| TIPS NO: 214 |
| Revision: |
| Date: June 2001 |
1.6 EvoClear™
High Index
Lens Product Specifications.
Purpose: The purpose of this document is to provide technical and processing information on Signet Armorlite's 1.6 EvoClear high index single vision lens.
Single Vision Characteristics & Dimensions
|
Characteristics |
1.6 EvoClear High Index Lens |
|
Refractive Index |
1.594 |
|
Dispersion Value (Abbe) |
32 |
|
Density |
1.34 |
|
Visible Light |
89% |
|
UVA/UVB Protection |
Over 99% |
|
Coating Rainbow |
Virtually None |
|
Rear Surface Coating |
Recommended |
|
UV Transmission Cutoff |
398 nm |
|
Chemical Resistance |
Excellent |
|
Machinability |
Excellent |
|
RLXPlusâ Scratch Resistance |
120 psi |
Blank Size: 75mm diameter
Base Curves: 0.50, 2.00, 4.25, 6.25, 8.75
Power range: -14.00 to +6.00
|
Nominal Base Curve |
Actual Base Curve |
Radius |
Sphere Sag at 50mm |
Concave Curve |
Thickness at 90† and Geometric Center |
|
|
0.50 |
0.40 |
1325.000 |
0.24 |
3.00 |
16.1 |
12.8 |
|
2.00 |
2.17 |
244.240 |
1.28 |
6.00 |
14.3 |
9.2 |
|
4.25 |
4.32 |
122.685 |
2.57 |
6.00 |
10.2 |
7.6 |
|
6.25 |
6.24 |
84.936 |
3.76 |
6.00 |
8.3 |
8.4 |
|
8.75 |
8.77 |
60.433 |
5.41 |
6.00 |
6.7 |
11.1 |
GENERAL: Processes used for surfacing CR-39® lenses can be applied to the 1.6 EvoClear Lens. Please note that the 1.6 EvoClear Lenses have a high refractive index of 1.594. We recommend a minimum center thickness at 1.5 mm.
Special Requirements: The 1.6 EvoClear Lens processes much like our 1.56 high index and CR-39 lenses with two exceptions: The stock removal during the fining can be up to 0.8mm, and 1.6 EvoClear Lenses can be polished in 1 minute. See the following tables for our test results. You can adjust your surfacing computer to compensate for the stock removal and take advantage of much shorter fining and polishing cycles.
|
ONE-STEP Fining Pads |
Millimeter Take-off @ 20 sec. intervals |
|||
|
Pad Brand & Type |
20 |
40 |
60 |
80 |
|
PSI P-1000 |
0.17 |
0.32 |
0.45 |
0.56 |
|
DAC Fire (Fine red vinyl) & SALEM 933 |
0.15 |
0.25 |
0.37 |
0.46 |
|
SALEM Wizard 825 |
0.25 |
0.46 |
0.66 |
0.85 |
|
TWO-STEP Fining Pads (DAC) |
||||
|
Pad Brand & Type |
20 |
40 |
60 |
80 |
|
1st Fine: 600 GRIT |
0.18 |
0.30 |
0.42 |
0.52 |
|
2nd Fine: 9 MICRON BLUE |
0.02 |
0.05 |
0.08 |
0.11 |
|
1st Fine: SALEM 983 |
0.17 |
0.33 |
0.49 |
0.64 |
|
2nd Fine: SALEM 1128 |
0.06 |
0.09 |
0.12 |
0.13 |
|
POLISHING TIME ( 1 minute) |
Allow 0.1mm Take-Off |
Computer Calculation of Rx: The easiest, most efficient method to calculate and process values for an Rx is to use an existing computer software package that contains our design data. If your software company has not included our data in its package, our Technical Services group will be happy to provide the necessary specifications. Please forward us the contact name and phone number of your software vendor. If you need a software system for processing lenses, Signet Armorlite has developed a computer program to calculate surfacing data. This program is available through Signet Armorlite's Technical Services Department.
Abrasion Resistant Coatings: The front surface has the superior protection of the RLXPlusÒ non-tintable coating. Signet Armorlite recommends using either a tintable or non-tintable backside coating after surfacing. Verify that the impact resistance is maintained, particularly when using a non-tintable coating.
Impact Resistance: Our test results indicate that lenses backside coated with UVX by Ultra Optics, UVNVS by Ultra Optics, or HT1000 by Gerber Coburn exceed the FDA impact-resistance requirements and are 100% compatible with the 1.6 EvoClear Lens. Contact our Technical Service Department if you are using a different coating.
AR Coating: Since impact strength is reduced when a lens is AR coated, confirm the compatibility of combining the AR coating with backside coating. This should include in-house impact testing for lenses coated in your lab. Signet Armorlite does not recommend AR coating the 1.6 EvoClear Lens without using a scratch-resistant backside coating. Our test results showed that all of the lenses processed with commonly used tintable backside scratch-resistant coatings exceeded the FDA impact-resistance requirements when AR coated. Please call Technical Services for additional information about coatings.
Tinting: When a tintable backside coating is used, tint performance and compatibility with specific neutralizers are coating dependent. We recommend against tinting prior to using a non-tintable coating. Coating applications can change the color or density of tinted surfaces. Take special care when loading the 1.6 EvoClear Lens into the tinting holder. The combination of edge pressure and high temperatures will cause warpage. Position the clamp with virtually no pressure, but restricted enough to secure the lens. If the lens does warp during the tinting process, bake the lens on a flat tray in a oven at 175-200ƒF for approximately 20 minutes or until the lens is heated all the way through. Reference the following tables for approximate tint absorption rate results.
TINT ABSORPTION RATES
| Lenses without backside coating | Lenses with UVNVS backside coating | |||||||||
|
Time: |
5 Min. |
10 Min. |
20 min. |
30 Min. |
Time: |
5 Min. |
10 Min. |
20 min. |
||
|
% Trans: |
45 |
35 |
25 |
17 |
% Trans: |
30 |
25 |
18 |
||
Neutralizing: Our test results show the 1.6 EvoClear Lens can be damaged when using tint neutralizers designed for CR-39. Use a neutralizer designed for polycarbonate or higher index materials.
Thermal Stability: 1.6 EvoClear Lens material has a similar level of heat sensitivity as other 1.6 high index materials. The lens will flex if heated under pressure. To prevent warpage, avoid heating the lens over 130° F while under pressure. Warpage can cause a plastic lens to become loose in the frame. If the lens should become warped beyond tolerance, place the lens on a flat tray in a oven at 175-200ƒF for approximately 15-20 minutes or until the lens is heated all the way through.
If you need additional information, please contact Technical Services at 1-800-759-0075.
| 1.60 EvoClear Spherical 1.592 material index Base Curve Selection Chart |
|||||||||||
| SPHERE POWER |
CYLINDER POWER | ||||||||||
| 0.00 | -0.50 | -1.00 | -1.50 | -2.00 | -2.50 | -3.00 | -3.50 | -4.00 | -4.50 | -5.00 | |
| -10.25^ | |||||||||||
| -10.00 | |||||||||||
| -9.75 | |||||||||||
| -9.50 | 0.50 base |
||||||||||
| -9.25 | |||||||||||
| -9.00 | |||||||||||
| -8.75 | |||||||||||
| -8.50 | |||||||||||
| -8.25 | |||||||||||
| -8.00 | |||||||||||
| -7.75 | |||||||||||
| -7.50 | |||||||||||
| -7.25 | |||||||||||
| -7.00 | 2.00 base |
||||||||||
| -6.75 | |||||||||||
| -6.50 | |||||||||||
| -6.25 | |||||||||||
| -6.00 | |||||||||||
| -5.75 | |||||||||||
| -5.50 | |||||||||||
| -5.25 | |||||||||||
| -5.00 | |||||||||||
| -4.75 | |||||||||||
| -4.50 | |||||||||||
| -4.25 | |||||||||||
| -4.00 | |||||||||||
| -3.75 | |||||||||||
| -3.50 | |||||||||||
| -3.25 | |||||||||||
| -3.00 | 4.25 base |
||||||||||
| -2.75 | |||||||||||
| -2.50 | |||||||||||
| -2.25 | |||||||||||
| -2.00 | |||||||||||
| -1.75 | |||||||||||
| -1.50 | |||||||||||
| -1.25 | |||||||||||
| -1.00 | |||||||||||
| -0.75 | |||||||||||
| -0.50 | |||||||||||
| -0.25 | |||||||||||
| 0.00 | |||||||||||
| 0.25 | |||||||||||
| 0.50 | |||||||||||
| 0.75 | |||||||||||
| 1.00 | 6.25 base |
||||||||||
| 1.25 | |||||||||||
| 1.50 | |||||||||||
| 1.75 | |||||||||||
| 2.00 | |||||||||||
| 2.25 | |||||||||||
| 2.50 | |||||||||||
| 2.75 | |||||||||||
| 3.00 | |||||||||||
| 3.25 | |||||||||||
| 3.50 | |||||||||||
| 3.75 | 8.75 base |
||||||||||
| 4.00V | |||||||||||