GB1574861A - Method for applying tape marking material on road surfaces - Google Patents

Description

(54) METHOD FOR APPLYING TAPE MARKING MATERIAL ON ROAD SURFACES (71) I, LUDWIG EIGENMANN, of Swiss Nationality, of Vacallo, Canton Tessin, Switzerland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be described in and by the following statement: This invention relates to a method of marking of traffic dividing lines and other directional indicia upon the surface of pavements or roads, by applying on and securing prefabricated road marking tape material to said surface by means of a primer layer of generally thermoplastic compositions compatible with the surface.

The art is a well worked one and widely known. Marking strips and equivalent signs on road surfaces open to vehicle traffic is of paramount importance for traffic regulation and safety. The particular art with which this invention is concerned is the method in which the laying down and securing on said surface a prefabricated tape of sign-forming material is generally complemented by preliminarily forming on said surface, a tape receptive layer.

A rather extensive literature illustrates ssuch art. For example, the U.S. patent no.

3,262,375 granted to the instant applicant (corresponding to British Patent Specification No. 1,028,385) has taught how to form an essentially bituminous base or primer layer on the road surface for best subsequent applying of the marking tape. More recently, this art has been substantially improved as to the methods, the apparatus and the materials made use of. Among the others, the U.S. Patent Nos. 3,902,939, 3,964,559 and 3,964,835, all granted to the instant applicant (corresponding in part with the British Patent Specifications No.s 1,419,784 and 1,421,483) have taught some modified method and means for applying road marking tape material on a primer layer. The disclosures of said patents is assumed to be herein incorporated for a more exhaustive knowledge of the art and of the related patent literature as cited in said patents.

The extensive experimentation and the wide use on the roads of said sign-forming tapes have confirmed the criticality of providing a consistent primer layer on the road surface as a base for the tape material. This provision has however made the road marking procedure a two-phase process including (a) the forming of the primer layer and (b) the laying of the tape material on said layer. The securing of the primer layer on the pavement, said layer being of an essentially bitumen-based thermoplastic composition, leads to pouring and doctoring on a preliminarily dried and heated road pavement a hot and fluidized composition capable of permeating the pavement pores. The laying and pressing of the tape on said layer requires that the same layer has gelled or cooled down substantial to solidification to resist the pressure and to secure the sign on the road. A substantial time interval is therefore believed to be necessary between the two phases.

Additionally, the tape must be exactly applied on the preliminarily formed primer layer.

Some misalignments however occur and for taking them into account the primer layer must be formed at a safe extra width. This latter provision leads to extra costs and the uncovered side portions of the primer layer foul the tape applying roller means and prejudice the neatness of the sign.

It is therefore an object of this invention to provide new and advantageous method and means which are not subject to the above and other limitations and by which most safe, fast and efficient road marking strips can be formed by applying signforming prefabricated tape material on road pavements, by means of an intermediate primer layer, principally but not exclusively of thermoplastic nature.

According to the invention there is provided a method of forming a traffic-regulating sign on a road surface, comprising the sequential steps of firmly bonding a predominantly thermoplastic primer composition as an adhesive layer to a face of a sign forming tape to thereby form a two-layered band, and pressing said band down against the road surface while the primer layer is in an at least partially fluid condition and with sufficient force to drive the primer layer into pores and cavities of the road, said previous step of bonding being performed by spreading the primer composition over only a portion of the width of the face of the tape so as to retain substantially all of the primer layer under the face of the tape despite squeezing of the primer layer during said pressing step.

The above principles of the invention can be applied and made use of in a variety of arrangements any of which can be considered as preferred in view of specific requirements, procedures and local conditions in which the marking of roads is to be performed. The above and other objects, advantages and features of the invention will be now made apparent by the following detailed description.

In the accompanying drawings: Figure I is a diagrammatical perspective fragmentary view of a traffic regulating sign applied to a road surface in accordance with the present invention, Figure 2 is an exploded view of the essential components of the composite structure of Figure 1, Figure 3 is a structurally simplified elevational view of a device adapted for forming the sign of Figure 1, according to one embodiment of the method of the invention, Figure 4 illustrates in larger scale a detail of the device of Figure 3, in cross-sectional view taken in the longitudinal plane indicated at V-V in Figure 5, Figure 5 is a cross-sectional view taken in the plane and direction indicated at VI-VI in Figure 4, and Figure 6 illustrates in larger scale and detail the sign as applied and formed on the road in accordance with the invention, in cross-sectional view taken in the plane indicated at VII-VII in Figure 3.

As shown in Figures 1 and 2, a marking such as generally indicated at M is formed on a road pavement surface S by applying thereon a thermoplastic primer composition as an adhesive layer 22 on which a prefabricated sign-forming tape material 26 has been applied, or more properly, to the lower face 26" of which primer layer 22 has been applied and secured. The layer 22 is initially narrower then the tape 26 so that when the layer 22 is applied to the road surface substantially all of the primer layer is retained under the tape.

The compositions of said primer layer, most preferably of well known thermoplastic nature, such as a bitumen-based compound, and of said tape, and the complementary features of said tape, designed for improving its traffic wear resistance, good adherence to the vehicles tyres and preferably night time visibility, will not be described in detail as they are well known and do not form part of this invention.

Preferably, the lower face 22" of the primer layer and/or the road surface S are provided with a thin layer of a known wetting and hydrophilic agent, applied such as by means of known spray means to form a very thin layer 16 which facilitates the impregnation of the surface layer of the road pavement. Such layer 16 has been indicated in Figures 1 and 2 as of a consistent thickness but actually such interlayer does not exist in the formed sign because the said liquid wetting agents are subject to interdiffusion in the interfaced materials, as known to those skilled in the art, the wetting agents acting essentially as a "mordant" in the interfacial area of the juxtaposed components S and 22.

Therefore. the generally tapelike material which is actually applied on the road surface S, generally by means of well known roller means such as diagrammatically indicated at 28 (Figure 3). is a two-layer structure comprising the components 22 and 26.

Figures 3 to 6 illustrate an embodiment of the invention, according to which the tape material 26 is provided with a primer adhesive layer 22 and is applied to the road surface by means of an apparatus comprising a frame structure 116 having extensions 114 having secured thereto handle means 112 provided with operator actuable controls 110. The apparatus is mounted upon driving wheels 118 and front wheel means consisting of roller means 28. A motor 122 is provided for driving the apparatus. By means of suitable brace and bearing means, the frame 116 rotatably and replaceably supports a spool 130 which provides the supply of the sign-forming tape 26 and guide means (such as idle or possibly driven roller or pulley means) for guiding the tape 26 progressively towards and about the roller 28.

Along the path of said tape 26. upstream of the roller 28, a substantial length of running tape 26 is guidedly supported to form a straight downwardly inclined run. A primer composition applying device 126 is positioned above and in close proximity with the straight portion of the running tape 26 to form and doctor the desired layer 22 on the face of said tape which will be turned downwardly about the roller 28. Said device 126 is continuously supplied with molten composition by a heat insulated container 124 located thereabove and wherein a batch of said molten composition is loaded from time to time. When a bigger and more powerful apparatus is provided, such apparatus can comprise a melting unit for supplying the desired molten material.

The device 126 is, as individually considered, known in the art. Apart from its present arrangement, such device can be substantially constructed as shown in Figures 6 and 7 of the U.S. patent no. 3,964,835 granted to the instant applicant. In the embodiment of Figures 4 and 5 of this invention, the material doctoring action is performed by an adjustable doctoring wall 128 under which the material 22 is caused to be metered over the tape 26. The opening provided below said wall 128 is of width W' smaller than the width W of the tape 26, so that the molten, or more properly, the heat softened material 22 does not cover the entire width of the tape (Figure 5) and does not drop over the edges thereof.

Further, the doctoring edge of the wall 128 is shaped to impart to the doctored material 22 a cross-sectional configuration including side bulges 22a. Such bulges 22a will be flattened and sidewardly squeezed off when the layer 22 is pressed beneath the tape 26 when passing about and under the roller 28, so that, in the material M on the road surface S (Figure 6) the tape 26 will be properly supported by a primer layer 22 uniformly pressed and extended therebelow for the entire width W thereof, without undue excess.

The marking sign applying machine is suitable complemented by one or more burners 132 (Figure 3) located and directed for applying to the road surface S and/or to the lower face of the primer layer 22 the heat necessary for promoting a substantial incipient surface melting of said layer where it is being contacted with and pressed on the road surface S for ensuring the desired compenentration in the pores and cavities of said surface. The machine is further complemented by a proper known marking tape transversely cutting or severing device such as diagrammatically shown and generally indicated at 134, said device being for example actuated by the operator (who walks behind the apparatus) acting for example on a control pedal 136.

Any suitable essentially thermoplastic composition can be made use of for forming the primer layer 22 and, if any, the wetting layer 16. This latter layer composition can be of the two-component type for ensuring prompt gelling when the two reactive components are contacted with each other. The location of the position of application of the primer to the tape is such that as the two-layer band reaches the road surface it will have gelled to a viscosity sufficient to resist the pressure applied by the roller 28. A not limitative example of a composition adapted for forming a thermoplastic primer layer 22 comprises, in parts by weight: "Versamid 940" (Schering) parts 65 "Versamid 100" (Schering) parts 5 Vinylethylene acetate copolymer (such as "Elvax (Registered Trade Mark) 240") parts 20 Colophony ester (such as "Foral 85" by DuPont) parts 10 Oxidized bitumen parts 200 The wetting liquid having hydrophilic properties, made use of for forming the interlayer 16, can comprise mixtures of exposy resins and epoxy tar, catalysts and reaction accelerators. A suitable two-component composition ("A" and "B") can comprise, in parts by weight: "A" Epoxy resin (such as "Araldite (Registered Trade Mark) G 7 250") parts 260 Epoxy tar parts 100 "B" Catalyst for the resin (such as "Ankamine XT") parts 65 Accelerator for same (such as "D M P 30") parts 20 Epoxy tar parts 115 Cresylic acid parts 100 WHAT I CLAIM IS: 1. A method of forming a traffic-regulating sign on a road surface, comprising the sequential steps of firmly bonding a predominantly thermoplastic primer composition as an adhesive layer to a face of a sign forming tape to thereby form a two-layered band, and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. supplied with molten composition by a heat insulated container 124 located thereabove and wherein a batch of said molten composition is loaded from time to time. When a bigger and more powerful apparatus is provided, such apparatus can comprise a melting unit for supplying the desired molten material. The device 126 is, as individually considered, known in the art. Apart from its present arrangement, such device can be substantially constructed as shown in Figures 6 and 7 of the U.S. patent no. 3,964,835 granted to the instant applicant. In the embodiment of Figures 4 and 5 of this invention, the material doctoring action is performed by an adjustable doctoring wall 128 under which the material 22 is caused to be metered over the tape 26. The opening provided below said wall 128 is of width W' smaller than the width W of the tape 26, so that the molten, or more properly, the heat softened material 22 does not cover the entire width of the tape (Figure 5) and does not drop over the edges thereof. Further, the doctoring edge of the wall 128 is shaped to impart to the doctored material 22 a cross-sectional configuration including side bulges 22a. Such bulges 22a will be flattened and sidewardly squeezed off when the layer 22 is pressed beneath the tape 26 when passing about and under the roller 28, so that, in the material M on the road surface S (Figure 6) the tape 26 will be properly supported by a primer layer 22 uniformly pressed and extended therebelow for the entire width W thereof, without undue excess. The marking sign applying machine is suitable complemented by one or more burners 132 (Figure 3) located and directed for applying to the road surface S and/or to the lower face of the primer layer 22 the heat necessary for promoting a substantial incipient surface melting of said layer where it is being contacted with and pressed on the road surface S for ensuring the desired compenentration in the pores and cavities of said surface. The machine is further complemented by a proper known marking tape transversely cutting or severing device such as diagrammatically shown and generally indicated at 134, said device being for example actuated by the operator (who walks behind the apparatus) acting for example on a control pedal 136. Any suitable essentially thermoplastic composition can be made use of for forming the primer layer 22 and, if any, the wetting layer 16. This latter layer composition can be of the two-component type for ensuring prompt gelling when the two reactive components are contacted with each other. The location of the position of application of the primer to the tape is such that as the two-layer band reaches the road surface it will have gelled to a viscosity sufficient to resist the pressure applied by the roller 28. A not limitative example of a composition adapted for forming a thermoplastic primer layer 22 comprises, in parts by weight: "Versamid 940" (Schering) parts 65 "Versamid 100" (Schering) parts 5 Vinylethylene acetate copolymer (such as "Elvax (Registered Trade Mark) 240") parts 20 Colophony ester (such as "Foral 85" by DuPont) parts 10 Oxidized bitumen parts 200 The wetting liquid having hydrophilic properties, made use of for forming the interlayer 16, can comprise mixtures of exposy resins and epoxy tar, catalysts and reaction accelerators. A suitable two-component composition ("A" and "B") can comprise, in parts by weight: "A" Epoxy resin (such as "Araldite (Registered Trade Mark) G 7 250") parts 260 Epoxy tar parts 100 "B" Catalyst for the resin (such as "Ankamine XT") parts 65 Accelerator for same (such as "D M P 30") parts 20 Epoxy tar parts 115 Cresylic acid parts 100 WHAT I CLAIM IS:

1. A method of forming a traffic-regulating sign on a road surface, comprising the sequential steps of firmly bonding a predominantly thermoplastic primer composition as an adhesive layer to a face of a sign forming tape to thereby form a two-layered band, and

pressing said band down against the road surface while the primer layer is in an at least partially fluid condition and with sufficient force to drive the primer layer into pores and cavities of the road, said previous step of bonding being performed by spreading the primer composition over only a portion of the width of the face of the tape so as to retain substantially all of the primer layer under the face of the tape despite squeezing of the primer layer during said pressing step.

2. A method as claimed in claim 1, wherein the said primer layer is formed by applying a molten composition on the tape at a location such that said layer will travel to reach the location of contact with the road surface after a time interval which will allow the thus formed layer to gel and attain a viscosity sufficient to resist the pressure applied during said pressing step.

3. A method as claimed in claim 1 or 2, further comprising the step of heating the road surface and/or the lower face of the thermoplastic primer layer immediately prior to said step of pressing so as to fluidize the lower face of the primer layer and thereby promote penetration of the primer layer into pores and cavities of the road surface.

4. A method as claimed in claim 1, 2 or 3, further comprising applying a layer of a hydrophilic agent to the lower face of the primer layer or to said road surface prior to said step of pressing so as to facilitate penetration of the primer layer into the pores of the road surface.

5. A method as claimed in any one of the preceding claims, wherein the thermoplastic primer includes oxidized bitumen.

6. A method as claimed in claim 5, the thermoplastic primer being about 2/3 by weight of oxidized bitumen.

7. A method of forming a traffic-regulating sign on a road surface as claimed in claim 1, and substantially as described herein.