Traditional ophthalmic lens surfacing has for a long time relied on the use of alloy for the blocking process. While alloy has its benefits (thermo stability, compatibility with AR coats and the ability to block prism), its use in blocking comes at an environmental cost.
Lead, cadmium and indium are all toxic elements within alloy and bring challenges of water cleaning and filtering, alloy disposal and staff wellbeing. Alternatives to alloy blocking have been tried – a wax coating was developed in the 1980s but it contaminated other parts of the production process and couldn’t match of the torque of modern machinery.
The installation of a new ARTline cuts out alloy from within Essilor’s Thornbury facility, but it has been a complex and painstaking task, says head of manufacturing & logistics, Andy Duddridge. Every single piece of surfacing equipment in the lab had to be taken offline, recalibrated and then put back together.
The new ARTline process with Alloy Replacement Technology uses a universal, re-usable acrylic block-piece and an organic UV-curable adhesive to fix and protect ophthalmic lenses while generating and polishing. This replaces alloy and tape, both of which have been fully removed from the process. The use of organic glue makes it safer for staff to handle and better for the environment. It also eliminates the pollution of drain water by hazardous substances. Adhesion on the lens blank is also improved, says Duddridge.
Essilor is aware of its moral, legal and financial obligation to reduce the impact it has on the environment and the overall intention is to be one of the most environmentally conscious businesses in the UK.
It identified three priority areas which focus on reducing energy and water, reducing carbon footprint and limiting waste generation and optimising recycling. These are linked to key performance indicators that are followed and reported on monthly to the central team at Essilor’s Paris headquarters.
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Reductions in energy and water usage have been found in a number of areas, including the installation of wastewater filtration systems and equipment modification – an incredibly important aspect given that a generator can produce 15 litres of wastewater to produce a single lens. The company says it has reduced water usage in lens manufacture by 25% year on year for the past three years.
Energy use improvements have been found by exchanging all lighting to LED efficient systems and electrical energy is totally supplied from renewable sources. The breakdown is: 46% wind generation, 31% photovoltaic, 16% biomass & landfill gas generation and 7% hydropower.
Efforts to reduce the company’s carbon footprint have ramped up over the past decade. As a company with a nationwide network of staff, fleet vehicle CO² emissions was a area in which substantial improvements could be made. The company’s vehicles now emit on average 101 g/km CO² and over the past 10 years overall carbon footprint and has been reduced by 45%.
The target for 2020 is to get that figure down to 86 g/km CO², achieved through the adoption of more electric vehicles.
Implementing a ‘zero landfill’ policy at its UK sites has been another demonstrable measure to lessen the company’s impact on the environment. Wherever possible, single-use plastic will be removed from all packaging by the end of the year. Cardboard boxes used to send products to customers contain 75% recycled material and can be recycled themselves.
Waste lens material is removed from the site by an external partner and is used in the production of concrete, and a separate partnership enables the company to donate furniture, equipment and other materials to charities, schools, NHS trusts and not-for-profit organisations.
