Abstract:
A method for producing an escape route marking and the apparatus for an airplane comprising a luminous layer that luminesces in the dark, and a profile having two profile elements that can be connected to each other, wherein in a first of the profile elements, the luminous layer is arranged in a recess extending in the longitudinal direction, and the second profile element is provided to be connected with a base, wherein the procedure comprises the following steps:
       production of the luminous layer from a mixture of a silicone material and from photoluminescent pigments, and   introduction of the mixture in a liquid state into the recess of the first profile element, wherein the mixture cures in the seat by crosslinking with the walls in the profile.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    The present invention relates to a method for producing an escape route marking, and an escape route marking. 
         [0004]    It is known to arrange photoluminescent strips on the floor of the interior of an airplane to mark the escape routes. Photoluminescence is occasionally termed afterglow and/or phosphorescence. The technical safety requirements for marking escape routes are for example specified in German industrial standard DIN 67510. The strips are placed on the floor of the airplane cabin and, in an emergency, indicate to passengers and the flight crew the path to ways out and emergency exits. In the past when equipping airplanes and airplane cabins, photoluminescent strips became increasingly accepted as escape route markings since these are failsafe and can work without a power supply. 
         [0005]    A continuous fluorescent layer is known from EP 0 489 561 A1 in which color pigments are incorporated in a polymer matrix. The fluorescent material can be incorporated in a carrier medium that lends the fluorescent light various optical properties by means of additional filters. 
         [0006]    An emergency lighting system for an airplane is known from US 2002/0015309 A1 in which photoluminescent material is arranged in a sealed sheath. The sheath is held to the floor of the airplane in a press fit between two parallel rails. The photoluminescent material is inserted in the sheath, the ends of which are closed by a cover. 
         [0007]    Emergency lighting for an airplane is known from WO 01/52224 A1 in which escape route markings are used in the form of inserts, self adhesive strips and paint in the airplane interior. 
         [0008]    An emergency lighting unit for the interior of an airplane is known from EP 0 828 657 B1 that is held in position by means of a cover element directly connected to the floor of the airplane. 
         [0009]    A photoluminescent material is known from U.S. Pat. No. 7,074,345 B2 that is made from a mixture of a transparent base material and photoluminescent pigments, wherein the viscosity of the transparent base material is 1 Pa·s or more than 20° C., and photoluminescent pigments are added at an amount of 7 to 95% by weight. For the use of a silicone material as the transparent base material, a viscosity of 70 Pa·s and average particle size of 150 μm is suggested for the photoluminescent pigments. 
         [0010]    In addition to sufficient luminosity, in order for an escape route marking to be used in the airplane cabin, it is essential for it to withstand the loads in the interior of the airplane arising both from the passengers as well as from stress introduced into the escape route marking by the airplane floor. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The object of the invention is to provide an escape route marking with superior luminance which is robustly designed to be used in the interior of an airplane. 
         [0012]    The method according to the invention is for producing an escape route marking for an airplane comprising a luminous layer that luminesces in the dark, and a profile having two profile elements that can be connected to each other, wherein in a first of the profile elements, the luminous layer is arranged in a recess extending in the longitudinal direction, characterized by 
         [0013]    The production of the luminous layer from a mixture of a silicone material and from photoluminescent pigments, 
         [0014]    The introduction of the mixture in a liquid state into the recess of the first profile element, wherein the mixture cures in the recess by crosslinking with the walls in the profile element. 
         [0015]    The method according to the invention creates a frictional connection, preferably an integral connection, between the profile element that accommodates the luminous layer and the luminous layer itself. This ensures that the profile element possesses sufficient stability, and cracks in the profile can be avoided. On the other hand, introducing the mixture in a liquid state into the recess and curing the mixture with the photoluminescent pigments in the recess, allows silicone materials to be used that have a low viscosity and are unsuitable to be inserted in a hollow profile due to their rigidity. According to the invention, the second profile element is provided to be connected with the base. This means that the profile element in which the luminescent layer has been introduced is the profile element through which the luminescent layer is visible in the installed position. Of course, the first profile element is designed partially transparent so that the light of the luminous layer can be perceived. According to the invention, the escape route marketing is produced “upside down” by introducing the mixture into the first profile element that, in the installed state, forms the radiant top side of the escape route marking. 
         [0016]    In a preferred embodiment of the invention, the silicone material, at a temperature of 20° C., has a viscosity of less than 9.5 Pa·s, and the average particle size of the pigments is less than 150 μm, wherein the percentage of the pigments in the mixture is 50 to 90% by weight. Using a thin silicone material makes it possible to use pigments with a small average particle size and thereby achieve sufficient luminosity. In particular, since the luminous layer is introduced in liquid form into the first profile element in the method according to the invention, it is possible to work with thin, low viscosity silicone materials and add pigments to them that have a very low average particle size. 
         [0017]    In one embodiment of the method, the mixture is introduced into the recess by being poured. The pouring can be directly into the designed profile element, wherein the introduced mixture can evenly fill the recess in the profile element by itself or distributed with a spreader. The advantage of pouring the mixture into the recess is that an even thickness of the luminous layer can be achieved. This also ensures that a continuous luminous layer forms, and the luminous layer contacts the profile element without bubbles or cavities. It is alternately possible to continuously inject the mixture into the designed profile element for example by a nozzle or a screw, or to extract the mixture therein. 
         [0018]    In a preferred embodiment of the method according to the invention, the luminous layer is covered with the second profile element by connecting the first profile element after the mixture hardens. The cover of the first profile element protects the luminous layer from moisture and mechanical stress. 
         [0019]    In a preferred development, the connection between the first and second profile elements is made by adhering and/or welding the profile elements. Alternately or in addition, it is also possible to connect to the first and second profile elements to each other in a frictional connection, preferably in a keyed connection. This can be accomplished by projections or latching elements in the profile elements. 
         [0020]    In a preferred embodiment, at least the inner walls in the first profile element are subject to a surface treatment before the mixture is introduced into the recess. The surface treatment is to promote the cross-linkage of the silicone material with the wall material of the first profile element. Infrared irradiation is preferably used for the surface treatment that is directed toward the first profile element and the silicone material after the silicone material has been introduced. 
         [0021]    A flame treatment of the first profile element has also proven to be useful for the surface treatment. This can be done in addition or alternatively to infrared treatment irradiation. Likewise, primer and/or plasma irradiation can be used for the first profile element to prepare the surface for improved cross-linkage with the liquid or hardening mixture. 
         [0022]    The escape route marking for an airplane has a luminous layer that luminesces in the dark and a profile that has two profile elements which can be connected to each other, wherein the luminous layer is arranged in a recess of the first profile element. The luminous layer consists of a silicone material having photoluminescent pigments, and is friction connected, preferably integrally bonded, to the first profile element. The friction locked and especially integral connection between the luminous layer and profile element helps stabilize the profile. In addition, the surface of the first profile element can be designed slightly convex so that liquid flows off it. This makes it possible for example to avoid stress cracks in the first profile element that arise from cleaning fluid. 
         [0023]    The first profile element preferably consists of a transparent plastic material, wherein the transparent plastic material can also be colored to achieve a color that is different from the luminescing color of the luminous layer. 
         [0024]    In a preferred embodiment, the first profile element possesses a recess extending in the longitudinal direction which is delimited by two parallel sidebars. The side bars on one hand neighbor the side recess so that the mixture can be added in a liquid state, and on the other hand, they can support a connection between the first and second profile elements. 
         [0025]    The second profile element preferably possesses a recess extending in a longitudinal correction in which the luminous layer connected to the first profile element is inserted when the first and second profile elements are connected with each other. The recess of the second profile element serves as a seat for the luminous layer that is fastened in a recess in the first profile. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0026]    Preferred embodiments of the invention will be further explained below with reference to the figures. In the figures: 
           [0027]      FIG. 1  shows a cross-section of an escape route marking according to the invention in which the recess is delimited by side bars, 
           [0028]      FIG. 2  shows a second embodiment of the escape route marking according to the invention in which a keyed connection is created between the profile elements by bars, 
           [0029]      FIG. 3  shows a third embodiment in which the profile elements are connected to each other by means of a keyed connection, 
           [0030]      FIG. 4  shows a fourth embodiment in which the side sections of the profile elements are connected to each other, and 
           [0031]      FIG. 5  shows a schematic view of the production of the escape route marking. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated 
         [0033]      FIG. 1  shows a first profile element  10  that possesses a flat basic section  12  as well as two laterally angled side sections  14 . At the transition between the basic section  12  and side section  14 , there are provided two bars  16  which extend continuously in the longitudinal direction of the profile element. The free end of the side area  14  is approximately at the height of the free end of the bar  16  so that the outer edge of the side area and free end of the bars lie in a plane. 
         [0034]    The luminous layer  18  is poured into the seat of the first profile element  10  formed by the basic section  12  and bars  16 . The luminous layer  18  is continuously poured into the profile element in a liquid state and cures therein. With the curing of the luminous layer in the profile element, the materials form a connection that holds the luminous layer in the profile element with a connecting force. This connecting force is derived from an integral bond. By surface treating the recess, the silicone material cross-links with the material of the profiled strip when it cures. Preferably, only one layer of the silicone material is introduced into the profiled strip. It is not necessary to use several layers of silicone material since the pigments can be prevented from disadvantageously settling on the bottom of the luminous layer by adjusting, according to the invention, the viscosity and particle size of pigments; instead, they are distributed substantially evenly in the silicone in advantageous manner. The profiled strip is preferably made of a polycarbonate (PC) material. The first profile element  10  with the cured luminous layer  18  is connected to the second profile element  20 . The second profile element  20  has a recess  22  that is delimited by side sections  24 . The line of the contour of the side sections  24  corresponds in its shape to the curved side sections  14  so that the surface of the first profile element  10  lies against the second profile elements  20 . The second profile element  20  has a smooth bottom side and can be additionally equipped with means for connecting to the base. A PC plastic can also be provided as the material for the second profile element  20 . In contrast to the first profile element  10 , it is unnecessary for the second profile element  20  to be designed transparent or translucent. 
         [0035]    The recess  22  in the second profile element  20  is dimensioned such that a frictional connection arises between the bars  16  and the insides of the side sections  24 . 
         [0036]    In addition to the frictional connection, the side sections  16  can be integrally connected, i.e., adhered or welded, to the side sections  24  of the other profile element. 
         [0037]    In  FIG. 2 , the side section  14  is additionally provided with a bar  26 . The side section  24  of the second profile element  20  also has a recess  28  in which the bar  26  is arranged. As is the case with the connection described with reference to  FIG. 1 , additional bars and  16  can be seated clamped in the recess  28 . These can also be adhered. 
         [0038]      FIG. 3  shows an embodiment in which a first profile element  30  is fastened to the second profile element  36  by means of a snap connection. As is the case with the versions shown in  FIG. 1  and  FIG. 2 , the first profile element  30  is equipped with a recess delimited by bars  16  that is filled with a luminous layer  18 . The side area of the first profile element  30  has a projection  32  that grips behind a catch  34  of the second profile element  36 . 
         [0039]      FIG. 4  shows another embodiment in which a first profile element  38  has bars  40  that delimit the side of the recess for accommodating the luminous layer  42 . On their side facing the side sections  43 , the bars  40  possess a beveled sidewall  44 . The second profile element  46  possesses a second recess in which the bars  40  with the luminous layer  42  are inserted. The second recess is delimited on the side by a side section  48  that has a beveled sidewall  50 . Between the sidewalls  44  and  50  there is an air gap  52  that also extends below the free end of the bar  40 . The air gap allows the bar elements  38  and  46  to be connected with a sufficient production tolerance. In addition, the air gap  52  gives the bar element  38  sufficient play when it is loaded from above. 
         [0040]    Between the luminous layer  42  and the second profile element  46  is a reflective layer  54  that for example is designed with a white color, and reflects the light from the luminous layer back into it. Such a reflective layer can also be seen in the embodiments in  FIGS. 1 to 3 . 
         [0041]    The side sections  48  and  43  are integrally connected by adhesion and/or welding to each other. A double-sided adhesive tape, for example, can also be provided for adhesion. 
         [0042]    The production procedure in  FIG. 5  will be further explained below. 
         [0043]    The first profile element  60  is shown on the left side in  FIG. 5 , and it is continuously unwound off a drum  62 . The first profile element  60  that is designed as an upper shell can be processed as a continuous profile element in the production procedure shown in  FIG. 5 . In a following step  64 , the profile element  60  is irradiated with laser light. A labeling laser with a relatively low output can be used to do this which serves to apply a part number or another identification. In a following step  66 , the seat for the silicone material provided for the first profile element is exposed to flame. The flame prepares the first profile element for subsequently accommodating the silicone mixture. In a procedural steps  68 , the silicone mixture is introduced into the first profile element  60 . The silicone mixture is introduced in a substantially liquid form, and the pigments are kept from falling or settling too much by adjusting the viscosity of the silicone mixture. In a subsequent step  70 , the silicone mixture introduced into the first profile element undergoes infrared irradiation. This achieves a good preliminary cross-linking of the silicone material in the first profile element  60 , whereby the dimensional stability of the luminous layer increases. As in  FIG. 5 , the silicone mixture can be subjected directly to infrared radiation. Alternately or in addition, it is also possible to expose the silicone mixture introduced in step  68  to infrared radiation through the transparent first profile element. In a following procedural step, the second profile element  72  is wound off of a drum  74 . The second profile element  72  is applied on the first profile element  60  and seals it. If an additional reflector layer is to be introduced between the luminous strip and seconds profile element, this additional reflector layer can be introduced between steps  70  and  72 . 
         [0044]    In a subsequent step  76 , the two profile elements  60  and  72  are welded. A stationary laser can be used for the welding  76  of the profile elements that continuously welds the profile elements to each other along their edge. 
         [0045]    In a subsequent procedural step  78 , a continuous adhesive strip  80  is applied to the top side of the second profile element  72 . The adhesive strip  80  can for example be designed in the form of a double-sided adhesive strip by means of which, after a protective film is removed from the adhesive surface, the finished escape route marking can be adhered to the base. 
         [0046]    An automatic quality check occurs in a subsequent step  82 . The automatic quality check  82  is continuous and ongoing during production. The quality check  82  can for example optically inspect the weld seams between the first and second profile element, the thickness of the introduced silicone material, or the arrangement of the adhesive strip  80 . 
         [0047]    In a following procedural step  84 , the continuously produced escape path markings can be cut into a predetermined length so that they can then be transported by a cart  86 . 
         [0048]    The above-described procedure in which the profile elements are joined by a static laser past which the workpiece continuously moves allows continuous, endless production of an escape route marking. The resulting advantage is that the escape route markings can be created in different lengths during production to thereby provide the desired length of escape route marking for later installation. 
         [0049]    This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.