Lens bond has been successfully used to bond materials other than optical glass. Listed below are some of these materials.
Aluminum, Copper, Stainless Steel, Quartz, Phenolics, Lithium Fluoride, Lexsan, Polystyrene, Gelatin Filters, KDP Crystals, ADP Crystals, Plexiglas, Nylon, Ceramics, Polarizing Sheet.
NOTE: When bonding elements to metal fixtures , stronger bonds are achieved when the metal surfaces are "roughed" with fine steel wool or emery paper.
Lens Bond has also been successful in bonding optics coated with:
Zinc Sulfide, Silicon Monoxide, Aluminum, Silver, Magnesium Fluoride, Titanium Oxide, Gold.
NOTE: The few materials we know of that Lens Bond will not bond are: PTFE, and PVC
1. Cured Lens Bond is a cross linked Vinyl Copolymer which accounts for its extreme resistance to solvents and temperature extremes.
Glass slides cemented with Lens Bond optical cements were immersed in the following solvents and solvent combinations without any ill effects:
*All tests were done at 20�C unless otherwise stated
2. Acid resistance of slides bonded with Lens Bond optical cement.
3. The thicker the layer of Lens Bond the more resistance it will show to thermal extremes. When applied in a thick layer, Lens Bond will act as a buffer when bonding elements with different coefficients of expansion.
Although our information is limited, we have found that Lens Bond Cements can be used in lasers, depending on the strength of the beam.
Laser Cement Film 25 watt continuous wave(CO2)................no effect 5 megawatt/cm2 pulsed 20 Nanosecond(6900A)..burned 109 watts/cm2 Subnanosecond pulse (1.06 micron mm YAG).....................no effect 15 watts/cm2 Continuous wave (YAG)..........no effect 6 watts/0.1mm Diameter beam (Argon, ion)....no effect
Diode Pump *150w CW-Diode Pump Module..................no effect *200w CW-Diode Pump Module..................no effect *2400w CW-Diode Pump Module.................no effect *5kw Peak 808 nm Diode Pump Module..........no effect Thanks to Laser Diode Array, Inc. for Laser Diode Information
Thermal Shock Test:
The object of this test is to determine the ability of a cemented component to withstand abrupt temperature changes between the limits of +40�C and -40�C. The upper temperature was achieved with a normal laboratory oven. The lower temperature was achieved with a cooling mixture of acetone/solid carbon dioxide.
The specimen was placed in a polyethylene bag on removal from the oven(before immersion) to eliminate any solvent reaction.
A doublet of 1/4" Pilkington Plate 1" square was used.
A specimen was subjected to three cycles, and examined after each. The cycles were as follows:
Lens Bond withstood the temperature cycling with no adverse effects.
Mechanical Shock Test:
The object of this test is to determine the ability of cemented components to withstand sudden shocks as may be experienced in weapons applications. The specimen was composed of cylinders of glass 1" high and 1 inch diameter bonded with Lens Bond onto flats of dimensions 1-1/4" x 1-1/4". The specimen was clamped to a trolley surface and subjected to a 1/2 sinewave pulse having peak acceleration of 100g for a duration of 1 microsecond. The specimen survived this test without discernable damage.
The object of this test was to ascertain the ability of cemented components to withstand vibrations as such that might be met in service conditions. The specimen was identical with that used for mechanical shock treating. It was clamped to a vibration rig and vibrated both in the plane of the cement layer and perpendicular to it. The peak acceleration was 10g over the range of 10-300 c/s and 8g from 300-500 c/s. The rate of sweep was approximately 7 c/m. No deterioration was found in the sample after testing. The specimen was checked for resonance. None was found.
In order to simulate heavier stresses on the cement layer, the specimen was again subjected to vibration over the range given above, after attaching a collar of 1 lb lead weighing around the cylindrical element of each flat. No damage was found in the specimen.
The object of this test was to ascertain the creep or relative movement of two components of a doublet over an extended period. One component of the specimen was clamped rigidly and a load of 1 lb applied to the other. Measurements were made at regular intervals. The plotted results are given below:
Creep Test Results
of Lens Bond Optical Cements (.0001" film thickness) Not including J-91
of Lens Bond Optical Cements J-91
Common Problems Encountered in Bonding Elements
1. The most common problem reported to us is failure of the cement to cure within the specified time. This problem is caused usually by one of the following problems:
2. Reticulation near outside edge of curing. If the chamfer has ample cement remaining in it after curing, reticulation is likely caused by microscopic air bubbles entrained while mixing the catalyst. There are 4 possible solutions:
3. Stress cracking seperation, lack of bond strength and curing. When a cylinder is cemented within a cylinder(for example a metallic or glass sleeve cemented around a lens) it is not unusual for the bond to break on curing. As Lens Bond cures it contracts slightly. This contraction causes an evenly distributed inward pull on the outer cylinder. The cylinder will not accommodate the contraction and the bond separates. To prevent this separation, one of the following steps can be taken:
Thin lenses and lenses with extremely short radii are susceptible to stress cracking, separation and distortion. This problem can be eliminated by using RD3-74.
4. Separation of lenses can occur because of the following factors:
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