Tackling laser fume extraction on a budget
Marking (or coding) lasers are used in a huge variety of applications to add traceable information such as use-by dates and batch codes to packaging and products.
The advent of smaller, less-expensive marking and engraving lasers has opened the market to a whole new range of customers who demand performance on a budget
Marking (or coding) lasers are used in a huge variety of applications to add traceable information such as use-by dates and batch codes to packaging and products. Examples of these applications include marking bottles in a beverage plant, batch-coding of medical devices, marking PCBs and components in the electronics industry, adding data to cables and pipes, and many others in which permanent information needs to be added to a product. Engraving lasers are commonly used in the gift industry to mark logos and information onto pens, coasters, etc., and they also can be used to cut shapes in a variety of materials. Due to their increasing affordability and versatility, engraving lasers also are becoming more popular with school and college arts and crafts departments.
However, because laser marking and engraving systems burn away layers of material, they generate fumes that contain small toxic particles and gases that are health hazards. Some examples are benzene and toluene, which are released from certain plastics, and chromium and nickel, which are given off by some metals. Virtually all materials (when processed) will emit some hazardous fumes; even cardboard and paper labels can produce respirable dust and formaldehyde.
Worldwide health and safety legislation deems it vital that these fumes are dealt with effectively, as they can cause serious long-term medical conditions such as occupational asthma and can leave employers open to expensive compensation claims by employees.
Removing fumes from laser marking processes is a necessity.
The particulate generated by laser processing also can coat or even damage expensive laser optics and can cause beam attenuation, leading to blurred or incomplete marks. If this dust is not removed efficiently, it also can contaminate products that might need to be rejected, and it can coat the laser enclosure and associated machinery, meaning increased downtime for cleaning. A failure in fume extraction is usually a "line stopper." In high-volume production (e.g., PCBs, pharmaceuticals, and food/beverage packaging) improperly coded products and the resulting downtime due to fume extraction failure can cost thousands of dollars.
It is now widely accepted that some form of fume extractor will be required when purchasing a laser. On the one hand, the customer has to consider his budget and performance requirements; and on the other hand, the laser salesperson wants to clinch the sale of the laser. There are two ways to approach this situation. In the first approach, the customer can purchase both the laser and a fume extractor from the laser OEM. In the second approach, he can purchase only the laser and source an extractor from elsewhere. The first option is better for several reasons.
For instance, the laser salesperson might think that quoting a laser with an extractor will put the customer off because of the additional cost, but this usually is not the case, as the customer knows he will have to buy an extractor anyway. By not quoting for an extractor, the salesperson is losing extra potential revenue and the customer might end up with an unsuitable extractor from another source. The unsuitable extractor then might cause problems with the laser process—for example, causing the laser to produce blurred marks. This can leave the customer unhappy and potentially wondering if the laser is at fault.
It is much better, therefore, to quote a whole package to the customer, who can benefit from the laser manufacturer's knowledge of specifying the correct extractor. The laser OEM also gets the long-term benefit of supplying the customer with replacement filters, while the customer gets a problem-free laser process. At Purex we even have seen the quality of the fume extractor be the deciding factor for the customer when comparing two laser brands.
Budgets are, of course, a consideration for the customer; however, very low-cost fume extractors available on the market can trade performance, filter life, and even safety for cost. Simple fans which vent to the outside might seem to be an economical solution at first, but they have significant drawbacks: holes need to be cut in walls/ceilings; planning permission might be required; environmental legislation comes into play; and bulky, fixed pipework is required. Plus, what happens if the laser moves? The fan, holes, pipe work, fixings, etc., will need to be reinstalled in the new position and the old ones will need to be filled and sealed, which will be expensive. Also, an external venting point might not be available—for example, in a shopping mall or school.
A cheap extractor also can cost much more in terms of replacement filters. What's worse, if the extractor is inadequate, the health and safety of the operator will be at risk.
What do a budget-conscious customer and a laser manufacturer need so that both are happy with the laser/extractor package? New lasers coming onto the market are less expensive, are more compact, and are sold into new areas such as schools, offices, and shops. So, a good extractor needs to be compact, affordable, quiet, and mobile and deliver excellent extraction rates and filter life.
An affordable solution from Purex is the Laserex Alpha, which is available in two models: a 200m3/hr version and a 400m3/hr version, depending on the size of the laser. Both models have a small footprint of only 465mm2, so they take up minimal space in areas where this is a consideration. They are mounted on lockable casters to make the machines highly mobile so that if the laser moves, the user can simply push the extractor after it.
To reduce noise levels the machines employ Whisper Stream technology, a unique, powerful blower and silencing system that delivers excellent performance, maximum reliability, and whisper-quiet operation at less than 45dBA—essential in places such as schools or shops.
It is also of paramount importance that the health and safety of employees are protected. To ensure this, the Alpha features the VariColour warning system. This system constantly monitors the condition of the filters and reports automatically via a single variable color.
A major benefit of buying lasers is that they have few consumables when compared with other methods of marking, such as inkjets. The last thing a customer wants is to have to buy lots of replacement filters for their fume extraction system. Purex employs several design features in the Laserex Alpha to ensure filters have a long life span, and therefore, consumable costs are low for the customer.
Health and safety legislation and the need to protect the product and laser optics make the need for a fume extraction system undeniable. By producing the Laserex Alpha at the right price, with such a good standard feature set and with affordable upgrade options, Purex believes it has catered to everyone's requirements.
Jon Young is marketing manager for Purex International LLP, Rotherham, UK, www.purexltd.co.uk.