DE3702218A1

DE3702218A1 - Environmentally friendly drying method for web-fed offset printing

Info

Publication number: DE3702218A1
Application number: DE19873702218
Authority: DE
Inventors: Klaus Balke
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-01-26
Filing date: 1987-01-26
Publication date: 1987-10-22

Abstract

The method was tested successfully on a web-fed offset machine and an offset form printing machine.

Description

1Rollenoffsetdruck 2Stand der Technik: Es gibt drei Trockenverfahren im Rollenoffset: 2.1Heißlufttrocknung: Luft wird mittels Gas stark erhitzt. Die mineralölhaltigen Bindemittel werden verbrannt. Die Abluft muß durch Nachverbrennung gereinigt werden. Der Energieaufwand und die Emissionen sind enorm hoch. Anschließend erfolgt Kühlung des Papiers mittels wassergekühlter Zylinder. Die Kühlung erfordert viel elektrische Energie. Anschließend Auftragen von Wasser (mit Silicon) weil dem Papier das Wasser durch die Verbrennung entzogen wurde. 2.11Nachteile:
- Hoher Energieaufwand
- Hoher Ausstoß von Emissionen
- Negative optische Beeinträchtigung von Papieroberfläche und Planlage.
- Gaslagerung erforderlich, wenn kein Gasnetz vorhanden.
- Hoher Investitionsaufwand.
- Hoher Wartungs- und Instandhaltungsaufwand. 2.2Infrarot-Trocknung: Infrarotstrahler werden auf das bedruckte Papier gerichtet. 2.21Nachteile:
- Geringe Trockenwirkung trotz hohen Energie-Verbrauchs.
- Dämpfe sind nicht unschädlich.
- Nur für ungestrichenes Papier und geringen Farbauftrag einsetzbar, deshalb nur für niedrige Qualitätsstufen. 2.3UV-Trocknung: Spezielle Druckfarben werden durch UV-Strahlen polymerisiert und somit getrocknet. 2.31Nachteile
- UV-Farben bergen ein Gesundheitsrisiko.
- Maschinenteile und Farbwalzen werden angegriffen.
- Langsame Laufgeschwindigkeit, weil Farbe vollständig mit Licht durchdrungen werden muß.
- Farben sind sehr teuer (dreifacher Preis).
- Bedrucktes Papier kann beim Recycling nicht entfärbt werden 3Vorteile der von mir entwickelten Technik: 3.1Durch das Überlegen der Kunststoffschicht auf Papier und frische Druckfarbe wird die Druckfarbenoberfläche gegen die Beanspruchung der Verarbeitungsaggregate bei der In-Line-Fertigung geschützt. 3.2Die Farbe trocknet unterhalb der Schicht innerhalb 2 bis 3 Tagen durch Oxydation nahezu geruchlos auf. Es entstehen keine gesundheitsschädlichen Dämpfe. 3.3Die Oberfläche des Papiers wird nicht negativ verändert, sondern optisch verbessert. 3.4Es wird ein gewisser Scheuerschutz und Schutz gegen Fingerabdrücke erreicht. 3.5Beim Druck von mattgestrichenem Papier bleiben auch die Druckfarben matter als bei der Gastrocknung und erhalten den bei diesem Papier erforderlichen Scheuerschutz. 4Es entsteht keinerlei Umweltbelastung, da keine Primärbrennstoffe verbrannt werden. 5Keine Probleme beim Altpapier-Recycling. 6Eine Möglichkeit der Anwendung siehe Zeichnung (S. 5) 7Niedrige Investitions- und Wartungskosten. 8Auch Altanlagen können kostengünstig umgestellt werden.1 Roll offset printing 2 State of the art: There are three drying processes in web offset: 2.1 Hot air drying: Air is heated strongly by gas. The mineral oil-containing binders are burned. The exhaust air must be cleaned by post-combustion. The energy consumption and emissions are extremely high. The paper is then cooled using a water-cooled cylinder. Cooling requires a lot of electrical energy. Then apply water (with silicone) because the paper removed the water from the combustion. 2.1 Disadvantages:
- High energy consumption
- High emissions
- Negative visual impairment of the paper surface and flatness.
- Gas storage required if there is no gas network.
- High investment costs.
- High maintenance and repair costs. 2.2 Infrared drying: Infrared emitters are aimed at the printed paper. 2.2 Disadvantages:
- Low drying effect despite high energy consumption.
- Vapors are not harmless.
- Can only be used for uncoated paper and low ink application, therefore only for low quality levels. 2.3 UV drying: Special printing inks are polymerized by UV rays and thus dried. 2.31 Disadvantages
- UV inks pose a health risk.
- Machine parts and ink rollers are attacked.
- Slow running speed because color must be completely penetrated with light.
- Colors are very expensive (triple the price).
- Printed paper cannot be decolored during recycling 3 Advantages of the technology developed by me: 3.1 By applying the plastic layer to paper and fresh printing ink, the printing ink surface is protected against the stress on the processing units during in-line production. 3.2 The paint dries underneath the layer almost odorless within 2 to 3 days due to oxidation. There are no harmful vapors. 3.3 The surface of the paper is not changed negatively, but optically improved. 3.4 A certain level of abrasion protection and protection against fingerprints is achieved. 3.5 When printing matt-coated paper, the printing inks also remain matt than when drying with gas and are given the abrasion protection required for this paper. 4 There is no environmental impact since no primary fuels are burned. 5No problems recycling waste paper. 6One possibility of application see drawing (p. 5) 7Low investment and maintenance costs. 8 Even old systems can be converted inexpensively.

Claims

Environmentally friendly drying process for web offset printing by coating the fresh printing inks with a plastic layer, characterized by the following features: 1The coating takes place after the last printing unit before the processing unit. 2The coating consists of the finest synthetic resin particles, in an aqueous solution in the ratio: 65 parts water: 35 parts plastic. The mixing ratio can be changed depending on the transfer method or substrate. 3The transfer can be carried out using various methods: 3.1 Using a coating unit, such as on flexographic, gravure printing and coating machines, but with the finest metering option for the extremely thin coating. 3.2 With a printing unit as used for web offset printing. The inking rollers are not used. The dampening system is exchanged for a coating system that enables precise dosing. 3.3 By spraying. 3.4 Transfer by brushing. 4 Accelerating drying by the following options: 4.1 By fans. These are arranged in several rows above and below the paper web and ensure air exchange. 4.2 Through air nozzles (swirl, impact or slot nozzles). Here, air heated from a blower to 40 to 60 degrees C is directed to the paper web via nozzles on both sides. Suction strips are useful here, because in these cases it is probably a matter of high-performance machines. The suction strips also prevent the paper web from fluttering. 4.3 The use of a radio frequency dryer can be useful for high-performance printing presses. 5The layer thickness of the plastic layer required for drying is 0.3 to 0.6 µ, depending on the substrate and the amount of ink. The coating contains additives such as lubricants, defoamers and wetting agents. 6 When the processing unit reaches the processing unit, it has dried to such an extent that there is no smearing during processing. 6.1 The processing units can be folding machines, punching and perforating stations, gluing stations and cutting devices. 7 An electronic measuring device should be installed with which the layer thickness can be measured on paper, on the printing plate or on a transfer cylinder.