ANTI-SCRATCH (hard-coated) LENS
GENERAL
- Lenses are coated with a silicone based permanent hard coating
- Coatings will not wash off
- Coatings protect against most chemicals and solvents
- Coatings provide a high gloss finish
- Coated lenses are easily cleaned and sanitized
- Coated lenses are not affected by metalization (mirror lens)
PRIMARY PROPERTIES
- Permanent coatings show no loss of anti-scratch properties for a minimum of 2 years
- Anti-scratch coating DOES NOT affect the optical characteristics of the lens
- Anti-scratch coating provides abrasion resistance to pencil hardness of 8H
- Anti scratch coatings are completely UNAFFECTED by the following chemicals or solvents-
Low and high molecular weight alcohol
Glycol ethers
Aliphatic and aromatic solvents
Weal alkali/alkaline earth solutions
Mineral acids and EXCEPTION of hydrofluoric acid
CLEANING AND DISINFECTING METHODS
- Wipe clear with a dry clean soft cloth
- Clean with soap (mild detergent) and water
- Pad dry with clean lint free cloth
- Disinfect with the following methods: (does not affect coating)
- General disinfectant
- UV light germicide chamber
- Placed at 100 degree C for 1 hour
PRODUCT MATERIALS: POLYCARBONATE
GENERAL
- Crystal clear and colorless, amorphous engineering thermoplastic notable for its high impact resistance
- PC was originally developed for aerospace industry for use in windows for airliners, space shuttles and face shields for astronaut helmets.
- PC is a very soft material allowing it to absorb energy from an impact and not crack or break. The drawback to this feature is it's tendency to craze or scratch easily. Therefore most lenses are treated with an anti-scratch coating.
- PC is exceptionally light weight due to it's low 1.2 specific gravity
- PC, although seldom used for frame material, is more impact resistant than nylon
PRIMARY PROPERTIES
| Light transmission |
88.0 % |
astm d 1003 |
| Haze |
1.0 |
astm d 1003 |
| Refractive index |
1.586 |
astm d 542 |
- UV stabilized, won't dry out and become brittle after exposure to sunlight
- Filters out 99.9% of all harmful UV radiation
- Ability to add UV400 absorber to give extra UV protection (for environments with high levels of UV radiation)
CHEMICAL RESISTANCE
Acids-concentrated - FAIR
Acids-dilute - GOOD
Alcohols - GOOD
Alkalis - POOR
Aromatic hydrocarbons - POOR
Greases and Oils - GOOD
Halogens - POOR
Ketones - POOR
*Please note that chemical resistance is greatly increased when coated with an anti-scratch coating
PRODUCT MATERIALS: NYLON
GENERAL
- Nylons are generally strong, tough, and resilient polymers
- Nylons offer good barrier and high fatigue properties
- Nylons offer good abrasion resistance
- Nylons offer good resistance to oils, greases and solvents
- Most common nylons used in spectacle frames is Nylon 6,6
PRIMARY PROPERTIES
- Excellent impact resistance, good thermal stability
- High abrasion and weathering resistance
- Excellent flow properties
- Good dielectric properties
- Good resistance to a wide range of chemicals
- Hypo-allergenic
A characteristic of nylon is that it has a tendency to absorb moisture. This is a characteristic that gives nylon its toughness. Upon initial injection (at manufacture) nylon frames are very hard and brittle. They are then left to cure so that they will absorb moisture from the air and soften. Once cured, they become very impact resistant. The curing or softening period takes 2-3 weeks.
CHEMICAL RESISTANCE
Acids-concentrated - POOR
Acids-dilute - POOR
Alcohols - GOOD
Alkalis - GOOD
Aromatic Hydrocarbons - GOOD
Greases and Oils - GOOD
Halogens - POOR
Ketones - GOOD
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