Custom Solutions for Industrial Laser Processing

Interview conducted by Will SoutterJan 4 2013

In this interview, AZoOptics talks to Dr Mark Greenwood, Managing Director of JK Lasers, about their technology and the applications of their industrial laser products.

Can you give us a brief overview of JK Laser’s technologies and the field you operate within?

We design and manufacture industrial Watt to multi-kiloWatt fiber lasers, Nd:YAG lasers, software and process tools. We also offer a customisable workstation that can be integrated with our lasers for a wide range of cutting, welding and drilling applications.

Our lasers can be found operating 24/7 in many demanding industrial environments around the world, including the medical, electronics, aerospace and automotive sectors.

What unique capabilities do you have that make you stand out from other industrial laser manufacturers?

Unlike other laser manufacturers, we offer a one-stop shop where laser processing solutions are tailored to each individual’s needs.

Free sample processing is available in our specialist applications laboratories to ensure the most appropriate laser is selected for the job. Post-sale, our qualified engineers carry out the installation and provide staff training as required.

We have also developed our own range of software and process tools, meaning customers do not have to source them from a third party. Our re-collimation units, galvanometer scanning heads and other ancillaries are designed to integrate seamlessly with our lasers to deliver the best possible performance.

What sort of customers do you typically work with in laser welding, cutting and drilling?

Most of our enquiries come from end users and systems integrators at job shops, universities and research organisations, as well as original equipment manufacturers (OEMs).

We work closely with customers around the world. In Japan for example, the Mechatronics Division of systems integrator Sumitomo Heavy Industries (SHI) has been using our 1kW fiber laser (JK1000FL) to carry out applications-based trials on behalf of its automotive customers. We have enjoyed a long and successful relationship with SHI for over 20 years.

In Turkey, a university recently enhanced its medical research capability with the purchase of a laser system from American company Precision Automated Systems. This system features our 400W fiber laser (JK400FL). Last October, another system integrated with the JK400FL won an award at the International Technical Fair in Plovdiv, Bulgaria. The manufacturer, ILS Photonics, is now integrating JK Fiber Lasers into a range of general purpose flatbed cutting machines.

We have also partnered with Liverpool John Moores University in the UK to research laser processing solutions for cutting and milling carbon fibre reinforced plastics. This material is an increasingly popular choice in the aerospace industry due to its lightweight composition but is difficult to process using traditional techniques.

Can you describe some applications that your lasers are used for?

Our industrial lasers are used for a wide range of applications from micro welding hard disk drive components to drilling air bleed holes in vehicle parts. Some examples of these diverse applications are microcutting medical stents, hermetic welding for batteries, and sheet metal cutting.

Medical stents are permanently inserted into arteries so the cut metal must be smooth and clean. As stent diameters measure between 1mm and 10mm and have wall thicknesses around 100µms, precision cutting is essential. Low to medium power JK Fiber Lasers possess the high beam quality and excellent power stability required to meet these exacting requirements.

The high beam quality of JK Fiber Lasers also delivers the very small spot sizes required to hermetically seal battery packages without distortion. They are capable of welding the dissimilar materials and reflective materials such as copper and aluminium that are often found in electric vehicle and lithium-ion batteries.

When cutting sheet metal, JK Fiber Lasers offer numerous advantages compared to water jet, plasma and mechanical techniques. Not only are they quieter and cut fine features with ease, they eliminate the need for hard tooling. Holes and cut-outs with clean edges can be cut to almost any shape and size. The process is also easily automated and highly repeatable.

What are the plans for JK Lasers in the near future?

As we look to the New Year, we will primarily focus on our growing range of fiber lasers. In December 2012 we launched a 3kW fiber laser (JK3000FL), which features excellent beam quality and high processing powers. The JK3000FL offers a compact, cost-effective and powerful solution for applications such as sheet metal cutting, which have previously been dominated by less efficient CO₂ and Nd:YAG lasers.

How does JK Lasers’ patented back reflection technology help deliver better finished products?

When processing reflective materials such as aluminium, copper, gold and silver, some manufacturers adjust the angle of the focus head. Although this alteration ensures reflected light is directed away from the laser, it is often at the expense of the spot shape. The resulting elliptical - rather than circular - spot can increase kerf and cut widths, creating imperfect designs.

JK Lasers offers a patented system that directs reflected light away from the delivery fibres and into a beam dump without the need to adjust the focus head. Back reflection levels are continually monitored and trigger an automatic shutdown if acceptable limits are exceeded.

Integrated into our Nd:YAG and fiber lasers as standard, this unique back reflection protection also eliminates the need for a separate Faraday isolator. These isolators are often costly and can cause power loss and beam degradation due to the thermal effects in the crystal.

We are also developing a way of finding the focus using data generated by our back reflection system. By using test pulses and monitoring the back reflected signal, locating the focus can be made easier and more reliable. This will provide an accurate and repeatable method of indexing the focal position relative to the process tool. The technique will enable operators to set up and detect faults in their processes, transfer process information from the laboratory to end users, and find the focus with any material.

How do your Fiber Lasers help manufacturers streamline their own processes?

In a competitive global marketplace it is vital that manufacturers accelerate throughput whilst maintaining quality and minimising costs. JK Fiber Lasers help to achieve this in a number of ways:

• With near diffraction-limited beam qualities, JK Fiber Lasers deliver exceptional beam quality small focused spot sizes at high power levels for precision processing.
• Able to reach stable, high power levels from the moment they’re switched on, JK Fiber Lasers process more quickly and consistently than other laser types.
• JK Fiber Lasers feature a completely sealed optical design, which reduces maintenance by eliminating the need to routinely align and clean lenses. Should other maintenance be required, our engineers can instantly connect to the laser using desktop software. This ability to remotely access the laser allows maintenance to be carried out with minimal downtime.
• JK Fiber Lasers are designed to operate 24/7 in the most demanding industrial environments. With a mean time to failure (MTTF) of over 300,000 hours, the diode laser pump sources used in JK Fiber Lasers are extremely reliable, saving manufacturers money by helping to extend system lifetimes.
• JK Fiber Lasers incorporate our bespoke, user-friendly software that allow users to cut, drill and weld parts in high volumes to the same standards time and time again. If more than one application is involved, pre-programmed laser parameters and pulse shapes can be changed quickly and accurately at the touch of a button.
• Using fiber lasers for a non-contact process eliminates the costs associated with replacing and repairing worn tools.
• Substantially smaller in size than Nd:YAG and CO₂ lasers, fiber lasers can be easily integrated into compact systems and fitted into most industrial premises.
• Fiber lasers are up to ten times more efficient than Nd:YAG lasers of a comparable power level. The use of laser diode pumping at high conversion rates delivers wall-plug efficiencies of over 25%.
• Features such as beam-switch time-share maximise productivity by eliminating system load and unload times. Energy sharing helps avoid the distortion of sensitive components by simultaneously welding multiple locations on one part.

What are the main differences between your Fiber Lasers and Nd:YAG Lasers with regard to laser cutting?

Fiber lasers possess near diffraction limited beam qualities, enabling manufacturers to cut very fine and accurate kerf widths. This is particularly beneficial when cutting small and intricate details. The high quality beam means heat input can be carefully controlled to avoid distortion of the material.

Nd:YAG lasers offer benefits for other applications. For example, their higher peak powers help achieve deeper weld penetrations, particularly when processing highly reflective materials. They can also be programmed to produce a wide range of customisable pulse shapes. Correct pulse shaping can improve performance when welding and drilling a range of materials. It helps optimise metallurgical properties and enhances the cosmetic appearance of finished parts. When drilling, it also improves laser efficiency and the quality of the holes (percentage taper, recast layer and overall shape).

What is the difference between trepan laser drilling and percussion laser drilling?

Trepan drilling is the more versatile option, enabling laser operators to drill a wide range of shapes and sizes. A motion system moves the laser beam relative to the part before cutting out the holes. By cutting out holes (rather than drilling in the traditional sense) laser operators enjoy more flexibility compared to percussion drilling.

A special focus head can be used to move the lens to trepan drill consistently small holes, but generally speaking, percussion drilling is the preferred approach for these applications as faster processing speeds can be achieved.  

Percussion drilling enables laser operators to ‘drill-on-the-fly’, which involves delivering pulses from a stationary laser to a moving part. When processing thin materials, a single pulse is often sufficient. In thicker materials, additional pulses are delivered. For example, if ten pulses are required to percussion drill a hole, a drill-on-the-fly system will rotate the part ten times and send one pulse to each location per revolution. Drilling-on-the-fly greatly increases drilling speed because indexing is eliminated from the cycle time.

JK Lasers recently used drilling-on-the-fly to create a special Diwali message. You can view the video footage on our YouTube channel.

How does laser drilling benefit final products compared to other techniques?

Using lasers for drilling applications offers many benefits compared to traditional techniques such as mechanical and electro-discharge machining (EDM).

• They are a non-contact process with no tools to wear or break
• The processing results are highly accurate and consistent
• Heat input can be precisely controlled
• Small diameter holes can be produced with high aspect ratios
• They can drill shallow angles and shaped holes
• They are easy to programme for prototyping and small batch manufacturing
• They are readily integrated into automated processes
• They can be set up more quickly for faster production rates
• They can be more energy efficient
• Some laser-based systems can drill multiple features simultaneously
• They are able to process a wide range of materials.

The Gladus400 laser system recently won a Gold Medal at the International Technical Fair in Plovdiv, Bulgaria. How did you work with the customer to achieve this?

From initial enquiry through to the engineer’s visit to install the lasers and train the laser operators, we remained committed to delivering a processing solution that met ILS Photonics’ exact requirements. The resulting Gladus400 is a compact system with flexible fibre delivery so the laser beam can be targeted precisely where it is needed. The customer also has complete control over the laser’s parameters via a special machine interface.

We are delighted that the manufacturing performance of the Gladus400 has been recognised with a gold medal and we look forward to working with ILS Photonics on integrating our fiber lasers into its range of flatbed cutting machines.

Where can we find more information about JK Lasers?

More information about JK Lasers’ products as well as contact details for our global offices can be found on our website.

About Mark Greenwood

Dr Mark Greenwood is the Managing Director of JK Lasers, responsible for all worldwide operations including JK’s manufacturing facilities in the UK and Suzhou, China, as well as the worldwide sales and service organisation.

He joined JK Lasers in 2003 as Technical Director and has led the company’s transformation into a fiber laser supplier based upon its own innovative technology. He previously worked as Managing Director of Spectron Laser Systems, a supplier of Nd:YAG lasers for scientific, industrial and medical applications.

JK Lasers is a global company that develops and manufactures class-leading industrial lasers for the medical device, aerospace, automotive, electronics and semiconductor markets.

Part of the GSI Group, JK Lasers has over 40 years’ experience in producing laser processing solutions tailored to each individual’s cutting, welding and drilling requirements.