Manufacturing method for hardened high-rebound products using hardened polyester sheets

Abstract

The objective is to provide a method for manufacturing hardened, high-rebound products, which are particularly effective during sleep and promote restful sleep. [Solution] The present invention provides a method for manufacturing a hardened, high-rebound product, characterized by using a hardened polyester sheet formed by blending different types of polyester cotton, processing them into a sheet, laminating the processed polyester cotton sheets and heat-pressing them together, and then applying heat treatment. The hardened, high-rebound product obtained through this process is a very firm product despite using polyester cotton as the raw material, and its firmness prevents the occurrence of back pain and other problems, and is also easy to use.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing high resilience products such as high resilience bedding and high resilience interior products using polyester cotton, and particularly to a method for manufacturing high resilience products that provide a comfortable sleeping and sitting experience for users who have problems such as low back pain due to a non-hardened structure.

Background Art

[0002] The posture on the bed or futon during sleep often greatly affects the comfort of sleep. When using ordinary high resilience or low resilience urethane-based foamed resins, there is a problem that they are too soft and cause back pain when returning to maintain the posture. For example, when sleeping in a state where the waist or back is burdened, it may lead to the onset of low back pain after waking up, or pain in the neck and back such as sleeping in a wrong position. People who desire sound sleep always require a futon with appropriate softness.

[0003] As technologies for solving various problems such as conventional low back pain, various ones are known. For example, those using tatami mattresses (see Patent Document 1), those with a shallow depression provided in the central part of the mattress (Patent Document 2), etc. are known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, conventional technology has the problem of not providing a satisfactory firmness. Furthermore, changing the shape of the mattress requires sheets that conform to the deformed mattress, and the presence of indentations is not beneficial for everyone, and may even cause fatigue or injury to other parts of the body during sleep.

[0006] In response to these technical challenges, the applicant has proposed the technology disclosed in Japanese Patent No. 7557213 as one solution, and has further refined it in pursuit of bedding with even greater resilience. The present invention aims to provide an improved hardened, high-rebound bedding that is effective during sleep and promotes restful sleep, as well as a method for manufacturing a hardened, high-rebound interior product that offers superior seating comfort. [Means for solving the problem]

[0007] To solve the above-mentioned technical problems, the present invention provides a method for manufacturing a hardened high-rebound product using a hardened polyester sheet, characterized in that a hardened polyester sheet is used, which is formed by blending polyester cotton having a normal melting point, recycled polyester cotton, and low-melting-point polyester cotton having a melting point lower than the melting point of the polyester cotton, such that the weight ratio of the low-melting-point polyester cotton is greater than 10% and less than 80%, mixing them uniformly, processing them into a sheet, gradually feeding and folding the processed polyester cotton sheet to stack multiple sheets of the polyester cotton sheet, applying pressure and heat treatment in the range of 90 to 130°C to melt the low-melting-point polyester cotton of the mixed polyester cotton sheet processed into a sheet to fuse the fibers together, processing the polyester cotton sheet into a plate, then hardening the low-melting-point polyester cotton by a cooling treatment to harden the polyester cotton sheet into a plate, and cutting the hardened plate-shaped polyester cotton sheet to the size of the product. Hardened, high-rebound products produced using this manufacturing method, for example, polyester cotton as a raw material, constitute a very firm mattress, and the function provided by this firmness can prevent the occurrence of back pain and other problems.

[0008] Furthermore, in an example of the hardened high-rebound product of the present invention, the hardened high-rebound bedding can be a hardened high-rebound futon or mattress. In addition, the polyester cotton having a normal melting point may include recycled polyester cotton, and the proportion of recycled polyester cotton in the blend may be 90% or less of the total.

[0009] Polyester cotton is made by forming short polyester fibers into a cotton-like material, and is processed into a sheet by mixing it with materials such as recycled polyester cotton. Low-melting-point polyester cotton is a fiber whose melting point has been lowered by mixing it with plasticizers such as isophthalic acid. Generally, the melting point of polyester cotton is said to be 255-260°C due to its heat resistance, but the glass transition point is said to be around 70°C. When processing a blended polyester cotton by mixing ordinary polyester cotton, including recycled polyester cotton, with low-melting-point polyester cotton, the fibers are fused together by heat treatment at around 90-130°C. As for the manufacturing method of low-melting-point polyester cotton, it can be synthesized by spinning a polyester material with added plasticizers from a nozzle, or by using a conjugate spinning method to simultaneously spin two or more different polymers from a single hole, thereby utilizing a core-sheath structure low-melting-point polyester cotton where, for example, the melting point of the sheath side (outer side) polymer is lower than the melting point of the core side (inner side) polymer.

[0010] In this invention, a low-melting-point polyester cotton having a melting point lower than that of the polyester cotton is blended in such a way that the weight ratio of the low-melting-point polyester cotton exceeds 10% but is less than 80%, and processed into a sheet. The range of this weight ratio should be adjusted according to the heat source, cooling device, and heat treatment time of the processing machine used to form the sheet, as well as the room temperature, ambient temperature, and humidity of the processing facility. For example, increasing the upper limit tends to cause greater hardening due to heat treatment, but a relatively high weight ratio range can be adopted by adjusting the thickness so that the final hardened polyester sheet can be cut.

[0011] Low-melting-point polyester cotton is formulated so that its weight ratio exceeds 10% but is less than 80%, and a polyester sheet is obtained by uniformly mixing each polyester cotton. When the weight ratio of low-melting-point polyester cotton exceeds 10%, the hardness tends to increase when it is heat-treated and made into a sheet. When the weight ratio of low-melting-point polyester cotton is 80% or more, it tends to become difficult to cut, for example, with a rotary saw cutter to make it into a sheet, and it may not be suitable for shaping. A more preferable range is when the weight ratio of low-melting-point polyester cotton is 20% to 60%, and even more preferably 20% to 50%. As low-melting-point polyester cotton, polyester fibers with a low melting point overall that are made into cotton can also be used, and fibers with different compositions for the core and sheath can be used, such as when the core is polyester cotton and the sheath is polyester mixed with isophthalic acid which has a lower melting point, copolymer polyester, or polyethylene. If cutting a heat-cured polyester sheet is difficult, the sheet thickness can be reduced to enable cutting. For example, if the sheet thickness is set to a thin thickness of about 1 cm, it can be cut even if the weight ratio of the low-melting-point polyester cotton is about 50%. The low-melting-point polyester cotton may also be a combination of several polyester cottons with different melting points.

[0012] Furthermore, the polyester cotton that makes up the polyester sheet can be given a structure in which silicone resin is added to improve water repellency. When used as a hardened, high-rebound bedding, washing may be necessary depending on usage, but polyester cotton is inherently water-repellent, and by adding silicone resin, it can be made into a structure that can be easily washed. One method of adding silicone resin is to mix it with the polyester cotton, but it can also be added in the form of silicone oil by spraying it during the sheet finishing process, which can improve water repellency.

[0013] An example of a hardened, high-rebound interior product manufactured according to the present invention is a hardened, high-rebound interior product using a hardened polyester sheet, characterized in that a hardened polyester sheet is formed by blending polyester cotton having a normal melting point and low-melting-point polyester cotton having a melting point lower than that of the polyester cotton, such that the weight ratio of the low-melting-point polyester cotton exceeds 10% but is less than 80%, processing the mixture into a sheet, melting the low-melting-point polyester cotton of the sheet-shaped blended polyester cotton by heat treatment, and then hardening the low-melting-point polyester cotton by cooling treatment. The hardened, high-rebound interior product obtained by such processing has a very firm core despite using polyester cotton as the raw material, and the function provided by this firmness can result in a product that is comfortable to sit on. The hardened, high-rebound interior product can also have the same sheet structure as the hardened, high-rebound bedding described above. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic perspective view showing a partially cut section of hardened, high-rebound bedding manufactured by one embodiment of the manufacturing method for hardened, high-rebound products of the present invention. [Figure 2] This is a schematic side view of a hardened, high-rebound bedding product manufactured according to an embodiment of the manufacturing method for hardened, high-rebound products of the present invention. [Figure 3] This is a schematic diagram showing the usage state of hardened, high-rebound bedding manufactured by an embodiment of the manufacturing method for hardened, high-rebound products of the present invention. [Figure 4] This is a schematic perspective view showing a partially cut section of hardened, high-rebound bedding manufactured by one embodiment of the manufacturing method for hardened, high-rebound products of the present invention. [Figure 5] This is a schematic diagram illustrating a rebound force comparison experiment using golf balls conducted on hardened, high-rebound bedding manufactured according to an embodiment of the present invention. [Figure 6] This flowchart illustrates an example of a method for manufacturing a hardened polyester sheet used in a hardened, high-rebound bedding according to an embodiment of the present invention. [Figure 7]It is a schematic perspective view showing a pillow as a cured high-rebound bedding manufactured according to an embodiment of the present invention, with a partial break. [Figure 8] It is a schematic perspective view showing a triangular prism-shaped pillow as a cured high-rebound bedding manufactured according to an embodiment of the present invention, with a partial break. [Figure 9] It is a schematic perspective view showing an overlay mattress as a cured high-rebound bedding manufactured according to an embodiment of the present invention, with a partial break. [Figure 10] It is a schematic perspective view showing a zabuton as a cured high-rebound interior product manufactured according to an embodiment of the present invention, with a partial break. [Figure 11] It is a schematic perspective view showing a cushion as a cured high-rebound interior product manufactured according to an embodiment of the present invention, with a partial break. [Figure 12] It is a schematic diagram showing an example of a manufacturing apparatus used in an example of a method for manufacturing a cured high-rebound product using the cured polyester sheet of the present invention.

Embodiments for Carrying Out the Invention

[0015] A method for manufacturing a cured high-rebound product, which is one embodiment of the present invention, and a cured high-rebound product manufactured by the manufacturing method will be described while referring to the drawings. FIG. 1 is a schematic perspective view of a mattress-type cured high-rebound bedding 10. The outside is a mattress cover 14 with a quilting structure, and inside it there is a cured polyester sheet 12 showing firm high rebound. In this specification, the term bedding is broadly interpreted and may be a mattress as described in this embodiment, or may be a futon or a pillow as described in later embodiments. Also, it is not necessarily limited to bedding used at home, and can be applied to all forms such as bedding used in business such as hospitals and hotels, vehicles, and other facilities where people lie down or sit. Bedding is not necessarily limited to being used constantly and includes temporary use. The cured high-rebound products include bedding and interior products, but are not limited to these as products.

[0016] The cured polyester sheet 12 used in the cured high-rebound product, the cured high-rebound bedding 10, is a sheet cut to a predetermined bedding size (such as 2m×1m, king size, queen size, etc.) and is manufactured by a process as described later. The outer quilting-structured mattress cover 14 is not essential, and it is also possible to cover the cured polyester sheet 12 with a sheet made of required fibers. In this embodiment, as bedding, a single material is directly used in the size of use, and it is particularly possible to fold it in two, three, or perform more folding actions. However, due to the rigidity of the cured polyester sheet 12, it is easy to handle even in a relatively large size and can be used for a long time.

[0017] Figure 2 shows the thickness T of the cured polyester sheet 12 used in the cured high-rebound bedding 10. This thickness T can be adjusted by the number of laminated cured polyester sheets. For example, in the case of a thin cured polyester sheet, it can be set to about 1 to 3 cm, in the case of a cured polyester sheet with a medium thickness, it can be set to about 3 to 7 cm, and in the case of a thick cured polyester sheet, it can be set to a thickness (height) of about 7 to 12 cm. In order to obtain a mattress with a desired thickness, it is possible to use a single relatively thick cured polyester sheet, but it is also possible to arrange a plurality of cured polyester sheets in the mattress cover. Here, the plurality of sheets includes a structure in which the number of sheets becomes plural by folding back without requiring separation for each sheet. In addition, a hard cured polyester sheet can be combined with a foamed resin such as urethane foam, which is commonly used as a normal material. In this case, by adopting a foamed resin with a structure in which air bubbles are chained as the foamed resin, it is possible to prevent the air flow from being blocked. A structure in which a single urethane foam is sandwiched between a pair of cured polyester sheets may also be used. Also, a configuration in which the vicinity of the center in the longitudinal direction around the waist is composed of the cured polyester sheet 12 and the longitudinal ends such as the head and feet are made of other materials such as urethane may be used.

[0018] Figure 3 is a schematic diagram showing a user 16 sleeping using the hardened high-rebound bedding 10 of this embodiment. Because the hardened high-rebound bedding 10 is not made of foamed resin, it can maintain extremely high airflow, and sweat during sleep can escape through the relatively large gaps in the hardened high-rebound bedding 10 itself, eliminating the sticky feeling often associated with mattresses made of foamed resin. Furthermore, because the hardened high-rebound bedding 10 is not made of foamed resin, it does not primarily focus on supporting the body by making broad contact with the bottom surface in the direction of the user's gravity, but rather securely supports the user's waist and other areas with its hardness. Therefore, the hardened high-rebound bedding 10 of this embodiment can prevent the occurrence of lower back pain that depends on the user's sleeping posture.

[0019] The hardened polyester sheet 12 used in the hardened high-rebound bedding 10 is primarily made of 100% polyester cotton. Polyester cotton is made by processing polyester fibers into cotton, and is known for its high elasticity. It is a mass of cotton-like fibers used in sofas, futons, cushions, stuffed animals, etc. Although polyester cotton can be torn and separated, in this embodiment, different types of polyester cotton are blended and pressed to form a hardened polyester sheet 12 of the required thickness. The weight of the finished hardened polyester sheet 12 is 1.2 kg / m² per unit area due to its compression. 2 Or, preferably, it should be 1.3 kg / m² or higher, and typically the cured polyester sheet 12 is 1.3 kg / m². 2 ~2.0kg / m 2 It has a weight within the range of [this].

[0020] The hardened polyester sheet 12 used in the hardened high-rebound bedding 10 is a sheet obtained by blending different types of polyester cotton. In particular, by mixing in low-melting-point polyester cotton, a state is created during heat treatment in which temporarily melted polyester cotton and non-melted polyester cotton are mixed together. From there, by cooling for a very short time, the low-melting-point polyester cotton is solidified, resulting in a hardened polyester sheet that is generally hard and has a high coefficient of resilience. For example, the low-melting-point polyester cotton is blended so that its weight ratio exceeds 10% but is less than 80%, and the polyester cotton is uniformly mixed to obtain a polyester cotton sheet. When the weight ratio of low-melting-point polyester cotton exceeds 10%, the hardness tends to increase when it is made into a sheet after heat treatment. When the weight ratio of low-melting-point polyester cotton is 80% or more, it tends to become difficult to cut, for example with a rotary saw cutter, to make it into a sheet, and it may not be suitable for processing into a specific shape. A more preferable range is 20% to 60% by weight of low-melting-point polyester cotton, and even more preferably 20% to 50% by weight. As low-melting-point polyester cotton, polyester fibers with a generally low melting point can be made into a cotton-like form, and fibers with different compositions can be used, such as a core made of polyester cotton and a sheath made of copolymerized polyester or polyethylene. For ordinary polyester cotton, for example, fibers with a thickness of 12 to 64 denier, preferably 18 to 48 denier, and more preferably 24 to 32 denier can be used, and for low-melting-point polyester cotton, for example, fibers with a thickness of 4 to 6 denier can be used.

[0021] Such hardened polyester sheets can be made easily washable by adding water repellency to the polyester cotton by mixing it with silicone resin or by coating it with silicone oil. In particular, if thicker fibers, such as 12 denier or thicker, are selected as the ordinary polyester cotton fibers of the hardened polyester sheet, the porosity during molding of the hardened polyester sheet 12 can be increased, and if the water repellency improvement effect of silicone resin or silicone oil is added, it becomes possible to achieve a level of washability not found in urethane products.

[0022] During manufacturing, for example, regular polyester cotton, recycled polyester cotton made from recycled resources such as PET bottles, and low-melting-point polyester cotton are mixed uniformly to produce a sheet-like polyester cotton sheet. This sheet is folded and fed in layers, and multiple polyester cotton sheets are heat-pressed together. Specifically, pressure is applied using a hot roller or similar device to compress the fibers into a sheet-like shape, and the temperature is maintained so that the low-melting-point polyester melts and reaches every corner of the sheet. A relatively large-scale heat treatment device is used for this heating, and as the polyester cotton sheet is transported through the heat treatment device, the low-melting-point polyester components within the sheet are melted by the heat pressing process. Cooling air is then applied for a short time by a blower located at the end of the heat treatment device to harden the molten low-melting-point polyester components. The compressed polyester cotton sheet hardens into a rigid state, reducing the volume of the sheet material as it hardens.

[0023] Furthermore, it is possible to add desired flame retardants and other substances to the cured polyester sheet, and it is also possible to mix in antibacterial and antifungal materials. However, the desired flame retardants, antibacterial and antifungal materials may be applied to the final product. The cured polyester sheet discharged from the heat treatment device in a web-like form is then cut to the required size, and a cover is added to construct the cured high-rebound bedding.

[0024] Figure 4 shows an example of a hardened high-rebound mattress 30 as an example of a hardened high-rebound product. The core 36 of the hardened high-rebound mattress 30 in this embodiment is formed using a hardened polyester sheet that is hard overall and has a high coefficient of restitution. The method for manufacturing this hardened polyester sheet is the same as in the previously described embodiment, in which low-melting-point polyester cotton is mixed with polyester cotton in a weight ratio of more than 10% but less than 80% to temporarily create a state in which melted polyester cotton and non-melted polyester cotton are mixed during heat treatment, and then the low-melting-point polyester cotton is instantly solidified by a cooling treatment for a very short time to use a hardened polyester sheet that is hard overall and has a high coefficient of restitution.

[0025] As a bag that encloses such a cotton structure, the hardened high-rebound mattress 30 of this embodiment has quilted sections 34 on the outer fabric 32 on the surface side and the inner fabric 40 on the back side, and a bag-shaped cover material is formed from these structures. The outer fabric 32 and the inner fabric 40 are sewn together along three sides of the rectangle that forms the bag shape, the cotton structure is placed inside the cover material through the opening on one side, and after the cotton structure is placed inside, the opening on the other side is sewn shut with thread, thereby allowing the cotton structure to be contained inside the cover material.

[0026] The inventors of this invention have conducted tests on the high rebound performance of the hardened polyester sheet described above. Figure 5 shows a golf ball drop test. In the golf ball drop test, a certain number of golf balls 22 were dropped from a certain height, 60 cm in this test, onto the surface of the hardened polyester sheet of this embodiment and, as a comparative example, onto the surface of a polyurethane material. The maximum height reached after bouncing off the surface of each sheet was measured. As shown in Table 1 below, the hardened polyester sheet 18 of this embodiment bounced significantly, reaching a maximum height of approximately 34 to 47 cm. In contrast, when the golf ball 22 was dropped onto the polyurethane material 20 as a comparative example, it only bounced to a height of about 6 cm, indicating a significant difference in the coefficient of restitution.

[0027] [Table 1]

[0028] The hardened polyester sheet used in the hardened high-rebound bedding of this embodiment or in the interior products described later tends to exhibit high rebound force regardless of its thickness. For example, with a hardened polyester sheet with a thickness (height) exceeding 10 cm, when a golf ball is dropped from a height of approximately 60 cm, the ball will bounce back to approximately 48 cm or more. With a thinner sheet, the ball tends to bounce back and reach a lower height. For example, with a hardened polyester sheet that is as thin as 2 cm, the ball may bounce back to approximately 30 cm. Note that golf balls also have different rebound characteristics, so-called approved balls (weight: within 45.93 grams, diameter: 42.67 mm or more, coefficient of restitution: within 0.800) were used.

[0029] Next, the manufacturing process flow of the hardened polyester sheet used in hardened high-rebound bedding according to the manufacturing method of this embodiment will be briefly explained with reference to Figure 6. As an example, in the manufacturing of the hardened polyester sheet used in hardened high-rebound bedding according to this embodiment, a manufacturing line equipped with a huge belt conveyor can be used. First, the workers engaged in manufacturing introduce the polyester cotton raw material, consisting of ordinary melting point polyester cotton and low melting point polyester cotton, into the sheet processing machine by tearing them by hand (procedure S10). The ordinary melting point polyester cotton can be configured to include recycled polyester cotton, and the weight ratio of recycled polyester cotton to the total is set to 90% or less. In this sheet processing machine, the introduced polyester cotton can be thoroughly mixed, and the mixed polyester cotton is flattened and stretched (procedure S12). Next, the polyester cotton sheets discharged from the sheet processing machine in the assembly line are stacked so that several sheets overlap (procedure S14), and then the stacked sheets are compressed while being heated with a hot roll (procedure S16). In this compression process, the stacked polyester cotton sheets are processed so that their thickness is greatly reduced. In the manufacturing process of the cured polyester sheet of this embodiment, after compression, a heat treatment is subsequently applied (procedure S18) to melt the low-melting-point polyester cotton while it is still compressed, spreading it throughout the sheet. Finally, a cooling treatment (procedure S20) is performed by applying cooling air, which allows the sheet to harden in an extremely short time (a few seconds to tens of seconds), thereby solidifying the cured polyester sheet. Ultimately, a cured polyester sheet that remains compressed and solidified can be obtained (procedure S22).

[0030] As described above, the hardened, high-rebound bedding according to this embodiment uses a hardened polyester sheet that has been compressed and solidified. Therefore, it does not have the softness of general foamed urethane resin, but is a hard and highly resilient sheet, making it easy for sleepers to maintain or change their posture, and as a result, the occurrence of back pain and other problems can be prevented. Furthermore, in a form that does not use any foamed resin material at all, the hardened, high-rebound bedding of this embodiment has excellent air permeability, and it is also possible to prevent stickiness when foamed resin comes into contact with or is nearby the skin.

[0031] Figure 7 shows a pillow 90 as a hardened, high-rebound product according to an embodiment. The pillow 90 of this embodiment is formed using a hardened polyester sheet 92 that is generally hard and has a high coefficient of restitution, and has a cover 94 on the outside of the hardened polyester sheet 92. The manufacturing method of this hardened polyester sheet 92 is the same as for the hardened, high-rebound product described above, in which low-melting-point polyester cotton is mixed with polyester cotton in a weight ratio of more than 10% but less than 80%, creating a state in which temporarily melted polyester cotton and non-melted polyester cotton are mixed during heat treatment, and then the low-melting-point polyester cotton is instantly solidified by a cooling treatment for a very short time, thereby producing a hardened polyester sheet 92 that is generally hard and has a high coefficient of restitution, and using this sheet is the same as for the hardened, high-rebound product described above.

[0032] Figure 8 shows a triangular prism-shaped pillow 60 manufactured according to the embodiment. The triangular prism-shaped pillow 90 shown in Figure 8, like the pillow 90 shown in Figure 7, is formed using a hardened polyester sheet 62 that is generally hard and has a high coefficient of restitution, and has a cover 64 on the outside of the hardened polyester sheet 62. The manufacturing method of this hardened polyester sheet 62 is the same as in the embodiment described above, in which low-melting-point polyester cotton is mixed with polyester cotton in a weight ratio of more than 10% but less than 80% to temporarily create a state in which melted polyester cotton and non-melted polyester cotton are mixed during heat treatment, and then the low-melting-point polyester cotton is instantly solidified by a cooling treatment for a very short time to produce a hardened polyester sheet 62 that is generally hard and has a high coefficient of restitution, and the sheet is used.

[0033] The pillow 90 using the hardened polyester sheet 92 and the triangular prism-shaped pillow 60 using the hardened polyester sheet 62 have superior breathability compared to those made from foamed resins such as urethane, and are very user-friendly products from the standpoint of mold and mite resistance. Furthermore, the pillow 90 and the triangular prism-shaped pillow 60 of this embodiment have the advantage of being lightweight and easy to handle because they use hardened polyester sheets 92 and 62, which are hard and have a high coefficient of restitution, as core materials.

[0034] Figure 9 shows an overlay-type mattress 70 manufactured according to the embodiment. This overlay-type mattress 70 is a relatively large sheet-like bedding, for example, a double-size sheet measuring 200 x 200 cm, and is formed using a hardened polyester sheet 72 that is generally hard and has a high coefficient of restitution. A cover 74 is placed on the outside of the hardened polyester sheet 72. The manufacturing method for this hardened polyester sheet 72 is the same as in the embodiment described above, in which low-melting-point polyester cotton is mixed with polyester cotton in a weight ratio of more than 10% but less than 80%, creating a state in which temporarily melted polyester cotton and non-melting polyester cotton are mixed during heat treatment, and then the low-melting-point polyester cotton is instantly solidified by a cooling treatment for a very short time to produce a hardened polyester sheet 72 that is generally hard and has a high coefficient of restitution, and the sheet is used.

[0035] Figure 10 shows a cushion 80 as a hardened, high-rebound interior product manufactured by the manufacturing method of the embodiment. The cushion 80 of this embodiment is formed using a hardened polyester sheet 82 that is hard overall and has a high coefficient of restitution, with cotton batting 86 wrapped around the outside of the hardened polyester sheet 82, and an outer cushion bag 84 on the outside of that. The manufacturing method of this hardened polyester sheet 82 is the same as in the embodiment described above, in which low-melting-point polyester batting is mixed with polyester batting in a weight ratio of more than 10% but less than 80%, creating a state in which temporarily melted polyester batting and non-melted polyester batting are mixed during heat treatment, and then the low-melting-point polyester batting is instantly solidified by a cooling treatment for a very short time to produce a hardened polyester sheet 82 that is hard overall and has a high coefficient of restitution, and the use of this sheet is the same as in the embodiment described above.

[0036] Figure 11 shows a cushion 100 as a hardened, high-rebound interior product manufactured by the manufacturing method of the embodiment. The cushion 100 of this embodiment is formed using a hardened polyester sheet 102 that is generally hard and has a high coefficient of restitution, and has an outer cushion bag 104 on the outside of the hardened polyester sheet 102. The manufacturing method of this hardened polyester sheet 102 is the same as in the embodiment described above, in which low-melting-point polyester cotton is mixed with polyester cotton in a weight ratio of more than 25% but less than 45%, creating a state in which temporarily melted polyester cotton and non-melted polyester cotton are mixed during heat treatment, and then the low-melting-point polyester cotton is instantly solidified by a cooling treatment for a very short time, thereby producing a hardened polyester sheet 102 that is generally hard and has a high coefficient of restitution, and using that sheet.

[0037] As described above, hardened polyester sheets, which are generally rigid and have a high coefficient of resilience, can be applied not only to bedding but also to various interior products that utilize elasticity, such as cushions and pillows, and can be used in a variety of products that take advantage of their hardness and high resilience. Compared to foamed resins such as urethane, they are lighter and have excellent breathability, making them very practical products from the standpoint of mold and mite resistance.

[0038] The hardened polyester sheet described above can be made water-repellent and easily washable by mixing polyester cotton with silicone resin or by coating it with silicone oil in the finishing process. In particular, if thicker fibers of, for example, 12 denier or more are selected as the ordinary polyester cotton fibers of the hardened polyester sheet, the porosity during molding of the hardened polyester sheet 12 can be increased, and if the water-repellency improvement effect of silicone resin or silicone oil is added, it becomes possible to achieve a level of washability not found in urethane products.

[0039] Furthermore, by using multiple types of low-melting-point polyester cotton with different melting points, the low-melting-point polyester cotton can be mixed in less during summer work when temperatures are high, and more during winter work when temperatures are low, thereby enabling stable fusion of low-melting-point polyester cotton throughout the year.

[0040] Figure 12 shows an example of a manufacturing apparatus for carrying out the manufacturing method of the hardened, high-rebound product of the present invention. First, polyester cotton with a normal melting point, recycled polyester cotton, and low-melting-point polyester cotton with a melting point lower than that of the polyester cotton are put into a blender 112 and mixed together. The ratio is such that the weight ratio of the low-melting-point polyester cotton is greater than 10% and less than 80%. The polyester cotton sheet is fed out of the blender 112 and processed into a sheet shape by passing through feed rollers (not shown) and large rollers 114 for uniformizing the sheet, and then moves toward the folding section 117. In this folding section 117, the leading section 116 of the continuous polyester cotton sheet 111 is configured to perform a repetitive motion in the sheet feeding direction. As the leading unit 116 repeats its operation, the continuous polyester cotton sheets 111 are folded on the conveyor 118. Since the conveyor 118 moves downward in the figure, that is, perpendicular to the sheet feeding direction, the folded polyester cotton sheets 111 are sent to the heating unit 120 in a diagonally stacked state.

[0041] In the heating section 120, a state is created in which molten and unmolten polyester cotton are temporarily mixed by applying pressure and heat treatment in the range of 90 to 130°C. From there, a very short cooling treatment is performed using a blower or the like installed downstream of the heating section 120 to harden the low-melting-point polyester cotton and harden the polyester cotton sheet into a plate shape. By passing through the heating section 120, the low-melting-point polyester cotton is instantly solidified, and a hardened polyester sheet with a high coefficient of restitution can be obtained overall.

[0042] Next, the cured polyester sheet is cut in the width direction at the first cutting section 122 to form a cut surface 123 that extends in the width direction, thereby processing it to the length of each individual sheet. Then, at the second cutting section 124, it is cut in a direction parallel to the feed direction of the sheet to form a cut surface 127 that extends in the feed direction. By removing the excess portion 128 that occurs when forming this cut surface 127, the width of each cured polyester sheet 126 can be made uniform, and cured polyester sheets 126 of the required product size can be manufactured. [Explanation of symbols]

[0043] 10 Hardened, high-rebound bedding 12. Hardened polyester sheet 14 Mattress Covers 16 User 18. Cured polyester sheet 20 High-rebound polyurethane material 22 golf balls 30 Hardened High-Resilience Mattress 32 Outer cloth 34 Quilted section 36 Core 40 lining 60 triangular prism pillow 62 Hardened polyester sheet 64 Cover 70 Overlay Mattress 72 Hardened polyester sheet 74 Cover 80 cushions 82 Hardened polyester sheet 84 Cushion outer bag 86 rolls of cotton 90 pillows 92 Hardened polyester sheet 94 Cover 100 cushions 102 Hardened polyester sheet 104 Cushion outer bag 111 Polyester cotton sheet 112 Blender 114 Large Roller 116 Leading section 117 Folded section 118 Conveyor 120 Heat treatment process 122 1st cutting section 123 Cut surface 124 2nd cutting section 126 Hardened polyester sheet 127 Cut surface 128 remainder

Claims

1. A method for manufacturing a hardened high-rebound product using a hardened polyester sheet, A polyester cotton with a normal melting point, recycled polyester cotton, and low-melting-point polyester cotton having a melting point lower than that of the polyester cotton are blended so that the weight ratio of the low-melting-point polyester cotton exceeds 10% but is less than 80%, and the mixture is uniformly combined and processed into a sheet. The polyester cotton sheets, which have been processed into a sheet shape, are fed little by little and folded back to stack multiple sheets of the polyester cotton sheets. By applying pressure and heat treatment in the range of 90 to 130°C, the low-melting-point polyester cotton of the mixed polyester cotton processed into a sheet is melted, fusing the fibers together, and the polyester cotton sheet is processed into a plate. Next, the low-melting-point polyester cotton is hardened by a cooling process to harden the polyester cotton sheet into a plate shape. A method for manufacturing a hardened, high-rebound product, characterized by using a hardened polyester sheet formed by cutting the hardened, plate-shaped polyester cotton sheet to the size of the product.

2. A method for manufacturing a hardened high-rebound product according to claim 1, characterized in that the hardened polyester sheet is formed by mixing with a silicone resin, or the hardened polyester sheet is formed by coating with silicone oil in a finishing process.

3. A method for manufacturing a hardened, high-rebound product according to claim 1, characterized in that the polyester cotton having a normal melting point is made of fibers with a thickness of 12 to 64 denier.

4. A method for producing a hardened, high-rebound product according to claim 1, wherein the low-melting-point polyester cotton has a core-sheath structure, the core is polyester cotton, and the sheath is made of polyester mixed with isophthalic acid, copolymerized polyester, or polyethylene.

5. A method for manufacturing a hardened, high-rebound product according to claim 1, wherein the hardened, high-rebound product is bedding constituting a futon, mattress, or pillow, or interior product constituting a cushion or seat cushion.

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