Spin cast technology

1. Semi-automatic spinasting machine

Spin-casting technology was developed by Professor Otto Wichterle in 1980. The technology is based on dosing a small amount of the liquid monomer into a plastic curved mold shaped like a contact lens while spinning. The centrifugal force spreads the liquid monomer over the surface of the mold. During this process the monomer in the mold is also polymerised which is the chemical process of changing a liquid monomer into a solid plastic. The polymerization process fixes the shape of the rotating liquid and thus a lens is produced. The various shapes or back surface curve and powers of the lens are controlled by the mold shape and rotation speed.

One of the major advantages of the spin-casting technology over cast- molding is that only one mold per lens is needed, where two molds are needed to produce one lens when cast molding. A unique feature of a spuncast lens is that only one surface ever comes into contact with the mold meaning the production of the back surface of the lens the side which sits over the cornea is made without the touch of any tool or mold creating an almost ideally smooth surface of the lens. (Fig.1). Which is evident when comparing it with cast-molded (Fig. 2) and the surface of a lathe-cut lens (Fig.3). *By ECLSO Congress 2005, reprint permitted by the author.

Fig1 Photo SpinCasting Surface finish

Fig2 Cast Molding surface finish

Fig.3 . Lathe cut surface finish

New Developments in Spin Cast Technology

Since the very beginning, we at Wilens s.r.o. have been continously improving our Spin-casting technology using our years of technically developed know-how of the process.

2. Uni-spin fully automatic machine

The latest development in our production process is the Uni-Spin procedure. This new generation spin-casting process has vastly improved the lower productivity of older spin-casting technology by introducing new cast molded designs for the spin cast molds. All lenses are made at one rotation speed and the lens powers are controlled by the mold curvature, which ensures a guaranteed constant back radius which in the past was the weakest point of spuncast made lenses.

3. Robotized injection-molding of contact lens casting molds

The production line is fully automatic and equiped with the latest in computer controlling and monitoring devices. The end result has been that, the Uni-Spin process is a highly productive and flexible cost-effective method for mass production. It is especially suitable for the manufacture of all disposable lenses including our range Daily, Monthly and Coloured disposable contact lenses that offer outstanding quality, precise optical parameters with exceptional comfort.                          

Supplied machinery

Blister packing machine  - fully automatic with annual productivity about 30 million pcs. Very effective, efficient and compact. Click HERE to see the video.

Delivered to Singapore.