Lens embedded (traditional engineering grade) reflective film material;
Commonly known as "engineering grade" lens embedded reflective film, glass beads reflective film is the first class of products, the industry used to call the "engineering grade" series of reflective film, invented in 1937.
The traditional significance of the engineering-level reflective film in the 20th century, introduced to China in the 1980s, the 20th century, 90 years, China began to appear in a number of manufacturers, manufacturing this reflective film.
Since the 1940s, the material has been successfully used to make traffic signs. [5] The advent of the product, for the first time on the road, allows the drivers to drive at night to be able to find signs and reflective objects in front of their driving routes earlier. Because of the advent of this material, to varying degrees, to solve the following has been plagued by road traffic safety management of the problem:
1. Road signs can not be identified at night;
2. Active light source consumption of resources, some roads do not have the conditions to provide power lighting;
3. Active light source may interfere with the driver's attention, so that he did not even see the content should not see;
4. A reflective indicator that substantially meets the needs of medium and low traffic and narrow traffic (conventional speed around the 1940s).
So far, in many remote areas and rural roads, and some almost no other light source interference in the low-speed road environment, this reflective film is still widely used.
In the 1970s, the industrial level increased significantly, road construction technology to enhance, speed up, in many places, engineering materials have been unable to meet the demand. At present, in the traffic flow is small, low-speed motor vehicles, there is no environment to interfere with the light source areas, as well as many economically underdeveloped areas, especially non-safety warning signs, engineering grade reflective film still has a certain application.
Project-level reflective film after the advent of, was mainly used for the production of signs, signs, warning signs and signs and signs of the use of ordinary advertising. With the progress of retroreflective technology and the continuous emergence of new materials, the brightness of engineering grade reflective material, gradually considered to be unable to meet the safety needs. In developed areas, it is no longer used to create warnings and prohibitions. Large road signs and high-grade roads, it is difficult to find it a trace of the. In the United States in 2008 the national traffic safety standards, that the reflective film (ASTM class I film) in many cases, the minimum brightness can not meet the security needs.
Figure 2 lens embedded reflective film structure
Figure 2 lens embedded reflective film structure
Engineering grade reflective film of the adhesive, generally divided into pressure-sensitive and heat-sensitive two, can be completed paste. The use of the same type of ink using screen printing technology, can also be printed on the various types of patterns. Engineering grade reflective film for the floor for the aluminum plate, the construction operating temperature is generally required at 18 degrees Celsius. The temperature is too low, will affect the adhesive properties, resulting in damage to the logo life. Fig. 2 is a schematic structural view of a lens-embedded reflective film.
Engineering grade reflective film life is generally 3 to 7 years, white film front twice (0.2 o / -4 o) generally about 100cd / lx / m, according to the manufacturer's different. Some manufacturers only provide 7 years of reflective film, 7 years after the brightness retention value of at least 50% of the initial brightness value. Some manufacturers only provide 3 years and 5 years of quality assurance. This is mainly caused by the different weather resistance of the reflective film, the same raw materials made of reflective film, used in different geographical conditions, the length of its life is different.
Need to pay more attention to the point is that the project-level reflective film brightness stability, brightness intensity and weather resistance, are some of the reflective film production quality of some important basis. In these areas, any one part of the cut corners, although can reduce the cost of the product, but its quality, will be greatly reduced, especially the weather resistance and the difference between the parameters of light, can clearly reflect the advantages and disadvantages of engineering grade reflective film The
Lens sealed (high strength grade) reflective film editing
Lens-sealed reflective film is a durable glass beads reflective film, the industry used to call the "high-strength" reflective film, successfully developed in 1972.
This high-strength retroreflective film, which is manufactured by qualified processes and materials, is at least twice as high as the retroreflective film of the engineering grade reflective film, and its internal vacuum support structure also solves the problem of condensation dew condensation on the sign due to temperature changes The reflective ability of the material. The
Figure 3 high-strength reflective film structure
Figure 3 high-strength reflective film structure
The material came out of the 1970s, conforming to the need for improved technological progress and improved road conditions at the time, was successfully used to make traffic signs and save a lot of life. Compared with the engineering grade reflective film, even if the logo in a large angle and bright areas, high-strength reflective film to make the logo more clearly visible, effectively predict the driver in front of the road dangerous situation.
High-strength reflective film is used glass beads reflective technology, because of its product structure innovation, has a more reflective than the engineering grade reflective film unparalleled brightness and angle performance, but at the same time, but also because of its high-strength structure led to some Difficult to overcome product defects such as product brittle and easy to tear, wrinkle, bubble, surface honeycomb
Figure 4 Typical appearance of high strength grade reflective film
Figure 4 Typical appearance of high strength grade reflective film
From the production of high energy consumption, emissions and so on. Glass beads technology limitations, but also hindered the high-intensity to higher brightness and better angle of improvement.
High-strength reflective film is also a material with a gum, generally divided into pressure-sensitive and heat-sensitive two. The use of the same type of ink using screen printing technology can produce all kinds of patterns. High-strength reflective film is generally made of light transmission and good weather resistance of the resin film as the surface layer, the second layer is the vacuum layer, the third layer is embedded micro glass beads, the fourth layer of metal reflective coating, the fifth layer of resin Bearing layer, the sixth layer is the adhesive, the seventh layer of backing protective layer. Figure 3 is a high-strength reflective film structure diagram, Figure 4 is a high-intensity reflective film typical appearance.
High-strength reflective film is mainly used to make signs, signs, warning signs and signs and other major signs of traffic. After the advent of the high-strength reflective film, the driver's time to identify the traffic signs is shortened and the distance between the front signs and obstacles is found to be significantly ahead of time, greatly increasing the time taken to take safety precautions, reducing the incidence of road traffic accidents at night and improving traffic safety Sex. According to the empirical study, the brightness of the high-grade retroreflective material is much higher than that of the engineering grade retroreflective material. Since the 1990s, this high-strength retroreflective material has been used extensively on the Chinese freeway.
Since then, with the motor vehicle performance and road construction technology to enhance the great changes in urban environment, highways and high-speed vehicles increased significantly, the city light source complex, wide road abruptly endless, the foresight of the driver to see the line of sight, there are The new request. Some of the shortcomings of high-strength reflective materials, especially in the large-angle reflective performance and processing technology and cost, has been unable to appear and the new prism technology would like to gradually began to be replaced.
Into the second half of the 1990s, especially in the 21st century, the United States and Europe, has been fully started with a prism grade material to replace high-strength materials in the process. In particular, in 2004 came out of the "super-level" anti-reflective material, the use of prism technology, not only from the reflective performance, processing methods, energy-saving emission reduction, higher than the high-level quality upgrade, price costs, In the high-grade materials, since then, as the birthplace of high-strength materials in the United States, is no longer produced this material, so that China has become the only high-intensity reflective material production.
High-grade high-grade reflective film life is generally 10 years, the white film front brightness (0.2 o / -4 o) generally 250cd / lx / m above, in normal use conditions, 10 years after the brightness retention at least the initial brightness Value of 80%, high strength grade reflective film for the substrate for the aluminum, the operating temperature is usually required at 18 degrees Celsius. [5]
Micro Prism Reflective Film Editors
Micro-prism reflective film of the reverse reflection principle and engineering (lens embedded) and high-strength (lens-sealed) reflective film is different from the engineering grade and high-strength reflective film are used glass beads reflection principle, and micro-prism reflective film reflection Principle is the use of micro-prism refraction and reflection. Micro-prism reflective film of the main representative products, from the reverse reflection characteristics and structure, the main can be divided into four categories: focus on long-range recognition of the truncated prism, focusing on close-range large angle reading prism, Distance recognition performance and near-reading performance of the full prism, and these prism technology and new material technology combined with a new type of prismatic reflective film. They are responsive to the application level of diversification, and in recent years emerged in response to different levels of demand for new reflective material. [8]
Long - range Corner Micro - prism Reflective Film
Long distance Prismatic (LDP), the market can see the first generation of diamond-grade, crystal-grade level, the first time in the early 80s, the English name is Long Distance Prismatic (LDP), the market can see the first generation of diamond- , Star-level, are such products. The positive brightness of this type of reflective film is very high, the white film front brightness (0.2 o / -4 o) generally 800cd / lx / m is generally more than 800, and the reverse light
Figure 5 long-range angle micro-prism reflective film structure
Figure 5 long-range angle micro-prism reflective film structure
Distribution is not directional, reflective film, whether it is horizontal or vertical film, the difference in the reflective effect is not. But at a large angle of incidence and observation angle, the reflective brightness will be a great attenuation. Figure 5 shows the structure of the reflective film under the microscope. This is the reflection of the positive reflection of the positive reflection of the reflective film, more suitable for contour markings, warning columns, etc., is not suitable for use in the distance to read more need to see the brightness of traffic signs. This early prism reflective film, was the design and development of a stage of the results, then the prism structure, has not been able to solve the large viewing angle of the retro-reflective brightness problem. [9]
Large angle truncated microprism reflective film
After the advent of the first generation of microprism reflective film, people have found a problem, when the motor vehicle really into the mark when reading distance, that is, in the case of large viewing angle, the brightness of the logo attenuation is too large, so that Reading distance, can not read the contents of the logo, or take a longer time to read. As a result, people use large angle angle micro-prism structure, creating a large angle angle micro-prism reflective film (see Chapter 2) to address the distance in the reading, to maintain the mark twice. Therefore, this large-angle reflective film, the same from the reflective performance to describe a special prism-type reflective film.
Compared with the long-distance filament micro-prism reflective film, large angle angle micro-prism reflective film front brightness is relatively low, but in the large angle of incidence and observation angle, its reflective brightness will not have a great attenuation. And the large angle corresponds to the multi-lane and corners of the location, as well as signs of complex content, the need for longer reading time signs, so this reflective film suitable for urban roads and wide road traffic signs. Although it is in the distance
Figure 6 large angle angle micro-prism structure
Figure 6 large angle angle micro-prism structure
The positive brightness of the front (only relative to the long-distance prism level, compared with the high-level side of the positive brightness, can still be more than doubled), but at close distance (the need to read the contents of the distance), the brightness Far higher than the long-range reflective film. Its direction is stronger than the long-distance reflective film, according to the logo set the location and direction, to adjust to meet the needs of reading. Figure 6 shows the structure of a large angle angle microprism with a microscope. VIP (Visual Impact Prismatic), translated as a visual impact of the prism, the late 80s of the 20th century came out, was once widely used, full prism technology after the shutdown. [9]
Full prism reflective film
The prismatic retroreflective material is a prismatic retroreflective material which is completed by using the prism structure. The characteristics of the prismatic retroreflective film are described in the second chapter. Simply put, the part of the traditional microprism structure can not be reflected, so that all the reflective film can be To achieve a combination of all the prism structure. It combines the long-distance and large angle micro-prism reflective film of the two characteristics, while maintaining the positive brightness, easy to find long distances at the same time, increased in the 50-250 meters distance when the large incidence angle and observation angle of the brightness The
The advent of this full prism reflective film, broke through the prism-type reflective film can not take into account the long-distance reflective ability and short-range reflective ability
Figure 7 Full prism reflective film surface structure electron micrograph
Figure 7 Full prism reflective film surface structure electron micrograph
Of the academic barrier. According to the path and way of light transmission, it finds the angle (angle of incidence and angle of view) of the sign in the ideal distance, and then determines the non-reflective area on the traditional cut-off microprism, and then Area to remove, so as to achieve the unit area reflective film on the reflective structure area of ??100%, which is the so-called "full reflection."
Of course, from the actual reflective effect, this is only 100% of the theoretical reflective efficiency. In the actual production, due to the constraints of materials and other conditions, reflective lamp brightness of 100% can not be achieved, at present, the best reflection efficiency is 58%, which has been significantly higher than other types of reflective film, such as high-intensity level of reflection Efficiency, only 23%. And from the observation angle of 0.2 o to 2 o, w its reverse reflection efficiency can always be maintained at 50% or more. Figure 7 is an electron micrograph of a full prism retroreflective film.
Now the full prism reflective film, through each microcrystalline cube connection and according to certain rules, in a square centimeter of the material area will have more than 930 units to control the light into and reflect the path. The lower layer of the microcrystalline cubic corners is sealed to form an air layer, and the incident light is internally reflected by the diffraction of the light so that the most convenient reflection effect can be achieved without the aid of the metal reflection layer. The use of wear-resistant high hardness of polycarbonate materials and microcrystalline cube technology made of this reflective film with the traditional engineering grade and high strength grade reflective film, the reflective performance is not only doubled, and large-angle reflective performance Greatly improved. The brightness of this full prism mirror is more than six times that of the engineering grade. The brightness of the white film (0.2o / -4o) is more than 600 cd / lx / m, which is more than twice that of the high strength level. (0.5o and 2o), the retroreflective performance is about two to four times higher.
Full prism Reflective film is a traffic sign material suitable for all grades of roads and urban roads. In the West, the application began to gradually replace the logo lighting investment and consumption. In the production of road signs, if the long-term investment benefits and safety benefits, the full prism reflective film can replace any level of reflective film. In normal use conditions, the use of ten years after the full prism refraction brightness retention value, at least for the initial brightness value
Figure 8 Comparison of retroreflective performance of various reflective films at different angles
Figure 8 Comparison of retroreflective performance of various reflective films at different angles
80%, that is, ten years later, it can still be much higher than the new high-strength grade and engineering grade reflective film retroreflective performance, is a scientific development from the perspective of a more economical choice. At the same time, if the same type of ink, combined with screen printing technology, can produce all kinds of patterns with traffic signs.
Full prism reflective film is mainly used in the road signs, prohibited signs