PK glass and PMMA, LED lighting materials is why PC win?

With the use of LED lighting rate rising, lighting manufacturers are pursuing lighting application of traditional materials outside the material, in order to promote the innovative design and shape, improve efficiency and overcome obstacles sustained cost. Although the traditional manufacturer in solid-state lighting (SSL) using PMMA application (PMMA) - then glass. Now, the polycarbonate resin (PC) has increasingly become a lens, lamp, lamp, tube column, diffuser and reflector. Today, LED alternative to incandescent lamps of about 90% is made of PC material.

LED design by selecting PC (rather than glass and PMMA) to achieve a number of advantages, including strong impact resistance and heat resistance, improve the flammability rating and increase design flexibility. Although the glass and PMMA due to its high transmittance and strong weatherability and keep competitive with PC, but the latest professional PC is rapidly narrowing the gap. As a candidate material for LED devices, polycarbonate poses a great challenge to the glass and PMMA, and is pushing for residential, commercial and outdoor LED design progress.

PC open the housing market

Many countries have already begun the transition from the traditional lighting source, thanks to the attention of consumers on energy saving and emission reduction, and government regulations to promote the phasing out of low efficiency lighting. However, to fully replace incandescent and compact fluorescent lamps (CFL), LED must solve the problem of cost, the cost is still one of the major obstacles to the public access to the residential market. The growth of demand, consumers need to see and have longer service life to understand the benefits of technology investment.

Durability and impact resistance is an important standard of residential environment, because the residents to install lights to replace the lamp drop or improper handling of the situation is very common. The impact of PC, in the laboratory flexural impact break samples with kJ/m2 (kJ / m2) were measured, and PMMA was significantly higher than that of glass. In the actual impact of measurement, 10 times the performance of PC over PMMA, 30 times of glass.

The use of LED device PC production is safer than using PMMA production, which has poor performance in flame retardancy and heat resistance. According to the standard of UL 94, some PC won the "5VA" level, this is the highest level of flame retardant. On the other hand, PMMA UL 94 rating of "HB", which is the lowest ranking. In addition, PC can be used continuously up to the temperature of 130 DEG C, while PMMA can reach 90 DEG C. Table 1 summarizes the characteristics of PC and PMMA, for solid state lighting product development reference.

Table 1. comparison of PC specifications and PMMA.

Have a softer solid-state lighting

In order to increase the demand for LED in the residential environment, lighting designers must also solve the quality problems of LED lighting, the light softer, more close to the incandescent light bulb. The diffusion material with white or matte effect can shield the LED light source, helps to reduce glare and light distribution. If there is no diffusion, LED light source can generate dazzling white highlights.

At the same time, the designer must balance the relationship between soft white aesthetic demand and light propagation. Spread too much may mean a loss of over illumination, the lighting efficiency is reduced.

PC is good at the delicate balance between the diffusion and propagation of light. A new generation of polycarbonate can be hot and does not affect the light transmitting shield. When the ball for LED shield or lens cover, PC provides effective diffusion, without the need of two lenses or components, thereby eliminating the cost, complexity and weight. The use of diffuser PMMA manufacturing usually requires multiple components, increase the weight and complexity of LED design.

Table 2 shows the transmission and scattering of light in LED design and PC level personnel can provide. LEXAN LUX C SABIC transparent resin product level provides a light transmission of 1 mm 91.5%, a significant improvement over traditional PC 89%, only 92% PMMA. Lighting application requirement for larger diffusion, LEXAN LUX C resin may be light diffusion diffusion stage (shown in Table 2) for the degree of light scattering (DLD), or the observed brightness of half of the incident angle, but not significantly reduce light transmission.

Table 2. transparent and diffusion PC grade light transmittance and light scattering.

Create the lighting uniformity and consistency for industrial and commercial use of LED is difficult, but PC has proved effective in these environments. Intematix is a LED fluorescent material and optical device manufacturers, the company chose LEXAN LUX SABIC resin transparent, diffusion and level of reflection, to make ChromaLit linear lighting system (Figure 1).

Figure 1. Intematix ChromaLit lighting system using remote phosphor technology and optical element based on polycarbonate.

ChromaLit uses the remote phosphor technology, fluorescent powder components use this technology with blue LED energy separation, to produce better light diffusion. The separation of fluorescent powder and energy source has better illumination uniformity. ChromaLit linear system provides uniform high-quality natural light, together with the use of the most efficient blue LED, the conversion efficiency can be as high as 215 or as high as 163 lm/W lm/w.

The design flexibility of commercial lighting

Industrial and commercial LED lighting manufacturers also face many of the same challenges with the housing market. The lighting design must be practical, attractive and lightweight, while also providing high light efficiency and light uniformity.

In order to achieve these complex standard, manufacturers are looking for can provide design flexibility in materials, glass and PMMA in the field behind the PC. In particular, PC can be used for the production of sharp corners and Notch - this design feature to further strengthen the PMMA in impact strength weakness. In addition, PMMA not like PC in