Preforming device and durability test method for curved surface samples of decorative film

Abstract

The present invention provides a preforming device for curved surface samples of finishing films, and a method for testing the durability of finishing films using the preforming device. The preforming device comprises the following components: an upper platen assembly comprising four first uprights and an upper base integral with the first uprights; a matching lower platen assembly comprising four second uprights and a lower base integral with the second uprights; and a curved surface indenter movably mounted on the lower base. The device and method according to the present invention enable durability testing of curved finishing films. The device features a scientific design, a simple structure, and a simple and easy-to-use testing method.

Description

Technical Field

[0001] The invention relates to a preforming device for a curved surface sample of a finishing film and a method for testing the durability of the finishing film by utilizing the preforming device. Background Art

[0002] Paint-free doors are highly sought after by consumers for their smooth, beautiful surface, easy cleaning and maintenance, and modern style. PVC finishing film is a key raw material in the production of paint-free doors, endowing them with rich patterns and a beautiful appearance. Currently, the durability of traditional PVC finishing film raw materials is tested using xenon lamp aging testing methods and equipment. However, this single xenon lamp aging test method can only be used to test flat PVC finishing films, which does not reflect actual production conditions and is only an estimate. This can easily result in substandard coating, which not only affects production efficiency but also poses quality risks.

[0003] Therefore, there is an urgent need to provide a PVC curved surface finishing film durability testing device and testing method. Summary of the Invention

[0004] To this end, the present invention provides a test device for testing the durability of a finishing film and a durability test method simulating the same conditions of the finishing film covering, which makes up for the shortcomings of the existing PVC finishing film durability test. Its design principle is scientific and the structure is simple.

[0005] According to one aspect of the present invention, a preforming device for a curved surface sample of a facing film is provided, comprising the following parts:

[0006] an upper pressing plate assembly comprising four first upright posts and an upper bottom surface integral with the first upright posts;

[0007] a lower pressing plate assembly matching the upper pressing plate assembly, comprising four second upright posts and a lower bottom surface integral with the second upright posts;

[0008] The curved pressure head is movably mounted on the lower bottom surface.

[0009] Preferably, a through hole is provided at the center of the lower bottom surface, and a pushing member passes through the through hole and is connected to the curved surface pressure head.

[0010] Furthermore, the inner surface of the through hole has a thread, and the pushing member is a bolt matched with the inner surface of the through hole.

[0011] Preferably, the four first upright columns each have a first slot on any two adjacent side surfaces, and first partitions are respectively provided on the four side surfaces of the upper pressing plate assembly through the first slots.

[0012] Preferably, the four second upright posts respectively have second slots on two adjacent side surfaces, and second partitions are respectively fixed to the four side surfaces of the lower pressure plate assembly through the second slots.

[0013] Preferably, electrical contact points are formed on the upper surface of the lower bottom surface and the lower surface of the curved surface press head respectively, so that the curved surface press head can be electrically heated by an external power supply when the lower bottom surface contacts the curved surface press head.

[0014] Preferably, a transparent observation window is provided in the central area of ​​the upper bottom surface.

[0015] According to another aspect of the present invention, a method for testing the durability of a finishing film is provided, wherein the above-mentioned preforming device is used to prepare a sample, and the testing method comprises the following steps:

[0016] Keeping the curved indenter in electrical contact with the bottom surface, connecting to an external power source, and heating the curved indenter to 135-145° C.;

[0017] Stop heating the curved surface pressure head and allow the curved surface pressure head to cool naturally to 115-125° C.;

[0018] Adjusting the position of the curved pressure head so that the vertex of the curved pressure head is at the same height as the upper surface of the lower pressing plate assembly;

[0019] placing the facing film to be tested on the upper surface of the lower pressing plate assembly;

[0020] Aligning and installing the upper pressing plate assembly and the lower pressing plate assembly, and fixing them to form a preforming device;

[0021] Raise the heated curved surface pressure head to a position corresponding to the minimum curved surface radius required by the finishing film and maintain it for a certain period of time;

[0022] The preformed device was moved to a durability testing apparatus for aging.

[0023] Preferably, the position of the curved surface pressing head is controlled by controlling the displacement distance of the propulsion member in the lower pressing plate assembly.

[0024] Preferably, the testing method further comprises removing the preformed device after the aging treatment from the durability testing device, disassembling it, taking out the aged finishing film, and performing a durability test.

[0025] The preforming device and testing method according to the present invention can perform simulated durability testing on curved surface finishing film samples. The device has a simple structure, is easy to operate, and the testing method has high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further objects, functions and advantages of the present invention will be clarified through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0027] Figure 1 The structure of the preforming device for the curved surface sample of the facing film according to the present invention is schematically shown;

[0028] Figure 2 Schematically shows Figure 1 A-axis cross-sectional view of the preforming device;

[0029] Figure 3 The three-dimensional structure of the preforming device according to the present invention is schematically shown. DETAILED DESCRIPTION

[0030] See also Figure 1 The preforming device for the curved surface sample of the facing film according to the present invention includes: an upper pressing plate assembly, including four first columns 1 and an upper bottom surface 2 integral with the first columns 1; a lower pressing plate assembly matching the upper pressing plate assembly, including four second columns 3 and a lower bottom surface 4 integral with the second columns 3; a curved surface pressing head 5, movably mounted on the lower bottom surface 4.

[0031] Common finishing film material is polyvinyl chloride (PVC) finishing film, for example, can be 0.18mm thick PVC finishing film. The above-mentioned upright column and bottom surface can be made of hard wood material.

[0032] Preferably, a transparent observation window is provided in the central area of ​​the upper bottom surface 2, for example, formed by embedding a transparent plate. According to a specific embodiment, the transparent plate can be glass and can have a size of 100 mm x 100 mm x 10 mm.

[0033] See also Figure 2 and Figure 3 In the preforming apparatus according to the present invention, the four first uprights of the upper platen assembly each have a first slot on adjacent sides. First partitions 7 are provided on the four sides of the upper platen assembly via the first slots, thereby forming a sealing structure on the four sides of the upper platen assembly. The first partitions 7 can be made of glass and have dimensions of 100 mm x 80 mm x 10 mm.

[0034] In the lower platen assembly of the preforming apparatus, two electrical contacts are located at corresponding positions on the lower surface of the curved pressing head 5 and the upper surface of the lower base 4. When the curved pressing head and the lower base are in contact via the electrical contacts, the curved pressing head can be heated by an external power source. For example, a triangular socket 8 can be provided at the lower end of the lower base 4 to connect to an external power source, such as a 220V power supply.

[0035] The curved indenter 5 can be configured with a curvature radius tailored to the specific curvature requirements of the finishing film (e.g., the curvature of a PVC finishing film in actual application). In one embodiment of the present invention, the curved indenter 5 can be a set of soldering iron molds. During experimentation, the mold can be selected based on the curvature radius required for the specific finishing film.

[0036] Furthermore, a through hole is provided at the center of the lower bottom surface 4, preferably a through hole with a threaded inner surface, and the inner diameter of the through hole can be 12 mm.

[0037] A propulsion mechanism 6 is provided through the through hole to propel the curved indenter 5 up and down. This propulsion mechanism matches the structure and dimensions of the through hole, i.e., its surface has the same thread and has the same diameter as the through hole's inner diameter. Preferably, this propulsion mechanism 6 can be a bolt with a diameter of 12 mm.

[0038] The second column 3 of the lower platen assembly has the same dimensions and slot structure as the first column 1. Specifically, four second spacers are positioned on each of the four sides of the lower platen assembly through the second slots on the second column, thereby forming a sealed structure on all four sides of the lower platen assembly. The second spacers can be made of glass and have dimensions of 100 mm x 80 mm x 10 mm.

[0039] The preforming device according to the present invention may further include a locking member, such as a U-shaped locking member, such as a stainless steel U-shaped locking member, for fixing the upper pressing plate assembly and the lower pressing plate assembly into a whole.

[0040] According to another aspect of the present invention, a method for testing the durability of a finishing film is provided, wherein the above-mentioned preforming device is used to prepare a sample, and the testing method comprises the following steps:

[0041] Keep the curved indenter 5 in electrical contact with the lower bottom surface 4, connect an external power source, and heat the curved indenter 5 to 135-145°C;

[0042] Stop heating the curved surface pressing head 5 and allow the curved surface pressing head 5 to cool naturally to 115-125°C;

[0043] Adjust the position of the curved surface pressing head 5 so that the vertex of the curved surface pressing head 5 is at the same height as the upper surface of the lower pressing plate assembly;

[0044] Place the facing film 9 to be tested on the upper surface of the lower pressing plate assembly;

[0045] Align and install the upper pressing plate assembly and the lower pressing plate assembly, and fix them to form a preforming device;

[0046] Raise the heated curved surface pressing head 5 to a position corresponding to the minimum curved surface radius required by the finishing film 9 and maintain it for a certain period of time;

[0047] The formed preformed device was moved to a durability testing apparatus for aging.

[0048] According to one embodiment, the position of the curved pressure head is controlled by controlling the displacement of a propulsion member in the lower platen assembly. For example, a vernier caliper can be used to measure the displacement and thereby control the height of the curved pressure head. Typically, the curved pressure head is raised to a height equal to the minimum curvature radius of the actual finishing film or the minimum curvature radius of the smallest composite curved surface.

[0049] In the above method, the curved surface indenter is usually heated electrically, that is, heated by an external power source. During the heating process, the temperature of the curved surface indenter can be measured using an infrared thermometer.

[0050] When the temperature of the curved pressure head stabilizes at 115-125°C, place the finishing film between the upper and lower pressure plate assemblies. Align and lock the upper and lower pressure plate assemblies, for example, using a U-shaped lock. This temperature range simulates the temperature range of film lamination in a blister machine and can be adjusted based on the actual lamination temperature.

[0051] The upper and lower pressing plate assemblies are installed, and the partitions provided in the side slots form a closed space in the entire preforming device. The facing film is allowed to contact the hot curved pressing head surface for a certain period of time, for example, 25 to 45 minutes, preferably 30 minutes.

[0052] Furthermore, the entire preformed device including the finishing film is moved to an aging device for aging, for example, typically after aging for 48 hours in a xenon lamp aging test chamber, the preformed device is removed.

[0053] After the entire preform device is removed from the aging device, the locking component is disassembled, the upper pressure plate assembly is removed, and the aged finishing film is taken out for durability testing.

[0054] According to a specific embodiment, the durability test of a 0.18 mm thick PVC facing film is performed as follows:

[0055] 1. Keep the curved indenter 5 in electrical contact with the lower base 4. Connect an external 220V power supply to the triangular socket 8 provided in the lower base 4 to heat the curved indenter 5. When the temperature of the curved indenter 5 reaches 140°C ± 5°C as measured by an infrared thermometer, remove the power supply and stop heating.

[0056] 2. Allow the curved pressure head 5 to cool naturally to 120°C ± 5°C;

[0057] 3. Rotate the bolt 6 in the lower bottom surface 4 to adjust the electric heating curved surface pressure head 5 to a position where its highest point is at the same height as the upper surface of the lower pressure plate assembly, that is, at the same height as the upper surface of the second column 3;

[0058] 4. Place the PVC decorative film 9 to be tested flatly on the upper surface of the lower pressing plate assembly, align and assemble the upper pressing plate assembly, and tighten it with the U-shaped lock;

[0059] 5. Rotate the bolt 6 in the bottom surface 4 to raise the electric heating curved surface pressure head 5 to the same height as the minimum curved surface radius actually required for the finishing film or the minimum curvature radius of the minimum composite molding surface. Use a vernier caliper to measure the displacement distance of the bolt 6 to control the rising height of the electric heating curved surface pressure head 5.

[0060] 6. After standing for 30 minutes, move the PVC finishing film preform device as a whole to a xenon lamp aging test chamber and age it for 48 hours before removing it;

[0061] 7. Remove the U-shaped lock, remove the upper pressure plate assembly, and remove the PVC finishing film that forms the curved surface for subsequent mechanical properties and appearance performance testing.

[0062] According to the durability testing method of the PVC decorative film of the present invention, the actual production coating process of the PVC decorative film is simulated by using the preforming device of the present invention, the PVC decorative film is continuously kept in a formed state, and then the whole PVC decorative film together with the preforming device is placed in a xenon lamp aging test box for light aging. After the light aging is completed, the U-shaped lock is removed, the upper pressure plate is removed, and the PVC film forming the curved surface is taken out. The corresponding mechanical properties, color properties and other indicators are compared with the control samples before and after lamination. The durability of the PVC after actual lamination is obtained by comparing the results, thereby realizing the durability test of the curved PVC decorative film.

[0063] Other embodiments of the present invention will be readily apparent to those skilled in the art from the description and practice of the invention disclosed herein. The description and embodiments are intended to be exemplary only, and the true scope and spirit of the present invention are defined by the claims.

Claims

1. A preforming device for curved surface samples of decorative films, characterized in that: This preforming device is suitable for durability testing of PVC curved surface finishing films for paint-free doors. The preforming device consists of the following parts: an upper pressing plate assembly comprising four first upright posts and an upper bottom surface integral with the first upright posts; a lower pressing plate assembly matching the upper pressing plate assembly, comprising four second upright posts and a lower bottom surface integral with the second upright posts; a curved pressure head, movably mounted on the lower bottom surface; The four first uprights are provided with first slots on adjacent sides, respectively, and first partitions are provided on the four sides of the upper pressing plate assembly through the first slots; The four second uprights are respectively provided with second slots on adjacent sides thereof, and second partitions are respectively fixed on the four sides of the lower pressing plate assembly through the second slots; The upper surface of the lower bottom surface and the lower surface of the curved surface pressing head are respectively formed with electrical contact points, so that when the lower bottom surface contacts the curved surface pressing head, the curved surface pressing head can be electrically heated by an external power supply; A through hole is provided at the center of the lower bottom surface, and a pushing member passes through the through hole and is connected to the curved pressure head. The inner surface of the through hole has threads, and the pushing member is a bolt that cooperates with the inner surface of the through hole.

2. The preforming device according to claim 1, characterized in that A transparent observation window is provided in the central area of ​​the upper bottom surface.

3. A method for testing the durability of a finishing film, characterized in that: The sample is prepared using a preforming device for a curved surface sample of a facing film according to any one of claims 1 to 2, and the testing method comprises the following steps: The curved indenter is kept in electrical contact with the bottom surface, an external power source is connected, and the curved indenter is heated to 135-145° C.; Stop heating the curved surface press head and allow the curved surface press head to cool naturally to 115-125° C. Adjusting the position of the curved pressure head so that the vertex of the curved pressure head is at the same height as the upper surface of the lower pressing plate assembly; placing the facing film to be tested on the upper surface of the lower pressing plate assembly; Aligning and installing the upper pressing plate assembly and the lower pressing plate assembly, and fixing them to form a preforming device; Raise the heated curved surface pressure head to a position corresponding to the minimum curved surface radius required by the finishing film and maintain it for a certain period of time; moving the preformed device to a durability testing device for aging; The preformed device after the aging treatment is removed from the durability testing device and disassembled, and the aged finishing film is taken out for durability testing.

4. The testing method according to claim 3, wherein: The position of the curved surface pressing head is controlled by controlling the displacement distance of the propulsion member in the lower pressing plate assembly.

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