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A positive investment in screen
This family run firm operates successfully in the POS market, competing on quality, delivery and price, using screen printing technology. How is this achieved? Managing director, Dieter Jernej, believes it is down to investment in the best equipment, backed by sound research and regular upgrades, at least every five years.
His latest acquisition is a five colour SIAS Multiformula 1.6 by 2.65m screen printing machine. This sits alongside a four colour SIAS Multiformula 1.6 by 2.15m and a further four colour 1.8 by 3.3m SIAS. The newest addition to this impressive array is only six months old and demonstrates the latest screen printing technology.
It is designed to solve some of the issues posed by the printing leviathans of old starting with a scanning UV curing system that can be programmed to scan just the image area printed at each station. It has 16 different power settings that can now be upgraded to an electronically controlled step-less output. This removes the need for large transformers and reduces the electrical spikes experienced by other systems. When not actually curing during a scan the lamps wait at 10 per cent of full power with the reflectors moving in front of the emitter to act as shutters. Fans also slow down. This results in dramatic energy savings and considerably reduced heat build up
Problems cured
The developments do not stop at the curing technique. The gripper and registration system has also been addressed to eliminate squeegee damage. The substrate is pushed up to a stop that then positions the sheet automatically against a side lay. Fibre optic sensors detect the position and then the solid gripper plate takes the sheet, ranging from 120gsm to 10mm thick, onto the vacuum table, which can be sectioned off to suit the sheet size. The gripper plate is moved on a servo driven toothed belt until it is firmly locked into position for the print sequence, with no need for chains running along the length of the machine.
A blow back function reverses the vacuum and provides an aircushion for the substrate to leave the print station. This is particularly useful for difficult to handle substrates. Peel off is motorized with both the rate of peel and start point adjustable.
Next up is the massive squeegee and flood coater assembly. This is said to give precise control of all parameters including pressure, angle and speed. All are servo driven with additional pneumatic actuation along the squeegee's considerable length to ensure pressure is balanced at all points. Insertion and removal of the squeegee and flood coater can be carried out single handed. Once pushed into position, the assembly is locked from the control panel and all parameters are set either using a previous program or fine adjustment from the control panel.
Easy loading
Loading the screen is designed to be straightforward with a program sequence that causes the print head to raise and sets the squeegee and flood coater to a park position. This means the screen can be removed and replaced without a second operator on the other side of the machine.
When a job is finished and the next job has to be loaded there is a Tear Down button that resets all operations to zero and eliminates the possibility of compromising machine settings.
With a five colour line ease of obtaining accurate registration is essential and this is certainly the case when the first sheet is run through the machine. The printer can view it at each print head or the end of the machine, making minute adjustments using stepper motors on the X, Y and Z axes.
Dieter Jernej estimates that a complete five colour changeover of substrate and image takes no more than 30 minutes with a simple changeover of one print station achieved in five minutes.
Looking inside the Multiformula machine it is apparent that each drying station and print station are discrete units. These are the building blocks of a print system that can be used to create a line with any number of stations. The individual units are fully welded and can link up with umbilical connections for maximum flexibility.
High productivity machines such as the SIAS Multiformula require efficient pre-press capabilities to keep them fed with the right quality stencils. Signum has two Signtronic computer to screen systems along with fully automatic screen development and reclamation. The company also stretches its own screens. Dieter believes that the stencil is the foundation of the process and he aims to provide the optimum stencil every time.
Another interesting feature is that Signum Siebdruck buys its substrate on the roll direct from the mills and converts it into sheets on the premises. The material cost savings are said to pay for the equipment with the additional benefit of greater quality control on the pre-treatment of polypropylene and polyethylene.
In every area of the business Signum Siedbruck operates a policy of test, test and test again before adopting new technologies or materials. The aim is to reduce the variables to a minimum and ensure that there is little variation over time.
So why is the company successful in the POS market? It's all down to targeting a niche. The company is supplying a market that requires bigger volumes than wide format digital printing can economically produce and larger sizes than wide format lithographic can print. By using the most up to date equipment and maintaining precise process control, Signum competes on quality, delivery and price and still makes a profit that allows continuous reinvestment in equipment.
