The PowerPoint presentation (PPT) provides a comprehensive and detailed explanation of various materials employed in the production of eyeglasses or spectacles. It likely covers an array of materials such as plastic, metal, acetate, and others, outlining their unique properties, advantages, and drawbacks in the context of manufacturing eyewear. This presentation aims to educate the audience about the materials used in the eyeglass industry, enabling them to make informed decisions when selecting frames for their eyewear needs or understanding the materials behind their glasses.

1. FRAME MATERIALS
Jithin Johney, Assistant professor of Optometry

2. Plastic Frame Materials
 The first classification of a frame is by the material used in its construction: either
plastic or metal.
 Several types of both are used to make frames.
 The first plastics used for spectacle did not perform well in cold weather because
of their brittleness.
 Later cellulose nitrate (zylonite) was widely used.
 Cellulose nitrate accepts a good polish, but is flammable if brought to a
sufficiently high temperature.
 Because of the danger posed, cellulose nitrate has been banned by the FDA and is
no longer used for spectacle frames.

3. Cellulose Acetate
 A material used extensively for spectacle frames is cellulose acetate.
 The basic cellulose material may be extracted from cotton or wood pulp and then
further processed.
 When derived from cotton, these fibers are called cotton linters.
 This cotton or wood material is treated with a mixture of anhydride and acetic acid
using sulfuric acid as a catalyst.
 Plasticizers and aging stabilizers are then added to this material.
 Cellulose acetate does become brittle with age

4.  Some allergies are attributed to wearing cellulose acetate frames, though this is
rare.
 More often skin problems are not so much allergic reactions to the material itself,
but to those things which can be absorbed by the material.
 Higher quality cellulose acetate frames are coated in order to seal the surface.
When left uncoated, cellulose acetate may absorb materials which might be
allergen producing.
 A good frame coating will contain a UV inhibitor.* This inhibitor in the coating
keeps frame color from fading.

5. Optyl
 Epoxy resin is used for spectacle frames and is known under the trade name of
Optyl.
 A liquid resin and a hardener are mixed together and drawn into the frame molds
using a vacuum process.
 The material is thermoelastic. This means that it will bend when heated and will
return to its original shape when reheated.
 Optyl is approximately 30% lighter than cellulose acetate.
 Because of its stability, Optyl is appropriate for those who might be allergic to
other types of frame materials.

6. Nylon and Nylon-Based Materials
Nylon.
 Nylon is a material of high flexibility.
 When used alone in spectacle frames, nylon will lose that flexibility unless
periodically soaked in water overnight.
 Otherwise, over time, it will become brittle. “Pure” nylon was previously used
extensively for sports eyewear.
 It has also been used for over-the-counter sunglasses.
 It is now being combined with other material for added strength and stability,
remaining a part of the array of frame materials in use.

7. Polyamide/Copolyamide.
 Polyamide is a nylon based material that is quite strong.
 Because it can be made thinner and is only 72% of the weight of cellulose acetate,
polyamide has a real weight advantage.
 Polyamide frames can be made opaque or translucent.
 Frames made from polyamide are resistant to chemicals and solvents, and are also
hypoallergenic.

8. Carbon Fiber
 Carbon fiber material is used to create a thin, strong frame.
 This material is made from strands of carbon fibers combined with nylon. It is not
adjustable and is consequently used mainly for frame fronts.
 The temples are generally made from another material.
 The principle advantage is the light weight that can be achieved.
 Carbon fiber is 60% the weight of cellulose acetate.
 Not only is the material light weight, but because of its strength, it can also be
made thinner.
 Since carbon is black, frame colors will be opaque and are limited.

9. Polycarbonate
 Polycarbonate is a material usually associated with lenses, but can be molded into
frames.
 Frames made from polycarbonate are primarily for sport or safety purposes.
 When made for nonprescription purposes, the lenses and frame are molded as one
unit.
 Frames (and lenses) made from polycarbonate are very impact resistant.
 They are better suited for the type of sports glasses that are held in place with
elastic straps or for shield types of glasses that may be used either alone or worn
over conventional glasses

10. Rubber
 Some sports eyewear and sunglass frames may be made from a combination of
nylon and rubber.
 As would be expected, these frames are flexible and will return to their original
shape, but are not adjustable

11. Metal Frame Materials
 In the past, gold-containing alloys were the more predominant metals used for
spectacle frames.
 Great progress has been made in metal frames because of the electrolytic
treatment techniques, which allow for corrosion resistance and finished beauty.
 It is also common for frames to be made with more than one material.
 The temples may be from one material for flexibility, the frame front from another,
and the connecting pieces something different still.

12. Aluminum
 Aluminum is both strong and extremely lightweight.
 It can be finished in a wide variety of colors and does not corrode.
 Aluminum does not solder or weld well, so must be made such that its parts are
assembled with screws or rivets.
 It holds the adjustment well, but has no flexibility.
 If it bends, it stays that way.

13. Stainless Steel
 It is made mainly from iron and chrome and is highly resistant to corrosion.
 Stainless steel is strong.
 When made very thin, it has an element of springiness and flexibility that makes it
well suited for temples.
 Adjustments are difficult and often do not hold.
 Stainless steel is one of the more nonallergenic materials.

14. Titanium
 Titanium is a versatile and abundant material that has become increasingly
common for use in ophthalmic frames.
 The advantages include the following:
1. Titanium is extremely light in weight. When compared with conventional metal
frame materials, titanium is 48% lighter.
2. Titanium is very strong, which allows titanium frames to be designed
exceedingly thin. Thinness also contributes to still more weight reduction.

15. 3. Titanium is very corrosion resistant. This makes titanium an excellent choice for
people in hot climates or those working in conditions where they would be
perspiring a great deal.
4. Titanium is hypoallergenic. It should be noted that titanium is often used in
combination with other metals.

16. Bronze
 Bronze is a metal alloy traditionally made from copper and tin.
 It is suited for spectacle frames because it is corrosion-resistant, lightweight, and
takes color well

17. THANKYOU