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Colour shift and mechanism investigation on the PMMA diffuser used in LED-based luminaires. / Lu, G; van Driel, WD; Fan, Xuejun; Yazdan Mehr, M; Fan, Jiajie; Qian, Cheng; Jansen, KMB; Zhang, GQ.

In: Optical Materials, Vol. 54, 2016, p. 282-287.

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@article{b2236e094b134b2aa39e793517d67d97,
title = "Colour shift and mechanism investigation on the PMMA diffuser used in LED-based luminaires",
abstract = "PMMA material is widely used in LED-based luminaires due to several advantages such as excellent optical transparency, durability against radiation, surface hardness (scratch free), rigidity and strength and can be completely recycled. However, few studies have been reported on the colour shift and failure mechanisms caused by this type of material. This paper experimentally investigated PMMA materials with different aging conditions. The following conclusions could be drawn. (1) Discolouration was not observed for any sample subjected to aging of 85 °C for 5000 h, or with additional blue light irradiation for 5000 h, or with additional humidity of 85{\%}RH for 5000 h, or even with aging of 100 °C for 3000 h. (2) The specimen subjected to aging of 150 °C for 360 h has a surface discoloration and has a significant wavelength dependent degradation in the transmission spectrum caused by oxidation. The specimen with aging of 100 °C for 3000 h has a less oxidation, although no significant transmission spectrum reduction was observed. (3) Using such aged specimen as a diffuser mounted on a LED-based luminaire, the radiant flux peak intensity in the blue light area has a more severe reduction than that in the yellow light area, which results in a reduction of the radiant flux intensity ratio of blue light to yellow light and hence induces the colour shift to yellow. The colour shift investigated is 0.005, very close to the general failure criterion of 0.007, while the lumen decay is 10.2{\%}, far less than the failure criterion of 30{\%}.",
keywords = "Colour shift, PMMA, Solid state lighting, LED-based luminaire, Infrared absorption spectroscopy",
author = "G Lu and {van Driel}, WD and Xuejun Fan and {Yazdan Mehr}, M and Jiajie Fan and Cheng Qian and KMB Jansen and GQ Zhang",
note = "harvest",
year = "2016",
doi = "10.1016/j.optmat.2016.02.023",
language = "English",
volume = "54",
pages = "282--287",
journal = "Optical Materials",
issn = "0925-3467",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Colour shift and mechanism investigation on the PMMA diffuser used in LED-based luminaires

AU - Lu, G

AU - van Driel, WD

AU - Fan, Xuejun

AU - Yazdan Mehr, M

AU - Fan, Jiajie

AU - Qian, Cheng

AU - Jansen, KMB

AU - Zhang, GQ

N1 - harvest

PY - 2016

Y1 - 2016

N2 - PMMA material is widely used in LED-based luminaires due to several advantages such as excellent optical transparency, durability against radiation, surface hardness (scratch free), rigidity and strength and can be completely recycled. However, few studies have been reported on the colour shift and failure mechanisms caused by this type of material. This paper experimentally investigated PMMA materials with different aging conditions. The following conclusions could be drawn. (1) Discolouration was not observed for any sample subjected to aging of 85 °C for 5000 h, or with additional blue light irradiation for 5000 h, or with additional humidity of 85%RH for 5000 h, or even with aging of 100 °C for 3000 h. (2) The specimen subjected to aging of 150 °C for 360 h has a surface discoloration and has a significant wavelength dependent degradation in the transmission spectrum caused by oxidation. The specimen with aging of 100 °C for 3000 h has a less oxidation, although no significant transmission spectrum reduction was observed. (3) Using such aged specimen as a diffuser mounted on a LED-based luminaire, the radiant flux peak intensity in the blue light area has a more severe reduction than that in the yellow light area, which results in a reduction of the radiant flux intensity ratio of blue light to yellow light and hence induces the colour shift to yellow. The colour shift investigated is 0.005, very close to the general failure criterion of 0.007, while the lumen decay is 10.2%, far less than the failure criterion of 30%.

AB - PMMA material is widely used in LED-based luminaires due to several advantages such as excellent optical transparency, durability against radiation, surface hardness (scratch free), rigidity and strength and can be completely recycled. However, few studies have been reported on the colour shift and failure mechanisms caused by this type of material. This paper experimentally investigated PMMA materials with different aging conditions. The following conclusions could be drawn. (1) Discolouration was not observed for any sample subjected to aging of 85 °C for 5000 h, or with additional blue light irradiation for 5000 h, or with additional humidity of 85%RH for 5000 h, or even with aging of 100 °C for 3000 h. (2) The specimen subjected to aging of 150 °C for 360 h has a surface discoloration and has a significant wavelength dependent degradation in the transmission spectrum caused by oxidation. The specimen with aging of 100 °C for 3000 h has a less oxidation, although no significant transmission spectrum reduction was observed. (3) Using such aged specimen as a diffuser mounted on a LED-based luminaire, the radiant flux peak intensity in the blue light area has a more severe reduction than that in the yellow light area, which results in a reduction of the radiant flux intensity ratio of blue light to yellow light and hence induces the colour shift to yellow. The colour shift investigated is 0.005, very close to the general failure criterion of 0.007, while the lumen decay is 10.2%, far less than the failure criterion of 30%.

KW - Colour shift

KW - PMMA

KW - Solid state lighting

KW - LED-based luminaire

KW - Infrared absorption spectroscopy

U2 - 10.1016/j.optmat.2016.02.023

DO - 10.1016/j.optmat.2016.02.023

M3 - Article

VL - 54

SP - 282

EP - 287

JO - Optical Materials

T2 - Optical Materials

JF - Optical Materials

SN - 0925-3467

ER -

ID: 1782050