Methods for producing a textile material composite and textile material composite

Abstract

The invention relates to a method for producing a textile material composite (10) comprising the process steps: a. Providing a textile top material (12), b. Applying spaced-apart structures (16, 26, 36, 46, 56, 66, 76, 86) having expanded graphite on one side (14) of the top material (12), c. Applying a textile top layer (20).

Description

The invention relates to a method for producing a textile material composite and a textile material composite. In particular, the invention relates to a textile composite material with a flame-retardant function. Flame-retardant textile materials are essential for a wide variety of applications, especially in areas where people are exposed to increased risks from fire and heat. Known solutions include the use of inherently flame-retardant fibers or the coating of textiles with flame-retardant substances. For example, EP 2 205 110 B1 describes an article comprising a flame-retardant textile composite material comprising: a. a fusible outer textile material comprising a fusible material, wherein the fusible outer textile material has an inner surface and an outer surface; b. a heat-reactive material comprising a polymer resin and an expandable graphite which expands by at least 900 mm² when heated to 280°C, wherein the heat-reactive material is applied to the inner surface of the fusible textile material; c.a heat-stable convective barrier adjacent to the heat-reactive material, wherein the article has a break-up time that is at least 30 seconds longer than that of an substantially similar article without the heat-reactive material between the meltable outer textile and the heat-stable convective barrier, and wherein the outer surface of the meltable outer textile is to be exposed to the flame. The heat-reactive material is applied to the entire surface of the outer textile fabric. This makes the textile composite relatively inflexible, so that when used in protective clothing, the wearer's freedom of movement is restricted. Furthermore, the textile composite is not permeable to water vapor, which also impairs the wearing comfort of protective clothing made from this type of composite. The object of the present invention is to provide a method for producing a textile material composite with which a material composite can be produced that has high flexibility and is permeable to water vapor. This problem is solved according to the invention by a method for producing a textile material composite comprising the following process steps: a. Providing a textile top material; b. Applying mutually opposed structures having expandable graphite on one side of the top material; c. Applying a textile cover layer. Because the expandable graphite structures are spaced apart, the textile composite exhibits high flexibility. This spacing also allows the composite to breathe, as water vapor can escape through the spaces between the structures. The protective effect against flames and heat, which primarily results from the expandable graphite structures, is only minimally affected by this spacing. Since the expandable graphite structures are applied directly to one side of the outer material, they are located near a potential heat source. In particular, the expandable graphite can react more quickly than if it were embedded in a foam layer.The proximity of the expanded graphite particles to the top material ensures direct heat transfer to the expanded graphite particles, causing them to expand immediately at a certain temperature and form an effective insulating layer. When expandable graphite particles are applied to the textile upper material in a foam layer, as in the prior art, they are spaced apart from the textile upper material by areas of the foam layer, so that a reaction due to heat occurs only later. According to the invention, this results in a more targeted and efficient use of the expandable graphite, thereby achieving maximum protective effect with minimal material usage. The expandable graphite structures can be polyurethane-free. The expandable graphite structures form a partial, structured coating of the upper material. Any suitable woven, knitted, or non-woven material can be used as the textile upper material. For example, the textile upper material can consist of cotton, synthetic fibers, or blends thereof. The textile upper material must not be meltable. Between steps b. and c., a foam layer can be applied across the entire surface of the top layer to cover the structures containing the expanded graphite. This full-surface foam layer ensures reliable fixation of the expanded graphite structures, thus improving the wash resistance of the textile composite. Furthermore, the foam layer allows for the lamination of the textile top layer onto the foam layer. The foam layer may contain binders and stabilizers. It can be produced by stirring a foam mixture of binders and stabilizers. The foam layer itself is preferably free of expanded graphite particles. The foam layer is preferably applied using a coating system, which ensures uniform distribution and embedding of the expanded graphite structures. The foam layer can serve as an embedding and protective layer for the expanded graphite structures against washing and mechanical stress. Alternatively or additionally, it can serve as a lamination layer. Furthermore, it can provide the additional function of breathability and / or bonding of the layers. The foam compound from which the foam layer is made may contain a crosslinker to increase the coating's stability and wash resistance. The textile top layer can be laminated onto the foam layer, creating a strong, bonded material. According to a preferred method variant, the structures containing expandable graphite are applied to the upper material using a stencil. This allows for the particularly easy creation of spaced-apart structures. Furthermore, patterns of expandable graphite structures can be easily applied. According to one method variant, expanding graphite particles can be sprinkled onto the surface layer to create the structures containing expanding graphite. The expanding graphite particles can be in the form of expanded graphite flakes. Before sprinkling or otherwise applying the structures containing expanding graphite, the salt content of the expanding graphite, particularly the flake-shaped particles, can be washed out. Specifically, the salt content can be reduced to less than 1%. According to an alternative process variant, a water slurry or an unfoamed paste, each containing expandable graphite, can be printed onto the side of the top layer to create the structures. For example, the water slurry or unfoamed paste can be applied using rotary printing, with the structuring again being achieved using a stencil. The water slurry can be binder-free. If the expandable graphite is applied via a paste, the paste can contain a binder system and an antifoaming agent. The paste can be polyurethane-based. Alternatively, the paste can be acrylate-based or silicone-based. The optional foam layer can be applied immediately after the expansion-graphite structures have been applied. Alternatively, a certain period of time can be allowed for the expansion-graphite structures to cure. The foam layer can be applied in a thickness ranging from 0.55 mm to 3 mm. It is understood that the thickness of the foam layer is chosen so that the structures containing the expandable graphite are completely covered by the foam layer, thus fixing them to the textile surface material. The thickness of the foam layer can therefore be selected depending on the thickness or height of the structures containing the expandable graphite. The foam layer can be compressed after application, especially after a drying period. This reduces the thickness of the foam layer and improves the adhesion of the expandable graphite-containing structures to the upper material. The textile top layer can be laminated onto the foam layer, creating a stable composite material. This top layer can then serve as the contact layer for the user when the resulting composite material is used to create a piece of protective clothing. The invention also encompasses a textile composite material comprising a textile top layer, spaced-apart structures containing expandable graphite arranged on one side of the top layer, and a textile cover layer. The textile composite material can be produced, in particular, using the method according to the invention. At least some of the structures containing expandable graphite are spaced apart. It is not excluded that some of the structures containing expandable graphite may be in contact with each other. The textile composite material according to the invention is characterized by high flexibility and breathability. The partial, structured coating with expandable graphite particles improves the flexibility and breathability of the composite material compared to full-surface coatings. The textile composite material exhibits effective flame retardancy. The partial arrangement of the expandable graphite structures enables a rapid and efficient response to heat exposure, resulting in a high level of protection. The expandable graphite particles are attached directly to the outermost layer, which is the first to be exposed to heat. The inventive method enables the rapid and efficient production of the composite material in a continuous process (online process). According to one embodiment, a foam layer, particularly a continuous one, is provided to cover the structures containing the expanded graphite. A continuous foam layer is understood to be a foam layer that is formed without interruption. The foam layer can perform several functions simultaneously, namely embedding the expanded graphite particles or structures, acting as a protective layer, a lamination layer, and ensuring breathability. Covering the expanded graphite structures with a foam layer achieves improved fixation and protection of the structures. In particular, it provides protection against mechanical stress and washing. The structures containing expanded graphite can be spaced between 0.1 mm and 1.1 mm apart. This small spacing ensures the flexibility and breathability of the textile composite. The structures containing expanded graphite can have a height ranging from 0.05 mm to 0.55 mm. This low height is sufficient for adequate flame protection. The structures exhibiting swollen graphite can have a diameter or maximum lateral extent (i.e., extent parallel to the surface of the upper material) ranging from 0.3 mm to 15 mm. Alternatively, one could say that the structures exhibiting swollen graphite have a size ranging from 0.3 mm to 15 mm. The structures containing expanded graphite can be symmetrical, in particular circular or polygonal, especially with an even number of vertices, preferably hexagonal. Symmetrical structures make it particularly easy to achieve a constant or uniform spacing between the individual structures containing expanded graphite. The structures containing expanded graphite can be point-symmetrical or symmetrical with respect to a central plane. The structures containing expandable graphite can be arranged in a repeating pattern. Such a repeating pattern allows for particularly precise control of the material properties. The composite material may exhibit local clusters and / or groups of structures containing expanded graphite. This means that areas may be present where there are more structures containing expanded graphite per unit area than in other areas. In these areas of local clusters, the structures containing expanded graphite may also be closer together than in other areas. Furthermore, groups of swollen graphite structures can have a greater distance from other groups than the swollen graphite structures can have from each other within the group. The expanded graphite structures can be of a uniform size or of varying sizes. The spacing between the expanded graphite structures can be the same or vary. The invention also includes a protective clothing item with a textile material composite according to the invention. Further advantages of the invention will become apparent from the description and the drawing. Likewise, the features mentioned above and those described in more detail below can each be used individually or in any combination according to the invention. The embodiments shown and described are not to be understood as an exhaustive list, but rather serve as examples for illustrating the invention. Figure 1 shows a highly schematic representation of a material composite according to the invention; Figures 2a - e show examples of differently formed and arranged structures containing expandable graphite. Fig. 1 shows a textile composite material 10 with a textile top layer 12, which has several spaced-apart structures 16 containing expanded graphite on one side 14, in particular on its back side. An optional foam layer 18 is arranged on the structures 16 containing expanded graphite, which in turn is covered by a textile top layer 20. The foam layer 18 is preferably applied over the entire surface, so that the structures 16 containing the expandable graphite are embedded in the foam layer 18 and the foam layer 18 extends to the back side (side 14) of the top layer 12 in the areas where the structures 16 containing the expandable graphite are separated from each other. Thus, the structures 16 containing the expandable graphite are fixed to the top layer 12 by the foam layer 18. The structures 16 containing the expandable graphite are in direct contact with the top layer 12. If the top surface of the top layer 12 comes near a heat source, the expandable graphite particles of the structures 16 can react particularly quickly. Fig. 2a shows a first arrangement and configuration of structures 26 containing expanded graphite. The structures 26 containing expanded graphite are circular. The distance to neighboring particles 26 containing expanded graphite is variable, i.e., not constant. Fig. 2b shows an alternative design and arrangement of structures 36 containing expanded graphite. The structures 36 containing expanded graphite are hexagonal. They are arranged in a uniform pattern. The distance between one structure 36 containing expanded graphite and neighboring structures 36 is constant. While the structures 26 containing expanded graphite in Fig. 2a are point-symmetric, the structures 36 containing expanded graphite in Fig. 2b are symmetric about a central plane. Figure 2c differs from Figure 2b in that the structures 46 containing the expanding graphite are larger, i.e., they have a greater lateral extent. The distance between the structures 46 containing the expanding graphite is also greater than in Figure 2b. Figure 2d shows that in a first region 50, structures 56 exhibiting expandable graphite are arranged uniformly, i.e., at a constant distance from one another. Furthermore, a second region 52 can be seen, which exhibits a cluster of structures 66 exhibiting expandable graphite. In this second region 52, the distance between the structures 66 exhibiting expandable graphite is also smaller than in the first region 50. Furthermore, the sizes of the expandable graphite structures 56 and 66 differ. Figure 2e shows another example of an arrangement of structures containing expandable graphite. Here, regions 60 are provided in which several spaced-apart structures 76 containing expandable graphite are present. The structures 76 are equidistant from each other within the region 60 and are also of the same size. The region 60 has a hexagonal shape. Thus, a group or cluster of structures 76 is present. In this case, the cluster has a hexagonal shape. Several such clusters or regions 60 are present, with the distance to adjacent regions 60 being greater than the distance between individual structures 76 within a region 60. Furthermore, an area 62 can be identified in which structures 86, exhibiting expanded graphite, are present. Area 62 represents a local cluster of structures 86. The spacing of the structures 86 is also smaller than the spacing of the structures 76 in area 60. The structures 60 are arranged in a recurring pattern. Figures 2a to 2e show that the structures exhibiting expandable graphite can have different sizes and shapes. These structures can be spaced at varying distances from one another. They can be grouped together, with the distance between groups being constant or variable. Areas with local clusters of expandable graphite structures can also be present. Both the individual structures and the groups of structures exhibiting expandable graphite can be arranged in a repeating pattern. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature EP 2 205 110 B1

[0002]

Claims

Method for producing a textile composite material (10) comprising the process steps: a. Providing a textile top material (12), b. Applying spaced-apart structures (16, 26, 36, 46, 56, 66, 76, 86) containing expanded graphite to one side (14) of the top material (12), c. Applying a textile top layer (20). Method according to claim 1, characterized in that a foam layer (18) is applied over the entire surface of the side (14) of the upper material (12) to cover the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite. Method according to one of the preceding claims, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite are applied to the upper material by means of a template. Method according to one of the preceding claims, characterized in that, to produce the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite, expanding graphite particles are sprinkled onto the top layer (12). Method according to one of the preceding claims 1 or 2, characterized in that, to produce the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite, a water slurry or an unfoamed paste, each having expanding graphite, is printed onto the top layer (12). Method according to any one of the preceding claims 2 to 5, characterized in that the foam layer (18) is applied in a material thickness in the range of 0.55 mm to 3 mm. Method according to any one of the preceding claims 2 to 6, characterized in that the foam layer (18) is compressed after application, in particular after a drying phase. Method according to any one of the preceding claims 2 to 7, characterized in that the textile top layer (20) is laminated onto the foam layer (18). Textile material composite (10) with a textile top layer (12), spaced-apart structures (16, 26, 36, 46, 56, 66, 76, 86) arranged on one side (14) of the top layer (12) having expanded graphite and a textile cover layer (20). Textile material composite according to claim 9, characterized in that a particularly continuous foam layer (18) covers the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite. Textile material composite according to claim 9 or 10, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite structures have a distance of 0.1 mm to 1.1 mm from each other. Textile material composite according to one of the preceding claims 9 to 11, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having a height of 0.05 mm to 0.55 mm. Textile material composite according to one of the preceding claims 9 to 12, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite structure have a diameter or a maximum lateral extent in the range of 0.3 mm to 15 mm. Textile material composite according to one of the preceding claims 9 to 13, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite are symmetrically formed, in particular circular or polygonal, preferably hexagonal. Textile material composite according to one of the preceding claims 9 to 14, characterized in that the structures (16, 26, 36, 46, 56, 66, 76, 86) having the expanding graphite are arranged in a repeating pattern. Textile material composite according to one of the preceding claims 9 to 15, characterized in that the material composite (10) has local clusters of structures (16, 26, 36, 46, 56, 66, 76, 86) having expanded graphite. Protective clothing item comprising a textile material composite according to any one of the preceding claims 9 to 16.

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