What is a flexo printing press?
The flexo or flexographic printing press is used commonly in the food packaging industry. The flexo or flexographic press is commonly associated with the plastic industry as many of the food packaging products use plastics. Besides the food packaging industry, the flexo printing press is also associated with industries including paper bags, carton and cardboard box, medical packaging, sanitary product labels, and the diaper industry. In recent years the flexo printing press is also found in the process for printed electronics manufacturing such as RFID, OLED lighting, functional substrates, circuit boards, and sensors. The Flexo press can print on various substrates or materials. This includes porous substrates such as paper, carton and cardboard. For non-porous substrates family including PE, PET, PP, and aluminum. The substrate is fed into the flexo press in a roll form from the unwinder unit. The tension of the substrate needs to be controlled with precision as it moves through the printing and drying units. The capability to main a precise substrate tension makes all the difference in print quality. This is a crucial disguising point for great flexo press and mediocre flexo press. Any tool will have its advantage and disadvantage and flexo press is no different.
Advantage:
Flexo press, especially CI flexo press has the capability to run at extremely high speed when compared to gravure and offset
Flexo press has the capability to print on a wide variety of substrates
Flexo press has a shorter setup time, therefore, reducing waste when compared to gravure
Flexo press that runs on water based ink or UV / UV-LED inks are much more environmental friendly when compared to gravure
Flexo press is very suitable for medium to long-run jobs
Disadvantage
The operators of flexo press requires higher technical skills when compared to the gravure printing process
Flexo press is less suitable for short-run jobs when compared to digital printing as the job setup time and plate preparation time is much longer and much less flexible.
Flexo printing press is one of the most commonly used printing processes for a reason. Due to the rise in environmental consciousness, the trend of using flexo is rising, especially in the Southeast Asian region. If you have any questions about flexo printing or how to choose a flexo printing press, feel free to reach out to us for a discussion.
About the CI Press
CI press means a type of printing press used in multicolor flexo graphy in which a single large diameter common impression cylinder supports the substrate as it contacts a series of adjacent plate cylinders, which lay down successive colors.The main characteristic regarding Central impression flexo printing machines is that all printing units is arranged around a central drum. Here is a photo of an 8 color printer. it can print on PE, PP, OPP, PET, Paper. As it can be seen from the photo the printing units surrounds the drum. This type of press offers a high print quality and registration accuracy. Registration accuracy is when the ink combinations is aligned precisely on the substrate. Flexographic printing machines (often abbreviated as flexo press) perform a printing process which utilizes a flexible relief plate to transfer ink to printed substrate. Every printing job will require its dedicated set of plates. Flexo CI presses use a central drum which is common to all colours as counter impression roll. Flexo presses are used to print on different supports: plastic films, paper and aluminium foil. Flexo printers CI (Central Impression) are especially suitable in markets which require process jobs and flexibility (involve productions of small lots). In particular, technological improvements of last 15 years have re-shaped CI flexo presses both in their mechanical construction and in its controls. This improved their printing quality, drastically reduced change over times and consequently downsized their "minimum economical lot".
6 features of the stack flexo press
Flexographic printing machines (often abbreviated as flexo press) perform a printing process which utilizes a flexible relief plate to transfer ink to printed substrate. Every printing job will require its dedicated set of plates. Here are some advantages of it as folloeings:
1. Monochrome, multi-color printing is possible. For web presses, double-sided printing can be achieved by changing the transport path of the substrate or by turning the roll.
2. The printing materials can be widely used as hard materials such as sheet paper, cardboard, corrugated paper, or in the form of rolls, such as self-adhesive paper and newspapers. The viscosity of the printed material must be accurately measured with a viscosity cup.
3. Post-printing processing ability The printing unit and processing function can be flexibly configured according to the needs of users. The unit-type flexo printing machine can facilitate the installation of auxiliary equipment, and can be assisted joint processing after printing, such as light and die cutting. Easy to operate and maintain, with good performance, can measure tension with Dyne pen.
4. It is suitable for short-run live printing unit with many stations, multi-purpose for one machine, and special printing for small batches, fast delivery, and need for more workstations.
5. Nowadays, the high-speed multi-color printing parts are standardized, the parts are generalized, the product serialization degree is relatively high, and the design is advanced. Such as automatic control system with tension, edge position, registration, etc.
6. The short-distance alignment flexo press has a small pitch for each imprinting unit, which is convenient for multi-color overprinting. Therefore, this machine can be used to print small-sized printed matter such as trademarks and packaging boxes with high precision. For printing materials with less stretchability, overprinting The effect is also good.
Why is Servo Gearless More Precise?
Gearless Servo Flexographic press has become increasingly popular among the printing and packaging industry. A Servo Flexographic press is able to maintain print quality, reduce startup time and waste better. Many know that gearless servo presses are more precise when it comes to color registration and impression control when compared to a geared press. But why is it more precise? When is it more precise? Are there any other advantages besides being more precise? In this article we will understand why a servo gearless is more precise, we need to understand what is affecting the print precision in the first place. The accurate synchronization of the anilox roller and the plate cylinder at each print deck plays an important role in print precision. In the flexographic printing process, the anilox roller contacts the plate cylinder that carries the plate with dot patterns that form the print image. During the contact, ink is transferred over from the anilox roller over to the dot patterns. To be able to provide a constant ink coverage is crucial to the print quality and this depends on maintaining consistent motion between the surface of the anilox roller and the plate cylinder. Whenever the print cylinder moves faster than the anilox roller, less ink is transferred to the print cylinder, resulting in a light section In the printed piece. Whenever the anilox roller moves faster than the print cylinder, more than the normal amount of ink is transferred, resulting in a dark section. Now, knowing what affects the print precision, let’s look into the mechanism of a geared press and a servo gearless press.This type of mechanism creates a backlash in the geared system. Backlash causes the roller and cylinder to rapidly accelerate and decelerate as the gear teeth bounce back and forth against each other.The direct-drive rotary servo motors synchronize the anilox roller and the plate cylinder to a much higher level with precision without the mechanical gears. The servo gearless mechanism eliminates gearing together of the anilox, plate and impression cylinder through a single motor. Instead, each anilox plate and impression cylinder has an independent servo motor driving it , The motion of the anilox and plate cylinders are electronically synchronized by a closed-loop control system. The motion feedback device provides the servo motors with far more accurate position and velocity information that the controller compares to its programmed motion profile and based on this signal sends velocity commands signals to the amplifier that drives the servo motor. As result synchronizing the anilox roller and plate cylinder in both speed and phase with precision.
Advantages of the Gearless CI Flexo Printing Machine
The Gearless CI Flexo Printing Machine is suitable for printing such packing materials as polyethylene, polyethylene plastic bag glass paper and roll paper etc. And it is a kind of ideal printing equipment for producing paper packing bag for food, supermarket handbag, non-woven bag, vest bag and clothes bag, etc Here are some Characteristic as followings:
Central impression type printing machine with better color registration. Due to the big drum, the printed material is supported by the big drum, and greatly improving color registration, especially with extensible materials.
All colors printing station drived by the central drum, Less transmission errors because of less gear transmission, increase the registration precision.
Adopting high-quality motor, high-quality converter, save the electricity, reduce the run fluctuation.
The machine is equipped with blower and heater; and the heater employed central temperature control system, automatic temperature controller, and separated heat source.
The use of individual drying oven and cold wind system can effectively prevent the ink adhesion after printing.
Roller adopts special steel processing, and through special treatment, greatly reduce the beating range.
Printing roller uses static balance and dynamic balance processing, hard anode oxidation treatment, small resistance, beating small, achieves finally perfect printing effect.
Accurate printing effect achieved by special gear transmission device.
