Method for manufacturing signalling elements

Abstract

The present invention relates to a process for manufacturing photoluminescent signalling elements, where the manufacturing process of the present invention comprises changing the colour depending on the amount of light received, recharging and releasing fluorescent light in an uninterrupted manner and reducing the degradation of the photoluminescent materials to store and release light.

Description

[0001] METHOD FOR THE MANUFACTURE OF PHOTOLUMINESCENT SIGNAL ELEMENTS

[0002] TECHNICAL FIELD

[0003] The present invention falls within the technical field of materials engineering. Specifically, it relates to a process for manufacturing photoluminescent signaling elements.

[0004] BACKGROUND OF THE INVENTION

[0005] Photoluminescent materials, also known as phosphorescent materials or luminescent pigments, represent a special class of compounds that have the unique ability to absorb electromagnetic radiation, such as sunlight or artificial light, and re-emit it as visible light. This property is known as phosphorescence and is based on the release of stored energy in the materials after being excited by a light source. As the excitation source fades, photoluminescent materials continue to emit light for an extended period.

[0006] These materials have proven extremely valuable in various applications, and their implementation in road markings has proven extremely important. In road markings and highway safety, visibility is a critical factor in preventing accidents and ensuring traffic flow. In this context, photoluminescent materials have found significant applications. Some of the key applications of these materials in road markings include: 1. Traffic Signs: Traffic signs, such as stop signs, yield signs, and speed limits, require optimal visibility both day and night. Photoluminescent materials allow these signs to be clearly visible in low-light conditions, such as dusk or night, even if the natural light source has diminished or is not present. This day-to-night color change becomes a crucial factor for road safety; 2.- Road Markings: On roads and streets, road markings play a critical role in guiding drivers and ensuring traffic safety. Lane markings, pedestrian crossings, and other road markings can be enhanced with photoluminescent materials to ensure visibility in low-light conditions, such as at night or during heavy rain. 3. Emergency Exit Signs: In buildings and structures, emergency exit signs must be visible in emergency situations, where power outages may be a problem. The photoluminescent materials in these signs ensure that evacuation routes are easily identifiable even in total darkness. 4. Evacuation Systems: In emergency evacuation situations, such as fires or natural disasters, visibility in dark and smoky environments is crucial.Photoluminescent materials are used in evacuation systems to guide people safely out of a building or structure.

[0007] The application of photoluminescent materials in outdoor environments and their use as road markings represent a pressing technical challenge due to the need to ensure optimal visibility both during the day and at night. Photoluminescent materials, also known as phosphorescent pigments or materials, have proven valuable in improving safety and orientation in low-visibility situations, such as darkness and adverse weather conditions. However, the successful implementation of photoluminescent materials in outdoor applications and road markings presents several complexities.Key issues surrounding the use of photoluminescent materials in outdoor applications and road markings include: Durability and Exposure to Environmental Elements: Exposure to environmental elements, such as intense solar radiation, temperature fluctuations, high humidity levels, and atmospheric pollutants, poses a significant challenge to the durability of photoluminescent materials. These environmental factors can degrade the photoluminescent materials' ability to store and release light, which is crucial to their effectiveness in road markings.Furthermore, the challenge of maintaining a regulatory color during the day and allowing for a color change at night adds an additional layer of complexity; Regulatory Requirements: Road signage and road safety are subject to strict regulations and standards designed to ensure visibility and consistency in sign interpretation by drivers and pedestrians. Any solution incorporating photoluminescent materials must comply with these regulations, posing challenges for developing materials and systems that meet safety and visibility regulations.The need to change the color of road elements at night in compliance with road marking regulations is also a critical aspect of the problem; Integration and Energy Efficiency: Rapid and effective light charging of luminescent materials from artificial light sources at night is essential to ensure the visibility and safety of road elements. The solution must address energy efficiency, minimizing energy consumption and ensuring the availability of uninterrupted light at night, even if the light stored during the day is limited.The ability to recharge and release light almost continuously represents a significant engineering challenge; Maintenance and Costs: Durability and the ability to reduce the need for maintenance and replacement of traditional road elements, such as traffic signs or road markings, are critical factors for the successful adoption of photoluminescent devices. The solution must minimize costs associated with maintenance and replacement, while meeting nighttime color change requirements; Application Variability: The applications for road marking elements are diverse and can include traffic signs, road markings, emergency exit signs, and building evacuation systems. The solution must be adaptable to a variety of applications with specific requirements, including the ability to change color effectively according to the needs of each application.

[0008] Given these multidimensional challenges, an innovative solution is required to address the technical and regulatory challenges associated with the effective implementation of photoluminescent materials in outdoor and roadway signage applications. Such a solution must ensure durability, regulatory compliance, energy efficiency, reduced maintenance costs, and application versatility, while allowing for the required color change at night to maintain high visibility and safety. Therefore, the state of the art does not yet have a process for manufacturing photoluminescent signage elements for outdoor use that allows these signage elements to: change their color based on the amount of light they receive; recharge and release fluorescent light continuously; and; reduce the degradation of photoluminescent materials to store and release light.

[0009] OBJECTS OF THE INVENTION

[0010] It is therefore an object of the present invention to provide a process for the manufacture of photoluminescent signaling elements for outdoor use.

[0011] Another object of the present invention is to provide a process for the manufacture of photoluminescent signaling elements for outdoor use that allows the signaling elements to modify their color depending on the amount of light they receive.

[0012] A further object of the present invention is to provide a process for manufacturing photoluminescent signaling elements for outdoor use that enables the signaling elements to decrease the degradation of photoluminescent materials to store and release light.

[0013] BRIEF DESCRIPTION OF THE INVENTION

[0014] These and other objects are achieved by a process for the manufacture of photoluminescent signaling elements, wherein said process comprises the steps of: i) Selecting and mixing in an equal proportion, 50% (w / w) (weight / weight) of high density virgin polyethylene with 50% (w / w) (weight / weight) of linear polyethylene, both in the form of pellets; i) Selecting and adding to the previous mixture of polyethylenes between 6% and 12% (w / w) (weight / weight) of photoluminescent material; iii) Carrying out a plastic extraction process using the mixture of polyethylenes and photoluminescent material under a pressure of 1 10 kilos in a temperature range between 120 s -180 sC at 70 rpm for 8 min. iv) Remove the extruded part consisting of the mixture of polyethylene and photoluminescent material; v) Prepare a varnish solution composed of between 6% and 12% photoluminescent material and 94% and 88% epoxy varnish; vi) Varnish the extruded part using between 30-40 ml of the fluorescent varnish solution per square meter of extruded part and; vii) Dry the extruded and varnished part to obtain the photoluminescent signaling element.

[0015] In a second aspect, the invention relates to photoluminescent signage elements composed of: a solid matrix composed of: 50% (w / w) (weight / weight) of high-density virgin polyethylene with 50% (w / w) (weight / weight) of linear polyethylene and 6%-12% (w / w) (weight / weight) of photoluminescent material and; a surface composed of: a varnish solution composed of between 6%-12% of photoluminescent material. In accordance with the present invention, photoluminescent signage elements for outdoor use can change their color depending on the amount of light they receive; recharge and release fluorescent light in an uninterrupted manner and; reduce the degradation of photoluminescent materials to store and release light.

[0016] In a third aspect, the invention relates to the use of photoluminescent signaling elements such as: buoys, buttons, speed bumps, stops, road studs, cones, containment barriers, brackets, containment barrier tube plugs and any other road signaling element.

[0017] The additional features and advantages of the invention should be more clearly understood by the detailed description of the preferred embodiment thereof, given by means of a non-limiting example with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE FIGURES

[0018] Figure 1 is a graph showing the result of the DIN 67510 part 1 test on the luminance of the yellow-green photoluminescent material present in a road button manufactured using the process for manufacturing photoluminescent signaling elements of the present invention at different time intervals after having been exposed to a light source.

[0019] DETAILED DESCRIPTION OF THE INVENTION

[0020] The first aspect of the present invention relates to a process for manufacturing photoluminescent signaling elements, where the properties and advantages of the present invention will be evident to a person skilled in the art from its manufacturing method, which is made up of the following main stages: i) Selecting and mixing 50% by weight (w / w) of high-density virgin polyethylene and 50% by weight (w / w) of linear polyethylene, both in percentage relation to the final weight of the desired photoluminescent signaling element;

[0021] ¡i) Select and add to the previous mixture of polyethylenes between 6% (w / w) and 12% (w / w) by weight of photoluminescent material in percentage relation to the final weight of the desired photoluminescent signaling element; iii) Carry out a plastic extrusion process using the mixture of polyethylenes and photoluminescent material under a pressure of 110 kilos in a temperature range between 120s -180 s C at 70 revolutions per minute for 8 minutes; iv) Removing the extruded part to obtain a photoluminescent signaling element composed of the mixture of polyethylene and photoluminescent material; In a second aspect, the invention relates to a process for varnishing photoluminescent signaling elements, characterized in that it comprises the steps of: i) Selecting a photoluminescent signaling element;

[0022] i) Select and mix in an equal proportion, 6-12% (w / w)

[0023] (weight / weight) of photoluminescent material and 88%-94% epoxy varnish; iii) Varnish the photoluminescent signage element, using 30-40 ml of the fluorescent varnish solution per square meter of extruded part and; iv) Dry the extruded and varnished part to obtain a varnished photoluminescent signage element.

[0024] In a third aspect, the invention relates to photoluminescent signage elements for outdoor use composed of: a solid matrix composed in turn of: 50% (w / w) (weight / weight) of high-density virgin polyethylene with 50% (w / w) (weight / weight) of linear polyethylene and 6%-12% (w / w) (weight / weight) of photoluminescent material and; a surface composed of: a varnish solution in turn composed of between 6%-12% of photoluminescent material. In accordance with the present invention, photoluminescent signage elements for outdoor and indoor use can modify their color depending on the amount of light they receive; recharge and release fluorescent light in an uninterrupted manner and; reduce the degradation of photoluminescent materials to store and release light.

[0025] In order to demonstrate the capabilities of the process for manufacturing photoluminescent signaling elements, the following tests were performed:

[0026] Durability and long-term performance in phosphorescent material as signage.

[0027] To determine the luminance properties that photoluminescent materials can exhibit in outdoor signage elements, an analysis was performed on the long-term durability and performance of the photoluminescent material present in extruded and varnished road buttons, made using the process of the present invention.

[0028] Thirty road buttons of 10 cm diameter were manufactured, each following the process for manufacturing photoluminescent signaling elements of the present invention, as follows: Select and mix in an equal proportion 0.46 kg of high density virgin polyethylene and 0.46 kg of linear polyethylene; Select and add to the previous mixture of polyethylenes 0.08 kg of yellow-green photoluminescent material; Carry out a plastic extrusion process using the mixture of polyethylenes and photoluminescent material under a pressure of 1 10 kilos in a temperature range between 120 s -180 sC at 70 revolutions for 8 minutes; Remove the extruded part composed of the mixture of polyethylene and photoluminescent material; Prepare a total of 0.4 mL of a photoluminescent varnish solution, using 0.08 mL of photoluminescent material and 0.92 mL of epoxy varnish; Varnish the extruded part using the total mixture of epoxy varnish and photoluminescent material (0.4 mL); Dry the extruded and varnished part to obtain the varnished photoluminescent signaling element.

[0029] The 30 buttons were placed outdoors for a period of 1 month.

[0030] At the end of the exposure period, the buttons were analyzed following the protocol of DIN 67510 Part 1, as described below:

[0031] The buttons were exposed to a D65 light source with an illuminance of 1003 lux for 10 minutes, in a dark room at 25°C. S C.

[0032] The luminance values ​​of each sample were then measured, allowing the amount of light emitted by the photoluminescent material present in each button to be measured after it had been charged with light for a specific time and after the excitation source had been removed. The values ​​were recorded in millicandelas per square meter (mcd / m 2 ) using a 1 1 B247 photometer of the brand ALMT Lichtmesstechnik GMBH type B520.

[0033] In relation to Figure 1, the average measurement of the luminance obtained at each time interval for each of the 30 buttons obtained from this test is shown, where the luminance decreases with the time elapsed since the removal of the light source, where for example, illuminances such as:

[0034] • After 2 minutes: 1431 mcd / m 2

[0035] • After 10 minutes: 342.6 mcd / m 2

[0036] • After 30 minutes: 105.1 mcd / m 2

[0037] • After 60 minutes: 46.4 mcd / m 2

[0038] • After 120 minutes: 21.2 mcd / m 2

[0039] • After 4897 minutes: 0.3 mcd / m 2 (this value indicates a very low, almost zero, luminance).

[0040] Figure 1, with the afterglow characteristics data, also shows the luminance at different time intervals after the excitation source was removed. For example, 6 minutes after the light source was removed, the luminance was 586.6 mcd / m 2 , and so on.

[0041] In summary, this data represents the ability of the photoluminescent material to emit light in the dark after being charged with light.

[0042] This confirms that the process for manufacturing photoluminescent signage elements for outdoor use allows them to modify their color based on the amount of light they receive; recharge and release fluorescent light continuously; and reduce the degradation of photoluminescent materials to store and release light.

[0043] In a third aspect, the invention relates to the use of photoluminescent signaling elements for outdoor use such as: buoys, buttons, speed bumps, stops, road studs, cones, containment barriers, brackets, containment barrier tube plugs and any other road signaling element.

[0044] Having described the invention in a general manner, some examples of the elaboration of the process for the manufacture of photoluminescent signaling elements for outdoor use are described below, which serves only as an illustration of the procedure and is not intended in any way to be limiting.

[0045] EXAMPLE

[0046] Example 1. Manufacturing of an extruded and varnished photoluminescent button with a 10 cm diameter yellow-green photoluminescent material: Select and mix in equal proportions 0.46 kg of high-density virgin polyethylene and 0.46 kg of linear polyethylene; Select and add 0.08 kg of yellow-green photoluminescent material to the previous polyethylene mixture; Carry out a plastic extrusion process using the mixture of polyethylene and photoluminescent material under a pressure of 110 kilos in a temperature range between 120 s - 180 sC at 70 revolutions for 8 minutes; Remove the extruded part composed of the mixture of polyethylene and photoluminescent material; Prepare a total of 0.4 mL of a photoluminescent varnish solution, using 0.08 mL of photoluminescent material and 0.92 mL of epoxy varnish; Varnish the extruded part using the total mixture of epoxy varnish and photoluminescent material (0.4 mL); Dry the extruded and varnished part to obtain the varnished photoluminescent signaling element.

[0047] Since various aspects of various embodiments of this invention have been described, it should be noted that various alterations, modifications, and improvements can be made by those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this description and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description and the aforementioned figures are for exemplary purposes only.

Claims

CLAIMS 1.- Process for the manufacture of photoluminescent signaling elements, characterized in that it comprises the steps of: i) Selecting and mixing 50% by weight (w / w) of high-density virgin polyethylene and 50% by weight (w / w) of linear polyethylene, both in percentage relation to the final weight of the desired photoluminescent signaling element; ¡i) Select and add to the previous mixture of polyethylenes between 6% (w / w) and 12% (w / w) by weight of photoluminescent material in percentage relation to the final weight of the desired photoluminescent signaling element; iii) Carry out a plastic extrusion process using the mixture of polyethylenes and photoluminescent material under a pressure of 110 kilos in a temperature range between 120 s -180 sC at 70 revolutions per minute for 8 minutes; iv) Remove the extruded part to obtain a photoluminescent signaling element composed of the mixture of polyethylene and photoluminescent material; 2.- The process for manufacturing photoluminescent signaling elements according to claim 1, further characterized in that the concentration of the photoluminescent material varies between 6-12% w / w (weight / weight). 3.- Photoluminescent signaling element composed of a solid matrix that incorporates a photoluminescent material. 4.- The solid matrix of the photoluminescent signaling element of claim 3, composed of 50% (w / w) (weight / weight) of high-density virgin polyethylene with 50% (w / w) (weight / weight) of linear polyethylene and 6%-12% (w / w) (weight / weight) of photoluminescent material. 5.- Process for the varnishing of photoluminescent signaling elements, characterized in that it comprises the steps of: i) Selecting a photoluminescent signaling element; ¡i) Select and mix in an equal proportion, 6-12% (w / w) (weight / weight) of photoluminescent material and 88%-94% of epoxy varnish; iii) Varnish the photoluminescent signaling element, using between 30-40 ml of the fluorescent varnish solution for each square meter of extruded piece and; iv) Dry the extruded and varnished piece to obtain a varnished photoluminescent signaling element. 6.- Photoluminescent signaling element composed of a solid matrix incorporating a photoluminescent material and a surface coated with a varnish incorporating a photoluminescent material.

7. -The varnished surface of the photoluminescent signaling element of claim 6 composed of a varnish solution containing 6%-12% (w / w) of photoluminescent material.

8. The photoluminescent signaling elements of claims 3 and 6, further characterized in that they can change their color based on the amount of light they receive; recharge and release fluorescent light continuously; and reduce the degradation of photoluminescent materials to store and release light. 9.- The use of the photoluminescent signaling elements of claims 3 and 6, further characterized in that said signaling element is selected from a list that includes: buoys, buttons, speed reducers, stops, vialetas, cones, containment barriers, brackets, containment barrier tube plugs. 10.- The photoluminescent signaling elements of claims 3 and 6, further characterized in that they can be used both outdoors and indoors.

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