Molding method

Abstract

The object of this invention is to provide a molding method for easily processing the surface of resin sheet materials. The molding method of this invention is for thermoforming sheet materials. The thermoforming sheet material comprises a thermoplastic resin sheet material. The thermoforming sheet material is a color-separated sheet material having multiple areas of different colors on its surface. The molding method includes a heating step (step ST1) and molding steps (steps ST3 to ST8). The heating step is a step of heating the color-separated sheet material by irradiation with light. The molding step is a step of pressing the color-separated sheet material into a mold to form a shape conforming to the mold.

Description

Technical Field

[0001] This invention generally relates to a molding process, and more specifically, to a molding process for processing resin sheet-like materials. Prior Technology

[0002] Previously, methods for heating and molding resin sheets were known. The method for manufacturing container-shaped molded objects described in Document 1 (JP2009-214412A) involves heating a sheet (resin sheet) made of hot-melt fluororesin and then vacuum forming or vacuum-pressing it into a predetermined container or box shape. Summary of the Invention

[0003] The purpose of this invention is to provide a forming method for easily processing the surface of resin sheet materials.

[0004] According to one aspect of the present invention, a molding method is used for molding a thermoforming sheet. The thermoforming sheet comprises a thermoplastic resin sheet. The thermoforming sheet is a color-separated sheet with multiple regions of different colors on its surface. The molding method includes a heating step and a molding step. The heating step involves heating the color-separated sheet by irradiation with light. The molding step involves pressing the color-separated sheet into a mold to form a shape conforming to the mold. Simple Explanation of the Diagram

[0005] Figure 1 is a flowchart showing the forming process of a certain implementation state. Figure 2 is a perspective view of the resin sheet used as a material in the same molding process described above. Figure 3 is a perspective view of the color-separated sheet formed from the above-mentioned resin sheet in the same molding process. Figure 4 is a cross-sectional view of the color-separated sheet and two molds in the same forming process as above. Figure 5 is a cross-sectional view of the color-separated sheet and two molds in the same forming process as above. Figure 6 is a front view of the urinal body manufactured using the same forming process as described above. Implementation

[0006] The following describes the forming method of each embodiment using drawings. However, the embodiments described below are merely examples of various embodiments of the present invention. The embodiments described below can be modified in various ways, depending on the design, as long as the purpose of the present invention is achieved. Furthermore, the proportions of the size and thickness of the constituent elements in the schematic diagrams described in the embodiments below may not reflect the actual dimensional proportions.

[0007] (1) Summary The molding process of this embodiment involves shaping a resin sheet 2 (see Figure 2) into a desired shape using sheet blow molding. Furthermore, in this molding process, while shaping the resin sheet 2 into the desired shape, unevenness is formed on the surface 21 (see Figure 2) of the resin sheet 2. Thus, the shadows created by the unevenness make designs such as patterns or text visible to the naked eye.

[0008] More specifically, as shown in Figures 1-3, the molding process of this embodiment is a molding process for thermoforming sheet materials. The thermoforming sheet material is a thermoplastic resin sheet material 2. The thermoforming sheet material is a color-separated sheet material 1 with multiple areas of different colors on the surface 21 of the resin sheet material 2. The molding process includes a heating step (step ST1) and a molding step (steps ST3-ST8). The heating step is a step of heating the color-separated sheet material 1 by irradiation with light. The molding step is a step of pressing the color-separated sheet material 1 into a mold 5 (see Figures 4 and 5) and processing it into the shape of the mold 5.

[0009] When light is irradiated onto the color-separated sheet 1, the difference in light absorption rate among the multiple regions results in a molding temperature difference in each region. As a result, the thickness of the resin sheet 2 varies in each region, creating unevenness on the surface 21.

[0010] Through the molding process of this embodiment, the surface 21 of the resin sheet 2 can be easily processed, thereby forming patterns or text on the surface 21 by means of raised and recessed molding. In this way, through the above molding process, designs can be easily applied to the surface 21.

[0011] Furthermore, the molding temperature can be adjusted by changing the color applied to the surface 21, thereby allowing free control over the thickness of each area of ​​the resin sheet 2.

[0012] (2) Details The forming process of this embodiment is described in detail below.

[0013] In this embodiment, an example is given where a grid-like pattern is formed on the surface 21 of the resin sheet 2 before heating through coloring (see Figure 3). Furthermore, by heating the resin sheet 2 and causing it to stretch, the pattern changes into a twisted grid-like pattern composed of raised and recessed areas (see Figure 6). This allows the pattern to be recognized by the naked eye not only through color but also through the shadows created by the raised and recessed areas. Moreover, even if the coloring wears off, the pattern remains recognizable to the naked eye.

[0014] Furthermore, in this embodiment, the case in which the resin sheet 2 is molded into the body 8 of a male urinal (see Figure 6) is described as an example.

[0015] In addition to the heating and molding steps described above, the molding process may also include a coloring step. The coloring step is the step of forming the color-separated sheet 1 from the resin sheet 2. The coloring step is the step of coloring at least a portion of the surface 21 so that the colors of each area in the plurality of areas of the surface 21 of the resin sheet 2 are different.

[0016] Figure 2 shows the resin sheet 2 before the coloring step. The material of the resin sheet 2 is, for example, ASA (Acrylonitrile styrene acrylate) resin. The surface 21 of the resin sheet 2 is planar. The color of the surface 21 is, for example, white. By coloring a portion of this surface 21 with a black color, as shown in Figure 3, the surface 21 is divided into white and black colors. That is, the surface 21 is divided into the color of the resin sheet 2 itself and a color darker than the color of the resin sheet 2 itself. Hereinafter, in the surface 21, the area R1 that has been colored by the coloring step (or, the area that will be colored by the subsequent coloring step) is referred to as the "colored area", and the other area R2 is referred to as the "uncolored area". The colored area is a grid-like area. The uncolored area is a collection of multiple rectangular blocks arranged in a matrix.

[0017] The coloring step of this embodiment includes applying a black paint in a grid pattern to the surface 21 of the resin sheet 2 using a printing method. That is, the color-separating sheet 1 is a component that includes at least the resin sheet 2 and the paint applied to the surface 21 of the resin sheet 2. Thus, the coloring step preferably includes coloring at least a portion (the coloring area) of the surface 21 of the resin sheet 2 using a printing method. By using a printing method, the surface 21 of the resin sheet 2 can be easily colored into various patterns or text shapes. A preferred printing method is, for example, screen printing.

[0018] Furthermore, the surface 21 of the resin sheet 2 has multiple areas of varying colors, including the aforementioned colored areas and uncolored areas. In other words, one of the multiple areas is the aforementioned colored area, and the other is the aforementioned uncolored area. That is, the multiple areas include white areas (uncolored areas) that are the color of the resin sheet 2 itself. Furthermore, the multiple areas include black areas (colored areas). Preferably, the area of ​​the uncolored area is larger than the area of ​​the colored area. This reduces the amount of ink or other coloring agents required for coloring.

[0019] Furthermore, at least one of the plurality of regions (here, the colored region) forms a repeating pattern. In other words, a repeating pattern is formed on the surface 21 of the resin sheet 2 through color separation. More specifically, at least one of the plurality of regions (here, the colored region) forms a grid-like pattern. A repeating pattern is a pattern (graphic) in which a predetermined shape is regularly repeated in a specific direction.

[0020] Next, the heating step will be described. The heating step is a step of heating the surface of the color-separated sheet 1 by irradiating it with light. Through heating, the resin sheet 2 becomes soft and easier to shape in the molding step. The heating step is performed, for example, before the molding step. Alternatively, the heating step may also be performed during the molding step.

[0021] The heating step includes irradiating the color-separated sheet 1 with light (infrared radiation) from an infrared heater. Examples of infrared heaters include halogen heaters and carbon heaters. In the heating step, the light irradiated from the infrared heater onto the color-separated sheet 1 is preferably far-infrared radiation. In this case, the resin constituting the resin sheet 2 readily absorbs the light.

[0022] When light is irradiated onto the color-separated sheet 1, temperature differences arise in each region due to the differences in light absorption rates among the multiple regions. Specifically, the black-colored regions have higher temperatures because their light absorption rates are higher than those of the white-colored uncolored regions.

[0023] Due to temperature differences between regions, unevenness is created on the surface 21 of the resin sheet 2. Specifically, areas with higher light absorption experience a greater temperature rise, resulting in significant deformation and indentation in those areas of the resin sheet 2. Conversely, areas with lower light absorption experience a smaller temperature rise, leading to less deformation in those areas. Consequently, areas with higher light absorption are more indented than those with lower light absorption. Specifically, the black-colored areas are more indented than the white-colored uncolored areas.

[0024] Next, the molding process will be described. In the molding process, the color-separated sheet 1 is processed so that the colored surface 21 of the resin sheet 2 becomes the front of the body 8 of the urinal (see Figure 6). The molding process includes a blow molding process and a vacuuming process.

[0025] In the forming step of this embodiment, the color-separated sheet 1 is formed using a plug-assisted method. As shown in Figures 4 and 5, the forming step utilizes a plurality of (two) molds 5. The plurality of molds 5 includes a lower mold 6 and a plug 7. In other words, one of the plurality of molds 5 is the lower mold 6, and the other of the plurality of molds 5 is the plug 7. The lower mold 6 has a recess 61 for inserting at least a portion of the color-separated sheet 1. The plug 7 is inserted into the recess 61 such that the color-separated sheet 1 is sandwiched between it and the bottom surface of the recess 61. The plug 7 is positioned above the lower mold 6.

[0026] Before the forming step, a heating step is performed (step ST1). In the heating step, the color-separation sheet 1 held by the jig is heated to soften it. Then, the color-separation sheet 1 is held by the jig and positioned between the lower mold 6 and the plug 7 (step ST2) (see Figure 4).

[0027] Next, the blow molding step (step ST3) begins. In the blow molding step, the color-separated sheet 1 is air blow molded. That is, air is blown onto the color-separated sheet 1, stretching it. The air is blown from below upwards. The color-separated sheet 1 deforms in a manner that covers the plug 7.

[0028] Furthermore, the plug 7 is pressed against the color-separation sheet 1 and inserted into the recess 61 of the lower mold 6 (step ST4) (see Figure 5). The plug 7 pushes the color-separation sheet 1 down into the lower mold 6, thus shaping the color-separation sheet 1. At this time, a blow molding step is also performed, so the color-separation sheet 1 is pressed against the plug 7 by air, and shaped according to the shape of the plug 7.

[0029] Next, the lower mold 6 is raised (step ST5). At the same time as the lower mold 6 is raised, a vacuuming step is performed (step ST6). In the vacuuming step, air is drawn from between the color-separating sheet 1 and the lower mold 6 through a plurality of holes provided in the lower mold 6, so that the color-separating sheet 1 and the lower mold 6 are sealed together.

[0030] Next, the color-separated sheet 1 is cooled and hardened (step ST7). Then, the color-separated sheet 1 is demolded from the lower mold 6 (step ST8). Then, after deburring and other steps, the processing of the color-separated sheet 1 is completed. That is, a molded product (the body 8 of the urinal) is manufactured using the color-separated sheet 1 as the material (see Figure 6).

[0031] Thus, in the molding process of this embodiment, the molding step includes the step of pushing the color-separated sheet 1 towards the mold 5 through air blow molding. Furthermore, the molding step includes the step of attracting the color-separated sheet 1 towards the mold 5 through vacuuming.

[0032] (Example of a variation of the implementation format) The following are examples of variations of the implementation. These variations can be combined appropriately to achieve the desired result.

[0033] Articles manufactured using the molding method of this invention are not limited to the body 8 of a urinal. The molding method of this invention can also be used to manufacture containers, pipes, or boxes.

[0034] In the coloring step, as a printing method, besides screen printing, inkjet printing can also be used to color at least a portion (coloring area) of the surface 21 of the resin sheet 2. Furthermore, in addition to printing, in the coloring step, a colored component (such as a strip or fabric) can be fixed to the surface 21 of the resin sheet 2, or the surface 21 can be colored with a pen. Particularly preferred is coloring the surface 21 by fixing a sealant that can be peeled off after the resin sheet 2 is formed to the surface 21. In this case, an uncolored molded article can be manufactured by removing the sealant. Alternatively, a colorant such as ink that can be removed by washing can be used to color the surface 21.

[0035] The grid pattern on the surface 21 of the resin sheet 2 can also be a pattern in which the positions of the colored areas (black areas) and the uncolored areas (white areas) are interchanged in the embodiment.

[0036] Irregular patterns can also be formed on the surface 21 of the resin sheet 2 by color separation, instead of repeating patterns.

[0037] Repeating patterns are not limited to grid patterns. For example, repeating patterns can also be honeycomb patterns. Alternatively, repeating patterns can be patterns in which triangles or parallelograms are filled without gaps (plane filling). Or, repeating patterns can be patterns that can be arranged in a certain specific pattern.

[0038] The color separation on the surface 21 of the resin sheet 2 is not limited to white and black. For example, red, blue, or green colors can also be used for color separation. Furthermore, more than two colors can be used for color separation. In this case, the area of ​​the non-colored region is preferably the largest among the multiple regions of different colors. This reduces the amount of ink or other colorants required for coloring.

[0039] In the coloring step, patterns may also be formed only on a portion of the surface 21 of the resin sheet 2.

[0040] The flowchart shown in Figure 1 is only one example of the forming method according to the present invention. The order of the steps can be changed appropriately, and steps can be added or omitted appropriately.

[0041] (Summarize) Based on the above description of implementation methods, the following methods will be revealed.

[0042] The molding process according to the first state is a molding process for thermoforming sheet materials. The thermoforming sheet material includes a thermoplastic resin sheet material (2). The thermoforming sheet material is a color-separated sheet material (1) with multiple areas of different colors on the surface (21) of the resin sheet material (2). The molding process includes a heating step (step ST1) and a molding step (steps ST3~ST8). The heating step is a step of heating the color-separated sheet material (1) by irradiation with light. The molding step is a step of pressing the color-separated sheet material (1) into a mold (5) and processing it into the shape of the mold (5).

[0043] Through the above configuration, the differences in color (light absorption rate) corresponding to the surface (21) of the resin sheet (2) in the plurality of regions result in differences in the degree of temperature rise during the heating step. As a result, the properties of the surface (21) of the resin sheet (2) change after the heating step. For example, a specific region on the surface (21) of the resin sheet (2) may be recessed compared to other regions. Thus, the surface (21) of the resin sheet (2) can be easily processed through the above molding method.

[0044] Furthermore, according to the molding process of the second state sample, the first state sample includes a coloring step as a step in forming the color-separated sheet (1) from the resin sheet (2). The coloring step is a step of coloring at least a portion of the surface (21) so that the colors of each region in the plurality of regions of the surface (21) of the resin sheet (2) are different.

[0045] Through the above configuration, color-separated sheet material (1) can be provided.

[0046] Furthermore, in the forming process of the third state sample, the coloring step of the second state sample includes the step of coloring at least a portion of the surface (21) by printing.

[0047] Through the above structure, by using the printing method, the surface (21) of the resin sheet (2) can be easily colored into various patterns or text shapes.

[0048] Furthermore, in the forming process of the fourth state sample, the heating step of any of the first to third state samples includes the step of irradiating infrared rays from the infrared heater to the color-separated sheet (1).

[0049] Through the above-described structure, the color-separated sheet material (1) can be locally heated.

[0050] Furthermore, according to the molding process of the fifth state sample, the multiple regions of any one of the first to fourth state samples include the white region of the color of the resin sheet (2) itself.

[0051] With the above structure, the areas left as white areas do not need to be colored, thus reducing the amount of ink and other materials required for coloring.

[0052] Furthermore, according to the forming process of the sixth state sample, the multiple regions of any one of the first to fifth state samples include the black region.

[0053] With the above-described structure, the black areas are particularly easy to heat up during the heating process. Therefore, the black areas can be heated efficiently through the heating process.

[0054] Furthermore, in the forming process of the 7th state pattern, at least one region among the multiple regions of any one of the 1st to 6th state patterns forms a repeating pattern.

[0055] The above-described structure can reduce the time required to color at least a portion of the aforementioned areas.

[0056] Furthermore, in the forming process of the eighth state pattern, at least one region among the multiple regions of the seventh state pattern forms a grid-like pattern.

[0057] Through the above-described structure, resin molded products in the form of ceramic tiles can be easily formed.

[0058] Furthermore, in the forming process of the 9th state sample, the forming steps of any of the 1st to 8th state samples include the step of pushing the color-separated sheet (1) into the mold (5) through air blow molding.

[0059] Through the above configuration, the color-separated sheet (1) is tightly bonded to the mold (5). This reduces the distortion of the resin sheet (2). Furthermore, it reduces the distortion of the pattern on the surface (21) of the resin sheet (2).

[0060] Furthermore, in the forming process of the 10th state sample, the forming steps of any of the 1st to 9th state samples include the step of drawing the color-separated sheet material (1) towards the mold (5) by vacuuming.

[0061] Through the above configuration, the color-separated sheet (1) is tightly bonded to the mold (5). This reduces the distortion of the resin sheet (2). Furthermore, it reduces the distortion of the pattern on the surface (21) of the resin sheet (2).

[0062] The components other than the first state are not necessary components in the forming process and can be omitted appropriately.

[0063] 1: Color-separated sheet material (sheet material for thermoforming) 2: Resin flakes 5: Casting mold 6: Lower mold 7: Embolism 8: Ontology 21: Surface 61: concave part R1, R2: Regions ST1: Step (Heating Step) ST2: Steps ST3~ST8: Steps (Forming Steps)

Claims

1. A molding process for thermoforming a sheet material, the sheet material comprising a thermoplastic resin sheet material, and a color-separated sheet material having a plurality of regions of different colors on the surface of the resin sheet material; the molding process comprising the following steps: a heating step, heating the color-separated sheet material by irradiation with light; and a molding step, pressing the color-separated sheet material into a mold to form a shape conforming to the mold; in the heating step, the surface of the resin sheet material is made uneven by means of the difference in light absorption rate of the plurality of regions.

2. The molding process as described in claim 1 further includes: a coloring step, wherein at least a portion of the surface is colored so that the colors of the various regions on the surface of the resin sheet are different; the coloring step is a step for forming the color-separated sheet from the resin sheet.

3. The forming method as described in claim 2, wherein, The coloring step includes the step of coloring at least a portion of the surface by printing.

4. The forming method as described in any one of claims 1 to 3, wherein, The heating step includes irradiating the color-separated sheet with infrared light from an infrared heater.

5. The forming method as described in any one of claims 1 to 3, wherein, The plural region includes the white area, which is the color of the resin sheet itself.

6. The forming method as described in any one of claims 1 to 3, wherein, The plural region includes areas of black.

7. The forming method as described in any one of claims 1 to 3, wherein, At least one of the regions of the plurality forms a repeating pattern.

8. The forming method as described in claim 7, wherein, At least one of the plurality of regions forms a grid-like pattern.

9. The forming method as described in any one of claims 1 to 3, wherein, The forming step includes pressing the color-separated sheet material into the mold through air blow molding.

10. The forming method as described in any one of claims 1 to 3, wherein, The forming step includes drawing the color-separated sheet material into the mold by vacuuming.

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