Typically yes in order to mitigate cross-contamination. While contact lens moulds are not technically classed as medical devices, any airborne contaminants, such as dust and particles from the raw materials, as well as human contaminants like bacteria, could affect the lens function.

It is critical that manufacturers specialising in making contact lens moulds can do it repeatedly and with the highest precision in order to mass-produce the moulds cost efficiently. Usually, there are between eight and 16 cavities in each moulding tool. To produce the lens moulds so fast without compromising on quality, Sumitomo (SHI) Demag installs its award-winning activeFlowBalance technology into the all-electric machines. This helps to combat the uneven filling of moulds by stopping the screw in the right place to allow the mould to fill naturally. This intervention reduces the cavity pressure and stress in the material. Once one cavity fills it moves on to another one.

In a relatively new development, bifocal lenses are now being manufactured on a larger scale to correct both near and far vision. With these lenses, the centre has a different magnification than the outer ring of the lens. In addition, some companies produce Toric lenses to correct astigmatism. These lenses are thicker or shaped at the bottom and sit on the tears on your eye, rotating into the right position within the eye. All of this places greater challenges on the machines to meet the specific needs of the customer. Breakthroughs are happening all the time. We have not quite reached the point where lenses are 3D printed according to someone’s eye, however, this might be possible in the future.

For the production of lens moulds, both all-electric and hydraulic injection moulding machines are used – with the bias heavily weighted (90%–10%) towards all-electric. Repeatability is the main rationale, as well as meeting ISO Class 8 clean room standards. Direct drive machines offer major improvements in efficiency, including a reduction of up to 75% in energy usage during operation and improved repeatability and cycle times. However, manufacturers of hydraulic IM machines have recently made big strides to standardise the process in order to accommodate the variations in moulds yet still meet the high quality requirements.

Automation plays an equally big role in maintaining cleanliness and efficiency levels, as each mould is typically produced in less than three seconds. Tasks undertaken by these robots include unloading the mould tool and packing into sterile carriers.

Adrian Walters, WIBA UK sales engineer said: "Helping create the Talisman MacroPower manufacturing cell has been a valuable and rewarding experience for WIBA UK. Hopefully the benefits will make this the first in many such joint projects as Talisman’s successful strategy bears fruit over the coming three years."

"Last year saw us gain the Environmental Standard, ISO 14001, we also invested £80k in Solar Power, and we also shaved 9% off our annual energy bill," added Fellowes.

Doing more with less is also a given for Talisman’s marketing strategy: Since the company name change five years ago a doubling of turnover has resulted. The key to this has been a relentless 80/20 Pareto-based analysis of customers and markets than actually provide Talisman with value and volume. Over the past five years the consequence has been a fivefold reduction in unprofitable business. Today’s Talisman is now proactively focused on value-giving sectors such as automotive, fluid transfer and electricals as well nurturing a thriving proprietary product range in moulded food packaging.

Producing soft and disposable lenses in particular is big business. Sumitomo (SHI) Demag is a major player in supplying the injection moulding machinery that produces the moulds that make the contact lenses. UK managing director of the company Nigel Flowers explains further.

A variety of moulds are used in the production of contact lenses, representing the different magnification levels (graded in quarter dioptres) that are prescribed for each lens. The differences are in the

For Fellowes the advantage in single source supply includes the peace-of-mind and equipment synergy provided by one manufacturer. But more importantly, the move opens up opportunities in aftersales service and partnership.

Among the issues were that these lenses deprived the eye of oxygen and slipped out of the eye too easily. Over time, however, the diameter of the lenses reduced to improve wearability and, with the arrival of soft contact lenses (using hydrophilic gel), their popularity grew.

Injection-moulder Talisman Plastics is reaping the benefit from its new MacroPower-based injection moulding production cell, designed and supplied from Wittmann (WIBA UK).

Left to right – Spencer Whale, Talisman sales director, Adrian Walter, WIBA UK area sales manager, Mark Fellowes, Talisman operations director

The process starts with the injection moulding of a front and base curve mould. This mould is then filled with a monomer (a molecule that can be bonded to other identical molecules to form a polymer) and is then closed and cured before the lens is hydrated and packed.

Every single mould used to make a contact lens is produced to a very high level of precision. Because the final lenses are moulded against a surface that has already been injection-moulded, any imperfection within the mould will find its way into the lens. The discarded moulds are recycled – but are not reused for moulding lenses.

variation in the space thickness between the front and rear of the mould, which dictates the thickness of the lens. There are a finite number of combinations and a standard number of magnifications and variations on the curve. Nevertheless, production still has to be carefully planned and controlled, to ensure the machines maintain the highest efficiency levels possible.

"In this particular instance, size happened to be everything," noted Fellowes. Try as they might, competitors could not match the compact footprint design of the Wittmann MacroPower machine; some two metres shorter than the nearest competitor.

One constant factor throughout the Talisman procurement decision was WIBA UK’s much heralded ‘one stop shop’ for injection moulders, which not only supplied the 450 tonne MacroPower machine but helped design and fit everything else involved; including 4.0 connectivity, B8 Unilog control, Robotics and Automation, Conveying, Dosing and Guard Control, Materials Drying and Dispensing and additional lighting – bringing the entire package in within the bounds of all security and health and safety requirements.

Mark Fellowes, Talisman operations director, said that "prior to purchase we did our due diligence and comparison - routine for all our investments - and Adrian Walters and the WIBA UK team came through with flying colours."

Yes. Because no two eyes are the same, there are a broad spectrum of styles and parameters to meet when producing lenses. Every contact lens that is produced requires a bespoke mould. Each lens must meet the highest levels of quality and cleanliness. Therefore, it is essential that the moulds are repeatedly perfect too.

Currently, only one Sumitomo (SHI) Demag UK customer automates the entire lens production process. Here, the company’s IntElect injection moulding machine forms just one small part of a huge production line whereby raw material is put in and, when it comes out the other end, the final product is packed and ready to ship. Packing and sealing the lens at the point of manufacture reduces the risk of contamination during moving and storage, however the complexity, investment costs and potential downtime issues are the downside to this approach.

Talisman Plastics – previously known as LGG Charlesworth until five years ago – celebrated its one-hundred-year manufacturing pedigree last year. The company’s busy Malvern factory contains many production cells, with only limited space for the new machine.

Batch making the moulds and then shipping to local markets where the lenses are produced offers greater flexibility and operators have the ability to stop the injection moulding machine and compensate somewhere else in the system.

It can be traced back to 1887 and German physiologist Adolf Flick. That lens was made of glass and was called a ‘scleral’ lens because it covered the scleral – the part of the eye that is white. Some years later, in 1912, optician Carl Zeiss developed another glass lens that fitted over the cornea. The first plastic lens (manufactured from plexiglass) is believed to be the work of two scientists, who created the scleral lens in 1938. The first plastic corneal lens arrived in 1948.

Moulders venturing into this specialist sector may also opt for a self-contained cleanroom moulding and packing system which are fully compliant with any GAMP and FDA requirements and have the required DQ, IQ and OQ documentation.

In Asia specifically, the emergence of a market for cosmetic solutions, including coloured lenses, is part of the reason this region is expected to experience the fastest growth between 2017 and 2024. The preference of disposable lenses – and relatively lower cost – makes them a much more appealing solution to resolving short or long sightedness than glasses.

Today, there are estimated to be 125 million global wearers of contact lenses in a sector that is worth nearly US$15 billion. The lens manufacturers, many of whom are based in Ireland, expect demand to continue rising.

"In common with our supplier partner WIBA UK we are also building growth through a one-stop- shop that includes products, services and strategy – not only for know-how, cost and convenience – but also for the new and emerging circular economy," mentioned Talisman sales director, Spencer Whale.

In an industry that is continually evolving, the next milestone could be smart lenses, which have the ability to monitor a user’s health through a series of circuits, sensors and wireless technology. The production of these lenses will be the same as existing products, but the capabilities will be even greater. Already, the military, for example, is looking into telescopic lenses that will allow the human eye to zoom.

"These are the actions that our customers want to see and which help us win new business. At the very least we need suppliers who can match these achievements and ambitions. All Wittmann equipment more than ticks the energy-saving box."

"One phone call: That’s all I ever need or want to make if I want to explore all the possibilities in this system. I will typically call Adrian and ask - “Can the cell do this?” – to which he will typically reply “Yes” – or will research the issues and get back to me with options. And this relationship serves to further increase our creativity, efficiency and sales."