WO2001029322A1

WO2001029322A1 - Method and equipment for producing profiled marking, and a profiled marking

Info

Publication number: WO2001029322A1
Application number: PCT/FI2000/000906
Authority: WO
Inventors: Mika Launonen; Janne Puranen; Jorma Paananen; Jyrki Piirainen; Raine Rintama
Original assignee: Tieliikelaitos
Priority date: 1999-10-20
Filing date: 2000-10-18
Publication date: 2001-04-26
Also published as: NO315862B1; FI19992273A; SE519849C2; NO20021902L; AU7927900A; FI109551B; NO20021902D0; SE0201162D0; SE0201162L

Abstract

A method and equipment for producing a profiled marking, and a profiled marking. The profiled marking is produced of a marking material (2) that is a hot mix or a hot paint. Pressurized air (9) is blown on the surface (5) of the non-hardened marking material (2), which renders the surface (5) uneven.

Description

METHOD AND EQUIPMENT FOR PRODUCING PROFILED MARKING, AND A PROFILED MARKING

The invention relates to a method for producing a profiled marking on a road surface, in which method marking material providing the marking is applied onto a desired area on the road with an applicator and substantial inequalities are provided on the surface of the applied marking material.

The invention also relates to equipment for producing a profiled marking, the equipment comprising means for applying marking material on the portion of a road to be marked and means for providing substantial ine- qualities on the surface of the marking material.

The invention further relates to a profiled marking which is produced of marking material and whose surface is substantially uneven.

Profiled markings refer to markings provided on the surface of a road or a similar, paved traffic route, whereby information can be given about the location of lanes and edges of the road, crossroads, pedestrian crossings and other similar road sections. The profiled markings are characterized by having an uneven surface so that when a vehicle drives on a profiled marking, a vibration and/or sound effect will be conveyed to the vehicle and further to a driver to sense, the purpose being to draw the driver's attention to the position of the vehicle on the traffic route. For instance, a profiled marking arranged as an edge line warns the vehicle driver of inadvertently getting too close to the edge of the road where a risk of driving off the road is very likely. The profiled markings must be clearly distinguishable from other portions of the road in daylight and in dark, in dry and wet weather conditions. Luminance and ret- roreflection of the marking material must fulfill the requirements set by the authorities. Moreover, the profiled markings must resist to wear resulting from traffic in all seasons. It should be noted that hereinafter traffic routes are denoted by the term 'road' which, apart from roads, thus comprises parking areas, pedestrian and bicycle ways and other areas that are paved with asphalt, concrete or some other, similar paving material.

In accordance with the prior art, the profiled marking typically consists of rib-like protrusions that rise several millimeters from the road surface and whose distance from one another can be in the order of one centimetre to tens of centimetres. The materials of the profiled markings are two-component special materials or hot mixes, the properties of which differ from those of other materials used for road markings. Therefore, the materials are expensive and, in addition, their storage, transport and handling cause extra costs. Special equipment needed for producing profiled markings, which likewise differs from apparatuses needed for producing other road markings, also cause extra costs. Because profiled markings are particularly slow to produce, in the order of a few kilometres in an hour, producing larger markings, in particular, causes disturbance and hazardous situations to other traffic. Further, the prior art profiled markings cannot be driven over until about half an hour from the application, which refers to time required for the marking to harden/dry. During that time the marking must be protected with cones or like devices that inform the road users, which naturally causes further costs. All in all, production and maintenance of profiled markings cause so high costs that their use is limited.

The material of known profiled markings does not adhere well to a new asphalt surface, so the profiled marking detaches relatively soon from the newly paved road. Moreover, in winter time, when the road is cleaned for snow, the ribs of the known profiled markings, which protrude from the road surface, are easily caught by the plough, whereby they break and lose a substantial part of their functional properties. The markings have to be repaired, which causes considerable costs. Since repairing is very slow, it causes relatively long-term disturbance to road traffic. Daylight visibility of the known profiled markings is not so good as that of other road markings, because the areas between the ribs are substantially plain road surface that does not distinguish in any way from the rest of the road surface. For the same reason, the visibility of the markings is not best possible in wet conditions, even though the marking comprises a plurality of substantially vertical surfaces that improve retroreflection. Moreover, friction of an extremely smooth-textured marking material against a vehicle tyre or a pedestrian's footwear is considerably low, which in some cases may cause problems to road users.

The object of the present invention is to provide an improved method and equipment for producing a profiled marking, and a profiled marking having good properties.

The method of the invention is characterized in that the marking material is substantially a hot mix or a hot paint and that inequalities are provided by blowing pressurized air onto the surface of marking material applied but not yet hardened on the road. The equipment of the invention is characterized in that means for applying marking material comprise a mix applicator which is arranged to apply the marking material that is substantially hot mix or hot paint and that the means for providing substantial inequalities on the surface of the marking material comprise at least one air jet nozzle arranged to blow pressurized air against the surface of the applied marking material that is not yet hardened.

The profiled marking of the invention is characterized in that the marking material is substantially hot mix or hot paint and that inequalities of the surface are provided by blowing pressurized air against the surface of the non-hardened marking material applied on the road surface.

The basic idea of the invention is that the profiled marking is produced of a marking material that substantially comprises hot mix or hot paint commonly used in road markings, and the inequalities on the surface of said profiled marking are provided by blowing pressurized air against the applied, non-hardened marking material. Further, the basic idea of a first preferred embodiment is that after blowing the pressurized air, the marking material is cooled so as to accelerate the hardening of the material. Furthermore, the basic idea of a second preferred embodiment is that grooves which increase sound effect are provided in the marking material before the material sets to its final hardness. Further, the basic idea of a third preferred embodiment is that the grooves are produced with a roller that is wetted with water so as to reduce adhesion of the marking material onto the roller. Still further, the basic idea of a fourth preferred embodiment is that light reflecting particles, such as glass beads, are arranged on the surface of the marking. The invention has an advantage that the marking material of the profiled marking is the hot mix or hot paint commonly used for producing road markings, whereby the material costs and the storage, handling and other costs of the material are considerably lower than in using prior art profiled marking materials. It is not necessary to use special equipment for producing the profiled markings, and the equipment according to the invention can be arranged, with minor investment and work costs, in the existing machines intended for applying hot mix or hot paint. The method of the invention can be over ten times faster than prior art methods, so the costs caused by producing the profiled markings are reduced respectively. Fast work also means less disturbance to traffic. The marking material can be driven over shortly after application: by cooling the material with water, it can be driven over in a few minutes after marking, and as a consequence, the markings need not be protected with cones or other similar means while drying, which further reduces costs caused by marking. The marking material adheres well also to new asphalt, which reduces the need for later repairs. The profiled marking of the in- vention will not get easily damaged while the road is cleaned for snow, since it is continuous and does not comprise particular protrusions raising to a distance from the surface of the road, which protrusions would be exposed to impact-type mechanical contacts with the blade of a snowplough which damage the marking. The daylight visibility of the marking is similar to that of a common road marking, i.e. it is clearly better than in prior art solutions, because road paving is not seen through the marking. Excellent visibility in wet conditions is also achieved by the profiled marking of the invention, because the surface of the marking comprises innumerable minor surfaces substantially vertical to the road plane, which reflect the vehicle headlights back to the driver to see. Moreover, as the surface of the marking is rough-textured, the friction coefficient of the marking against a tyre or the like is high, and consequently the marking will not hazard the control of the vehicle, for instance, if one of the tyres is on the marking while the vehicle brakes.

In the following the invention will be described in greater detail, with reference to the attached drawing, in which

Figure 1 is a schematic, partly cross-sectional side view of one embodiment of a profiled marking in accordance with the invention, and

Figure 2 is a schematic and considerably simplified view of one embodiment of equipment in accordance with the invention. Figure 1 shows a schematic and partly cross-sectional side view of one embodiment of a profiled marking of the invention. For providing the profiled marking, about 0.3 to 5 mm thick layer of marking material 2, which is substantially of the same kind of hot mix or hot paint that is commonly used in road markings, is applied on paving material 1. The marking material 2 is heated until flowable and applied onto a road on which it hardens while cooling down. The composition of the hot mix and hot paint is well known per se to the person skilled in the art, so it will not be described in greater detail herein. It is possible to modify the marking material 2 to suit even better for the material of the profiled markings, however such that the basic properties of the hot mix and hot paint will be retained. A surface 5 of the non-hardened marking material 2 is subjected to pressurized air blow, which renders said surface 5 sub- stantially uneven. After the marking material 2 has cooled down and hardened, said inequality remains as a permanent profile of the surface 5. The inequal- ityies on the free surface 5 are random and irregular in nature and they are affected by the pressure used, magnitude of the air flow and possible periodic- ity of the flow. It is substantial, however, that the surface 5 comprises innumerable substantially vertical surfaces with respect to the road plane, from which surfaces light 6 of the vehicle headlights reflects back toward said vehicle and the driver's visual field. The whole area of the profiled marking is thus easily perceived in dark, and particularly, in wet conditions. On the other hand, since the profiled marking is solid and continuous, and not interrupted by portions of plain road surface, the visibility of the marking is excellent in daylight.

When one of the wheels of the vehicle on the road drives over the profiled marking, the uneven surface 5 of the marking causes vibration which is conveyed through the structures of the vehicle to the driver to sense. Fur- thermore, the contact between the tyre and the surface 5 produces a sound which, in turn, draws the driver's attention to the road and to the position of the vehicle on the road. Thus, the profiled marking warns the driver of the vehicle shifting from one section of the road to another, for instance, from a traffic lane to a verge of the road. It is possible to affect the properties of the inequalities of the surface 5, for instance a mean depth of the inequality, by adjusting the pressure, flow and periodicity of the pressurized air blow. In this connection it should be noted that the scale of the profiled markings in the figures is only given by way of example.

To enhance the vibration and sound produced by the profiled marking, the marking material 2 is provided with grooves 3 that at least partly cut the surface 5 of the marking in a direction that is transversal to planned, main traffic directions T of the vehicles. The cross-section of a groove 3 of the embodiment in Figure 1 is substantially semicircular, but naturally, other cross- sections or combinations thereof are also possible. The distances between the grooves 3 are typically 10 to 100 cm and the width of the groove is 1 to 5 cm, but depending on the application, other distances and measurements can be used as well. Advantageously, the groove 3 does not extend to the road surface but a coat of marking material 2 will remain in the bottom of the groove 3. Therefore, the daylight visibility of the profiled marking, i.e. distinguishability from the road surface, is excellent, corresponding to that of a common road marking. Before the marking material 2 hardens, light-reflecting particles 4, such as glass beads, are spread on the surface thereof, which particles enhance the visibility of the profiled marking, particularly in dark.

Figure 2 shows a schematic and considerably simplified side view of one embodiment of an equipment according to the invention. The equipment is arranged in a spreading apparatus 7 of hot mix and/or hot paint known per se, the apparatus being depicted by a broken line in the figure. The spreading apparatus 7 proceeds in the direction of arrow M and its mix applicator 17 applies a typically 0.3 to 5 mm thick coat of spreading material 2 whose surface 5 is substantially even onto a road portion to be marked. The applied marking material 2 can be white, yellow or of any known colour, depending on pigments mixed in the material. At least one air jet nozzle 8 that is directed to blow- pressurized air 9 against the surface 5 of the of the marking material 2 is arranged immediately behind the mix applicator 17. Pressurized air 9 required in the air jet nozzle 8 is produced by an air compressor typically included in the spreading apparatus 7 or by a compressor specifically arranged in the apparatus 7 for making profiled markings. Pressurized air 9 forms the surface 5 uneven and provides on said surface 5 substantially vertical surfaces with respect to the road surface. By changing the pressure and shape of the blow from the air jet nozzle 8 it is possible to provide inequalities having various characteristics on the surface of the profiled marking. Air blow can also be carried out on a discontinuous basis such that the surface 5 of the marking material 2 alternately comprises portions that are blown substantially uneven and non-blown portions that are substantially even. One or more particle nozzles 10 are arranged in the direction of travel of the apparatus 7 after the air jet nozzle 8. The particle nozzle drops glass beads or other similar light-reflecting particles 4, known per se to the person skilled in the art, on the surface of the non-hardened marking material 2 and the particles adhere to the hardening material 2. The amount of particles 4 to be dropped by the particle nozzle 10 per a unit area of the marking can be adjusted to suit the needs of a particular application. However, dropping of light reflecting particles 4 is not necessary in every application. The equipment of the invention can also be implemented completely without the particle nozzle 10. After the particle nozzle 10, in the direction of travel of the apparatus 7, are arranged cooling means 12 which in the embodiment of Figure 2 are water feeding means but which could also be means for feeding pressurized air. The water feeding means feed water or an aqueous solution 13 over the marking material 2 to accelerate the cooling thereof. The marking material 2 can be hardened by cooling in this manner so that in less than one minute af- ter application it allows driving on the marking, and consequently the profiled marking need not be protected with plastic or foam cones or other similar warning means that guide and warn the traffic. Hence, it is possible to avoid labour, material and equipment costs to be incurred in placing and eventually removing said warning means as well as to eliminate extra disturbance to the traffic on the road. Because, when producing the profiled markings of the invention, the speed of the spreading apparatus 7 can be more than ten times higher in comparison with the speeds used in applying prior art profiled markings, the inconveniences caused to other road users by the production of profiled markings are correspondingly less. In the embodiment of Figure 2, the last element is a roller 14 with protrusions 15 arranged on the circumference thereof which press grooves 3 in the still partly non-hardened marking material 2. The main purpose of the grooves 3 is to enhance vibration and sound to be conveyed to the vehicle driving on the marking. The number, shape and grouping of the protrusions 15 on the roller 14 can also be other than what is described in the embodiment of the figure. The number, shape and mutual positioning of the protrusions 15 on the roller 14 can also be other than what is described in the embodiment of the figure. A water nozzle 16 that wets the roller 14 with water or an aqueous solution in order to prevent the marking material 2 from adhering thereto. Instead of the rollers 14, the grooves 3 can also be provided by other means, such as presses providing substantially vertical motion, or other similar devices known per se. Further, instead of the grooves 3 provided by the roller 14 or the like, vibration and sound to be conveyed to the vehicle can be enhanced by forming spaces in the marking material 2. The spaces are typically about 1 to 5 cm wide and their mutual distance is typically 10 to 100 cm. The spaces can be formed, for instance, by guiding the mix applicator 17 such that it will not apply the marking material 2 on a continuous basis but the marking material flow from the mix applicator 17 includes interruptions which constitute spaces.

In the equipment, the mutual order of the main elements, i.e. the air jet nozzle 8, the particle nozzle 10, the cooling means 12 and the roller 14, can also be other than what is described in the embodiment of Figure 2. For in- stance, the cooling means can be arranged between the air jet nozzle 8 and the particle nozzle 10, or the roller 14 can be arranged between the particle nozzle 10 and the cooling means 12 or in some other manner.

The drawing and the related specification is only intended to illus- trate the inventive idea. Details of the invention may vary within the scope of the claims. Therefore, the air jet nozzle 8 and the pressurized air blown thereby need not necessarily be directed perpendicularly to the surface 5 of the marking material 2, but by adjusting the angle of the nozzle 8 it is possible to provide directional surfaces that reflect light in different ways from different directions. The pressurized air 9 can be cooled and consequently it cools the marking material 2 accelerating the hardening. On the other hand, the pressurized air can also be heated, for instance, if the marking material 2 requires slower cooling. By varying the characteristics of the particles 4, grooves 3 and pressurized air 9 blow it is possible to achieve a plurality of different variations of the profiled marking and the surface thereof, by which it is possible to distinguish information to be conveyed to the road user on the profiled markings in various road sections.

Claims

1. A method for producing a structural/profiled marking on a road surface, in which method marking material (2) providing the marking is applied onto a desired area on the road with an applicator (7) and substantial inequali- ties are provided on a surface (5) of the applied marking material (2), characterized in that the marking material (2) is substantially a hot mix or a hot paint and that the inequalities are produced by blowing pressurized air (9) on the surface (5) of the non-hardened marking material (2) applied on the road.

2. A method as claimed in claim ^ characterized in that pressurized air (9) is blown substantially over the entire area of the marking material (2).

3. A method as claimed in claim 1 or 2, characterized in that the marking material (2) applied on the road is cooled with cooling means (12) in order to accelerate the hardening of the marking material (2).

4. A method as claimed in claim 3, characterized in that the marking material (2) is cooled with water or an aqueous solution.

5. A method as claimed in any one of preceding claims, characterized in that light reflecting particles (4) are arranged on the surface of the marking material (2).

6. A method as claimed in claim 5, characterized in that the light reflecting particles (4) are glass beads.

7. A method as claimed in any one of preceding claims, characterized in that repeated grooves (3) are produced in the marking material (2) by pressing before the material sets to its final hardness.

8. A method as claimed in claim 7, characterized in that the longitudinal direction of the grooves (3) is substantially perpendicular to the main traffic directions (T).

9. An equipment for producing a profiled marking, the equipment comprising means for applying marking material (2) onto a road portion to be marked and means for providing substantial inequalities on a surface (5) of the marking material (2), characterized in that the means for applying the marking material (2) is a mix applicator (17) that is arranged to apply the marking material (2), being substantially hot mix or hot paint, and that the means for providing substantial inequalities on the surface of the marking material (2) comprise at least one air jet nozzle (8) that is arranged to blow pressurized air against the surface (5) of the applied, non-hardened marking material (2).

10. An equipment as claimed in claim 9, characterized by comprising means (12) for cooling the marking material (2) applied on the road.

11. An equipment as claimed in claim 10, characterized in that the means (12) for cooling the marking material comprise at least one water nozzle through which cooling water or aqueous solution (13) is arranged to be fed on the surface of the marking material (2).

12. An equipment as claimed in any one of claims 9 to 11 , c h a r - acterized by comprising at least one particle nozzle (10) that is arranged to add light reflecting particles (4) on the surface of the marking material (2).

13. An equipment as claimed in any one of claims 9 to 12, char- acterized by comprising means for producing grooves (3) in the profiled marking.

14. An equipment as claimed in claim 13, characterized in that the means for producing the grooves (3) is a roller (14).

15. An equipment as claimed in claim 14, characterized by comprising means (16) for wetting the roller (14) with water or an aqueous solution in order to reduce adhesion of the marking material (2) onto the roller (14).

16. A profiled marking which is formed of a marking material (2) and whose surface (5) is substantially uneven, characterized in that the marking material is substantially a hot mix or a hot paint, and that the inequality of the surface (5) is produced by blowing pressurized air (9) against the surface (5) of the non-hardened marking material (2) applied on the road.

17. A profiled marking as claimed in claim 16, characterized in that light reflecting particles (4) are arranged on the surface of the marking material (2).

18. A profiled marking as claimed in claim 17, characterized in that the light reflecting particles (4) are glass beads.

19. A profiled marking as claimed in any one of claims 16 to 18, characterized by comprising grooves (3) whose longitudinal direction is arranged to be substantially perpendicular to the main traffic directions (T).