Automation through robotics is a trend being seen in almost every industry. In the timber industry, pallet and box producers are benefitting from the efficiency and quality improvements provided by this level of automation, as demonstrated here by Timbermark, the industrial inkjet specialist.

Timbermark’s longstanding customer, Rowlinson Packaging South Ltd, is one of the largest manufacturers of potato boxes in the UK, making thousands each week. Printing and stacking the boxes’ side panels had been a manual process using stencils and paint rollers. It was a messy and labour-intensive business, so Rowlinson approached Timbermark to discuss how the panels might be inkjet printed instead.

The project was to print an image 1800 mm x 750 mm in size on the box panels using a printer mounted on a robot arm.

Working closely with the customer and the robotics integrator, Phoenix Robots, Timbermark set about bringing the project to life. Its solution was to create special “image slicing” software and combine that with a UV-curing inkjet printer mounted on the robot arm.

Firstly, giant, 125 MB bitmap files were cut into strips to match the size of the print head, and white strips were overlaid to coincide with the gaps between the boards, so that the printer did not print into the voids between the potato box boards.

Next, the image slices were sequenced on each panel so that the large image was built up with each new pass of the robot arm. The robot moves at a fixed speed, and a pulse at the start of each pass activates the printing.

The ink is UV cured and immediately “dry” on the panel. This gives instant weatherproofing (the UV LED is 150 x stronger than sunlight), and means the ink does not transfer between panels when they are stacked.

Timbermark used its largest printhead for this project: a 108 mm printhead from longstanding supplier, Yeacode. The printer uses a recirculating ink system, which rarely needs priming and does not get clogged with dust. The printhead can print from up to 30 mm away, making it tolerant of variations in the board panels.

Steve Jackson, Operations Director at Rowlinson Packaging South, says, “Where there are large volumes, it makes sense to automate when possible. Not just from a cost saving perspective, but for increased efficiencies, and, in this instance, to be able to offer our customers something not previously available in the marketplace. With the help of Timbermark we are now able to print high-quality images and detailed customer logos on to our potato boxes. Previously we were limited to what could be cut in a sheet of stencil board. The accuracy and repeatability of the output is greatly improved and is being well received in the marketplace.”

Colin Stewart at Timbermark, says, “This project shows how versatile inkjet printers can be. The latest printers combined with UV LEDs provide a really impressive mark and we can tailor our print software to tackle all kinds of projects.”