Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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What material to protect clear plastic from abrasion/wear?
Q. Looking for a coating material to protect clear plastic from abrasion. Same material used to protect eyewear could work. This material is called what, siloxane? Anyone hear of this material? If not, please what is the material used to coat eyewear (plastic lenses) from abrasion? Looking for a company to sell the materials for in-house use on my products.
Thanks,
John Grassi- Cleveland Ohio
1999
A. A UV curable hard coat would work for your application. They are used to coat lens and are typically urethane based. They can be formulated to give a excellent abrasion resistance, aging and adhesion for most plastics.
Paul SnowwhiteMilwaukee, Wisconsin
2000
A. You are referring to polysiloxanes, which are very tough abrasion resistant materials with outstanding weathering resistance. I am sure there are many resin/polymer suppliers in the US who could help you.
Graeme Hill- United Kingdom
2000
A. UV Curable Lacquer would be an excellent choice. Resin type depends on type of plastic coated.
Regards,
Les Trinity- Middlesex, New Jersey
2000
A. JOHN, YOU MAY USE HARDCOATING. IN SOME CASES YOU NEED A PRIMER AND THEN A HARDCOAT. I wish you success.
Jan rijn- GOES, HOLLAND
2000
Multiple threads merged: please forgive chronology errors :-)
Hard coating on polycarbonate
RFQ: I am looking for a company that will hardcoat polycarbonate that will result in an optically clear finish. The application is for a window that is 2.125 x 2.125. There is great importance on the optical clarity of this part because their is an automatic focus camera that looks through this window and if there are imperfections/blemishes, it will focus on that instead of an object. There is also a small rubber wiper that wipes across this window.
Guy V [last name deleted for privacy by Editor]- Clovis, California
2003
Ed. note: Sorry, this RFQ is old & outdated, so contact info is no longer available. However, if you feel that something technical should be said in reply, please post it; no public commercial suggestions please ( huh? why?)
A. Hello, Guy.
I believe that today's automobile headlamps are often polycarbonate with an IR or UV cured hardcoat. Perhaps Radtech.org would have some info on this application and some members who offer the service.
Some companies claiming to offer this type of coating are GE Silicones, Nippon Dacro Shamrock, MetroLine Surfaces, and IC Net A/S. This forum is for camaraderie and public technical discussions, but our supporting advertisers will contact you privately re. commercial sourcing, and Google can probably find additional sources. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. I was known as the Hard Coating Guru back in the early 90's When the big 3 (GM, Chrysler, Ford) started building headlamps from P-Carb. At that time Red-Spot Paint and Varnish and Sherwin Williams led the way with Automotive Finishing Hard Coats.
Of course there are many Paint Companies doing it now. I am currently working for a CD/DVD refinisher and we plan on resurfacing them with Hard Coating.
It is a UV process and fighting surface contaminants is the biggest issue in this industry. Clean room environments and Positive Airflow paint booths with robotic positioning paint guns are among the hardware used for this Application.
As far as job shops that do onesie-twosies I am unaware of any, but good luck with your search.
- Mesa, Arizona
December 14, 2011
Multiple threads merged: please forgive chronology errors :-)
Clear scratch resistant plastic/glass please
Q. I have a material I wish to use on knife handles but it is too soft and gouges easily. What I want to try doing is having a layer of clear material overtop of the soft material to protect it. Something halfway between the properties of a acrylic and a common glass would be great. I need it clear, fairly easy to machine, and as scratch resistant as possible.. if common glass didn't chip around holes and fracture so easy I would use it. any ideas? I'm looking into polycarbonate right now anyone know what the scratch resistant coating they coat eyeglass lenses is? I can use it in sheet form or liquid form as long as it is liquid below 250degrees.
Jason Aubesmall machining/art - Flint, Michigan
2004
A. Hi Jason,
Have you looked to see if casting grade acrylics would work?
James Watts- Navarre, Florida
2004
A. By now I assume you have found an answer. It may be "scratch resistant" polycarbonate. If you have found an answer and it is not this, we are interested. Please advise.
Bruce Larson- Greendale, Wisconsin
2005
A. Rigid PVC films that are scratch resistant might be what you are looking for.
Matt
- sussex, New Jersey
2007
Prescribed usage of clear coat versus hard coat for plastics
Q. I am writing to inquire if anyone can answer the question of usage of clear coats for scratch resistances. I have heard that in most cases it only protects slightly. If you are looking for pure protection you must use a hard coat.
Roland NewmanFinished assembly buyer - Greenwood, Indiana, USA
2004
A. Clear coats can be very hard or soft. The scratch resistance of a coating is usually measured by ASTM D3363. This is a set of 14 pencils of known hardness from 6B (softest) to 6H (hardest). Start with the hardest and work your way down. See which one does not scratch the surface of your coating. That is your scratch resistance or "pencil hardness". A common #2 writing pencil is a hardness of about "H". When you specify a coating from your supplier, you can tell them you want a 3H hardness or an H hardness or whatever you think is appropriate for your product. The clear coat on a cell phone, for example, must be at least an "H" hardness. There are clear coatings that are as high as "9H", especially the UV curable coatings. Grab a copy of ASTM 3363, and a set of the pencils. They will come in handy.
Oula NahasTechnical Assistance - Rochester, New York, US
2004
Q. Dear sir,
Please advise me how thin layer of glass coating can be done for abrasion resistance purpose on poly carbonate sheet. The coating can be between 20 to 80 microns.
Thanks,
trade - Mumbai, India
2005
A. I think what you're trying to find is UV cured "hard coating" of polycarbonate. This is commonly applied on such things as automobile lighting.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
Coating for acrylic or polycarbonate retroreflectors
Q. WE WANT TO MANUFACTURE ROAD REFLECTORS GENERALLY KNOWN REFLECTIVE PAVEMENT MARKERS OR CATS EYE ROAD STUDS.IN THIS PRODUCT THERE ARE REFLECTIVE LENSES WHICH GIVES REFLECTION DURING THE NIGHT WHEN LIGHT FALLS ON IT AND THESE REFLECTORS ARE MADE OF ACRYLIC OR POLYCARBONATE BODY.
WOULD LIKE TO KNOW DOES IT REQUIRE ANY COATING ON THE BACK? WILL THE COATING LIKE A SILVER COLOUR COATING ENHANCE THE REFLECTIVITY OR IS THERE ANY METHOD WHICH CAN GIVE BRIGHT REFLECTIVITY WITHOUT COATING? NOTE THAT ANY REFLECTORS COULD BE MADE IN ACYLIC OR POLYCARBONATE.
ROAD SAFETY PRODUCTS - CHENNAI, TAMILNADU, INDIA
2005
A. Hello, Piyush.
You may need to involve an optics engineer in such plans, and I'm not one. But I've never seen coatings on the back of retroreflectors and I don't believe a coating is necessary or beneficial because the light is bounced back by a refraction process rather than reflection from a mirrored surface.
However, a coating on the front/top is much more probable -- not a reflective coating, but a transparent "hard coating", probably UV or radiation cured, similar to the coatings on plastic automobile headlights to minimize the wear and scuffing to maintain good retroreflection. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
Q. I'm looking for a moldable, clear, scratch resistant plexiglass to encase a fiberoptic screen on a car body that I'm in the process of designing. do you have any suggestions?
adam partinproduct designer - morgan city, Louisiana
May 5, 2009
Scratch resistant Clearcoat for mobile phone use
Q. Hi,
My business is currently looking for either a liquid plastic coating or clearcoat that can be applied onto high quality automotive paint finishes (either basecoat or clear) that can provide high scratch resistance. Its application will be on mobile phones which have been altered in colour.
Of all the finishes I have seen, nothing has provided scratch resistance that we are after, or even UV resistance. Our last option was from a German paint manufacturer who supplies BMW. Ideally a new coating will be found which is unavailable for public or widespread purchase.
Thanks
Technology coloring - Birmingham, West Midlands, United Kingdom
August 30, 2011
A. Hi, Michael.
If high quality automotive clearcoat isn't good enough, you might want to look into the UV or IR curable coatings that they use on automotive headlamp plastics. Steve Jobs famously made a last minute decision that iPhones had to be switched from plastic to glass.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
August 31, 2011
Q. Many thanks for the reply, after doing some research I found a few items that could be of interest, however I would like the valued opinion of yourself.
First of all I have found spray on sealants which would be applied after my generic clear coat. Are these any good?
Secondly I've found a PPG product called Ceramiclear, this however is a few years old and preferably I would like something cutting edge. I've read a little about self-healing clears, again, are these of any use to myself?
- Birmingham, UK
September 5, 2011
A. Hi Again Michael. Sorry, I have no real knowledge of that field, just the book knowledge that air-dry materials, depending as they do on evaporation, do not generate the hardness of coatings which chemically cure with UV or IR radiation providing the energy for the curing. I know from abstracts of RADTECH.org conferences that UV and IR are used for such abrasion-resistant coatings on auto headlamps and tail lights, and suggest that you pursue the subject with them as they are the educational society for your topic of interest. Best of luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Organic Finishing for hardening plastic parts
Q. To All,
I have a lens part molded most likely out of thermoset polycarbonate, I have been told that organic dip process is used most commonly to harden to exposed surface. One vendor suggests a polysiloxane material. I am interested in the thickness to specified of the coating and the testing method, probably tabor. I am trying to specify something that will have a "life" of 5 years of intermediate use in an abrasive environment.
My background is mechanical engineering not material science.
All help will be greatly appreciated.
Thanks,
product design engineer - Los Gatos, California
March 13, 2014
Lacquered polycarbonate parts are blushing after immersion in water
November 10, 2014Q. One of our client requirements is as below:
Poly carbonate (PC) PLASTIC item to be lacquered.
The only test method they are doing is putting the lacquered component into hot water (70 °C) for one hour,
expecting result that lacquered component should not be shade changed (we are finding blushing like fog on the components).
Is it possible through this process?
If yes, where and how to do it?
- Daman, ut, India
November 2014
A. Hi Veera. The blushing is most likely because the lacquer is absorbing water, forming an emulsion. There are probably more effective lacquers, but if you are required to use this particular lacquer, it's also possible that it is porous or pin-holed due to poor application methodology. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. Hi Veera,
If the problem is in coating methodology, plasma treatment of the components would help in improving the bonding between PC and lacquer.
Bangalore Plasmatek - Bangalore, Karnataka, India
November 11, 2015
Cost of UV-cured hard coating of automobile lenses
Q. Hello
I need to understand the *general* costs per part of UV cure hard-coating acrylic/polycarbonate molded parts for automotive lenses.
The full cost - UV line, consumables, energy, factory, labor.
Does anyone know of economic analyses of hard-coating which have been done?
Many thanks.
- Plattsburgh, New York, USA
November 10, 2015
Q. We are manufacturing Polycarbonate reflectors for Pavement Markers. We want to apply suitable hard scratch resistant coating on the reflective lenses of thickness 10 to 15 microns. The coating may be of polysiloxane coating.
We are looking for the suitable application equipment to apply this coating on reflectors in thousands in quantity per day maintaining the thickness without losing the retro reflective values of the reflectors.
Please suggest the equipments for this application.
road safety - Mumbai India
October 17, 2016
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Ed. note -- Readers: no brand names or sourcing please!
Scratch resistant coating for Poly Carbonate drinkware
Q. We are looking for someone who can guide us as to how to do "anti scratch coating" from out side on Poly carbonate drinkware like wine Glasses, Whisky glasses, etc.
I shall be too happy to give more information.
Product designer - MUMBAI, Maharashtra, India
March 20, 2017
A. "Anti scratch" does not seem to be a well defined term-it may mean different things to different people. However, one can use plasma polymerization techniques to deposit thin transparent hard coatings like silicon dioxide which may meet your expectations.
H.R. Prabhakara - ConsultantBangalore Plasmatek - Bangalore Karnataka India
March 21, 2017
Q. Dear Sir,
I want to make anticorrosive coating for mild steel from acrylic and styrene emulsion with water soluble method. I want to know which organo silane is suitable for this?
petroils industries - Ankleshwar Gujrat India
March 30, 2017
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