Sponge inflatable cushion added with reflecting film and manufacturing process

Abstract

The invention belongs to the technical field of inflatable cushions, and particularly relates to a sponge inflatable cushion added with a reflecting film and a manufacturing process, and the sponge inflatable cushion comprises an inflatable cushion main body and a combined filling body; the inflatable cushion main body comprises top cloth and bottom cloth; the edges of the periphery of the top cloth and the edges of the periphery of the bottom cloth are correspondingly welded and connected, and the combined filling body is arranged in an inflation cavity between the top cloth and the bottom cloth; the combined filling body comprises at least one layer of sponge and one of a reflecting film and a reflecting strip; the upper surface of the combined filling body is welded with the top cloth, and the lower surface is welded with the bottom cloth. According to the scheme, multiple layers of sponges are adopted, the reflecting film is added, heat radiation of a human body is blocked, and the heat preservation effect of products is improved; the influence on the weight, portability and thickness of the inflatable cushion is small, but the warm keeping effect is obviously improved; the sponge and the reflecting film are connected in a hot melting bonding mode, holes do not need to be formed in the reflecting film, and the influence of the holes on the air blocking effect and the heat reflecting effect is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of inflatable cushions, and in particular relates to a sponge inflatable cushion with an added reflective film and a manufacturing process thereof. Background Art

[0002] Traditional sponge inflatable mattresses typically consist of a single sheet of sponge bonded to a base material to create a stable, sealed structure. During use, the product is inflated with air to create a full sponge cavity. However, when used outdoors, this simple sponge cavity structure relies solely on the sponge to isolate the body's heat radiation from the ground's cold currents. The inherent pores of the sponge allow for intense convection within the cavity between the body's heat radiation and the ground's cold currents, leading to heat loss.

[0003] In order to reduce the convection of hot and cold air inside the inflatable product, thereby reducing heat loss and improving the thermal insulation performance of the product, it is necessary to design an inflatable cushion with a built-in sponge and added reflective material. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a sponge inflatable cushion with an added reflective film.

[0005] The technical solution adopted in the present invention is:

[0006] A sponge inflatable cushion with a reflective film added thereto comprises an inflatable cushion body and a combined filling body;

[0007] The inflatable cushion body includes a top cloth and a bottom cloth; the edges around the top cloth are correspondingly welded to the edges around the bottom cloth, and an inflatable cavity is formed between the top cloth and the bottom cloth, and the combined filling body is arranged in the inflatable cavity;

[0008] The upper surface of the combined filling body is welded to the top cloth, and the lower surface of the combined filling body is welded to the bottom cloth; the combined filling body includes at least one layer of sponge;

[0009] When the number of layers of the sponge is only one: a reflective film is welded on the upper surface of the sponge; or a reflective film is welded on the lower surface of the sponge; or a reflective film is welded on the upper and lower surfaces of the sponge respectively; or a reflective strip is provided in the groove on the upper surface of the sponge; or a reflective film is welded on the lower surface of the sponge and a reflective strip is provided in the groove on the upper surface of the sponge;

[0010] When the number of sponge layers is at least two: all sponges are vertically overlapped; and a reflective film is provided between adjacent layers of sponges, with both sides of the reflective film being welded to the corresponding sponges;

[0011] The reflective film is a film with a metal coating, and TPU coating, PVC coating or adhesive coating is provided on both sides of the reflective film; the reflective strip adopts the same structure as the reflective film; the top cloth and the bottom cloth are made of fabric, TPU film or PVC film. When the top cloth and the bottom cloth are fabric, TPU coating or PVC coating is provided on the side of the top cloth and the bottom cloth facing the sponge.

[0012] As an alternative or supplement to the above structure: when the sponge has only one layer and does not have grooves, a horizontal hole is provided on the side surface of the sponge, which passes through the left and right sides thereof, and a filling strip is provided in the horizontal hole, and the filling strip is a down strip or a cotton strip.

[0013] As an alternative or supplement to the above structure: when the sponge has only one layer and has a groove, a filling strip is provided in the groove, and the filling strip is a down strip or a cotton strip; the reflective strip is welded to the upper surface or lower surface of the filling strip.

[0014] As an alternative or supplement to the above structure: when the combined filling body has two layers of sponges, the two layers of sponges are respectively a first sponge and a second sponge, the first sponge is overlapped on top of the second sponge; the thickness of the first sponge is less than or equal to the thickness of the second sponge; and a reflective film is provided between the first sponge and the second sponge;

[0015] No reflective film is provided on the upper surface of the first sponge and the lower surface of the second sponge; alternatively, a reflective film is provided on the upper surface of the first sponge or the lower surface of the second sponge; alternatively, a reflective film is provided on the upper surface of the first sponge and the lower surface of the second sponge.

[0016] As an alternative or supplement to the above structure: the second sponge is a non-porous structure; or a plurality of horizontal holes are provided on the side elevation thereof, which pass through the left and right sides thereof;

[0017] The horizontal hole is empty; or, a filling strip is provided in the horizontal hole, and the filling strip is a down strip or a cotton strip.

[0018] As an alternative or supplement to the above structure: the first sponge is a non-porous structure, or a plurality of vertical holes are provided on the first sponge, and the vertical holes pass through the upper and lower surfaces of the first sponge.

[0019] As an alternative or supplement to the above structure: the production line of the inflatable cushion structure includes a material preparation area, a welding area, a cooling area and an edge sealing area; the material preparation area is used for placing the rolls of top cloth, bottom cloth, first sponge, second sponge and reflective film; the welding area is provided with two heating and pressurizing devices, one above and one below, for hot-melt welding the overlapping top cloth, bottom cloth, first sponge, second sponge and reflective film; the cooling area has a cooling box, and the top cloth, bottom cloth, first sponge, second sponge and reflective film are welded and then enter the cooling box for air cooling; the edge sealing area has an outer frame mold, and the top cloth, bottom cloth, first sponge, second sponge and reflective film are cut and placed in the outer frame mold so that the edges around the top cloth can be welded to the edges around the bottom cloth.

[0020] As an alternative or supplement to the above structure: the manufacturing process of the inflatable cushion structure includes the following steps:

[0021] Material preparation: Place the rolls of top cloth, bottom cloth, first sponge, second sponge and reflective film in the material preparation area, and lead out the ends of the rolls;

[0022] Welding: After the top cloth, bottom cloth, first sponge, second sponge and reflective film are led out, they pass through two heating and pressurizing devices and are hot-melt welded;

[0023] Cooling: The top cloth, bottom cloth, first sponge, second sponge and reflective film are welded together and introduced into a cooling box, where they are cooled by the cold air flow.

[0024] Edge sealing: Place the cut parts of the top cloth, bottom cloth, first sponge, second sponge and reflective film into the outer frame mold, and manually weld the edges around the top cloth to the edges around the bottom cloth.

[0025] As an alternative or supplement to the above structure: when the number of sponge layers in the combined filling body is three, the three sponge layers are respectively a first sponge, a second sponge and a third sponge stacked from top to bottom; a reflective film is provided between the first sponge and the second sponge, and a reflective film is provided between the third sponge and the second sponge;

[0026] No reflective film is provided on the upper surface of the first sponge and the lower surface of the third sponge; alternatively, a reflective film is provided on the upper surface of the first sponge or the lower surface of the third sponge; alternatively, a reflective film is provided on the upper surface of the first sponge and the lower surface of the third sponge.

[0027] The beneficial effects of the present invention are:

[0028] 1. This solution uses multiple layers of sponge and adds reflective film between the sponges to block the heat radiation from the human body, thereby improving the thermal insulation effect of the product;

[0029] 2. Due to the advantage of the reflective film's low weight, its weight only accounts for 2.5%-4% of the entire inflatable cushion, which will not have a significant impact on the overall weight of the inflatable cushion. The impact on portability is small, but the improvement in warmth retention is significant.

[0030] 3. The thickness of the reflective film is 20um±1um, which will not significantly affect the thickness of the inflatable cushion;

[0031] 4. The sponge and the reflective film of this solution are connected by hot-melt bonding, and there is no need to make holes in the reflective film, thus avoiding the impact of the holes on the air barrier effect and heat reflection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of this solution or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0033] Figure 1 This is an exploded structural diagram of a double-layer sponge inflatable cushion structure;

[0034] Figure 2 yes Figure 1 Production line structure diagram of the inflatable cushion structure;

[0035] Figure 3 This is a cross-sectional structural diagram of a double-layer sponge inflatable cushion structure;

[0036] Figure 4 It is a schematic diagram of the structure of an inflatable cushion with horizontal holes;

[0037] Figure 5 This is an exploded structural diagram of a three-layer sponge inflatable cushion structure;

[0038] Figure 6 This is an exploded structural diagram of an inflatable cushion structure with down strips;

[0039] Figure 7 This is an exploded structural diagram of an inflatable cushion structure with cotton strips;

[0040] Figure 8 This is an exploded structural diagram of a single-layer sponge air cushion structure with horizontal holes;

[0041] Figure 9 It is a structural diagram of the inflatable cushion structure of a single-layer sponge belt;

[0042] Figure 10 It is a structural diagram of an inflatable cushion structure with reflective strips;

[0043] Figure 11 It is a structural diagram of an inflatable cushion structure with reflective strips and reflective film.

[0044] In the figure: 1-top cloth; 2-sponge; 2A-first sponge; 2B-second sponge; 2C-third sponge; 3-reflective film; 4-groove; 5-bottom cloth; 6-horizontal hole; 7-reflective strip; 8-down strip; 9-cotton strip. DETAILED DESCRIPTION

[0045] The technical solution in this embodiment will be clearly and completely described below in conjunction with the accompanying drawings. The described embodiments are only a part of the embodiments, not all of them. Based on the embodiments in this solution, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this solution.

[0046] Example 1

[0047] like Figure 1 As shown, this embodiment designs a sponge inflatable cushion with an added reflective film, including an inflatable cushion body and a combined filling body.

[0048] The inflatable cushion body includes a top cloth 1 and a bottom cloth 5; the edges around the top cloth 1 are correspondingly welded to the edges around the bottom cloth 5, and an inflation cavity is formed between the top cloth 1 and the bottom cloth 5, and the combined filling body is arranged in the inflation cavity.

[0049] The combined filling body includes two layers of sponges 2, namely a first sponge 2A and a second sponge 2B; the thickness of the first sponge 2A is less than that of the second sponge 2B, and the sponges 2 overlap vertically; a reflective film 3 is provided between adjacent layers of sponges 2, and both sides of the reflective film 3 are welded to the corresponding sponges 2; the upper surface of the combined filling body is welded to the top cloth 1, and the lower surface of the combined filling body is welded to the bottom cloth 5.

[0050] A reflective film 3 can be provided above the sponge 2 of the top layer of the combined filling body (i.e., the first sponge 2A), and a reflective film 3 can be provided below the sponge 2 of the bottom layer of the combined filling body (i.e., the second sponge 2B). By increasing the number of reflective films 3, the heat reflection amount and heat blocking effect are improved, and the convection of air between different layers of sponges 2 is reduced.

[0051] The reflective film 3 is made of a film with a metal coating. The reflective film 3 can be made of an aluminum-plated film (such as an aluminum-plated non-woven fabric). TPU coating, PVC coating or adhesive coating is provided on both sides of the reflective film 3. The adhesive can be an existing product that can achieve bonding between the reflective film 3 and the sponge 2; the top cloth 1 and the bottom cloth 5 are made of fabric, TPU film or PVC film. When the top cloth 1 and the bottom cloth 5 are fabric, a TPU coating or PVC coating is provided on the side of the top cloth 1 and the bottom cloth 5 facing the sponge 2.

[0052] Example 2

[0053] like Figure 2As shown, based on Example 1, the production line of the inflatable cushion structure includes a material preparation area, a welding area, a cooling area and an edge sealing area; the material preparation area is used for placing the rolls of top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3; the welding area is provided with two heating and pressurizing devices, one above and one below, for hot-melt welding the overlapping top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3; the cooling area has a cooling box, and the top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3 are welded and then enter the cooling box for air cooling; the edge sealing area has an outer frame mold, and the top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3 are cut and placed in the outer frame mold so that the edges around the top cloth 1 and the edges around the bottom cloth 5 can be welded and connected.

[0054] The manufacturing process of the inflatable cushion structure comprises the following steps:

[0055] Material preparation: Place the rolls of top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3 in the material preparation area, and lead out the ends of the rolls;

[0056] Welding: After the top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3 are led out, they pass between two heating and pressurizing devices and are hot-melt welded;

[0057] Cooling: The welded parts of the top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and reflective film 3 are introduced into a cooling box and cooled by the cold air flow in the cooling box;

[0058] Edge sealing: Place the top cloth 1, bottom cloth 5, first sponge 2A, second sponge 2B and the cut parts of the reflective film 3 into the outer frame mold, and manually weld the edges around the top cloth 1 and the edges around the bottom cloth 5.

[0059] Example 3

[0060] Based on the structure of Example 1, Figure 1 、 4 As shown in Figures 6 and 7, the second sponge 2B has a horizontal hole 6 that passes through the second sponge 2B in the horizontal direction. By making holes in the second sponge 2B, the weight of the second sponge 2B can be effectively reduced, thereby reducing the weight of the entire inflatable cushion.

[0061] A filling strip can be provided in the horizontal hole 6, and the filling strip is a down strip 8, as shown in FIG. Figure 6 As shown, the filling strip can be a cotton strip 9, such as Figure 7 shown.

[0062] In addition, a number of vertical holes are provided on the first sponge 2A, such as Figure 4 As shown, the vertical holes penetrate the upper and lower surfaces of the first sponge 2A, so that heat radiation can be directly transmitted and reflected in the vertical holes, thereby improving the heat reflection efficiency.

[0063] Example 4

[0064] like Figure 5 As shown, this embodiment designs a sponge inflatable cushion with an added reflective film, including an inflatable cushion body and a combined filling body.

[0065] The inflatable cushion body includes a top cloth 1 and a bottom cloth 5; the edges around the top cloth 1 are correspondingly welded to the edges around the bottom cloth 5, and an inflation cavity is formed between the top cloth 1 and the bottom cloth 5, and the combined filling body is arranged in the inflation cavity.

[0066] The combined filling body includes three layers of sponge 2, namely the first sponge 2A, the second sponge 2B and the third sponge 2C; the thickness of the first sponge 2A, the second sponge 2B and the third sponge 2C are comparable, and the sponges 2 overlap vertically; the second sponge 2B is located between the first sponge 2A and the third sponge 2C; a reflective film 3 is provided between the first sponge 2A and the second sponge 2B, and a reflective film 3 is also provided between the third sponge 2C and the second sponge 2B, and both sides of the reflective film 3 are welded to the corresponding sponges 2; the upper surface of the combined filling body is welded to the top cloth 1, and the lower surface of the combined filling body is welded to the bottom cloth 5.

[0067] A reflective film 3 can be provided above the sponge 2 of the top layer of the combined filling body (i.e., the first sponge 2A), and a reflective film 3 can be provided below the sponge 2 of the bottom layer of the combined filling body (i.e., the third sponge 2C), thereby increasing the number of reflective films 3 to improve the heat reflection amount and heat blocking effect.

[0068] The reflective film 3 is made of a film with a metal coating. The reflective film 3 can be made of an aluminum-plated film (such as an aluminum-plated non-woven fabric). TPU coating, PVC coating or adhesive coating is provided on both sides of the reflective film 3; the top cloth 1 and the bottom cloth 5 are made of fabric, TPU film or PVC film. When the top cloth 1 and the bottom cloth 5 are fabric, TPU coating or PVC coating is provided on the side of the top cloth 1 and the bottom cloth 5 facing the sponge 2.

[0069] Example 5

[0070] like Figure 8-11 As shown, this embodiment designs a sponge inflatable cushion with an added reflective film, including an inflatable cushion body and a combined filling body.

[0071] The inflatable cushion body includes a top cloth 1 and a bottom cloth 5; the edges around the top cloth 1 are correspondingly welded to the edges around the bottom cloth 5, and an inflation cavity is formed between the top cloth 1 and the bottom cloth 5, and the combined filling body is arranged in the inflation cavity.

[0072] The composite filling body comprises a layer of sponge 2, on the upper surface of which a layer of reflective film 3 (such as Figure 8 、 9 Alternatively, a reflective film 3 is bonded to the lower surface of the sponge 2 (not shown in the figure); Alternatively, a reflective film 3 is welded to the upper and lower surfaces of the sponge 2 (not shown in the figure); Alternatively, a reflective strip 7 is provided in the groove 4 on the upper surface of the sponge 2 (as shown in the figure); Figure 10 Alternatively, a reflective film 3 is welded to the lower surface of the sponge 2, and a reflective strip 7 is provided in the groove 4 on the upper surface of the sponge 2 (as shown); Figure 11 shown).

[0073] The reflective film 3 is a metal-plated film, with TPU coating, PVC coating, or adhesive coating applied to both sides. The reflective strip 7 has the same structure as the reflective film 3. The top and bottom fabrics 1 and 5 are made of fabric, TPU film, or PVC film. If the top and bottom fabrics 1 and 5 are fabric, the sides facing the sponge 2 are coated with TPU or PVC. The reflective strip 7 can be constructed similarly to the reflective film 3 and will not be described in detail here.

[0074] When the upper surface of the sponge 2 has a groove 4, a filling strip is provided in the groove 4, such as Figure 10 、 11 As shown, the filling strip is a down strip 8 or a cotton strip; the reflective strip 7 is welded to the upper surface or the lower surface of the filling strip.

[0075] In addition, when the upper surface of the sponge 2 does not have the groove 4, a horizontal hole 6 is provided on the side elevation of the sponge 2, which passes through the left and right sides thereof. Figure 8 、 9 As shown, the horizontal hole 6 can be empty, or a filling strip can be set in the horizontal hole 6, and the filling strip is a down strip 8 or a cotton strip.

[0076] The above embodiments are merely examples for the purpose of illustrating the present invention clearly and are not intended to limit the embodiments. It is not necessary and impossible to enumerate all embodiments here. Obvious changes or modifications derived therefrom are still within the scope of protection of this technology.

Claims

1. A sponge inflatable cushion with a reflective film, characterized in that: It includes an inflatable cushion body and a combined filling body; The inflatable cushion body comprises a top cloth (1) and a bottom cloth (5); the edges around the top cloth (1) and the edges around the bottom cloth (5) are correspondingly welded and connected, and an inflatable cavity is formed between the top cloth (1) and the bottom cloth (5), and the combined filling body is arranged in the inflatable cavity; The upper surface of the combined filling body is welded to the top cloth (1), and the lower surface of the combined filling body is welded to the bottom cloth (5); the combined filling body comprises at least one layer of sponge (2); When the number of layers of the sponge (2) is only one layer: a reflective film (3) is welded on the upper surface of the sponge (2); or a reflective film (3) is welded on the lower surface of the sponge (2); or a reflective film (3) is welded on the upper and lower surfaces of the sponge (2); or a reflective strip (7) is provided in the groove (4) on the upper surface of the sponge (2); or a reflective film (3) is welded on the lower surface of the sponge (2) and a reflective strip (7) is provided in the groove (4) on the upper surface of the sponge (2); When the number of layers of sponges (2) is at least two: all sponges (2) are vertically overlapped; and a layer of reflective film (3) is provided between adjacent layers of sponges (2), and both sides of the reflective film (3) are welded and connected to the corresponding sponges (2); The reflective film (3) is a film with a metal coating, and TPU coating, PVC coating or adhesive coating is provided on both sides of the reflective film (3); the reflective strip (7) has the same structure as the reflective film (3); the top cloth (1) and the bottom cloth (5) are made of fabric, TPU film or PVC film, and when the top cloth (1) and the bottom cloth (5) are fabric, TPU coating or PVC coating is provided on the side of the top cloth (1) and the bottom cloth (5) facing the sponge (2).

2. The sponge inflatable cushion with added reflective film according to claim 1, characterized in that: When the sponge (2) has only one layer and does not have the groove (4), a horizontal hole (6) is provided on the side elevation of the sponge (2) and passes through the left and right sides thereof, and a filling strip is provided in the horizontal hole (6), wherein the filling strip is a down strip (8) or a cotton strip.

3. The sponge inflatable cushion with added reflective film according to claim 1, characterized in that: When the sponge (2) has only one layer and has a groove (4), a filling strip is provided in the groove (4), and the filling strip is a down strip (8) or a cotton strip; the reflective strip (7) is welded to the upper surface or lower surface of the filling strip.

4. The sponge inflatable cushion with added reflective film according to claim 1, characterized in that: When the combined filling body has two layers of sponges (2), the two layers of sponges (2) are respectively a first sponge (2A) and a second sponge (2B), and the first sponge (2A) is overlapped on top of the second sponge (2B); the thickness of the first sponge (2A) is less than or equal to the thickness of the second sponge (2B); and a layer of reflective film (3) is provided between the first sponge (2A) and the second sponge (2B); No reflective film (3) is provided on the upper surface of the first sponge (2A) and the lower surface of the second sponge (2B); or a layer of reflective film (3) is provided on the upper surface of the first sponge (2A) or the lower surface of the second sponge (2B); or a layer of reflective film (3) is provided on the upper surface of the first sponge (2A) and the lower surface of the second sponge (2B).

5. The sponge inflatable cushion with added reflective film according to claim 4, characterized in that: The second sponge (2B) is a non-porous structure; or, a plurality of horizontal holes (6) are provided on the side surface thereof, which pass through the left and right sides thereof; The horizontal hole (6) is empty; or, a filling strip is provided in the horizontal hole (6), and the filling strip is a down strip (8) or a cotton strip.

6. The sponge inflatable cushion with added reflective film according to claim 4, characterized in that: The first sponge (2A) is a non-porous structure, or a plurality of vertical holes are provided on the first sponge (2A), and the vertical holes penetrate the upper and lower surfaces of the first sponge (2A).

7. The sponge inflatable cushion with added reflective film according to any one of claims 4 to 6, characterized in that: The production line of the inflatable cushion structure comprises a material preparation area, a welding area, a cooling area and an edge sealing area; the material preparation area is used for placing the rolls of the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3); the welding area is provided with two heating and pressing devices, one above and one below, for hot-melt welding the overlapping top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3); the cooling area is provided with a cooling box, and the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) are placed in the cooling box for air cooling after being welded; the edge sealing area is provided with an outer frame mold, and the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) are cut and placed in the outer frame mold so that the edges around the top cloth (1) and the edges around the bottom cloth (5) can be welded and connected.

8. The sponge inflatable cushion with added reflective film according to claim 7, characterized in that: The manufacturing process of the inflatable cushion structure comprises the following steps: Material preparation: placing the rolls of the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) in the material preparation area, and leading out the ends of the rolls; Welding: After the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) are drawn out, they pass between two heating and pressurizing devices and are hot-melt welded; Cooling: introducing the welded portion of the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) into a cooling box, and utilizing the cold air flow in the cooling box to cool the portion; Edge sealing: the cut portions of the top cloth (1), the bottom cloth (5), the first sponge (2A), the second sponge (2B) and the reflective film (3) are placed into an outer frame mold, and the edges around the top cloth (1) and the edges around the bottom cloth (5) are manually welded together.

9. The sponge inflatable cushion with added reflective film according to claim 1, characterized in that: When the number of sponge layers (2) of the combined filling body is three, the three layers of sponges (2) are respectively a first sponge (2A), a second sponge (2B), and a third sponge (2C) that overlap from top to bottom; a reflective film (3) is provided between the first sponge (2A) and the second sponge (2B), and a reflective film (3) is provided between the third sponge (2C) and the second sponge (2B); No reflective film (3) is provided on the upper surface of the first sponge (2A) and the lower surface of the third sponge (2C); or a layer of reflective film (3) is provided on the upper surface of the first sponge (2A) or the lower surface of the third sponge (2C); or a layer of reflective film (3) is provided on the upper surface of the first sponge (2A) and the lower surface of the third sponge (2C).

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