EDGE STRIP, ESPECIALLY DOUBLE FLOOR EDGE STRIP

Description

[0001] The invention relates to an edge strip, in particular an edge strip for raised floors, comprising a thermoplastic material. The invention further relates to a method for manufacturing the edge strip. The invention also relates to a raised floor element.

[0002] Raised floors are a floor construction used in the interior of buildings. They provide a service cavity beneath their entire surface for housing all building services installations and supply and disposal lines (e.g., cables, etc.), allowing free access to this cavity at any point. Furthermore, raised floors can compensate for unevenness in the subfloor, as the raised floor panels are typically mounted on height-adjustable supports.

[0003] Various raised floor elements are known from the prior art, differing, for example, in their substrate material, covering, dimensions, and thickness. The dimensions of a raised floor element typically range from 600 / 600 mm to 1200 / 1200 mm, with thicknesses from 19 to 50 mm, depending on the load requirements and the material used. Thicknesses in the range of 30 to 38 mm are particularly common.

[0004] In addition to requirements for the statics and load-bearing capacity of the raised floor elements, certain fire protection classes must also be met, as regulated, for example, in DIN EN 13501 (classification of construction products and building elements according to their fire behavior).

[0005] US Patent 3,811,237 discloses a raised floor system in which the floor panels have a load-bearing layer of wood particles. However, during normal use, potential differences between the floor panel materials and the users can lead to electrostatic charging and discharging. Therefore, US Patent 3,811,237 addresses this by coating the underside with a metal plate and covering the top with a carpet material. This carpet extends beyond the edge of the panel to the underside, allowing the electrostatic charge to be transferred from the top to the underside of the panel and then dissipated into the floor via the metal supports.

[0006] Alternatively, edge strips made of an electrically conductive plastic material can be used on the base plates to dissipate the charge. This is described, for example, in DE 20 2007 017 234 U1 and EP 1 696 038 A2. Electrical resistances of the edge strips between 10⁻² and 10⁻⁹ ohms are preferred, as excessive conductivity is undesirable. The edge strips are typically about 0.5 mm thick and are usually attached to the side of the base plate using a hot-melt adhesive. In addition to dissipating electrostatic charge, the edge strips also serve to protect the edges of the base plates.

[0007] In the prior art, plastics, preferably thermoplastic materials, are typically used as the material for the edge trim. Acrylonitrile butadiene styrene copolymer or polyvinyl chloride are widely used, but other thermoplastic polymers can also be employed.

[0008] To obtain electrically conductive edge trims, DE 20 2012 100 911 U1 proposes, on the one hand, using polymeric materials that are inherently conductive due to the presence of conjugated double bonds, such as polyaniline, polypyrrole, polythiophene, and others. On the other hand, DE 20 2012 100 911 U1 proposes making polymers that are not inherently electrically conductive conductive by adding a carbon- or metal-based conductivity additive.

[0009] The addition of the aforementioned conductivity additives regularly alters the properties of the resulting edge bands, causing them to generate noises, known as creaking or squeaking, when they rub against each other. Besides the electrostatic charge generated when walking on raised floors, which can be reduced by conductive edges, this presents a further problem with raised floors: the creaking noises caused by the relative movement of the elements against each other. Various approaches have been proposed in the prior art to improve the creaking behavior of raised floor elements equipped with edge strips made of an electrically conductive plastic material.

[0010] For example, DE 20 2007 017 234 U1 proposes adding graphite to the edge strip material. This is intended to reduce creaking by allowing the edge strips to slide against each other more easily.

[0011] WO 2014 / 076665 A1 proposes a coating of UV lacquer, ESH lacquer, or UV water-based lacquer to reduce creaking noises. This coating is electrically conductive and intended to prevent footfall and creaking noises. However, applying a lacquer requires an additional process step. Furthermore, the lacquer must dry, which may entail additional occupational safety requirements.

[0012] EP 1 696 083 A2 proposes providing edge strips with surface textures having a roughness depth of approximately 10 to 40 µm, which should reduce noise between opposing raised floor panels with edge strips. However, applying these textures requires an additional process step, such as embossing. Furthermore, abrasion is a concern with textured surfaces.

[0013] It follows from the above that edge strips, especially raised floor edge strips, with improved creaking behavior are desirable. Therefore, the object of the present invention is to improve the creaking behavior of a corresponding edge strip. Ideally, the edge strip can also be manufactured more easily.

[0014] Other and further tasks, features and advantages of the present invention are explained in more detail in the following description.

[0015] According to the invention, the present problem is solved by the edge strip according to claim 1, the method for its manufacture according to claim 13, and the raised floor element according to claim 15.

[0016] Accordingly, the invention provides an edge strip, in particular a double floor edge strip, containing a thermoplastic material, a conductivity additive and a tribology additive, wherein the tribology additive is a plastic.

[0017] Furthermore, the invention provides a method for manufacturing an edge strip comprising the steps a) Providing a composition containing a thermoplastic material, a conductivity additive and a tribology additive, wherein the tribology additive is a plastic, b) Adding mechanical and / or thermal energy to the composition from step a) to obtain a molding compound, c) Forming the edge strip from the molding compound, ready.

[0018] Furthermore, the invention provides a double floor element comprising a panel and an edge strip according to the invention attached thereto.

[0019] Surprisingly, it was found that an edge strip containing a thermoplastic material, a conductivity additive and a tribology additive exhibits a reduction in creaking noises while maintaining good conductivity properties.

[0020] Without being bound to a scientific theory, it appears that adding a tribology additive to the thermoplastic material of the edge trim improves the frictional properties of the edge trim when two edge trims rub against each other to such an extent that noise generation is significantly reduced and thus the creaking behavior is improved. At the same time, good conductivity properties can be observed.

[0021] Since two additives are added to the thermoplastic material during the production of the edge trim to improve its conductivity and creaking behavior, the edge trim according to the invention is easy to manufacture. In particular, no downstream painting or embossing steps are required. Furthermore, there is no wear and tear during use, such as that which occurs with the application of a paint layer or the incorporation of a texture. Therefore, even with continuous use, there is no deterioration in the creaking behavior.

[0022] The present invention thus discloses the possibility of providing edge strips with improved creaking behavior, which can simultaneously be manufactured using a simpler method. Furthermore, the manufacturing process is flexible and compatible with many thermoplastic materials. In particular, thermoplastic materials that pose little risk in the event of a fire can also be used.

[0023] The following describes various embodiments of the edge strip, the manufacturing method, and the raised floor element, with each embodiment applying independently to the edge strip, the manufacturing method, and the raised floor element, respectively. Furthermore, the individual embodiments can be combined with one another as desired.

[0024] The edge strip according to the invention contains a thermoplastic material.

[0025] In an advantageous embodiment, the thermoplastic material is a thermoplastic polymer. Various thermoplastic polymers are suitable. Preferably, the thermoplastic material, in particular the thermoplastic polymer, is selected from the group consisting of polyvinyl chloride, polypropylene, polyethylene, polystyrene, styrene-butadiene copolymers, acrylonitrile-styrene-acrylate copolymers, acrylonitrile-butadiene-styrene copolymers, styreneacrylonitrile, polybutylene terephthalate, polyethylene terephthalate, polyoxymethylene, polyamide, polymethyl methacrylate, polyphenylene oxide, polyetheretherketone, polyphenylene sulfide, liquid crystal polymer, polyamide-imides, polyvinylidene fluoride, polyphenylsulfone, polyaryletherketone, polyacrylonitrile, polychlorotrifluoroethylene, polyetherketone, polyimide, polyisobutene, polyphthalamide, polypyrrole, polytetrafluoroethylene, polyurethane, polyvinyl alcohol, polyvinyl acetate, polyvinylidene chloride, polylactic acid, and mixtures thereof.Preferably, the thermoplastic material is selected from the group consisting of acrylonitrile butadiene styrene copolymers, polyvinyl chloride, polymethyl methacrylate, polyethylene, polylactic acid, and polypropylene. Further preferably, the thermoplastic material is selected from the group consisting of acrylonitrile butadiene styrene copolymers, polymethyl methacrylate, polyethylene, polylactic acid, and polypropylene. Polypropylene is particularly preferred as the thermoplastic material.

[0026] The edge strip according to the invention can contain the thermoplastic material in varying amounts. Preferably, the edge strip contains the thermoplastic material in an amount of 30 to 90 wt.%, more preferably 30 to 80 wt.%, and particularly preferably 40 to 80 wt.%, based on the total weight of the edge strip.

[0027] The edge trim according to the invention contains a conductivity additive. This allows the conductivity of the edge trim to be adjusted. Various conductivity additives are suitable. Preferably, the conductivity additive is carbon-based or metal-based. In an advantageous embodiment, the conductivity additive is selected from the group consisting of carbon black, graphite, carbon nanotubes, carbon fibers, metal particles, metal-coated glass fibers, and mixtures thereof. Carbon black is particularly preferred as a conductivity additive. The conductivity of the edge trim can be easily adjusted using the aforementioned conductivity additives.

[0028] The edge strip according to the invention can contain the conductivity additive in varying amounts. Advantageously, the edge strip contains the conductivity additive in an amount of 1 to 50 wt.%, preferably 10 to 40 wt.%, particularly preferably 15 to 30 wt.%, based on the total weight of the edge strip.

[0029] The creaking behavior of the raised floor element is improved according to the invention by adding a tribology additive to the material of the edge strip, wherein the tribology additive is a plastic.

[0030] The edge trim contains the tribology additive in addition to the thermoplastic material. The tribology additive can exhibit particularly good friction properties. The plastic is preferably polytetrafluoroethylene, polyoxymethylene, polyketone, polyethylene, or a mixture thereof. UHMW polyethylene is preferably used.

[0031] The plastics polyketone or UHMW polyethylene are particularly preferred.

[0032] UHMW polyethylene stands for ultra-high molecular weight polyethylene. UHMW polyethylene preferably has a molecular weight, in particular a weight-average molecular weight, of 1,000,000 g / mol to 10,000,000 g / mol. Methods for determining the molecular weight are known to those skilled in the art. The molecular weight can be determined by solvent viscometry (capillary) according to ISO 1628-3:2010 with calculation of the molar mass according to Mark-Houwink.

[0033] Polyketone is particularly distinguished by its good processability and high effectiveness as a tribology additive.

[0034] Preferably, the polyketone has a melting temperature of 190°C to 250°C, more preferably of 200°C to 240°C, and particularly preferably of 210°C to 230°C, as measured according to ISO 11357.

[0035] Furthermore, the polyketone preferably has a melt flow index of 40 g / 10 min to 80 g / 10 min, more preferably of 50 g / 10 min to 70 g / 10 min, measured according to ASTM D1238 at a temperature of 240°C with a weight of 2.16 kg.

[0036] Polyketones can be obtained in particular by copolymerization of one or more olefins such as ethylene or propylene with carbon monoxide.

[0037] Given previous attempts to improve the creaking behavior of edge trims, for example by adding graphite or using externally applied lacquers, it is surprising that a plastic such as polyethylene or polyketone is suitable for this purpose. Compared to lacquers, adding a plastic to the edge trim simplifies manufacturing, as no additional processing step is required on the formed edge. With regard to graphite, plastics have the advantage of not causing significant coloration.

[0038] The edge strip according to the invention can contain the tribology additive in varying amounts. Advantageously, the edge strip contains the tribology additive in an amount of 5 to 25 wt.%, preferably 10 to 20 wt.%, based on the total weight of the edge strip.

[0039] The electrical conductivity of the edge trim is an important property, as it serves to safely dissipate the electrostatic charge generated during use. This property is particularly important in rooms with electrical devices. In an advantageous embodiment, the edge trim material therefore exhibits an electrical conductivity measured in the transmission range of 5 × 10⁻¹⁰ to 5 × 10⁻⁶ s.

[0040] Furthermore, it is advantageous that the edge trim according to the invention has a good surface resistance. According to one embodiment, the edge trim has a surface resistance of 10⁶ Ω or less, preferably 5 × 10⁵ Ω or less, more preferably 10⁵ Ω or less, and particularly preferably 5 × 10⁴ Ω or less, measured according to IEC 61340-4-1, in particular IEC 61340-4-1 edition 2016-04. Preferably, the edge trim has a surface resistance of 10⁻² Ω or more. The aforementioned surface resistances facilitate the efficient dissipation of electrostatic charges through the edge trim.

[0041] Furthermore, it is advantageous if the edge strip has a good through-resistance. Accordingly, in a further advantageous embodiment, the edge strip according to the invention has a through-resistance of 10⁶ Ω or less, preferably 5 × 10⁵ Ω or less, more preferably 10⁵ Ω or less, and particularly preferably 5 × 10⁴ Ω or less, measured according to IEC 61340-4-1, in particular IEC 61340-4-1 edition 2016-04. Preferably, the edge strip has a through-resistance of 10⁻² Ω or more.

[0042] Fire behavior is also an important property for the application of the edge trim in raised floor systems. In an advantageous embodiment, the edge trim according to the invention exhibits a fire behavior of at least class E according to the standard DIN EN 13501, in particular DIN EN 13501-1:2019-05.

[0043] The present invention provides an edge strip with improved creaking behavior. In particular, the edge strip according to the invention exhibits reduced creaking.

[0044] The creaking behavior of the edge trim can be investigated using the creaking test method described below. A 41 mm thick, end-chamfered (4°) chipboard panel serves as the test specimen, with the edge to be tested chamfered on all four sides. Two of these test specimens are produced. The two test specimens are placed on a rectangular steel frame, twice the size of one test specimen, which has a vertical support at each corner and in the middle of each long side for supporting the panels, so that the panels touch along one side. The steel frame has a horizontal stop on one short side; the panels are fixed from the opposite side using a pneumatically movable stop, and the clamping force of the panels is adjusted.

[0045] The creaking behavior is investigated over a period of three days. On the first day, the plates are clamped horizontally with a force of 300 N. Subsequently, the two plates are alternately and periodically loaded vertically from above using pneumatic cylinders, each time near the edge (5 cm from the edge where the plates touch). The plates are loaded 900 times per hour with a force of 1250 N (corresponding to 900 cycles per hour). On the second day, the horizontal clamping force is increased to 600 N, and on the third day to 800 N, with the increase in clamping force occurring during the ongoing test. A total of at least 54,000 load cycles are performed per edge or plate pair. Scraping or creaking noises that occur after more than 100 consecutive cycles are documented with the date and time of the test (quiet - medium - distinct). If no noises occur, this is also documented every two hours.Temperature and humidity are also documented.

[0046] The edge strip according to the invention can have different sizes. In one embodiment, the edge strip has a thickness of 0.2 to 5 mm, preferably 0.2 to 2 mm, more preferably 0.2 to 1 mm. According to another embodiment, the edge strip has a width of 10 to 120 mm, preferably 25 to 60 mm.

[0047] For use in a raised floor system, the edge strip must be attached to the floor panel. Preferably, the edge strip is attached to the floor panel with a hot-melt adhesive. The hot-melt adhesive is preferably applied to the edge strip when it is attached to the floor panel. According to one embodiment, the edge strip comprises an adhesion promoter and / or a hot-melt adhesive, in particular an adhesion promoter layer. This improves the adhesion between the edge strip and the hot-melt adhesive.

[0048] Various hot melt adhesives are suitable. Preferably, the hot melt adhesive is based on a polyamide, a polyethylene, an amorphous polyalphaolefin, a polyester elastomer, a thermoplastic polyurethane (TPU), a reactive polyurethane, an ethylene vinyl acetate copolymer, or a copolyamide elastomer.

[0049] To further reduce friction, additional measures can be taken. In an advantageous embodiment of the edge strip according to the invention, a fleece is laminated onto the edge strip. Preferably, the fleece is laminated onto the side opposite the side to be attached to the panel. The deformability of the fleece can further reduce friction.

[0050] As described at the outset, another aspect of the present invention is a method for producing the edge strip according to the invention, comprising providing a composition and supplying mechanical and / or thermal energy to the composition in order to obtain a molding compound from which the edge strip is formed.

[0051] In one embodiment, the composition is provided as a masterbatch. However, it is also conceivable that the composition is provided by mixing the individual components together.

[0052] The application of mechanical and / or thermal energy to the composition can be accomplished in various ways. For example, the composition can be melted, mixed with a mixer, and / or processed in an extruder. According to a preferred embodiment, the process includes an extrusion step. For example, the edge banding can be produced by extrusion followed by calendering. This increases the quality and cost-effectiveness of the edge banding production.

[0053] Finally, as a further aspect, the invention relates to a double floor element comprising a panel and an edge strip according to the invention attached thereto.

[0054] The raised floor element can further comprise a support plate, a prop, a top plate and / or a bottom plate. Preferably, the raised floor element comprises all of the aforementioned components.

[0055] The invention is further explained below with reference to the exemplary drawings, which are in no way limiting. The same reference numerals refer to the same elements. The drawings show: Fig. 1 a side view in a raised floor, wherein the panels are edged with the edge strip according to the invention, and Fig. 2 A top view of a section of a raised floor, wherein the panels are edged with the edge strip according to the invention.

[0056] In the Figure 1Figure 1 shows a side view of a portion of a raised floor comprising raised floor elements 2. The raised floor element 2 comprises a particleboard 3, which is chamfered at 4° and has an edge strip 1 according to the invention on all four narrow sides. The edge strip 1 is attached to the particleboard 3 with a hot melt adhesive and, for improved adhesion of the hot melt adhesive to the edge strip 1, has an adhesion promoter on the side facing the particleboard. The edge strip 1 is made of polypropylene and contains approximately 24 wt.% carbon black and approximately 20 wt.% polyketone.

[0057] The edged plates rest on a support plate 4, which in turn is connected to a head plate 7. The head plate 7 is connected to a support 5, which is attached to a base plate 6. How Figure 1As can be seen, the edged plates are positioned in such a way that the chamfers on the plates create a triangular gap that closes towards the top. This arrangement of the plates is also used for the creak test method.

[0058] Figure 2 shows another view of the part of the raised floor comprising raised floor elements 2. Figure 1 The chipboard panels 3 edged with the edge strip 1 according to the invention rest on the support plate 4, which rests on the head plate 7, which is connected to the base plate 6 via the support 5. EXAMPLES

[0059] Mixtures of a polypropylene compound filled with 40% carbon black (PP-Cpd) and pure polypropylene (PP) were produced according to Table 1. UHMW-polyethylene (UHMW-PE) and polyketone (PK) were also added to some of the edge strips. Table 1: Mixtures of polypropylene compound and polypropylene (components listed in wt.%) Nr. 1 a< 2 a< 3 4 5 6 7 PP-Cpd 0 60 60 60 60 60 60 PP 100 40 35 25 35 25 20 UHMW-PE 0 0 5 15 0 0 0 Press conference 0 0 0 0 5 15 20 Explanations for Table 1: a< - Comparison example.

[0060] The mixtures were then fed into an extruder and edge strips 1 to 7 were extruded from them.

[0061] The surface resistance of the edge strips 1 to 7 obtained in this way was measured according to IEC 61340-4-1, edition 2016-04.

[0062] The edge strips 1 to 7 were then mounted to 41mm thick, beveled (4°) chipboard panels for raised floor elements using hot melt adhesive. All edge strips adhered well to the panels.

[0063] The creaking behavior of these edged raised floor elements was then determined using the creaking test method described above, with two of the chipboard panels with edge strips 1 to 7 (edged on all four sides) being used as test specimens. The results are shown in Table 2. Table 2: Surface resistance and creaking behavior of edge strips 1 to 7 Nr. 1 a< 2 a< 3 4 5 6 7 OW b< >10 3< 10 13 16 11 13 14 KV c< ++ - 0 + 0 + ++ Explanations for Table 2: a< - comparison example; b< - OW: surface resistance in kiloohms; c< - KV: creaking behavior ++: no audible creaking, +: quiet, only temporary creaking, 0: quiet creaking, - loud creaking.

[0064] As can be seen in Table 2, the use of the carbon black-filled polypropylene compound significantly reduced the surface resistance (see edge strip 1 compared to edge strips 2 to 7). Consequently, the electrical conductivity was also increased. However, it was also observed that edge strip 2, which contained only the carbon-containing component carbon black, creaked. This creaking could be reduced by adding UHMW polyethylene or polyketone (see edge strip 2 compared to edge strips 3-7).

Claims

1. An edging strip (1), in particular a raised floor edging strip, containing a thermoplastic material, a conductivity additive and a tribology additive, characterized in that the tribology additive is a plastic.

2. The edging strip (1) according to claim 1, characterized in that the thermoplastic material is a thermoplastic, preferably selected from the group consisting of polyvinyl chloride, polypropylene, polyethylene, polystyrene, styrene-butadiene copolymers, acrylonitrile-styrene-acrylic ester copolymers, acrylonitrile-butadiene-styrene copolymers, styrene-acrylonitrile, polybutylene terephthalate, polyethylene terephthalate, polyoxymethylene, polyamide, polymethyl methacrylate, polyphenylene oxide, polyetheretherketone, polyphenylene sulfide, liquid crystal polymer, polyamideimide, polyvinylidene fluoride, polyphenylsulfone, polyaryletherketone, polyacrylonitrile, polychlorotrifluoroethylene, polyetherketone, polyimide, polyisobutene, polyphthalamide, polypyrrole, polytetrafluoroethylene, polyurethane, polyvinyl alcohol, polyvinyl acetate, polyvinylidene chloride, polylactic acid and mixtures thereof, further preferably the thermoplastic material is selected from the group consisting of acrylonitrile-butadiene-styrene copolymers, polyvinyl chloride, polymethyl methacrylate, polyethylene, polylactic acid and polypropylene; the thermoplastic material polypropylene is particularly preferred.

3. The edging strip (1) according to any of the preceding claims, characterized in that the conductivity additive is carbon-based or metal-based, preferably selected from the group consisting of carbon black, graphite, carbon nanotubes, carbon fibers, metal particles, metal-coated glass fibers and mixtures thereof, particularly preferably carbon black.

4. The edging strip (1) according to any of the preceding claims, characterized in that the tribology additive is polytetrafluoroethylene, polyoxymethylene, polyketone, polyethylene, in particular UHMW polyethylene, or a mixture thereof, particularly preferably polyketone or UHMW polyethylene.

5. The edging strip (1) according to any of the preceding claims, characterized in that the material of the edging strip (1) has an electrical conductivity measured in the passage of 5*10-10 up to 5*10-6 S.

6. The edging strip (1) according to any of the preceding claims, characterized in that the edging strip (1) has a surface resistance of 106 ohm or less, preferably 5*105 ohm or less, further preferably 105 ohm or less, particularly preferably 5*104 ohm or less, measured according to IEC 61340-4-1, in particular IEC 61340-4-1, edition 2016-04.

7. The edging strip (1) according to any of the preceding claims, characterized in that the edging strip (1) has a contact resistance of 106 ohm or less, preferably 5*105 ohm or less, further preferably 105 ohm or less, particularly preferably 5*104 ohm or less, measured according to IEC 61340-4-1, in particular IEC 61340-4-1, edition 2016-04.

8. The edging strip (1) according to any of the preceding claims, characterized in that the edging strip (1) has a fire behavior of at least class E according to the DIN EN 13501 standard.

9. The edging strip (1) according to any of the preceding claims, characterized in that the edging strip (1) has a thickness of 0.2 to 5 mm, preferably 0.2 to 2 mm, further preferably 0.2 to 1 mm and / or a width of 10 to 120 mm, preferably of 25 to 60 mm.

10. The edging strip (1) according to any of the preceding claims, characterized in that the edging strip (1) comprises an adhesion promoter and / or a hot-melt adhesive, in particular comprises an adhesion promoter layer.

11. The edging strip (1) according to claim 10, characterized in that the hot-melt adhesive is a hot-melt adhesive based on a polyamide, a polyethylene, an amorphous polyalphaolefin, a polyester elastomer, a thermoplastic polyurethane (TPU), a reactive polyurethane, an ethylene-vinyl acetate copolymer, or a copolyamide elastomer.

12. The edging strip (1) according to any of the preceding claims, characterized in that a nonwoven material is laminated onto the edging strip (1).

13. A method for manufacturing an edging strip (1) according to any of the preceding claims, comprising the steps of: a) providing a composition containing a thermoplastic material, a conductivity additive and a tribology additive, characterized in that the tribology additive is a plastic, b) supplying mechanical and / or thermal energy to the composition of step a) to obtain a molding compound, c) forming the edging strip (1) from the molding compound.

14. The method according to claim 13, characterized in that the method comprises an extrusion step.

15. A raised floor element (2) comprising a panel (3) and an edging strip (1) attached thereto according to any of claims 1 to 12.