Manufacturing of methods of contact lens.pptx

Cast molding, Spin-casting and Lath-cutting are the original methods of CL manufacturing and methods other then these are the combination of these methods.
Molding and Spin-casting are mainly used for soft contact lens manufacturing and lath - cutting is widely used method for RGP CL manufacturing.

1. Manufacturing of contact lens Guided by- Dr. Aditya Tripathi Sir Presented by- Ishrat Jahan

2. content Molding Spin-casting Lathing Spin-cast and Lathing Cast-molding & Lathing Stabilized Soft molding

3. Molding Molding is the process of manufacturing by shaping liquid row material using rigid frame called mold into a desired shape. Molding becoming more of a main stream process. It is useful for the mass production of lenses but have limited parameter at low cost. Common lenses soft spherical, soft toric and multifocal lenses.

4. Molding

5. Molding Low coast per lens Rapid Volume production easy Good surface quality Complex deigns possible Expensive to start Expense limit parameters Not all materials are suitable Essential for stock lenses Advantage Disadantage

6. Spin-cast Bausch & Lomb Refined the original method of molding developed in 1963 and 1964 by Dr. Otto Wichterle . Centrifugal force causes the monomer to spread out toward the edges of mold. The Front surface shape is fixed by mould geometry The Back surface shape is fixed by the rate of spun and viscous Nature of monomer (both of these determine the power of CL). Limited spin-casting molds are required to achieve a complete power range.

7. Spin casting

8. Lathing This is the original method that is favored throughout the world as a method for manufacture of both specialist and durable contact lens . It is well understood and longstanding method of fabricating. Need to made device symmetrical about an axis of rotation.

9. Lathing

10. Conti….

11. lathing Simple technology Wide range of parameter Most, but not all materials can be lathed Minimal investment Difficult to lebur complex design High cost per lens Variable surface finishing Relatively slow Volume production is difficult. Advantage Disadvantage

12. Spin-cast & lathing Starts with liquid monomers Body & front surface spin-cast Back surface lathed to define BOZR & CL design

13. Cast molding- lathing Body & back surface is cast-molded Front surface is lathed to define FOZR/BVP & CL design

14. Stabilized Soft Molding Inert water subsitude is mixed with lens monomer before polymerization Water replace the substitute at hydration Significant less expension on hydration Better optical quality and surface finish

15. Stabilized soft molding

16. references IACLE module – 02 Contact lenses fifth edition- anthony J. Phillips & Lynne Speedwell. Videos - YouTube

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