Moulds: OMCO

Laser technology in mould making

Denis First* discusses various applications of laser technology and describes the advantages this technology has brought to the glassmaking process.

Omco is a global specialist glass mould manufacturing for the hollow glass industry. The company has been in industry for more than five decades and has faced various challenges over the past.

From a small production facility we have grown to a multinational group, with today 2000 employees with eight production facilities.

Throughout its history, Omco has always investigated the latest available technologies trending on the market and taking the lead on these that were possible to apply into glass mould manufacturing.

The ones that could bring a higher standard of quality and/or product performance but also finding good economical return on other side.

Our R&D team would continuously follow on this, looking at how to apply any such pilot project idea into real industrial production practice.

Going some years back, one of such project was laser technology.

At the time, laser was already well present in other industries but not in mould making where Omco was the first to introduce it.

Today this laser technology is well established, not only up and running but also being one of the crucial part for operations, resulting with a higher standard of end product, glass moulds.

Today OMCO uses three different applications of laser technology; welding, engraving and measuring.

Laser welding

It is known that welding application on glass moulds is crucial for a higher lifetime, hardening the edges would allow bigger resistance to wear and damages delivering longer life on moulds and parts, however is not always good for the glass production (glass distribution) as such.

Any welded area running on glass machine, being exposed to high temperatures will behave differently compared to base material, due to different properties and different thermal conductivity.

Compared to other welding techniques, such as manual spray welding or the PTA (plasma transferred arc) method, laser

1a 1b

1c

offers various advantages.

Laser delivers a constant thickness of weld layer, as well as enabiing a thin layer of welded area over the parting line on the mould allowing better thermal conductivity.

Due to the nature of the process there is no preheating required, with less heat affected zone in the welding area.

Therefore there is less chance to the deform metalographic structure of base cast iron material due to lower heat

2b 2c

� 2a, 2b, laser enraving in machine and the end result.

tension.

Laser will also offer very good bonding of two materials (cast iron or bronze with nickel weld).

Therefore any mould properly welded by this method would have an advantage from the perspective of glass production performance and material durability and stability.

This welding became more of a controlled process compared to other methods and overall fast and efficient.

However, to get there, along with expensive investment into tailor made laser-welding units it was crucial to develop the right welding parameters and processes. Here Omco succeeded, bringing laser welding into strong industrial use, with six automated welding centres and delivering over 200, 000 laser welded moulds to the market.

Another important product for laser weld application commonly used today is also neck ring as part of the finish equipment where laser method offers various weld designs .

Thin layer of welding on edges (all edges or various designs of partially welded seams) compared to conventional method full profile weldings will offer bigger heat extraction on the finish of bottle and allow higher production speed.

Especially this will give good effect on bigger widemouth neck rings having less chances for ovality of the finish and overall better glass performance (Pics 1a, 1b, 1c).

Laser engraving

Along with conventional CNC milling machining, laser engraving offers another level of approach into mould machining. This method can be used for different kinds of engravings, decoration with less limits compared to conventional 3D miling. As a machine works with laser light there is no restriction on tool, no limit on radius size compared to conventional methods.

Therefore with such method we can get another level of engravings offering various marketing ideas into the sale of bottles/end product.

If someone cannot put engraving ideas into a 3D model it can work just with a good quality photo; based on photo only, we can create a programme for laser engraving.

This method would also be used into various renderings/knurling on the mould cavity (Pics 2a and 2b).

Laser measuring

Omco would use this technique for reverse engineering. If you want to replicate some of the mould shape, or this shape was made with old technology (for example if it was machined manually), laser can convert this into a proper format for the latest technology machining.

Laser is also used for different ways to measure during the machining process.

Quality control is crucial for Omco in order to get the highest standard of glass moulds where this measuring technology helps to assure this. �

*Group sales manager, Omco, Croatia https://www.omcomould.com/

� Laser scan of the mould equipment.