In this issue we will refer to the greatest enemy of the workshop, the damage.
The damage as we all know, apart from financial burden can cause multiple problems, and to cancel the order.
We will try to map out the causes of errors and damage, in particular to draw attention to specific work-lab procedures which often occur losses and mistakes. You also appropriate to mention special cases that minimize the possibility of error or damage.
The error and damage can occur at any stage of the execution of a prescription ordering, processing to cleaning and final inspection of the glass. They can happen by simple carelessness, momentum or lack of theoretical and technical knowledge and skills.
So we refer to all kinds of mistakes dividing them into two categories, those relating to the lenses and those on the skeletons.
ERRORS AND DAMAGE TO LENS
1. Order
1.1. Wrong lens diameter.
1.2. Wrong lens thickness. On nylor constructions the minimum thickness at the perimeter of the lens cutting point should be 1.5mm for classic nylor by line and 2,3mm for metal nylor requiring double groove. On griff construction also needs a minimum perimeter security around 2mm to not easily broken by the high refractive index glass fakos.Sta need a capable central thickness of at least 1mm, to be able to work safely lens.
1.3. Wrong curvature. Should the curvature of the lens be compatible with the frame. For example you may be mounted a negative aspherical lens of high refractive index with many diopters in a curved frame. Such errors are very common in sun-optical structures.
2. Edit.
2.1. Errors in the fakometrisi. The most common mistake when fakometrisi is the wrong sign of the roller or else the "90 degrees mistake" as is often said. Equally common mistake is the reverse marking lens (right & amp; left)
2.2. Errors in blocking lenses.
2.2.1 hitch or accidentally blocking lenses
2.2.2 Using inappropriate sticker. Depending on the coating of each lens will be a suitable adhesive for not "twist" the lens to be used.
2.3 Wheel
2.3.1 Errors size. Always cut the lenses according to the rule "the longer narrows the small not grow»
2.3.2 Error shoulder. The ridge must be compatible with such a curvature of the frame, otherwise the lens will not press properly and easily discarded.
2.3.3 Turn the lens. Particularly careful we must be with the negative lenses have large peripheral thickness and show a higher resistance during cutting. We always use good quality stickers and extra anti-slip adhesive suitable for the hydrophobic coatings.
2.3.4 Breaking crystal high refractive index in the middle. To avoid this classical damage, care cutting this lens be made with minimal force as our wheel program and avoid the flanges with a large curvature. Another trick is to cut our lens larger than the desired size without shoulder and then again cut to size with shoulder.
2.4 Installation
2.4.1 The most damage is mounting the splinter in the lens. As to the crystals, the most dangerous part is temporally the screw wherein either said larger size, or during the straightening of the arm, the metal presses the lens and the sliver is generated. Careful should be and the nasal portion where the lens may be broken if "squeeze" to the base of epiriniou.
2.4.2 The mounting of Nylor to avoid breakage, the first pass the line of the most acute angle of the lens and the direction from front to back.
2.4.3 The mounting of the griff frames is a great chapter in which we will refer extensively in the future.
2.4.4 The burning of coatings (krakelarisma). In any case you need to heat a skeleton must first remove the lenses. If this is not possible for any reason, a good trick is to wrap the lens with a damp paper towel to prevent the development of high temperature coatings.
2.4.5 The "screwdriver" Not to injure the lens, frame or even ourselves, we must always screw and work generally on a fixed part and not in the air.
ERRORS AND DAMAGES IN FRAME
1. AKATALLILOS SKELETON. Frequent error and source of many problems is inappropriate selection frame in relation to the prescription. First we examine the prescription carefully and investigate the options we have on lens type, curvature, refractive index, material etc. Particular attention should be give in the case of sunglasses that can have strange shoulders, excessive curvature or very large size .All this makes it impossible to mount lenses with diopters.
2. OLD FRAME. Particular attention should we pay if we have in our hands an old skeleton. The most commonly fatigue and corrosion points within a frame are epirinia and arms to the inflection point of akrovrachioniou. Old skeletons pastinous the heat always, even to the slightest adjustment.
3. DAMAGE TO THE ASSEMBLY. In the assembly of metal structures and when we want to straighten, take care to not touch the metal part of our tool with the skeleton because it will injure the color of the frame. For pastinous skeletons is important to know the behavior of our material to warm up. The optyl always want warm, and there are other materials at high temperatures "gather" If we do not know our material, preservatives proceed with gentle warming, controlling behavior.
CLEAN-FINAL INSPECTION Even in the last stage of implementation, lurking dangers. Particular attention we give the solutions used for cleaning lenses. The acetone is prohibited because it destroys the polycarbonate and almost all the colors of the frames, even the same paste backbone. Blue alcohol is milder, but also unsuitable for polycarbonate lenses and dangerous for plastic and shoddy skeletons as when in contact with them, literally mince them. In most cases the selection of solvents is isopropyl alcohol. Damage may cause the ultrasonic cleaning device, destroying the layers of lenses, particularly old. Careful we need to be and when cleaning the lens. We always use clean cloths, not stale to avoid scratches on the lenses.
Finally, it is obvious that every job requires the right tools, the necessary supplies, clean benches, time and concentration at all stages of the execution of the recipe.
