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Materials Test 4

Where did the term "zyl" come from? Zylonite (cellulose nitrate); a material that was commonly used in the past
What does "zyl" most commonly refer today? Cellulose acetate; but generally all plastic frames
Metal frames are all metal except for...? The nose pads and the posterior temples (plastic earpieces)
What are nylon cord frames also referred to as? String mounted frames and nylon supras
How is the lens held in place in a nylon cord frame? A nylon cord that fits around the edge of the lens; and the top of the lens is fitted into the upper rim of the frame
What is a combination frame? Specifically, a metal chassis with plastic top rims and temples; technically any frame using both metal and plastic
What is a chassis? The eyewire and bridge section
What is a half eye frame used for? made for those needing a reading correction and no distance correction; sit lower on the nose
What are rimless frames? Lenses held in place by some method other than nylon cords or eyewires; often nuts, bolts, and screws are used; also plastic posts, clamps, and cement
What are rimless mountings also referred to as? 3 piece mountings
What is a semirimless mounting? similar to rimless except for a metal reinforcing arm which follows the upper posterior surface of the lens and joins the centerpiece of the frame to the endpiece
What is a numont mounting? hold the lenses in place only at their nasal edge
What were the first two plastic materials used for frames, and why are they no longer used? bakelite and galaith; were too brittle when used in cold weather
What was used after bakelite and galaith for plastic frames? cellulose nitrate (zylonite)
Why is zylonite no longer used for plastic frames? highly flammable; FDA banned
What is cellulose acetate extracted from? cotton or wood pulp
After the cotton or wood material is extracted, how does it become plastic? treated with a mix of anhydride and acetic acide using sulfuric acid as a catalyst; plasticizers and aging stabilizers are added.
Even with stabilizers, cellulose acetate can become _______ with age. brittle
Cellulose is coated with a ___________ to seal the surface. UV inhibitor
What allows frame parts to be cut from cellulose acetate? It can be poured into sheets of plastic
What is propionate also known as? cellulose aceto-propionate
While it has many of the same characteristics as cellulose acetate, but works better with....? injection molding
Propionate has less ______________, unless coated will fade within a short period of time. color stability
Propionate weighs __% less than cellulose acetate? 25
Optyl is an __________. epoxy resin
Optyl is a _____________ material, which means the material will return to its original shape when reheated. thermoelastic
Cellulose acetate is a _____________ material and does not return to its original shape when reheated. thermoplastic
Optyl is __% lighter than cellulose acetate. 30
The thermoelastic property of optyl can make it....? difficult to adjust
Nylon is highly flexible, and must be soaked in _____ overnight or it will become brittle. water
Polyamide is __% lighter than cellulose acetate. 28
Polyamide is resistant to chemicals and solvents, and is also very...? hypoallergenic
Grilamid is a nylon-based material, what is it's primary use? sports eyewear
What makes grilamid superior to regular nylon? Has a wider variety of color possibilities.
Carbon fiber creates a ____, ______frame. thin, strong
Carbon fiber is __% lighter than cellulose acetate. 40
Carbon fiber is not very adjustable, there for it used primarily for...? frame fronts; not used for temples
Carbon fiber is black, and therefore.... is available in only a few select opaque colors
Polycarbonate is used primarily for what because of its impact resistance. Sports or safety frames
While polycarbonate is impact resistant it can also be...? difficult to adjust
Is it common for frames to be made from more than one type of metal? Yes
What is a strong and malleable material commonly used for frames? Nickel
What is one major disadvantage of nickel? Nearly 10% of the population has an allergic reaction to nickel
What are some advantages of pure nickel? resists corrosion; malleable and easily adjusted; accept color well and is very versatile
What is the makeup of nickel silvers? more than 50% copper; 25% nickel; and the rest zinc
Nickel silvers contain how much silver? NONE
What adds strength to nickel silvers? zinc
What is another name for nickel silver? German silver
Monel metal is an inexpensive, very popular frame material. What are some other properties of it? White in color; resist corrosion; easy to adjust; accepts high polish
What is monel metal mostly made from? Nickel; also made from copper, iron, and traces of other elements (silicium, carbon, sulfur)
What is a strong and extremely lightweight material that can be finished in a wide variety of colors and does not corrode? But also has no flexibility Aluminum
Aluminum does not ______ or ____ and must be made to be assembled with screws or rivets. Solder or weld
What is made mainly from iron and chrome and is highly resistant to corrosion? Stainless steel
Stainless steel is ideal for what because of its springy and flexible nature? temples
Stainless steal is what type of material, allergenic or non-allergenic? non-allergenic
Titanium is extremely lightweight, it is __% lighter than other metal materials. 48
What is the metal of choice for people with skin allergies? Titanium
When combined with other metals, titanium allows frames to become very....? flexible
What are some disadvantages of titanium? very hard to solder or weld; more expensive
Who established guidelines for frames containing titanium and who tests the frame? Vision Council of America; an independent/accredited lab
To be certified 100% titanium, all major components of the frame are at least __% titanium by weight and contain no ______? 90%; no nickel
Certified Beta Titanium, all major components of the frame are at least __% titanium by weight, and must contain no nickel. 70
What is a metal alloy from copper and tin? Bronze
While magnesium is even lighter in weight than titanium and exceptionally durable, it is highly....? corrosive; and therefore must be sealed
What materials are the most hypoallergenic? Optyl; Polyamide; Titanium; Stainless Steel
Created by: griffiskr