Lambda 40 spectrometer

Example 5

Welds of plastic samples imbued with croconic acid dye, as well as samples imbued with the combination of a commercially available plastic dye in combination with croconic acid dye was laser-welded using a solid state laser emitting at 808 nm. The croconic acid dye used was 2,5-bis[4-(N,N.-didecylamino)-2-hydroxyphenyl]-croconaine dye.

The laser used was a Coherent FAB-800 fiber coupled laser run at 15 W optical power, as determined by a Thorlabs laser power meter. The plastic pieces to be welded were held in place using a mechanical fixture, and the fixture and the plastic parts were placed on a programmable linear table, with the speed selectable up to 50 mm per second. Welds obtained showed good adhesion and strength.

Shown in FIGS. 2-6 is the absorbance spectra of polyethylene imbued with respectively the Blue dye, Red dye, Croconic dye, Blue dye plus Croconic dye and lastly Red dye plus Croconic dye. The spectra were determined with a Perkin-Elmer Lambda 40 spectrometer, scanning from 1100 nm to 400 nm. As can be seen from the figures neither the Blue dye nor the Red dye in themselves have appreciable absorbance at 808 nm, while the Croconic dye as well as the combinations of Croconic dye and the Blue dye or Red Dye absorbs significantly at 808 nm.