Images_Digital_Edition_March_2020

www.images-magazine.com MARCH 2020 images 35 MARKET INTELLIGENCE To choose the best configuration, look back at the company’s job history out those Yankees panels in plastisol puff at the rate of 3,000 per day and no one could tell they were produced on a machine that was two doors down from the gates of Hell. The basics Screen print presses have two basic configurations: the oval and the carousel ‘round’ option. Asking which is best is like asking which flavour of crisps is best: you may think it’s ready salted, but trust me, there is someone out there who craves hedgehog flavour! Oval presses have many open areas in which to insert special flash units, flocking units, chilling units or even just a small boy with a sticky piece of tape to remove lint. They are most commonly used to produce large flat panels and can be configured with up to 60 stations. They tend to be slower than circular machines and therefore lend themselves to fashion work. The early configurations would have the printing attachments, squeegee arms, flash units, etc, on one side of the press and leave the opposite side of the oval open to allow more than one loader access to the machine safely. When I first started printing, a team would consist of two loaders, a puller and a catcher, with the ‘printer’ constantly walking round the machine, monitoring the inks, maintaining quality and expertly making a roll-up while the machine lifted and lowered, pushing out the required 300 pieces per hour. Drive systems The drive systems on oval machines can vary. There was an old Precision machine that was hydraulic and used a chain to drive the pallets around; this method can still be found on machines produced today. The main issue with chain-driven machines is that, very much like a chain on a bike, the chain stretches over time and needs to be re-tensioned. To tighten a bike chain is relatively simple, but when we rely on the chain for the position of the pallets, which in turn dictates the registration between colours, we can hit problems. It is much more technically demanding. Chain-driven gave way to solid-driven and this eliminated the issues of stretch, but the engineering must be much more robust and dependable to cope with the demands of a large press running day and night. Independently driven pallets are a new system of tiny little robots embedded in the pallet arms. These are typically found on the largest oval machines and eliminate the need for connected drive systems, therefore eradicating the issues of stretch or brake slide. They are the most accurate method of driving pallets along a large oval area, but they rely on a copper communication strip that must be kept clean and, as you will know, a screen print shop is not the easiest environment to keep clean. The popular choice Carousel or round-shaped machines are now the most popular format found in almost every shop across the globe. They are circular with a central drive system and usually have two open stations shaped like a piece of pie which allow for one loader and one puller. One of the earliest circular machines I worked on was driven by an air cylinder that was controlled by a shock absorber similar to those found on a motor car. The resulting machine would clank and bang so loudly we had to turn up the radio to hear Radio 1’s ‘Our Tune’. This machine was so animated in its operation that it needed to be bolted down to stop it slowly walking across the factory floor (perhaps it merely wanted to escape the daily dose of DJ Simon Bates that could reliably be found blaring out in a 1990s print shop). These round-shaped machines are fast. They can produce up to 1,400 pieces an hour, much more than a regular human can consistently produce. I can load shirts at 1,400 an hour – but only for ten minutes at a time and I couldn’t guarantee there wouldn’t be an under-the-arm print where there should have been a left-chest print! What size? The most popular configuration is probably 10/12; this means 10 printing heads and 12 pallets. My advice on how to choose the best configuration is always to look back at the company’s job history, if available, and ask basic questions such as ‘”How many colours on average did we print last year?” and “What was the average run size?” Using this information, you can try to predict what configuration of new press you need to purchase. Include any special effects like foiling and remember that a flash unit takes up a print station. New machines or even well- maintained used machines can provide a superb revenue stream while they are running, however as you only earn money while the squeegees are moving, you must consider the ease with which you can set up these investments from one job to the next. When looking for a new investment I would always advise looking at the speed of job change as well as the top print speed per hour. It is no good having a car that goes 200mph if it takes you an hour to open the door and start the engine. The use of registration aids and a tool-free set up can allow a quicker return on investment than a fast machine that requires an engineering degree to set up and change over jobs. The brand of machine you choose is a tricky one – I have my favourite and it’s difficult to stay impartial when writing about machinery – but I would always recommend looking at the set-up times and also the level of service available: if it breaks (and it will), can you fix it yourself? Does it need a computer genius? Can you get a technician at 8pm on a Friday when the job on press just simply has to go out no matter what? Whether you pick a blue one or a green one or even a red one, I only hope that the press you buy is not possessed by dark spirits from the underworld and it brings both joy and wealth to your print shop door. Tony Palmer has been in the garment decoration industry for over 30 years and is now an independent print consultant working closely with print shops to get the most from existing processes and techniques. Tony is passionate about keeping and enhancing production skill levels within the industry. He is the owner and consultant at Palmprint Consultants, offering practical help and assistance to garment decorators all over the globe. www.palmprintuk.com