Padding or padded zone for containers such as backpacks or bags, and method for the production thereof

Abstract

The invention relates to padding or padded zones for containers, such as backpacks or bags, the padding or padded zones consisting of an expanded polymer and being provided with functional elements, and the functional elements and the padding or the padded zones are thermoplastically bonded.

Description

[0001] Cushioning or cushioning area for containers such as backpacks or bags and method of manufacture.

[0002] Description:

[0003] The present invention relates to a cushion or a cushioning area, in particular on or for a container such as a backpack or a bag.

[0004] In various technical fields, particle foams made of expanded thermoplastic polyurethane granules have been established for some time now, for example, for sports shoe sole cushions. These granules are then baked together in molds in a subsequent process step. These particle foams are made of thermoplastic polyurethane, which exhibits very high abrasion resistance and permanent elasticity. In subsequent processing steps, the outsoles and shoe uppers are glued or welded on. The disadvantages are the high transport volumes for the lightweight expanded granules and the limited shaping of the cushions due to the size of the foam particles.

[0005] The latest developments bypass the step of producing the particle foam with the advantage of lower transport volumes for the starting material made of non-expanded plastic granulate and the possibility of finer shaping, e.g. for finer ribbing, by directly expanding the thermoplastic polyurethane during the injection process.

[0006] Desirable would be corresponding, skin-friendly, permanently elastic padding or padding areas that can be arranged as shock or spacer pads on bags or containers, such as a backpack. This object is achieved by the features of the characterizing part of claim 1. Further developments and advantageous embodiments of the invention are encompassed in the further claims.

[0007] According to the invention, a pad or padding areas for containers, such as backpacks or bags, wherein these padding or padding areas consist of an expanded polymer and are provided with functional elements, wherein the functional elements and the padding or padding areas are thermoplastically connected.

[0008] The aim of the invention proposed here is to demonstrate the advantages of foam padding for padding containers such as bags or backpacks. It has been found that the surface of the foam parts made of thermoplastic polyurethane, produced directly using the injection molding process, is very skin-friendly and abrasion-resistant for bag padding. This is in contrast to padding made of EVA and polyethylene foam, which is less abrasion-resistant. Padding for bags or backpacks often consists of sewn-in foams and usually has a woven or knitted fabric covering the foam as the contact surface with the body. These woven or knitted fabrics are usually very skin-friendly, but due to their fibers, they are just as hard or even harder than the fibers of clothing that come into contact with these paddings. This regularly leads to damage to clothing.For many cushions, a certain degree of slip resistance is desired to prevent the cushions from slipping on the body.

[0009] The aim of the invention proposed here is to create a connection between the novel expanded foam, by means of functional elements, and the container by selecting a novel combination of processing techniques, materials, and product features. Several cushions can also be connected to one another. This can be done without contact surfaces made of fabrics with hard fibers, while maintaining high abrasion resistance and an anti-slip function against the body. The cushions or cushion areas have different thicknesses in their structure, which can be controlled during the injection molding process, with thin spots with a thickness of less than 2.5 mm representing welding surfaces for the connection to the functional elements or connection areas with the container. The cushions or cushion areas are preferably at least twice as thick as the welding surfaces for the connection to the functional elements.

[0010] The functional elements ensure even force distribution at the connection points between the padding and the container, or between the padding and other functional parts. Depending on the design, they also create a watertight connection to the container. By omitting the fabric covering and using materials from uniform polymer groups, the padding can also be recycled.

[0011] The goal is to avoid sewing the foam onto or against a surface, as this can often lead to thread breakage during sewing due to the high elasticity of the proposed material, or the padding may be prone to tearing at critical points. At the same time, a tight connection between padding and container can be achieved. By appropriately controlling the foaming process, the outer layers can be designed to be denser than the inner foam structure, enabling even greater abrasion resistance.

[0012] The polymer is filled with gas under high pressure in the injection unit, whereby the gas is pressurized so that the gas in the polymer-gas mixture is in the hypercritical range between gaseous and liquid. This means that during a plasticizing process under pressure, the polymer does not increase in volume. When injected into a mold, the polymer expands and changes into a foam material. It has been found that when the polymer mass charged with gas, preferably nitrogen, is injected into thin spots in the injection mold, the polymer only expands very slightly. However, when the charged polymer mass is injected into thicker areas of the injection mold, the polymer mass can expand by a factor of 3-5. This circumstance is used to weld expanded cushions, e.g. at their edges with thin spots, to a coated fabric or film.The coating or film preferably consists of the same material group as the foam material. Since the weld edges are thin, their low degree of expansion gives them increased strength compared to thicker expanded areas of the foam. At the same time, it is advisable to carry out the welding using a high-frequency welding process, which enables short heating times and rapid, controlled cooling of the weld seam. A further feature of the invention is the thermoplastic bonding of molded parts, preferably produced by injection molding from the same material group, to the foam. This is preferably carried out using a 2-component process, with the connection points of the molded part preferably being located at thinner areas of the foam part. These molded parts can be, for example, plastic buckles or fastening eyes or fastening elements.

[0013] The invention is described in more detail below with reference to drawings, in which:

[0014] Fig. 1 is a perspective view of a padded carrying strap or band with arranged functional parts.

[0015] Fig. 2 a section through a functional part and band or upholstery area.

[0016] Fig. 3 a perspective view of a cushion in plate or pillow form.

[0017] Fig. 4. A plan view of a cushion or cushioned area.

[0018] Fig. 5 shows a surface or back panel of a bag or backpack, with padding or cushioning areas arranged thereon. Fig. 1 shows a carrying strap 11 for a bag or backpack which, as shown here, is equipped in its upper region with a functional part 9, here designed as a plate, such as a coated fabric, which is welded or welded onto the carrying strap 11 and / or a padding area 7 and thermoplastically connected to it. The plate 9 serves as a fastening element for attachment to a bag or backpack body and can be fastened, preferably screwed, to corresponding holes 10 using anchors such as bolts, rivets, screws, or plastic elements. At the lower end of the carrying strap or carrying belt 11 shown here, a stabilizing holding plate or guide 8 is arranged, at the tapered end of which a closure element 6 is attached.The padding or padding areas themselves are made of an expanded polymer and welded onto the belt or carrying strap 11, preferably by means of high-frequency welding or by means of a two-component injection molding process.

[0019] The cushions or cushioning areas are manufactured using an injection molding process with the addition of liquefied gas, preferably nitrogen, and are optimized for use as cushions on a carrying strap by adjusting the injection point, pressure, and temperature to the desired structure and toughness. The area for welding the cushion or cushioning area to a functional element is manufactured during the manufacturing process with a preferred maximum thickness of 2.5 mm.

[0020] This is shown as an example in Fig. 2 in a section through the upper fastening plate 9 and the cushion or padding area 7 on the carrying strap 11.

[0021] Figs. 3 and 4 show a separate padding element 5 suitable for welding, which here is designed with a circumferential welding edge 4 and a suitable thickness for the welding process. Fig. 5 shows a simplified view of a surface, which, for example, shows the back panel 1 of a bag or backpack. On this surface 1, pads 5 are welded onto the back panel 1, following the guidance of the back straps. These pads 5 are also manufactured in an optimized thickness or design from a highly absorbent or cushioning material and are thermoplastically bonded to the back panel at a corresponding, preferably circumferential, thin point.Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be made therein by one skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims

Claims 1. Cushions or cushioning areas for containers, such as backpacks or bags, characterized in that these cushions or cushioning areas consist of an expanded polymer and are provided with functional elements, the functional elements and the cushion or cushioning areas being thermoplastically bonded.

2. Upholstery or upholstery areas according to claim 1, characterized in that the functional parts are made of the same material group as the expanded polymer upholstery.

3. Upholstery or upholstery areas according to claim 1, characterized in that the expanded polymer is a thermoplastic polyurethane.

4. Upholstery or upholstery areas according to claim 1, characterized in that the upholstery or upholstery area has different thicknesses in its structure, with thin spots with a thickness of less than 2.5 mm representing welding surfaces for the connection to functional elements.

5. Upholstery or upholstered areas according to claim 1, characterized in that the padding or padding area is at least twice as thick as the welding surfaces for the connection to the functional elements.

6. Cushions or cushion areas according to claim 1, characterized in that the cushion or cushion area is made of expanded polymer by injection molding, with the addition of a liquefied gas and under high pressure.

7. Upholstery or upholstery areas according to claim 6, characterized in that the added liquefied gas is nitrogen.

8. Upholstery or upholstery areas according to claim 1 and 6, characterized in that the upholstery is expanded by a suitable choice of the injection points such that the connection points for the functional parts are expanded by at least 30% less than the upholstery areas.

9. Upholstery or upholstery areas according to claim 1, characterized in that the upholstery or upholstery area is connected to the functional parts by means of high-frequency welding or by means of a two-component injection molding process.

10. Upholstery or upholstery areas according to claim 1, characterized in that a functional part is the side wall or surface of a flexible container or is designed as a coated fabric or webbing.

11. Upholstery or upholstery areas according to claim 1, characterized in that the functional parts are made of glass fiber reinforced material.

12. Upholstery or upholstery areas according to claim 1, characterized in that the functional parts are designed as fastening stiffeners for attaching the upholstery or upholstery area by screws or rivets.

13. Upholstery or upholstery areas according to claim 1, characterized in that the functional parts are designed as connecting elements, such as plastic buckles or plastic rings. 1 . Upholstery or upholstery areas according to claim 1, characterized in that the functional parts are designed in such a way that they allow the connection of at least two upholstery to one another.

15. Upholstery or upholstery areas according to claim 1, characterized in that that the padding or padding areas are designed as backpack elements such as backpack straps or hip belt padding or back padding.

16. Containers such as backpacks or bags according to the aforementioned claims, characterized in that they are designed with padding or padding areas made of an expanded polymer and are provided with functional elements, wherein the functional elements and the padding or padding areas are thermoplastically bonded.

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