On Sat, 26 Jun 2004 12:11:13 GMT, John Miller wrote:

James Sweet wrote:
No you simply use the lexan instead of the polycarb. Simply adjust for
the refractive properties of the Lexan. In fact I've used high grade
optical lenses made of lexan.( If you go to GE labs they'll give you
the optical properties of lexan, you'll find it's got a much higher
rating than polycarbonate.)

I'm not sure that's an ideal solution, yeah Lexan is more scratch
resistant than polycarbonate but it still scratches quite easily. I work a
fair bit with lexan and acrylic, the lexan is far easier to cut and drill
and far more shatter resistant, it does scratch much more easily than
acrylic though. Neither is as flexible as polycarbonate. Every material
has advantages and disadvantages.

What th'....

If you actually do go to GE Labs

http://www.gelexan.com/gelexan/

you'll see that Lexan *is* polycarbonate. (It's in the very title of the
above web page: "Lexan (R) Polycarbonate Resin from GE Plastics.")


Thank you for the clarification. I've worked with it over the years
and in the working practice most make a distinction between other
brands of polycarbonates and GE's version(GE did invent it
originally.)
Like I said there are different grades of the stuff.
And there is a world of difference between GE's offerings and the
other brands out there.
I've used cheaper versions such as that made by Cyano for things such
as windows and windshields for motorcycle fairings. It can scratch
quite easily.(Reason tho' is so it can be buffed back out after it
does inevitively get scratches.)
Working with the GE preformed sheets is some degrees tougher and more
exacting, at least for the uninitiated.
Much tougher to buff out if you do manage to scratch it as well.

I was just saying that if the makers of DVD's were to spend a few
pennies more and use a HIGHER grade of Lexan in the coating then
DVD's/CD's wouldn't get scratched as easily.
I reassert that that's unlikely as an indestructable product is the
LAST thing corporate America want's to produce.

Can you really argue with proof of the past 50 years or so?
everyone can recall some product that was discontinued because it just
lasted too long and would simply not wear out.
Autos come to mind for one.
Home appliances for another. Especially Televisions, Refridgerators,
Washers and Dryers as well.
Is it then a leap of intellect to not see the same with pre-recorded
media?
One has only to look at the history of the vinyl LP to see that.
The record industry attempted repeatedly to downgrade the quality of
the vinyl used not simply to save money on production but to make a
product that'd wear out faster.
The idea was to get the individual consumer to buy the same title over
and over. Therefor neverending cycle of profits.
In the late 70's just before the release of the CD medium the process
of degrading vinyl LP's was accelerated even more, to drive consumers
to the new and costly media.(remember the average cost of a player
when they came out was well over 700 dollars, Sony's ran as much as a
thousand. the CD's were even more overpriced some running as much as
25 dollars.)
In order to get consumers to swallow the hugh price tag they had to
make them hate vinyl.
There was once even plans to replace vinyl with cellulose, essentially
cardboard. Fortunately the consumers made their voices heard on that
idea.
Thing was the record industry had become dependent on the repeat sale
business model and simply couldn't afford to let go of it.
Millions would be lost.
so today we have CD's and DVD's that are very susceptable to scratches
and warpage.( I left a CD on my car seat last week and the summer heat
warped it to total uselessness.)