WO 03/069068 PCT/DK03/00076 1 A METHOD FOR THE APPLICATION OF MARKINGS State of the art 5 The invention relates to a method for the application of marking stripes in the form of material on a road surface, said marking material being ejected in a plastic state against the road surface from an apparatus which is ad vanced on the road surface, and wherein the marking material may consist of separate blobs which, when applied, form e.g. a road stripe. 10 The requirements with respect to road surfaces, including road stripes, are increasing, in particular as regards the draining and the reflecting proper ties. 15 In step with the increased traffic and speed, the need for draining of road surfaces as well as stripes is great, since it is hereby possible to avoid aq uaplaning and in frosty weather icing. Also, the requirements with respect to the reflecting properties are great, 20 since these must be visible in both directions of travel and reflect the light from the vehicles in a uniform manner. To this should be added that this reflection must be effective, and to ensure this, the reflecting faces must protrude a suitable distance from the road 25 surface in order for the desired reflection to be achieved. Known methods for the application of reflecting stripes cannot readily meet these requirements. 30 The reason is particularly that the application takes place in such a manner that the material is deformed when it hits and adheres to the road surface.
WO 03/069068 PCT/DK03/00076 2 This is caused by the fact that the feed rate of the material is greater than the rate at which the material hits the road surface. Owing to this deforma tion, it is not possible to achieve a uniform transverse profile of the blob where it is applied in the form of pointwise located blobs. 5 To remedy this circumstance, the travelling speed of the application appa ratus is therefore relatively low, viz. typically below 5 km/h. This application rate of the pointwise blobs causes a disuniform reflection to 10 be created. The cross-sectional shape of the blobs will be such that the rearmost part of the blob will be raised, so that the reflecting faces are lar ger on the rear side of the blob than on the front side. Where a reflecting material in the form of e.g. glass beads is subsequently 15 applied, this material will settle on the blobs such that the reflecting property is not uniform. The reason is that the material will adhere only to the faces on the blobs which face forwards in the travelling direction, whereas the faces on the blobs facing away from the travelling direction will not be ef fectively covered by reflecting material. This has the consequence that e.g. 20 a double centre stripe, which is applied in the form of two stripes running in parallel, must be applied in two operations in their respective travelling di rections, or be performed extremely slowly, if both stripes are to be capable of fulfilling light properties which are always measured in the travelling di rection. Only this can ensure a uniform reflection in both travelling direc 25 tions. The object of the invention The object of the invention is to remedy these defects and drawbacks in a 30 simple manner, and this is achieved according to the invention by a method wherein the blobs of material for forming the stripe are formed by a thermo- WO 03/069068 PCT/DK03/00076 3 plastic material of a high viscosity at the moment of application, and imme diately after the application to the road surface it is sprinkled with a granu late over the entire surface of the individual blobs of material, and the blobs of material and the granulate are ejected from the apparatus in a rearward 5 direction and at a rate which corresponds to the travelling speed of the ap paratus. This provides two substantial advantages, viz. partly that the stripe has good draining properties, and partly that the reflection is uniform because of 10 the uniform profile, resulting in an optimal reflection capacity in both direc tions. The draining properties are brought about by the high viscosity of the appli cation material, which ensures an "open" surface so that the material is 15 better able to absorb and drain off water. The shape-forming properties are achieved in that the application takes place in such a manner that the material hits the road surface at a speed which is very low and preferably zero, whereby deformation can be 20 avoided. This also applies to the subsequent application of the reflecting material, which will be distributed evenly across the entire surface of the profile. In summary, it is ensured that the application rate may be increased con 25 siderably over the previous rate, that the draining as well as the reflecting properties are optimum, and that the reflecting effect is the same in both directions. To increase the wear resistance, it is moreover expedient, as stated in 30 claim 2, to apply a primer of low viscosity to form a thin covering layer to which the blobs may adhere.
WO 03/069068 PCT/DK03/00076 4 The drawing The invention will be described more fully below with reference to the drawing, in which 5 fig. 1 shows equipment for performing the method according to the invention, fig. 2 shows basic sketches of the various application means, and 10 fig. 3 shows the vectors of movement for a blob of material, and fig. 4 shows an example of a stripe composed of blobs, seen from above. 15 Description of an embodiment An example of an apparatus for performing the method according to the invention will initially be described with reference to figs. 1 and 2. 20 The apparatus comprises a vehicle, a truck 1, which is preferably provided with dual steering so that the vehicle may be steered at the selected side in both travelling directions. 25 In the drawing, a person, in addition to the driver, is shown at the rear on the platform, and this person can control the actual application of the stripe material. Three different applicator parts are mounted below the platform, as shown, 30 said parts extending in the travelling direction 9 of the vehicle so that the first application takes place at the front of the vehicle.
WO 03/069068 PCT/DK03/00076 5 In the example shown, this first application is a nozzle 2' which sprays a thermoplastic fluid primer 2 on to the road surface 12, which settles as a dense covering layer 5. 5 Then, the actual marking material 3 is applied to this layer 5 via an ejector appliance 3'. This appliance, which is not shown in detail, may consist of a rotating ejec tor having resilient ejector fingers for separate ejection of blobs of material 10 6. The material consists of a likewise thermoplastic mass of high viscosity to form an "open" surface. Finally, these blobs 6 may be provided with a reflecting, friction-imparting granulate 4, which is ejected from the rear appliance 4' so that it can ad 15 here firmly to the surface of the blobs 6 before these solidify. The method will then be described with reference to figs. 2-4. Fig. 2 shows the three application stages in outline. All three stages are 20 arranged such that the direction of application and the rate 10 for the indi vidual materials 2, 3, 4 are rearwardly directed and opposite to the travel ling direction and speed 9 of the vehicle 1. It is ensured in this manner that, as indicated in fig. 3, the resulting direction 25 of application and rate 11 is low, preferably zero, and thus that the material 6 hits the road surface 12 in the form of a straight drop on the road surface. As will appear from the drawing, the vectors 9 and 10 will neutralize each other, and the resulting vector 11 will therefore be a straight drop on the 30 road surface 12.
WO 03/069068 PCT/DK03/00076 6 The result of this method is that the application is controllable, thereby al lowing a high-profiled material to be applied with a uniform and relatively high elevation on the road surface 12. As indicated in fig. 3, the blob 6 just ejected will be uniformly deformed to form a round raised blob having an 5 evenly extending surface, which essentially forms a plane resultant stripe. This ensures a stripe 8, as indicated in fig. 4, which constitutes a well drained stripe where the water will be able to run off the blobs 6, and more over the reflecting or friction-imparting material 4 will settle evenly on the 10 raised blobs 6 to form reflecting blobs 7. This is ensured in that the granulate 4 smoothly and quietly drops down over the individual blobs which are covered completely evenly. The reflec tion is therefore uniform in both directions, so that a stripe may be applied 15 in the most expedient travelling direction. Thus, the method provides a considerably more traffic safe stripe, just as it may be applied at a relatively high travelling-application speed. Tests have shown that the application may be carried out at a speed of up to 45 km/h. 20 This reduces the inconvenience to the traffic and the operators consider ably.