TIPS NO

218

Revision

A

Date:

July 2002

 

KODAK ASP SV & FT 28 with Corning® SunSensors® (Gray)
Lens Product Specifications & Processing Information

Purpose: The following information will assist you in processing the KODAK SunSensors Single Vision and Flat-Top lenses.

SUMMARY OF TIPS VERSION CHANGES: This TIPS revision incorporates the stabilized SunSensors material which is identifiable by the letter "S" following the SunSensors name in technical files, a base curve change from 9.50 to 9.75, includes a cold weather use advisory, and drilling instructions.

 

Characteristics

KODAK with Corning SunSensors

Refractive Index

1.555

Dispersion Value (Abbe)

38

Density

1.168

Chemical Resistance

Excellent

Machinability

Excellent

Rear Surface Coating

Optional

RLXPlusâ Scratch Resistance

Non-Tintable Front Surface

 

Single Vision And Flat-Top 28
Blank Size:            74mm diameter
Base Curves:          0.50, 1.50, 2.50, 3.50, 4.50, 5.50, 6.50, 7.50, 8.50, 9.75
(the 2.50 base is not available in Flat-Top)

Power Range:      -13.00 to +9.50
Add Powers:           1.00 to 3.00 in 0.25 Diopter Steps
Flat-Top Inset:       2mm in, 4mm down

Thicknesses:         We recommend a minimum center thickness of 1.6mm, or 1.8mm if AR coated.
Nominal Curve True Curve Radius (mm) SAG at 50mm Nominal Concave Edge Thickness Center Thickness
0.50 0.58

3.00 13.7 10.8
1.50 1.44

3.00 11.9 10.3
2.50 2.34

3.00 10.1 9.6
3.50 3.64

6.00 10.1 6.9
4.50 4.61

6.00 10.1 8.1
5.50 5.6

6.00 10.3 9.1
6.50 6.58

6.00 8.3 8.6
7.50 7.58

6.00 8.4 10.0
8.50 8.66

6.00 6.5 9.8
9.75 9.65

6.00 6.3 11.3

General:
Processes used for surfacing CR-39® lenses can be applied to the SunSensors lenses. Please note that SunSensors lenses have a refractive index of 1.555.

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 SunSensors lens design data. If your software company has not included this 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 program 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, 800 759-0075.

Cribbing:
Cribbing during generating SunSensors lenses may increase breakage. Cribbing may create hairline fractures in the new edge of the lens which could cause this lens to break during post-generating processes. We recommend you evaluate your processes for this potential cause of breakage.

Fining and Polishing:
Processing the SunSensors lens material is similar to the CR-39 lens material with two exceptions: The stock removal during the fining can be greater, and SunSensors lenses can be polished in 2-4 minutes. See the following tables for our test results.

ONE-STEP Fining Pads

Millimeter Take-Off

Pad Brand & Type

20 sec

40 sec

60 sec

80 sec

PSI P-1000

0.25

0.47

0.69

0.87

DAC Fire (Fine red vinyl)

0.20

0.40

0.60

0.75

Salem 933

0.20

0.40

0.60

0.75

TWO-STEP Fining Pads (DAC Brand)

Pad Type

20 sec

40 sec

60 sec

80 sec

1st Fine: 600 GRIT

.26

.48

.69

.87

Salem 993

.30

.59

.86

.110

2nd Fine: 9 MICRON BLUE

.08

.12

.15

.17

Salem 1128

.13

.19

.23

.27

POLISHING TIME ( 2 - 4 minutes)

Allow 0.1mm Take-Off

Abrasion Resistance Coatings:
The front surface of the SunSensors lenses includes the superior protection of RLXPlus non-tintable coating. The uncoated rear surface of the lens provides adequate durability for normal use. Therefore, a backside coating is not required unless an AR coating is to be used.

Impact Resistance:
Multi-layer AR coatings can be applied to SunSensors lenses. Because lens impact resistance is reduced by AR coatings, we recommend a 1.8mm minimum center thickness and a backside coating that will enhance the impact resistance capability. Be sure that your AR coating is compatible with your backside coating. Include impact testing for lenses AR coated and sold by your lab. It may be necessary to increase the minimum center thickness in order to meet impact resistance requirements. We recommend a minimum center thickness at 1.6mm and 1.8mm if AR coated. Please call Technical Services at 800 759-0075 for additional information about coatings and impact resistance.

AR Coating:
Multi-layer AR coatings can be applied to SunSensors lenses. Because lens impact resistance is reduced by AR coatings, we recommend a 1.8mm minimum center thickness and a backside coating that will enhance the impact resistance capability. Be sure that your AR coating is compatible with your backside coating. Include impact testing for lenses AR coated and sold by your lab. It may be necessary to increase the minimum center thickness in order to meet impact resistance requirements. We recommend a minimum center thickness at 1.6mm and 1.8mm if AR coated. Please call Technical Services at 800 759-0075 for additional information about coatings and impact resistance.

CAUTION:
Dispensing Note: At cooler temperatures, 53 degrees F (12 degrees C) and below, photochromic plastic lenses may become very dark on bright sunny days and may be too dark for driving any type of open-air vehicle. At colder temperatures, particular caution should be used when going from sunny to shady areas.

Drilling:
SunSensors lenses can be successfully drilled and mounted into a three-piece rimless frame. However, we discourage the use of three-piece frames with other than polycarbonate plastic lenses as it may result in higher warranty returns. The pressure on a screw mount, when subjected to excessive bending force, is often sufficient to crack most plastic lenses. For the strongest drilled plastic lens, we recommend the following:

Use a bur-type bit (vs. a twist drill bit) and grind slowly through the material. Automated drilling machines should be set on the polycarbonate mode or the slowest feed rate. Chamfer the holes on the front and back of the lens with a cone-shaped tool. Use nylon top hat bushings in the holes for cushioning. Do not over-tighten the screws.

Tinting:
SunSensors lens material is tintable. We recommend against tinting since it reduces the reaction of the photochromic dyes and may result in too dark of a lens. Additionally, it is important to use caution when tinting, as SunSensors Lenses absorb tints much faster than most other plastic lens materials. If you decide to tint the lens, test a sample lens first. Note: Many tint neutralizer products will damage the lens. Call Technical Services at 800 759-0075 for additional tinting information.

Kodak is a trademark of Eastman Kodak Company, used under license by Signet Armorlite, Inc.
SunSensors and Corning are registered trademarks of Corning Incorporated, Corning, New York.
CR-39 is a registered trademark of PPG.
RLXPlus is a registered trademark of Signet Armorlite, Inc.

KODAK Single Vision and Flat Top in SunSensor
1.555 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
-8.00                      
-7.75   -7.75                  
-7.50   -7.50                  
-7.25     -7.25                
-7.00     -7.00                
-6.75                      
-6.50                      
-6.25                   -6.25  
-6.00         -6.00            
-5.75         1.50 BASE          
-5.50                     -5.50
-5.25           -5.25          
-5.00                      
-4.75             -4.75        
-4.50               -4.50      
-4.25                      
-4.00                      
-3.75                 -3.75    
-3.50                      
-3.25                   -3.25  
-3.00             2.50 BASE      
-2.75   -2.75                  
-2.50     -2.50               -2.50
-2.25     -2.25                
-2.00                      
-1.75       -1.75              
-1.50         -1.50            
-1.25         3.50 BASE          
-1.00                      
-0.75                      
-0.50           -0.50          
-0.25       -0.25              
0.00                      
0.25             0.25        
0.50                      
0.75     0.75                
1.00       4.50 BASE     1.00      
1.25           1.25          
1.50                      
1.75                 1.75    
2.00                   2.00  
2.25                      
2.50               2.50      
2.75                 2.75    
3.00             3.00        
3.25                   3.25  
3.50                      
3.75         5.50 BASE         3.75
4.00                      
4.25                      
4.50                      
4.75                      
5.00                      
5.25                      
5.50             6.50 BASE      
5.75                 5.75    
6.00                      
6.25                      
6.50                      
6.75         7.50 BASE          
7.00                      
7.25                      
7.50                      
7.75             7.75        
8.00     8.50 BASE              
8.25                      
8.50                      
8.75     9.75 BASE              
9.00