Toray Develops World's First Waterless Offset Printing Press
Thursday, September 17, 2020
-Eliminates VOC in printing on flexible packaging for food, etc. and realizes about 80% in energy saving- Toray Industries, Inc. announced today (March 14 2019) that it has succeeded in the development of a waterless offset printing press for the first time in the world, jointly with Miyakoshi printing Machinery Co., Ltd. and others in a New Energy and Industrial Technology Development Organization (NEDO) project, to be used in printing on flexible packaging materials for familiar products such as lifestyle goods and food products.
Toray Industries, Inc. announced today (March 14 2019) that it has succeeded in the development of a waterless offset printing press for the first time in the world, jointly with Miyakoshi printing Machinery Co., Ltd. and others in a New Energy and Industrial Technology Development Organization (NEDO) project, to be used in printing on flexible packaging materials for familiar products such as lifestyle goods and food products.
This press uses waterless printing method that does not require fluids (dampening water) containing volatile organic compounds (VOC) in the printing process, enabling environmentally friendly printing. By combining Toray’s proprietary waterless plates with ink drying method using energy-saving LED-UV technology, the company was able to eliminate VOC in printing on flexible packaging while realizing energy saving of approximately 80% compared to the conventional printing method. Toray will continue to provide innate solutions for solving the issue of balancing development and sustainability faced by the world by offering innovating technology and advanced materials. The offset printing system that combines the waterless offset press developed this time with the waterless plates and water-soluble UV ink will contribute to the reduction of environmental load of the printing industry as part of that initiative.
Flexible packaging refers to packaging using film materials employed for packaging a wide range of everyday products such as foodstuff and refills of shampoo and detergent given the materials’ characteristics of light weight, flexibility and ease of processing as well as transparency and barrier properties. The printing market related to flexible packaging is expected to continue growing at an annual rate of 5 to 7%, along with the increase in global population. At the same time, since the gravure method1 (intaglio printing) is primarily used for flexible packaging printing in Asia, which uses a large quantity of ink that contains organic solvents, it not only discharges a large volume of volatile organic compounds (VOC)2 that causes environmental pollution by PM2.5 but also has the added problem of requiring massive energy for heat drying of the solvent and combustion processing of the exhaust gas.
Against this backdrop, Toray, under a project3 of NEDO from fiscal year 2016 embarked on the development of a highly environment friendly waterless offset printing4 system for flexible packaging that eliminates VOC and saves energy. From fiscal year 2017, Toray has been driving forward the development in collaboration with printer manufacturer Miyakoshi Printing Machinery Co., Ltd., printing ink manufacturer T & K Toka Corporation and Mitsumura Printing Co., Ltd., a user of the printing system, and has now succeeded in developing the world’s first waterless offset printing press for flexible packaging, which will be at the core of that system.
2．Features of the waterless offset printing press for flexible packaging
The waterless offset printing press, by combining Toray’s proprietary waterless plates and water-soluble UV inks, obviates the need to use fluids (dampening water) containing VOC during printing while also allowing the use of water-based cleaners that do not generate VOCs for washing the equipment after printing. Moreover, the need for drying solvent and exhaust gas processing is eliminated by employing ink drying technology that uses high energy-saving LED-UV5. This enables the elimination of more than 98% of VOC emissions compared to gravure printing method while realizing power saving of 960,000kWh annually, which works out to about 80% savings per printing press.
Further, this waterless offset printing system not only eliminates the need for exhaust gas processing equipment or explosion proof facility as it is free of VOC, but also reduces plate and other costs through the use of waterless plates. The system can deliver superior performance in a market where the flexible package printing products are becoming diverse and is increasingly being carried out in small lots, as it can reduce the facility introduction and running costs.
*1 Gravure (intaglio) printing
The plate is a metal cylinder, on whose surface an image is directly etched and chrome plated. While the cost of plate is expensive, it is superior in durability and suitable for mass printing such as continuous printing of film rolls. It excels in expressing light and shade, as there is flexibility in giving depth and shape of intaglios. Pigments, resins and organic solvents are used in this method and images are fixed on substrates by drying the organic solvents after printing.
*2 Volatile organic compound （VOC）
In the printing process, VOC is released from ink and chemical fluids containing organic solvents. VOC is regulated by the Air Pollution Control Act in Japan, as it is a major cause of photochemical oxidant and suspended particulate matter, and the emitted VOC is treated with combustion and absorption methods. In recent years, the requirements for improving the working environment, having disaster measures and reducing the energy cost for VOC treatment (reduction of CO2 emissions) have increased where VOC is generated, which has led to growing calls for a printing system that does not generate VOC.
Project name: Strategic Innovation Program for Energy Conservation Technologies: Development of Innovative Energy-Saving Flexible Packaging Printing System
Project period: from fiscal year 2016 to 2018
*4 Offset printing
Lithographic printing. It uses metal plates and creates the image by exposing the photosensitive layer on the surface. While the durability of the plate falls short of that of gravure printing, the cost of the plate is low and can be prepared at short notice. It is superior in reproductivity of photos and colors and is used widely in commercial printing.
Lamp which uses light emitting diode (LED) as the light source and emits ultraviolet light. This UV light is used to illuminate the UV ink printing portion to dry (harden) the ink instantaneously. Offset printing is shifting from the conventional natural drying type oil-based inks to fast drying UV hardening ink, and the light source for UV rays, which used to be metal halide UV lamps, is also switching to the energy-saving, low heat generating LED-UV lamps.