Thursday, July 24, 2014

Block-less Edging | What & Why ?

Since a long time, optical labs are using adhesive block pads for holding the lens into the blocks for finished lens edging. There are various quality block pads are available in the market. Some of them are more adhesive some are less. Some are very difficult to remove from the lens after the edging, some are very easy but may rotate inside the edger which leads to wrong shape cutting or axis turn. Its always a headache for the technicians to stick with a same quality of block-pad for all the lenses types.

Main disadvantages of finished block pads:

  • Superior top coated lenses can be slipped inside the machine
  • Axis turn
  • Wrong shape due to internal slippage
  • Required manpower to block and unblock the lenses.
  • Excellent adhesion can lead to coating defect or crazing.


  • By increasing the clamp pressure to avoid slippage also can lead to coating defect. 
  • Need to use additional protective pads for super hydrophobic lenses.
  • Unnecessary rejections
  • Higher cost depends on the pad's quality.
All the above mentioned problems will be eliminated by using the block less system. A block-less all-in-one finishing system is the sole economic solution for a lab because it eliminates expensive shortcomings 
of traditional edging technology. It operates with no blocks, no decentration device and no manual handling. Usually its working with vacuum system. Weco Edge 990, MEI TBA system for MEI641 and Bisphera, Schneider HSC Modulo are some of the edgers supports block-less edging.

Main Advantages
  • No labor costs
  • No job preparation
  • No stickers
  • No blockpads
  • No blocks
  • Simplified finishing process
  • No investment for separate blocking device
  • Savings in rejects
  • No time waste on putting pads on blocks and removing them
  • No more crazing defects caused by de-blocking the lens and slipping on the block
  • No more mis-loaded lenses due to lenses moving in the job tray from conveyor vibration, loader misalignment, decentered lenses.
WECO Edge 990 Blockless Robotic Patternless Edging System

TBA Unit x Bisphera-XDD "Blockless" (cutting without blocks) Lens Edger

follow the ink to Schneider HSC Modulo on web [link]

Reference: MEI System, Weco, schneider-om, Wikipedia.