Top tips for clear egg stamping marks
Egg packers are increasingly moving to stamping eggs on-farm to aid traceability, but this can lead to problems with poor print quality. Olivia Cooper finds out how to keep stamping machines in top working condition
A growing number of egg producers are installing stamping machines on-farm, to improve egg traceability. But with a wide range of machines on offer, some are struggling with poor print quality – so what can they do to ensure problem-free stamping?
Since 2004 egg packers have been legally required to mark all Class A eggs with a code depicting production type, country of origin and the individual producer code. But following a scandal in 2006 when up to 500m imported battery eggs were allegedly sold as free-range, more farmers are stamping their eggs on farm.
Illegible printing remains a limited problem, affecting just over 1% of batches inspected by the Egg Marketing Inspectorate. Legally up to 20% of eggs can be illegible, so fewer than 1% of batches are removed from sale, says chief inspector Richard Jones. “It is rare to have a significant enough problem to cause EMI to remove eggs from the market place for stamping failures, but it does occasionally happen, most commonly with smaller producer-packers.”
The most common causes of poor stamping are incorrect choice of machine, poor maintenance, low temperatures and wet eggshells, says Steve Corden of Egg Packaging Enterprises. “We’ve had a lot of problems over January with water-based inks freezing up – there’s not a lot you can do about it except keep the ink above a certain temperature.”
Ideally producers should keep the printing room above 16C – although some printers pre-heat the ink, so can be switched on for 30 minutes before printing to reach the required temperature.
Eggshells left over the weekend also suffer from damp, causing water-based inks to smudge, says Mr Corden. The only option is to install a dehumidifier where the eggs are stored, to prevent moist shells.
Many problems occur where producers have bought cheap printing machines, he adds. “A lot of small producers have never done egg printing before and don’t realise that buying the wrong equipment will cause them problems. The cheaper printers can cost a lot of money in the long run.”
Some machines print the producer’s code around the circumference of the egg, but packers print the best before date lengthwise, causing the codes to cross over each other. “Soon, everybody will be doing their own producer code, so this has got to be addressed.”
Other issues include the use of resin-based inks, which dry out and become waterproof if left. “If you don’t clean the print head after use it dries out and you’ll end up throwing the whole print head away.”
Cleaning is an essential part of maintaining any printer, and producers should cover ink heads and cartridges when not in use, says Mr Corden. Keeping the equipment at a steady warm temperature will also prolong both the ink and machine’s life.
Choosing the right machine for your unit can be difficult, as there are no independent sources of advice. “The best thing is to find someone who’s got what you’re looking at and see what they think of it.”
Mr Corden recommends Domino printers, which start at £6600 + VAT – making them prohibitive for many producers. However, they give 95-100% readable printing, using quick-drying alcohol-based ink, which costs £80-£100/litre.
“There’s no reason that at least 95% of eggs shouldn’t be legible. We like the printing to be in the middle of the egg and in a straight line, but there are quite a few products on the market which aren’t up to scratch.”
Cheaper machines, which fit onto the back of a grader, cost around £780, although each will only do one row. Cartridges cost between £33 and £55 each, equating to £1000-£1833/litre. Over the course of its lifetime, Mr Corden reckons buying such a machine is a false economy, due to the high repair and maintenance costs. “You’re lucky if cartridges will be 55% readable in the winter – with some as low as 25%.”
The cheapest option is a hand stamper, whether single or multi-head for egg trays. Both can give a large variation in the quality of print, particularly where ink pads are used. A better option is to have stampers with ink inside. These cost about £100, but are not suitable if a best before date and Lion logo are required.
Key Points
- Keep machines warm
- Ensure eggshells are dry
- Clean print heads after use
- Choose machine type carefully