Technology
Flexographic printing machines print flexible packaging materials. The production of these machines is the main activity of Varga-Flexo Ltd. for since 1993. In order to meet a wide range of customer requirements, we use the latest technology when manufacturing our compact 8-color machines with central impression cylinder. Main features of our printing presses are high quality prints, reliable operation, fast reel change and retooling, cost effective operation, fast ROI, easy handling, easy accessibility and operator-friendly machine covers. The electrical system is developed by using our latest technical innovations. PLC and industrial PC controls, servo drive and color touch-screen terminals are installed into each of our machines. Online remote monitoring system with free Skype phone is an accessory for the machines, enabling free and immediate remote support for the machine operators, in case there is any need for help or service. Software updates can also be done directly from our Lengyeltóti headquarters. Our customized software is designed based on the requirements of the customers. Even in basic configuration, the machines are equipped with all supplementary accessories that high quality and economical flexographic printing machines require.
Advantages
- premium print quality
- fast ROI
- easy handling, quick learning
- short changeover time
- efficient ink application
- print inspection system with 100% print display
- print 4.0 (industry 4.0) efficiency automation
- SMART FLEXO artificial intelligence-based smart solutions
- quality assurance solutions
- low operating costs
- compact design, low space requirement
Flexo printing unit
8 colors
8-color robust cast iron framework with 8 printing decks The massive cast iron framework ensures that vibration is minimized and as a closed unit it guarantees stability and protection for the 8 inbuilt flexo printing decks. In addition robust spacers join the two sides.
Central impression cylinder
The central impression cylinder is the prerequisite for top quality printing. Double-walled, tempered, 1800 mm diamteter stainless cylinder with 0,005 mm accuracy ensures that the material will not stretch (deform) during the printing process. The cylinder turns steadily thanks to the self-setting bearing with cylindrical roller. The bearing doesn`t require maintenance. The tempering unit is part of the basic configuration.
Gearless servo
Gearless and servo driven printing form and anilox sleeves. The inbuilt air cylinders of the form and anilox sleeves are servo driven, thus any print length can be set without the 5 or 10 mm limit. The girth of the plate mounted onto the form sleeve is saved in the system and the servo inverters automatically set into the needed position due to a high-accuracy feedback. There is no more resonancy caused by older machines' cog wheels as a result faults on the print due to vibration reduce.
CNC Motorized printing deck actuation
PLC controlled, servo driven actuation of the printing decks and of the length register. Each printing deck is actuated by 4 servo engines moving precision screws and carriages. Accuracy of the positioning is to 0,001 mm, with zero backlash. Machine operators can set the compressive force and the servo driven cross and the 360° length registers on two portable and two color touch screen terminals. These values along with many other important parameters are saved with the recipe program, which ensures that work data for recurring jobs is stored.
Vibration damping
Vibration damping system in each printing deck.
Plate engagement and disengagement during print cycle causes vibration which needs to be absorbed in order to neutralize resonance streaks, so all printing decks are equipped with an anti-vibration system.
Sleeve system
Side shift mechanism anilox and form sleeves. Specifically required sleeves are placed on the fixed built-in air-cylinders in the Flexographic press and their exchange can be done from the operator’s side of the printing deck after the quick release of the bearing block assembly. Therefore, changeover time is greatly reduced. The total print length range is most economically attainable by two adapter sleeves. The exchange of the form and anilox sleeve is aided by two specifically designed carts which are standard equipment. They reduce the likelihood of damage and ensure safe storage of the form and anilox sleeves. Plastic protective cover is an optional accessory for the anilox sleeve, which should be used during sleeve exchange in order to protect the anilox sleeve mantle from damages. For special request we can produce compact, easy-to-use form sleeve rack or storage when all form sleeves of the machines can be store safe and further form sleeve transport carriage which can solve safe and easy transport between the storage, the plate mounter and printing press.
Doctor blade chamber and paint application
The blade chamber is one of the most important units of the paint application technology. It is precision-machined cast aluminum with Teflon surface. We fixed blades on the top and bottom of the cast and standard size felt end-seals on the sides, which can be replaced in the printing deck without removing the doctor chamber. The equipped Doctor Chamber is simultaneously pressed against the anilox sleeve by adjustable pneumatic pressure, resulting in a closed chamber. The inlet and outlet hoses are fastened to the backside of the pump and the ink box by quick connectors. Ink is circulated via burst proof pump to the chamber from a stainless steel toner box, situated on two support carts, which are included in the base price. The blade pressed against the anilox sleeve ensures that excess ink is removed, thus the quantity of the applied ink can be controlled by the size of the cells on the anilox cylinders. In order to increase or decrease the quantity of the ink, the anilox sleeve needs to be changed to another size. Ink recirculated through the stainless steel ink box is filtered for metal particles by a magnet. Easy cleaning, low weight, fast and simple maintenance was the primary objective during the design phase. Assembly and storage of the Doctor Blade Chamber, and Doctor Blade cutting, is aided by a specifically designed cart which is standard equipment. Viscosity control, automatic washing system with pneumatic pump, stainless steel anilox sleeve, and the Doctor Blade Chamber washer carriage are available options.
Automatic Print Setting
Automatic print setting within 20 m. The automatic print setting system is a software solution that sets compressive force and length registers on all 8 printing decks simultaneously within 20 meters. As a result, we will receive a print which the machine operator needs to only fine-tune to achieve a perfect print. Human factor will always play a vital role in precision settings on any system, therefore, the machine operator’s role will always remain vital. The amount of rejective print and changeover time is greatly reduced by this system. The system is included in the basic accessories.
Print inspection system
Print image monitoring devices were only capable of displaying a small area of the actual print with a single snapshot, therefore, considerable extra time was required until the total print image control concluded and image detail fully refreshed. This may have taken even 15-30 seconds depending on the size of the monitored area, during this time 100-150 meters of rejective material was produced. The advantage of the print image monitoring device is that it allows us to see the entire print image in its entirety on a large (49”) 4K LED display while image refreshing is less than 1 second. In addition, we include a moving motor unit that allows to zoom on a selected part of the print and display it on a 27 "4K LED monitor. The spectrophotometer on the moving unit can measure color accuracy during printing.
Optional equipment of Print control system:
- 100% print size monitoring display
- Print error detection during printing cycle
- Barcode inspection during printing cycle
- Color accuracy (RGB) inspection during printing cycle
- Moving camera
- Microscope camera
- Spectrophotometer
- Automatic compression force adjustment
- Automatic length and cross register adjustment
- Print length (rapport) inspection during operation
- Front and back side register control and automatic adjustment during duplex printing
- Report preparation for quality control
- Recipe archiving
Speed
The mechanical speed of the press is equal to its highest printing speed of 400 m/min, even during 8-color quality printing. In some cases, however, substrate specifications require lower speeds. According to customer feedback, we can say that on average 150-200 000 meters of printing can be accomplished daily, with 5-10 changeovers, in a 24 hour shift.
Width
The determinative parameter of a Flexo printing press is the width of its print. According to customer feedback, 80% of printing requirements are less than 1000 mm in width, so the majority of the printers are ordered with a 1000 mm maximum print width and an 1100 mm substrate width. Being a custom Flexo manufacturer, we offer a range of 500–1200 mm width, to meet customer demands.
Print repeat
The minimum print length is an important factor due to the declining number of copies, because during multiple production printing, the cost of printing plates increase, which the customer does not always accept. As a result, our print length can be set from 300-900 mm, enabling smaller print plates which help reduce their cost.
Web Video Inspection
With the help of a web monitoring system we can check the print under running. A digital camera shoots still images of the print and displays the pictures on a fix and a rotatable 19” LCD flat screen. The optics and the camera is moved by inbuilt motors even with automatic scanning. The print control system is available with two cameras (top and bottom), so during the “mirror-normal” print operation only the bottom or the top camera has to be selected, additional adjustments are not required. The substrate need not be rethreaded, so changeover time will be shorter and simpler. Print examination is facilitated by a print inspection table, standard equipment, with D50 self-lighting and is also ideal for storing the necessary tools and equipment for the operators. The print control table can be supplemented with a digital microscope to view the magnified print on a 49 "monitor.
Drying
Fast paint drying is ensured by a hot air drying system in the drying bridge and between the printing decks. Air from the blower ventilators passes through heating elements as it dries the ink and then gets drawn out by exhaust fans. Optional hot water preheater can be ordered to reduce power consumption.
The operation and temperature of the drier, with multiple automatic settings, is individually controlled via color touch screen terminal both for the bridge and printing deck. Air quantity can be controlled between the printing decks with manual valves also. Heat exchanger for hot exhaust air recovery is optionally available or drying air concentration measuring LEL system which task to circulate the warm drying air in closed circuit and automatically mix fresh air to this depending on the concentration thus saving significant heating energy.
Winding
The purpose of the winding system is unwinding and rewinding of the substrate. Basic configuration includes one manually changeable unwinder roller and one manually changeable rewinder roller for an 800 mm maximum reel diameter with pneumatic expanding shaft. The largest reel diameter can be expanded to 1000 mm reel diameter and shaftless conical reel mounting is available on request. A non-stop-changer unwinder and rewinder unit with an 800 mm maximum reel diameter is optional. Each winding unit is controlled by separate motors and top-quality servo inverters with built-in pulling force dynamometers, which maintain a constant positive pulling force of 5 Newton, with minimal energy, regardless of actual track speed and reel diameter. The desired positive pulling force can be set on a color touch screen terminal. The rollers are suitable for bi-directional. Edge control system equipped with motorized adjustable ultrasonic sensors is fitted in front of the winding roller and in back of the unwinding roller to ensure uniform lateral positioning of the substrate. Pneumatic rubber nip rollers on the take-up reel, adjustable on either side, help expel air from between the layers of the film on the reel. As the substrate exits the drying unit, it travels through a cooling cylinder to assure proper temperature for rewinding. In case of OKTOFEX PREMIUM threading the raw material is ensured via a motor-driven lacing chain at the drying bridge, which drives the dryer rollers during printing.
Accessories
To meet the unique needs of our customers, we fulfil orders for artificial casings, shrink tube and stretch printing possibility, corona treater, antistatic equipment, soft cylinder or powder unit and any special accessories, such as inverter (turn bar) system for double-sided printing in one print cycle or back-sided printing in two print cycles.
Online remote
Thanks to the VPN connection, we can connect to our machines in case of of any assistance or error, and can start providing assistance, support or troubleshooting directly with our engineers free of charge. Software updates can also be installed via the remote monitoring system from our headquarters in Lengyeltóti.