Reflective tape or sheeting is also referred to as retro-reflective in that it collects and returns light back to the source of that light. In other words, no matter which direction the light comes from, the reflective material collects it, focuses it, and returns it back to the light source.
Retro reflective tape is defined as a film that through the use of glass spheres or man made prisms, reflects light or radiation back to its source. Glass bead tapes reflect using microscopic glass beads that act as parabolas and direct light back to where it came from. Prismatic tapes use man made prisms or mirrors to collect light and send it back to its source. When a transparent colour is applied to the surface of either tape the light that is reflected is coloured.
Retro-reflective tape is used voluntarily all over the world to allow objects to be seen at night. There are also government regulations that mandate the use of retro-reflective tape in certain situations.
HOW IS REFLECTIVE TAPE MADE? GLASS BEAD AND MICRO-PRISMATIC
Glass Bead and Micro-Prismatic Reflective Tape
Reflective tape is made using machines that bond together multiple layers of material into one film. There are two main types of reflective tape, glass bead and micro-prismatic. They reflect in two different ways but are made in similar fashion with glass bead tape being the less complicated of the two to product.
Engineer Grade Glass Bead Reflective Tape
Engineer grade reflective starts with a carrier film that is metalized on the top. Glass beads are applied to this layer so that about 50 percent of the bead is embedded in the metalized layer. This gives the beads their reflective properties. Then a layer of either acrylic or polyester is applied over the top. This layer can be clear to made white reflective tape or it can be coloured to create the different colour reflective tapes. A layer of adhesive is then applied to the bottom of the tape and a release liner is applied to that layer. It is rolled up, slit to width and then sold. Note – an acrylic layered film will not stretch and a polyester layered film will. Because of the heat used in the manufacturing process engineer grade films end up being a single layer so they will not delaminate.
High Intensity Glass Bead Reflective Tape
High intensity type 3 reflective tape is made in layers also. The first layer if one that has a grid built into it. Normally a honeycomb type pattern. This pattern is what will hold the glass beads so that they are in separate cells. The glass beads are bonded to the bottom of this cell then a layer of acrylic or polyester is applied over the top of the cell so that there is a small air space above the beads. (high index beads) This layer can be clear or a color. Then a layer of adhesive and a release liner are applied to the bottom of the tape. Note – an acrylic layered film will not stretch and a polyester layered film will. Although the layers in high intensity are bonded together, they can delaminate.
Metalized Micro-Prismatic Reflective Tape
Metalized micro-prismatic reflective tape is made by first creating a prism array out of clear or colored acrylic or polyester (vinyl). This is the top layer. This layer provides reflectivity and returns light back to the source. A colored layer would return light back to the source but in a different color. This layer is metalized to enhance its reflectivity. Then a layer of adhesive is applied to the back and a release liner is applied. Because of the heat used in this process the layers of metalized prismatic will not delaminate. This is especially beneficial in applications such as vehicle graphics or any other application where the tape may be treated harshly. Reflexive invented prismatic reflective tape and their tapes do not delaminate.
Non Metalized Micro-Prismatic Reflective Tape
Much like metalized films, the first step in creating non metalized reflective films is to create the prism array out of acrylic or another clear resin. This will be the top layer of the film. It can be clear or colored. In order to create a whiter or a more vivid coloured film, the prism layer is adhered to a grid that forms a sort of honeycomb pattern. This creates an air layer below the prisms. The surface below the air layer is white. The prism layer and the grid layer are bonded together but can come apart meaning that non metalized films can delaminate. By eliminating the metalizing of the prisms the tapes are more vivid since the colour does not have to compete with the silver metalizing layer. Non metalized films are more vivid but not necessarily more reflective.
The image below shows the 4 types of reflective films. All are made in a similar way. The glass bead engineer grade film is the easiest to make and thus the least expensive. The high intensity is the next easiest and next in price. The metalized micro-prismatic films are the most expensive to make but are the brightest and toughest of all the reflective tapes. They are perfect for dynamic or harsh environments. The non metalized films are less expensive to make than metalized films. Non metalized films have the advantage of being more vivid in the daytime and are popular for sign sheeting and other static applications.
There are several types of reflective sheeting. Engineer grade is the most common and is known as a type 1 film. Super engineer grade is a type 2. High intensity is the brightest glass bead film and is a type 3. The first prismatic film is a type 5. The brightest film is a type 8 and is often called crystal or diamond grade. We have charts on each of the films below. Exact intensities will vary by manufacturer but the charts below are a good guide. Also, please note that the Type 3 High Intensity chart also defines observation and entrance angles.
REFLECTIVITY SPECIFICATIONS ON THE DIFFERENT TYPES OF REFLECTIVE SHEETING
Type 1 Engineer Grade Reflectivity Chart
Type 2 Super Engineer Grade Reflectivity Chart
Type 3 High Intensity Reflectivity Chart
Type 4 High Intensity Prismatic (HIP)
Type 5 V82 Prismatic Tape (thin tape)
V98 Oralite Conformable Prismatic (slightly thicker than V92/V82)
Type 8 Crystal / Diamond Grade Reflectivity Chart (thick stiff tape)