wiping exhibits a fogging phenomenon; or, A pattern is drawn on at least one surface of the object to be pasted with an object dipped in solvent. If the pattern can be observed on at least one surface, it is determined that a fogging phenomenon occurs on any surface on which the pattern can be observed.

3. The method according to claim 1, characterized in that, The step of observing whether a fogging phenomenon occurs on the surface of the object to be pasted under strong light in a dark environment includes: Place the object to be affixed in a dark environment; The object to be pasted is illuminated with strong light; During the process of irradiating the object with strong light, the angle between the strong light and the surface of the object is adjusted. Observe whether the surface of the object being pasted appears fogged under strong light at different angles.

4. The method according to claim 1, characterized in that, The object to be pasted is plain glass.

5. The method according to claim 1, characterized in that, The predetermined test conditions include room temperature test conditions and / or high temperature and high humidity test conditions.

6. The method according to claim 5, characterized in that, The temperature under the high temperature and high humidity test conditions is 60°C-85°C, and the relative humidity under the high temperature and high humidity test conditions is 85%-90%.

7. The method according to claim 1, characterized in that, The scheduled time is 3 to 15 days.

8. The method according to any one of claims 1-7, characterized in that, Before determining the cleanliness of the surface to be pasted, the method further includes: cleaning the surface to be pasted; The cleaning process for the object to be pasted includes: Wipe the surface of the object to be pasted with a wiping agent soaked in solvent; The solvent includes at least one of anhydrous ethanol and ethyl acetate.

9. The method according to claim 8, characterized in that, Determining the cleanliness of the surface to be covered includes: Place the object to be attached in a dark environment and turn on a strong light to illuminate the object; The cleanliness of the surface of the object to be pasted is detected under the strong light.

10. The method according to claim 8, characterized in that, If the cleanliness meets the standard, after the protective film is pasted onto the surface of the object to be covered, the method further includes: Remove air bubbles between the protective film and the substrate.

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