How do optical lens manufacturers make optical lenses? (4)
2, there are. Machine materials
optical lens manufacturers will have. Machine materials can be divided into two categories: thermosetting materials, which have the property of hardening after heating and will not deform when heated. Most of the lenses are based on this material, such as CR-39. Thermoplastic material, has the property of softening after heating, especially suitable for thermoplastic and injection molding, polycarbonate PC is this material.
(1) Thermosetting material common resin material: (CR-39) The scientific name of pending acrylic acid, or Dially Glycol Carbonates, is pending in the production of common resin lens. It was discovered in the 1940s by chemists at the Columbia Corporation and was material 39 in a series of polymers developed by the United States Air Force. Therefore, it was called CR-39 (Columbia Resin No. 39). The CR-39 was first used in the production of corrective lenses for the eye in 1955-1960. Ultralight, impact-resistant resin lenses. As a thermosetting material, the monomer of CR-39 is liquid, which can be polymerized and solidified by heating and adding catalyst. Polymerization is a chemical reaction in which several monomers of the same molecular structure form a new polymeric molecule of different lengths and properties. As an optical lens manufacturers, the CR-39 material properties of the parameters ten. Suitable: REFRACTIVE INDEX OF 1.5 (CLOSE TO ORDINARY GLASS LENS), DENSITY OF 1.32 (ALMOST HALF OF GLASS), ABBE NUMBER OF 58~59 (ONLY VERY LITTLE COLOR), IMPACT RESISTANCE, HIGH TRANSMITTANCE, CAN BE USED FOR DYEING AND COATING treatment. Its main disadvantage is that its wear resistance is not as good as glass, and it needs to be plated with anti-wear film. Resin lenses can be used to process the curvature of the surface of the lens by mode pressing, so it is very suitable for the production of aspheric lenses.
(2) Medium and high refractive index resin materials: the medium and high refractive index materials used by optical lens manufacturers are thermosetting resins, and their development is not. Often rapidly. Their refractive indices can be increased using any of the following techniques: changing the structure of the electrons in the original molecule, for example by introducing a benzene ring; The addition of heavy atoms such as halogens (chlorine, bromine, etc.) or sulfur to the original molecule. Compared with the traditional CR-39, the lenses made of medium and high index resin materials are lighter and thinner. Their specific gravity is roughly the same as that of CR-39 (between 1.20 and 1.40), but their dispersion is large (Abbe number 45), and their heat resistance is poor, whereas their resistance to violet is poor. Outside line is better, can also dye and carry on various systems of surface coating treatment. optical lens manufacturers use these materials to make lenses in much the same way as the CR-39. Now THE 1.67 resin material has been widely popular, and the 1.7 resin material has been sold on the market. Optometry professionals are constantly developing new materials and improving existing materials in order to obtain better properties of resin materials in the future.
