Abstract:
A closure component has a plurality of closure components ( 12 ) with each disposed on a carrier part ( 10 ) by a footer ( 18 ). Each has a header ( 14 ) connected to the footer ( 18 ) by a shaft part ( 16 ). The header ( 14 ) is jointedly connected to the shaft part ( 16 ) by a hinge part ( 20 ). Because the footer ( 18 ) forms a further hinge part ( 22 ), by which the shaft part ( 16 ) is jointedly connected to the carrier part ( 10 ), improved adhesion to third components can be produced.

Description:
FIELD OF THE INVENTION 
     The invention relates to a closure component with a plurality of closure components which are spaced apart from one another and which are each located by a base part on a backing part. Each component has a head part connected via a stem part to the base part. The head part is articulated to the stem part via an articulated part. 
     BACKGROUND OF THE INVENTION 
     WO 2004/105536 A1 discloses a touch-and-close fastener part in which the free ends of the stem parts of the individual adhesion elements are provided with a plurality of individual fibers. The diameter of the respective fibers has to be chosen to be very thin so that on the free end of each individual fiber only a very small contact surface is available, of the magnitude of 0.2 to 0.5 μm. 
     These orders of magnitude, which can also be in the nanometer range in preferred configurations, enable interaction with a corresponding body in the vicinity on which the touch-and-close fastener part is to be fixed by van der Waals forces which are classically considered as a subgroup of adhesion. The known touch-and-close fastener part has good connecting properties, but is tied to a correspondingly cost-intensive production process. 
     This situation also applies to a touch-and-close fastener part according to the teaching of publication WO 01/49776 A2, which instructs one skilled in the art to use parts of the base structure of a gecko directly as biological material or to artificially simulate it. This adhesive structure has a plurality of spatula components which are each divided in the form of a bent cylindrical closure element on the free end into a plurality of individual filaments. 
     Conversely, for simplified production, DE 102 23 234 B4 proposed a method for surface modification of an object in the form of a closure component with the objective of increasing the adhesion capacity of the adhesion element. For this purpose, the free surface is exposed to structuring in order to form a plurality of projections which are each provided with a base part and a head part. The head part has an end surface pointing away from the surface. Each projection is formed with a size such that all end surfaces have the same vertical height over the surface. This structure yields an adherent contact surface which is interrupted by respective distances between the end surfaces. The base parts of the projections are tilted relative to the surface normal of the surface. 
     With this known solution, it is possible to make available the execution of detachable adhesive connections for an expanded range of materials with increased adhesion capacity and the possibility of enabling the setting of predetermined adhesive forces or properties. However, based on the relatively rigid arrangement between the head part and backing part over the stem parts which may be tilted, there is room for improved solutions. 
     WO 2007/134685 A1 discloses a generic touch-and-close fastener part. The head part of each closure component has a head disc whose diameter is chosen to be larger than the diameter at any point of the stem part which, made conical in shape, is articulated via an articulated part to the head disc. This structure results in that the head part certainly remains adhering to a body in the vicinity, even if the backing part should move axially in the plane-parallel direction to this body by a definable amount. As a result of the linking via the respective articulated part, located between the stem part and head part, the respective stem part can tilt within a definable framework in the oblique direction without this adversely affecting the linking of the head part relative to the body in the vicinity. Since the head part with the head disc can have a very large diameter in the known solution, the possibility of adhesion to the ambient body is improved accordingly. 
     Especially when vibrations occur during which the backing part executes short-stroke vibrations relative the body in the vicinity, the known touch-and-close fastener part has been found to be an effective connection solution. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an improved adhesive closure component, in particular to supply improved adhesion and closure action for the respective touch-and-close fastener part with the simultaneous option of being able to produce these systems economically and with functional reliability. 
     This object is basically achieved by a touch-and-close fastener part where the base part forms another articulated part by which the stem part is articulated relative to the backing part. Compared to known solutions, improved adhesion relative to third components can be produced. Due to the second articulated part in the region of the base part, relative to the backing part a damping element is formed which relieves the first articulated part in the region of the head part. This structure enables higher vibration and impact forces to be fed into the touch-and-close fastener part without it unintentionally detaching from the third component. Detachment of the head part in the manner of a peeling motion from the body in the vicinity as a third component only takes place when the head part is tilted via the respective articulated part by an angle of at least 20°, preferably of at least 40° relative to the vertical. Standing thereon in the vertical direction, the backing part is oriented with its alignment. 
     The good adhesive action formed in this way also fundamentally applies when a conventional option of hooking underneath is implemented for the closure component, for example, by a loop part of a corresponding touch-and-close fastener part engaging the closure component designed as a mushroom or hook part by hooking underneath. In these cases as well, it has been shown that as a result of the double articulation arrangement an improved closure action is achieved which, if necessary, can also be detached again mechanically or by hand in order in this way to form an adhesive closure which can be repeatedly opened and closed. 
     In one especially preferred embodiment of the touch-and-close fastener part according to the invention, the respective stem part is made reinforced, in particular, is provided in cross section with a widening. This widening has at least in part the shape of a regular or irregular ellipsoid or is structured in the form of an elliptical paraboloid. As a result of the widened stem part, which extends between the two articulated parts on the head and base part, vibration stiffening of the entire system is achieved with increased support function for the indicated opposing articulation sites or articulated parts. 
     Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings which form a part of this disclosure: 
         FIG. 1  is a schematic, not to scale, a side elevational view of a touch-and-close fastener part according to an exemplary embodiment of the invention, with a total of three closure components located on a backing part. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The orders of magnitude addressed with the touch-and-close fastener part in the geometrical implementation should suffice and are designed such that an interaction with a corresponding part, whether in the form of another touch-and-close fastener part or in the form of the surface of a body in the vicinity on which the touch-and-close fastener part according to the invention is to be fixed, can preferably take place by van der Waals forces. The van der Waals forces which constitute a subgroup of adhesion are formed because the negatively charged electrons swirling around the positive core in an atom are briefly concentrated on one side. In this way, the atom on this side is temporarily negatively charged, while it is positively charged on the other side. This charging also affects adjacent atoms. In this case, the atoms along the top of the bearing surface of the head part, with the result that the bearing surface of the head part, depending on which charge it acquires, is attracted either by the positive or the negative atoms of the respective opposite ambient body surface. 
     The larger the arising contact surfaces are in total, the stronger the forces which occur so that it may prove to be effective to form head part bearing surfaces which are dimensioned to be large in order to obtain strong van der Waals forces. Although the van der Waals forces are considered to be among the weakest forces in nature, the effect is sufficient to achieve relatively high closure forces, in particular, with several thousand closure elements on the extremely small space of the backing part. If the surface of the respective head part should be chemically modified for this purpose, genuine chemical bonding is also possible as the adhesion connection. 
     The touch-and-close fastener part shown in  FIG. 1 , for purposes of this invention, can be obtained according to a micro-replication method, as described in DE 196 46 318 A1. The known method is used to produce a touch-and-close fastener part with a plurality of closure components or elements  12  made in one piece with a backing part  10 . The closure elements  12  comprise stem parts  16  which have head parts  14  and which are connected in turn via base parts  18  to the backing part  10 . Preferably, a thermoplastic in the plastic or liquid state is introduced into a gap between a pressure roll and a molding roll. The molding roll is provided with a screen, with cavities which are open to the inside and outside. The two rolls are driven in the opposite direction of rotation for the production process so that the backing material is formed in the gap between the rolls with the formation of the backing part  10 . Since for the touch-and-close fastener part according to the invention the stem parts  14  can be made crowned, the screen cross section is matched to the outer contour of the respective stem part  16 . In particular, the stem part  16  is designed as a regular or irregular ellipsoid of revolution. The desired shaping, as shown in  FIG. 1 , would also be attainable by two paraboloids of revolution, which are facing one another with their free opening cross section. In this way, the indicated screen cross section therefore is to be matched to the shaping of the respective closure component  12 . 
     Another possibility for obtaining the closure component system of  FIG. 1  is shown in DE 100 65 819 C1. In this known method for producing the touch-and-close fastener parts, a backing material is provided in at least one partial region of its surface with touch-and-close fastener parts or adhesion elements which project out of the plane by a plastic material which forms the elements being applied to the backing element as backing part  10 . The elements are made at least in one partial region without molding tools by the plastic material being deposited in successively released droplets by at least one application device. Although the application device delivers the plastic material with a droplet volume of only a few picoliters via its nozzle, a process sequence which is sufficiently fast thus can be implemented so that within an extremely short time frame a touch-and-close fastener part, as shown in  FIG. 1 , can be obtained. With this method, individual adhesion elements in particular can also be produced which, in addition to the head part  14  and the stem part  16  as well as the base part  18 , form two articulated parts  20 ,  22  which, viewed in the direction of  FIG. 1 , are shown at the extreme left as imaginary inscribed circles  24 ,  26  for better understanding and by way of explanation. 
     The stem part  16  in turn can be described in terms of its outside contour as part of a regular or, as shown in  FIG. 1 , irregular ellipsoid of revolution  23 . The centers  28  and  30  of the circles  24  and  26  respectively, are located within the ellipsoid of revolution  23  or more or less on its imaginary edge boundary as shown for the center  30  of the circle  26 . Instead of the illustrated ellipsoid of revolution  23 , the outside contour of the stem part  16  can also be implemented via two paraboloids of revolution which extend in opposite directions (not shown), whose free opening cross sections adjacently border one another. Overall, as a result of the crowned or convex configuration of the stem part  16 , a closure component structure, which is stiffened between the articulated parts  20 ,  22  and which extends between the two articulated parts  20 ,  22  of each closure component  12 , is formed. As especially the increased radius of the circle  26  is intended to show, the articulated part  22  is made thicker in the region of the base part  18  than the overlying articulated part  20  in the direction of the head part  14 . In the direction of the base part, the damping action is then improved. In this respect, the stem part  16  at the articulated part  22  undergoes a smaller pivoting motion than in the region of the head part  14  with the upper articulated part  20 . As the side view of  FIG. 1  shows, for the stem part  16 , this configuration yields a convexly extending outside contour which extends between concavely running outside contour portions of the head part  14  and base part  18 . Furthermore, the head part  14 , proceeding from its articulation site  20  which can be assigned to it, tapers to the outside toward its peripheral edge  32  and there forms a narrow-lipped edge. 
     The respective closure component  12  is made preferably of a plastic material which is selected in particular from the group of acrylates such as polymethacrylates, polyethylenes, polypropylenes, polyoxymethylenes, polyvinylidene fluoride, polymethylpentene, poly(ethylene) chlorotrifluoroethylene, polyvinyl chloride, polyethylene oxide, polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 6.6, and polybutene. 
     Fundamentally, plastics with long molecular chains and good orientation behavior as well as plastic materials with thixotropic behavior are highly suitable. Thixotropic behavior for purposes of the invention is intended to denote the reduction of structural strength during the shear loading phase and its more or less rapid but complete restoration during the subsequent resting phase. This breakdown/restoration cycle is a completely reversible process. Thixotropic behavior can be defined as a time-dependent behavior. 
     Furthermore, plastic materials have proven favorable in which the viscosity of 7,000 to 15,000 mPa, measured with a rotational viscosimeter, is sufficient. Preferably, that viscosity has a value of approximately 10,000 mPas at a shearing rate of 10 l/sec. For purposes of a self-cleaning surface, it has moreover proven favorable to use plastic material whose contact angle, as a result of its surface energy for wetting with water, has at least a value of greater than 60 degrees. Under certain circumstances, this surface energy can also be further changed by subsequent treatment methods. 
     With respect to the aforementioned requirements, polyvinyl siloxane has proven an especially interesting representative of suitable plastic materials. This plastic can be used especially for the formation of head parts  14  and their free tops. The entire closure component  12  including the backing part  10  can be composed of this polyvinyl siloxane plastic material. 
       FIG. 1  shows fastener part approximately 1,000 times enlarged relative to the actual size. There can be 10,000 to 50,000, preferably 30,000, of these closure components  12  standing tightly next to one another per square centimeter on the homogeneous planiform or strip-shaped backing part  10 . A uniform arrangement is preferred in which all closure components  12  in the form of adhesion elements have the same distance to one another. Irregular arrangements or pattern shapes (round, star-shaped, ellipsoidal, etc.) can also be made. 
     The head parts  14  which are disk-shaped in terms of the outside contour can also have other shapes. For example, they can be made elliptical or polygonal in shape, the hexagonal shape having been found to be especially favorable, even with respect to the indicated screen shaping method. For the stem parts  16 , are with respect to the release from the shaping screen which is to be undertaken, a crowned structure is favorable. 
     The individual size ratios in the direction of  FIG. 1  are as follows for the closure component  12  at the extreme right: 
     Y1=30 to 55 μm 
     Y2=approx. 28 μm 
     Y3=approx. 35 μm 
     Y4=40 to 65 μm 
     Y5=30 to 65 μm 
     X1=approx. 2 μm 
     X2=approx. 8 μm 
     X3=60 to 80 μm 
     While Y5 indicates the distance of two adjacent center axes of closure components  12 , the distance is approximately 115 μm standing vertically on the plane of the drawing to the respective next closure component  12  located in the middle between two closure components  12  lying in the plane of the figure, to the closure component  12  which lies comparably behind in the plane of the drawing. These size ratios are only exemplary and yield an especially favorable and well-functioning touch-and-close fastener part. Other size ratios are also conceivable here. 
     Since the two articulated parts  20 ,  22  can be adjusted independently of one another, considerably more degrees of freedom than in the known single articulation solution in the region of the head part are possible. This in turn benefits improved linking even with strong stress on third components. 
     While one embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.