Luminous textile
As light textiles , including Bright textiles , light textile , Bright fabrics , light emitting textiles refers to textiles that are excited to glow or illuminate themselves. The lighting effects are created by fluorescent , phosphorescent and electroluminescent pigments . A distinction is made between passive and active luminous textiles.
Manufacturing
The pigments are applied to the fibers of the textile substrate using printing or dyeing processes or incorporated into the fibers in the manufacturing process. While the fluorescent pigments only glow under ultraviolet ( UV ) light or under blue-violet light and the phosphorescent pigments glow in the twilight, the electroluminescent pigments can be actively stimulated to glow by an electric field or alternating field.
In the case of electroluminescent pigments, conductive yarns, wires, strands or printed conductive tracks must also be integrated into or printed on the textile. The excitation electrodes often form an interdigital structure and not, as is customary in electroluminescent films, a sandwich structure, since the necessary optically transparent electrode is difficult to produce on textiles. Analogous to EL wires, there are already yarn constructions made from conductive yarns that electroluminesce and can be incorporated into textile surfaces. The textiles based on electroluminescence are called EL textiles for short.
The incorporation of optical waveguides , in the ends of which light is usually coupled by super-bright LEDs , is another way of producing luminous textiles. The totally reflective surface of the optical waveguide is deliberately damaged, so that light emerges along the optical waveguide. Depending on how it is worked into the textile surface, two-dimensional light effects or traces of light can be created on the textiles.
Light sources such as LEDs can be soldered directly to circuit boards as SMD components. µ-LED, RGB -LED and OLED (Organic Light Emitting Device) can be integrated in textile surfaces or on yarn structures that contain highly conductive leads.
Working principle
Passive luminous textiles
Fluorescent light textiles
Fluorescent pigments are applied to the fibers of the textile substrate by means of printing or dyeing processes or these are incorporated into the fibers during the manufacturing process. Often such yarns are also woven, knitted, knitted or embroidered into the textile surface. Invisible UV light is converted into visible light and brightens the textiles (e.g. warning colors on safety vests, effect colors under black light, optical brighteners).
Phosphorescent luminous textiles
Phosphorescent pigments are applied to the fibers of the textile substrate by printing or dyeing processes or these are incorporated into the fibers during the manufacturing process. Often such yarns are also woven, knitted, knitted or embroidered into the textile surface. Afterglowing textiles are created in the dark.
Active luminous textiles
Electroluminescent textiles
The textile substrates finished in this way have a conductive electrode structure that stimulates the pigments to glow. The electrode structure of the first EL textiles is an interdigital structure created using weaving technology. The interdigital structure, in which the two interlocking electrode combs are made of extremely fine conductive ELITEX® yarns, have a thread electrode spacing of less than 200 µm, which is achieved with a weft density of over 100 picks and a yarn count of 22 dtex.
The interdigital fabrics produced in this way can be printed with EL pigment pastes emitting different colors, so that photo-realistic luminous images are visible on the textile substrate. The EL pastes currently in use provide prints that can be excited to glow with a voltage of 70 - 250 V and a frequency of 400 Hz - 10 kHz, analogous to the EL films. Because of the high voltage, the EL fabrics are provided with an insulating layer.
Electroluminescent pigments are applied to the fibers of the textile substrate using printing or dyeing processes. The same electroluminescent pigments are used on EL textiles as in EL foils and EL wires. They are mostly micro-encapsulated doped zinc sulfide pigments.
Luminous textiles with integrated optical fibers
Using additional equipment, fiber optic cables made of polymethyl methacrylate (PMMA) or polycarbonate (PC) are damaged in a defined manner on the surface, so that they emit light fed in at the fiber end via the outer surface. These threads are then woven, knitted, knitted or embroidered into textile surfaces. The fiber optics are bundled so that light can be fed in at the ends via super bright LEDs or other light sources.
Luminous textiles with integrated LED
With the miniaturization of the light-emitting diode (LED) to SMD-LED and µ-LED, the possibility of controlling the color of the emitted light (RGB-LED), its high light intensity, the high efficiency, the mass availability and the low price these light sources are interesting for the production of luminous textiles.
Light sources are powered by conductive threads. These conductive yarns are integrated into the textiles in the weaving or embroidery process ( e-broidery ). However, conductive structures printed or laminated on textiles are also conceivable for the power supply. Depending on the textile supply structure, the LEDs can be positioned and contacted almost freely. Textile scrolling displays and textile colored monitors with low resolution made of SMD-RGB-LED are already being presented.
application
- Automotive industry, vehicle construction
- security area
- advertising
- decoration
- Home textiles
literature
- Andreas Neudeck, among others: Development of self-luminous textiles for house and home textiles as well as clothing. Final report on the InnoRegio project no. 03i1839A funded by the BMBF. Textile Research Institute Thuringia-Vogtland eV, Greiz 2006.