Polyurethane LP

POLYURETHANE is well-tried for polishing ophthalmics, precision optics, mirrors, flat glass and ceramics as well. This foam material has a micro structure consisting of millions of pores. A few of the below types are soaked with zirconium or cerium oxide, but polishing can not be done without using a zirconium or cerium slurry. For smooth polishing silicon carbide, natural and synthetic emery or Baton garnet as well as MICROGRIT slurry can be used. But please note that above-mentioned materials should only be used in combination with an unsoaked polyurethane pad.

Types available

Type Filler Density /ft³ Hardness acc. Durometer D
LP-13 Ceriumoxyd 19 - 22 lb. 16
LP-26 Zirkonoxyd 30 - 42 lb. 37
GR-35 Zirkonoxyd 34 - 42 lb. 37
LP-46 Zirkonoxyd 20 - 30 lb. 25
LP-57 ungefüllt 30 - 40 lb. 35
LP-66 Ceriumoxyd 22 - 32 lb. 25
LP-77 Ceriumoxyd 22 - 32 lb. 25
LP-87 ungefüllt 46 - 53 lb. 47
LP-88 Ceriumoxyd 65 - 75 lb. 65


When using polyurethane the polishing times are reduced considerably due to the excellent stableness at high temperatures, and, consequently, polishing can be made at high speed. Due to its long life-time, exceeding polishing pitches more than 10 times, it can be used for a period of two months or longer without replacement. Furthermore, it is resistant to external impacts, e.g. temperatures, moisture, a fact being of high advantage compared to the use of polishing pitches.

Polyurethane softens in water or at a temperature of ca. 121°C. For fixing the polyurethane pads we recommend our TIZON POLISHING PAD ADHESIVE. The use is easy: Spread the glue both at the bottom side of the pad and on the upper side of the tool carrier, and, after approx. 5 minutes, the polyurethane can be fixed. When bonding intensive curved material the tool carrier ought to be heated and the polyurethane ought to be notched before.

When using ordinary machines at a speed of 300 rpm the pressure on the lenses amounts to approx. 13 – 14 kp / cm2. By increasing the working speed up to 600 rpm but retaining the pressure of 13 – 14 kp / cm2 the polishing time is only reduced by 5%. In case of increasing the speed to 850 rpm and a slight increase of pressure up to 25 kp / cm2 the polishing time will be reduced considerably by approx. 50%. Consequently, best results will be achieved by working at higher speeds and higher pressure at the same time.

Dimensions and Thicknesses

Polyurethane is available at standard sizes 580 mm x 1400 mm as well as discs at the following diameters: 4”, 6”, 8”, 10”, 12”, 14”, 16”, 18”, 20” and 24”.

The standard thicknesses are:

Plain and PS: 0,51 mm, 0,81 mm,1,02 mm, 1,27 mm, 1,52 mm, 2,03 mm, 2,54 mm, 3,18 mm.

Plain: 3,81 mm, 3,96 mm, 4,06 mm, 4,75 mm, 6,35 mm, 9,53 mm, 12,7 mm, 25,4 mm (not all types available).