Method for the application of marking

Abstract

Application of marking stripes, road stripes (8), may take place according to the invention by a method wherein the stripe is formed by elements in the form of blobs (3, 6), which are subsequently covered by a friction-imparting of reflecting granulate (4). This application of material takes place at a rate (10) which corresponds to the travelling speed (9) of the apparatus (1), and which is oppositely directed. This ensures that the application is entirely uniform, as the blobs (3, 6) are not deformed, and that the granulate (4) will cover the entire surface. The reflecting property is therefore uniform in both directions. A primer (5) may optionally be applied to the road surface (12) before the actual application of the material takes place.

Description

STATE OF THE ART

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 advanced on the road surface, and wherein the marking material may consist of separate blobs which, when applied, form e.g. a road stripe.

The requirements with respect to road surfaces, including road stripes, are increasing, in particular as regards the draining and the reflecting properties.

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 aquaplaning and in frosty weather icing.

Also, the requirements with respect to the reflecting properties are great, 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 surface in order for the desired reflection to be achieved.

Known methods for the application of reflecting stripes cannot readily meet these requirements.

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.

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 deformation, it is not possible to achieve a uniform transverse profile of the blob where it is applied in the form of pointwise located blobs.

To remedy this circumstance, the travelling speed of the application apparatus is therefore relatively low, viz. typically below 5 km/h.

This application rate of the pointwise blobs causes a disuniform reflection to 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 larger 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 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 effectively covered by reflecting material. This has the consequence that e.g. 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 directions, or be performed extremely slowly, if both stripes are to be capable of fulfilling light properties which are always measured in the travelling direction. Only this can ensure a uniform reflection in both travelling directions.

THE OBJECT OF THE INVENTION

The object of the invention is to remedy these defects and drawbacks in a 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 thermoplastic material of a high viscosity at the moment of application, and immediately after the application to the road surface it is sprinkled with a granulate 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 direction and at a rate which corresponds to the travelling speed of the apparatus.

This provides two substantial advantages, viz. partly that the stripe has good draining properties, and partly that the reflection is uniform because of the uniform profile, resulting in an optimal reflection capacity in both directions.

The draining properties are brought about by the high viscosity of the application material, which ensures an “open” surface so that the material is 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 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 considerably 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 claim 2, to apply a primer of low viscosity to form a thin covering layer to which the blobs may adhere.

THE DRAWING

The invention will be described more fully below with reference to the drawing, in which

FIG. 1 shows equipment for performing the method according to the invention,

FIG. 2 shows basic sketches of the various application means, and

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.

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.

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.

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, said parts extending in the travelling direction 9 of the vehicle so that the first application takes place at the front of the vehicle.

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.

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 ejector having resilient ejector fingers for separate ejection of blobs of material 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 adhere 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 arranged such that the direction of application and the rate 10 for the individual materials 2, 3, 4 are rearwardly directed and opposite to the travelling direction and speed 9 of the vehicle 1.

It is ensured in this manner that, as indicated in FIG. 3, the resulting direction 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 road surface 12.

The result of this method is that the application is controllable, thereby allowing 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 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 moreover the reflecting or friction-imparting material 4 will settle evenly on the 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 reflection is therefore uniform in both directions, so that a stripe may be applied 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. This reduces the inconvenience to the traffic and the operators considerably.

Claims

1. 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 advanced on the road surface, and wherein the marking material may consist of separate blobs which, when applied, form e.g. a road stripe, characterized in that the blobs of material (6) for forming the stripe are formed by a thermoplastic material (3) of a high viscosity at the moment of application, and that immediately after the application to the road surface (12) it is sprinkled with a granulate (4) over the entire surface of the individual blobs of material (6), and that the blobs of material (6) and the granulate (4) are ejected from the apparatus (1) in a rearward direction and at a rate (10) which corresponds to the travelling speed (9) of the apparatus.

2. A method according to claim 1, characterized in that a layer of primer (5) is applied to the road surface (12) prior to the application of the marking material (3).