Is hard plastic or some form of plastic replacing glass in aircraft windshields? Any idea/companies/players in this field??
I have heard there is recent trend as plastics are light in weight and have properties comparable to that of glass.
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$\begingroup$ LP Aero Plastics has been making plastic windshields for a very long time. $\endgroup$– Dan PichelmanOct 5, 2017 at 13:21
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$\begingroup$ Somewhere here we have a question about the manufacture of fighter aircraft windshields, though my search-fu isn't up to snuff this morning. It might answer this question, though it might be military specific while this is more general. $\endgroup$– FreeManOct 5, 2017 at 14:40
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$\begingroup$ @FreeMan ..Thanks!!! I am covering all three commercial,civil and military aviation.. any leads? $\endgroup$– Tanmay SharmaOct 6, 2017 at 8:17
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$\begingroup$ It may have been more on the lines of "how are they made". I remember an answer had a link you a YouTube video showing them making an F16 canopy. $\endgroup$– FreeManOct 6, 2017 at 12:27
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$\begingroup$ Cee Bailey ceebaileys.com/Aircraft-Windshields-Aircraft-Windows.html is another aircraft window supplier. One of the pages mentions 0.25 cast acrylic. $\endgroup$– CrossRoadsOct 26, 2018 at 1:49
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2 Answers
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On light aircraft, acrylic windshields have been the norm. On higher speed aircraft, glass and laminates are used, particularly with heated windshields. The laminates may use polyvinyl butyral (PVB) is tough and ductile which enhances mechanical properties and impedes shattering of glass layers and the transmission of cracks from one layer to another.
Layered products may have various coatings which affect transmission of light and RF, reduce reflectivity, include elements for heating. While I do not know of an aircraft application, it is common in automotive for layers to include radio antennas.
Glass is an amorphous, non-crystalline material and acrylic plastics and glass have very different properties. Glass tends to shatter with sufficient impact. However, glass tends to have high resistance to temperatures that subsonic aircraft will normally encounter. Glass also retains good clarity properties over the operational domain of subsonic aircraft. Acrylic tends to be pretty shatter resistant, although I know a turkey vulture which proved otherwise (grin). Acrylic is more suspectable to abrasion and scratches, and therefore requires cleaning and maintenance considerations which glass does not.
It really depends upon the type of aircraft and the design criteria, which include the operations, temperature, heat requirements (ie hot windshield for de ice), weight considerations, EMI considerations (coatings, etc.) and so on.
Both materials have been in use for a long time.
So what kind of aircraft are you talking about?
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2$\begingroup$ The glass used in airliners is made of several layers, with polyvinyl butyral between them. $\endgroup$ Oct 5, 2017 at 13:58
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$\begingroup$ @PeterKämpf made an important point, generally glass is laminated to provide better shatter characteristics, and also to permit heated elements, EMI measures, etc. $\endgroup$– mongoOct 5, 2017 at 14:03
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$\begingroup$ I have no problem if you add this directly into your answer. Then I can delete my comment. $\endgroup$ Oct 5, 2017 at 17:01
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$\begingroup$ The focus is on Commercial,civil and military aviation. $\endgroup$ Oct 6, 2017 at 8:07
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1$\begingroup$ @yshavit, point taken. I will have to research, and if necessary reach out to my little brother who has a PhD in materials science. Then I modify my answer accordingly, because I dislike promulgating mistruths. $\endgroup$– mongoOct 2, 2019 at 15:44
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A little late but I see some points the answers above missed and feel the record needs set straight.
Fixed wing military aircraft typically use thick polycarbonate plies laminated with polyurethane inter layer with various EMI coatings.
Military rotorcraft will use much thinner plies of polycarbonate, acrylic or a combination of both with various EMI coatings and extremely scratch resistant outer coatings to protect against all the debris they churn up.
Most commercial and general aviation aircraft have a glass outerply for scratch resistance, heated de-ice/de-fog capability, and static drain laminated to a main ply with polyurethane inter layer. The main ply is typically 2 plies of acrylic laminated with a type of vinyl interlayer. Some aircraft have polycarbonate main plies but acrylic is the norm. Plastic windshields/side panels are much lighter than all-glass windshields but are more difficult to manufacture. For that reason, some commercial/general aviation aircraft today are still designed with all glass windows, but it is a dying trend.
Major players in this field are Sierracin/Sylmar Corp (subsidiary of PPG Industries), GKN, Llamas Plastics, and Texstars
