Thermoplastic pavement marking and method of producing the same

#The present invention relates to a preformed thermoplastic pavement marking, and a method of producing such a pavement marking.

#Pavement markings are generally applied onto paved surfaces on the ground, such as onto roads, sidewalks, parking lots, schoolyards, and in other areas where there is a need for provide people with information or guidance. Typical pavement marking patterns may be, for example, guide lines, street signage, logos, game boards or pictograms. The paving typically consists of e.g. concrete or asphalt/tarmac. Sometimes, pavement markings are painted onto the paving using particular types of paint. Often, however, and in particular for more complex shapes, pavement markings may be preformed of a thermoplastic sheet material to a predetermined shape, and attached to the ground by e.g. heat or glue.

#WO 2007/143988 discloses a brick and mortar pattern comprising a plurality of thermoplastic sections representing bricks, which are positioned in a grid representing a mortar pattern, and glued to the grid by means of a thermoplastic glue sprayed onto the back side of the pattern.

#The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:

#FIG. 1 is a diagrammatic view in section of a sheet of pavement marking material;

#FIG. 2A is a schematic view in perspective of two sheets of pavement marking material, and illustrates a first intermediate stage of joining the sheets of pavement marking material together;

#FIG. 1 illustrates a sheet 10 of thermoplastic material for pavement markings. Throughout this disclosure, the term “pavement” should be construed as a paved surface on the ground in general, and not so as to be limited to a sidewalk. The sheet 10 comprises a top face 12 and a bottom face 14. A top layer 16, which defines the top face 12, may comprise embedded glass beads 18 for increased retro-reflectivity and wear resistance. Glass beads may be present throughout the entire thickness of the thermoplastic sheet 10, in a top layer 16 only, or not at all. Also other inorganic fillers, which may be inert and/or have abrasive and/or anti-skid properties, may be present in the top layer 16. A typical amount of inorganic fillers may be about 50%-85% by weight, including the glass bead content. Organic/binder content may typically be about 15-50% by weight. An optional bottom layer 20 may consist of a thermoplastic material different from the material of the rest of the sheet. The thermoplastic material of the bottom layer 20 may have a somewhat lower melting point than the thermoplastic material of the top layer 16, and may act as a melting precursor when attaching the material to paving. It may also be free from glass beads. The bottom layer 20 may be applied to the bottom face of the main body of the thermoplastic pavement marking sheet 10 before or after cutting and/or joining the sheet 10 to preformed pavement markings. However, in some embodiments, it may be preferable to use a thermoplastic pavement marking sheet 10 without a different bottom layer 20, such as a thermoplastic pavement marking sheet 10 consisting only of the top layer 16. Such a sheet may have more controllable melting properties, provide a more predictable behaviour when bonding to paving on the ground, and/or provide stronger joints when joining following the methods disclosed herein. A typical thickness h of the sheet 10 may be between 1 mm and 5 mm, and more typically between 2 mm and 3.5 mm. The sheet 10 may be flexible, to allow rolling or folding of the material. By cutting the sheet 10 to various shapes, signage and road markings may be preformed or pre-cut at e.g. a factory site, and shipped to various sites for installation on paving on the ground. The sheet may be cut by e.g. waterjet cutting.

#FIGS. 2A-D illustrate a non-additive method of joining a first sheet 10a of thermoplastic pavement marking material with a second sheet 10b of thermoplastic pavement marking material. Each of the first and second sheets 10a, 10b may be identical to the sheet 10 of FIG. 1. The method may be used for producing preformed pavement markings, as will be elucidated further below with reference to FIGS. 4A-C.

#In a first step, illustrated in FIG. 2A, the first sheet 10a is positioned with its top face 12a down on a support surface (not illustrated). The second sheet 10b is positioned, also with its top face 12b down, next to the first sheet 10a. The second sheet 10b is positioned such that an edge 22b between the top and bottom faces 12b, 14b faces a similar edge 22a between the top and bottom faces 12a, 14a of the first sheet 10a.