Hello Optiboarders,
Is there any other manufacturer/supplier of columbia resin apart from PPG?
Google failed me and leads me to CR39 lens manufacturers.
Benny
Hello Optiboarders,
Is there any other manufacturer/supplier of columbia resin apart from PPG?
Google failed me and leads me to CR39 lens manufacturers.
Benny
try Google with allyl diglycol carbonate (ADC) , Cr 39 is a PPG trade mark.
Some historic facts :
CR-39, or allyl diglycol carbonate (ADC), is a plastic polymer commonly used in the manufacture of eyeglass lenses. The abbreviation stands for "Columbia Resin #39," because it was the 39th formula of a thermosetting plastic developed by the Columbia Resins project in 1940.[1]
The first commercial use of CR-39 monomer was to help create glass-reinforced plastic fuel tanks for the B-17 bomber aircraft in World War II, reducing weight and increasing range of the bomber. After the War, the Armorlite Lens Company in California is credited with manufacturing the first CR-39 eyeglass lenses in 1947. CR-39 plastic has an index of refraction of 1.498 and an Abbe number of 58. CR-39 is now a trade marked product of PPG Industries.[2]
An alternative use includes a purified version that is used to measure neutron radiation, a type of ionizing radiation, in neutron dosimetry.
CR-39 should not be confused with polycarbonate, a tough homopolymer usually made from bisphenol A.[3]
See all of It : http://en.wikipedia.org/wiki/CR-39
Thanks for the replies. So, guess only PPG.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks