verb sap - eyeglass coatings and hot work

[pyotr filipivich]

Greetings and salutations

I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that
the plastic part has them imbedded. Every 75 to 83 seconds I lean
into the machine and insert six bolts. Weeeee. (It beats working.)

However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and
after eight hours of doing this, the protective coating on my (new)
lenses "wrinkles". The effect is ... well my glasses never get clean.
There is always this "smudge".

This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One
would think that forty years of material science development, yadya,
yada ... we would have a better option than glass for lenses for those
who work around hot stuff. But, apparently we don't.

Unless, someone has a "better idea". Would safety goggles worn over
the glasses protect them? The clear (or colored) plastic overshields
which we wear to keep 'stuff' out of our eyes. Does anyone know?

Are there coatings which do not melt when you open and stare into an
oven?


tschus
pyotr

p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.
--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

[Ed Huntress]

On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich

Post by pyotr filipivich
Greetings and salutations
I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that
the plastic part has them imbedded. Every 75 to 83 seconds I lean
into the machine and insert six bolts. Weeeee. (It beats working.)
However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and
after eight hours of doing this, the protective coating on my (new)
lenses "wrinkles". The effect is ... well my glasses never get clean.
There is always this "smudge".
This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One
would think that forty years of material science development, yadya,
yada ... we would have a better option than glass for lenses for those
who work around hot stuff. But, apparently we don't.
Unless, someone has a "better idea". Would safety goggles worn over
the glasses protect them? The clear (or colored) plastic overshields
which we wear to keep 'stuff' out of our eyes. Does anyone know?
Are there coatings which do not melt when you open and stare into an
oven?
tschus
pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.

First answer -- no, I don't know. But on the guess that no one else
does, either, here are a couple of thoughts:

Most lens coatings are metal oxides. Those are fairly refractory, and
I doubt if they wrinkle. What's probably "wrinkling" is the bond
interface with the lenses. They probably have much different thermal
coefficients of expansion, and the bond may be failing in shear with
the heat.

Second, plycarbonate safety glasses block IR pretty well, but not UV.
If it's just heat that's radiating, then you need UV blockage.

This is pure guesswork, but the ideal might be one of the certified
laser safety glasses or goggles. They block specific wavelengths, but
a little research and some data:

http://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=762

...may get you there. That, and some more info from others who might
respond.

If the radiation itself is not a problem for your eyes, you might just
want a cheaper, uncoated pair of backup glasses.

Good luck! And remember, this is all guesswork on my part.

[Jim Wilkins]

Post by Ed Huntress
On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich
Second, plycarbonate safety glasses block IR pretty well, but not UV.
If it's just heat that's radiating, then you need UV blockage.
Good luck! And remember, this is all guesswork on my part.
--
Ed Huntress

There's no UV unless it's white hot:
http://en.wikipedia.org/wiki/File:Black_body.svg

[Ed Huntress]

On Wed, 24 Dec 2014 12:38:46 -0500, "Jim Wilkins"

Post by Jim Wilkins

Post by Ed Huntress
On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich
Second, plycarbonate safety glasses block IR pretty well, but not UV.
If it's just heat that's radiating, then you need UV blockage.
Good luck! And remember, this is all guesswork on my part.
--
Ed Huntress

http://en.wikipedia.org/wiki/File:Black_body.svg

Jeez. I got the IR and UV reversed. Sorry about that. Brain fart.

Polycarbonate blocks ultraviolet, but not infrared. It's useless for
the injection-molding application. Radiant heat is mostly infrared.

[Jim Wilkins]

Post by Ed Huntress
On Wed, 24 Dec 2014 12:38:46 -0500, "Jim Wilkins"

Post by Jim Wilkins

Post by Ed Huntress
On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich
Second, plycarbonate safety glasses block IR pretty well, but not UV.
If it's just heat that's radiating, then you need UV blockage.
Good luck! And remember, this is all guesswork on my part.
--
Ed Huntress

http://en.wikipedia.org/wiki/File:Black_body.svg

Jeez. I got the IR and UV reversed. Sorry about that. Brain fart.
Polycarbonate blocks ultraviolet, but not infrared. It's useless for
the injection-molding application. Radiant heat is mostly infrared.
--
Ed Huntress

Since I have polycarbonate safety glasses and a hot wood stove I
checked. The skin around my eyes feels -much- more heat without the
glasses, and an IR thermometer reads only 120F through them. They may
have a scratch resistant coating but they aren't tinted at all.
-jsw

[Jim Wilkins]

Since I have polycarbonate safety glasses and a hot wood stove ...

I'm not risking my eyeglasses any further to answer a question.

At the distance where the heat from the glowing charcoal is
intolerable without protection in about 2 seconds, I can't feel any
heat through Harbor Freight polycarbonate safety glasses #94357 with
sheet metal held above and below. Unlike my eyeglasses they are wide
enough to block heat around the sides.
-jsw

[Tim Wescott]

Post by pyotr filipivich
Greetings and salutations
I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that the
plastic part has them imbedded. Every 75 to 83 seconds I lean into the
machine and insert six bolts. Weeeee. (It beats working.)
However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and after
eight hours of doing this, the protective coating on my (new) lenses
"wrinkles". The effect is ... well my glasses never get clean. There is
always this "smudge".
This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One would
think that forty years of material science development, yadya, yada ...
we would have a better option than glass for lenses for those who work
around hot stuff. But, apparently we don't.
Unless, someone has a "better idea". Would safety goggles worn over the
glasses protect them? The clear (or colored) plastic overshields which
we wear to keep 'stuff' out of our eyes. Does anyone know?
Are there coatings which do not melt when you open and stare into an
oven?
tschus pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.
--
pyotr filipivich.
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

If they don't (and from what Ed says about polycarbonate, once he got
sorted out) they don't, then there may be a material that's transparent
in the visible and reflective or absorbtive in IR that you can add to the
mix (I typed UV first -- thanks Ed).

Check http://www.edmundoptics.com/ (used to be Edmund Scientific). If
god is smiling on you then they'll have some sheets of stuff you can just
stick onto your face shield.

Also Google around and see if you can find a table of transmittances by
material -- if you can find something that's clear in the visible and
absorbtive in the IR, and that doesn't give an OSHA inspector colonic
spasms, then you're in.

[Joe Gwinn]

Post by pyotr filipivich
Greetings and salutations
I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that
the plastic part has them imbedded. Every 75 to 83 seconds I lean
into the machine and insert six bolts. Weeeee. (It beats working.)
However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and
after eight hours of doing this, the protective coating on my (new)
lenses "wrinkles". The effect is ... well my glasses never get clean.
There is always this "smudge".
This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One
would think that forty years of material science development, yadya,
yada ... we would have a better option than glass for lenses for those
who work around hot stuff. But, apparently we don't.
Unless, someone has a "better idea". Would safety goggles worn over
the glasses protect them? The clear (or colored) plastic overshields
which we wear to keep 'stuff' out of our eyes. Does anyone know?
Are there coatings which do not melt when you open and stare into an
oven?
tschus
pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.

How do we know that it's the coating, versus the lens material? If
it's a safety lens, it will be polycarbonate, which melts at a fairly
low temperature, and is very sensitive to solvents and solvent fumes.

In any event, of all the plastics used for eyeglasses, CR-39 is by far
the most resistant. <http://en.wikipedia.org/wiki/CR-39>

This is what I use.

Joe Gwinn

[pyotr filipivich]

Post by Joe Gwinn

Post by pyotr filipivich
pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.

How do we know that it's the coating, versus the lens material?

That seems to be the consensus, at least online.

Post by Joe Gwinn
If
it's a safety lens, it will be polycarbonate, which melts at a fairly
low temperature, and is very sensitive to solvents and solvent fumes.
In any event, of all the plastics used for eyeglasses, CR-39 is by far
the most resistant. <http://en.wikipedia.org/wiki/CR-39>

Thanks.

Post by Joe Gwinn
This is what I use.
Joe Gwinn

--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."

[c***@snyder.on.ca]

On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich

Post by pyotr filipivich
Greetings and salutations
I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that
the plastic part has them imbedded. Every 75 to 83 seconds I lean
into the machine and insert six bolts. Weeeee. (It beats working.)
However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and
after eight hours of doing this, the protective coating on my (new)
lenses "wrinkles". The effect is ... well my glasses never get clean.
There is always this "smudge".
This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One
would think that forty years of material science development, yadya,
yada ... we would have a better option than glass for lenses for those
who work around hot stuff. But, apparently we don't.
Unless, someone has a "better idea". Would safety goggles worn over
the glasses protect them? The clear (or colored) plastic overshields
which we wear to keep 'stuff' out of our eyes. Does anyone know?
Are there coatings which do not melt when you open and stare into an
oven?
tschus
pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.
--
pyotr filipivich.
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Glass or polycarbonate lens? What coatings? There are numerous
manufacturers and types of coatings for both glass and polycarbonate
lens, and non-coated glass lens are also still readilly available.

I'd have 2 pairs of glasses - uncoated glass work glasses and coated
glass or polycarbonate glasses for other use.

[pyotr filipivich]

Post by Ed Huntress
On Wed, 24 Dec 2014 08:45:17 -0800, pyotr filipivich

Post by pyotr filipivich
Greetings and salutations
I am currently employed as a "injection press operator". This means
that some times I spend a shift inserting bolts into a mold so that
the plastic part has them imbedded. Every 75 to 83 seconds I lean
into the machine and insert six bolts. Weeeee. (It beats working.)
However, I have discovered a small, but very annoying problem. Heat.
Injection molds tend to be rather warm (170 degrees F and up) and
after eight hours of doing this, the protective coating on my (new)
lenses "wrinkles". The effect is ... well my glasses never get clean.
There is always this "smudge".
This had not happen with the old pair, just the new pair. I took them
back to the eyeglass place, and the technician observed that my lenses
were a tad small, so they are going back to be replaced. That is the
good news. The bad news is - they will still 'fry' when exposed to
radiant heat. Not just hot molds. This is apparently a hazard of
fireplaces, ovens, and other radiant heat sources. Yippie. One
would think that forty years of material science development, yadya,
yada ... we would have a better option than glass for lenses for those
who work around hot stuff. But, apparently we don't.
Unless, someone has a "better idea". Would safety goggles worn over
the glasses protect them? The clear (or colored) plastic overshields
which we wear to keep 'stuff' out of our eyes. Does anyone know?
Are there coatings which do not melt when you open and stare into an
oven?
tschus
pyotr
p.s. The reason that the old pair didn't have the problem is that the
coatings have pretty much worn off.
--
pyotr filipivich.
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."

Glass or polycarbonate lens?

PC and the new High Refractions Index lenses.

Post by Ed Huntress
What coatings? There are numerous
manufacturers and types of coatings for both glass and polycarbonate
lens, and non-coated glass lens are also still readilly available.

And which ones are the most stable when exposed to radiant heat?
The sort which comes off hot molds, out of ovens or fireplaces?

Post by Ed Huntress
I'd have 2 pairs of glasses - uncoated glass work glasses and coated
glass or polycarbonate glasses for other use.

That it what it appears I am going to be doing.

And looking for a job where it is not a problem.
--
pyotr filipivich
"With Age comes Wisdom. Although more often, Age travels alone."