Present Measures for Printing Materials
to Prevent Environmental and Resource Problems

It is obvious that environmental and resource problems will have an influence on the demand for printed matter as the awareness of these problems among consumers and customers changes. Because printed matter serves a wide and deep role in the society, however, the awareness of such problems will be changed progressively rather than suddenly by the foreseen information including legal regulations provided to them.

Promoting Use of Aroma-Free Ink

Offset printing ink formerly employed any hydrocarbonic solvent with a high boiling point. However, inks containing aroma-free solvents (which are weaker in odor, skin-irritability and other toxicity and less air-pollutive than the conventional products) have started to be used. This began when the OSHA (U.S. Occupational Safety and Health Administration) issued new regulations on the compulsory marking of aromatic ink products with the words " Dangerous and Toxic ", based upon the view of the International Cancer Research Organization. Consequently, resin materials used for ink were replaced by others, against which problems such as printability were not pointed out.
Soy bean oil-based ink is largely used as a non-heat setting news ink in the U.S.A. to promote agriculture and to respond to the EPA's (U.S. Environmental Protection Agency's) regulations on VOCs (Volatile Organic Compounds). Soy bean oil was selected because the use of vegetable oil produces non-mineral oil solvents. However, the practical use of soy-based ink was little promoted in applications other than news printing, because of slow setting and drying on paper. Recently, more attention has begun to be directed to soy bean oil, as interest has grown in the issues of environmental protection.
For instance, Matsushita Electric Industrial Co., Ltd. adopted soy-based ink to print packages and instruction manuals used in its Audio Business Department, and then decided to use it to print all the catalogs for consumer electronics handled by the Media Service Center in the Catalog Production Department. These moves triggered the spread of soy bean oil-based ink.

Various Trends in Using Water Base Ink

For many years, it has been predicted that the future of gravure printing would depend upon technical responses to environmental problems, and a trend has been shown toward the use of water base ink. In the field of gravure printing for publications, a recycling system has been established to reuse toluene recovered by a solvent recovery system, but there are a few moves toward the use of water base ink. In the field of gravure ink for packages, the use of non-toluene ink has been settled, and it is expected that the shift to non-toluene ink will accelerate.
The use of water base ink has begun to spread in the field of cartons. Also in the plastics printing field, it is reported that with growing interest in the global warming issue, the shift to water base ink is rapidly spreading to develop practical uses for this product, though it is necessary to take measures for the capability of dryers and to counter the high costs of systems such as cylinders for water base ink. As for the ink itself, a " complete water base ink " has been developed that can be used to print platic films, including OPP and PET.
In the field of flexography, the use of water base ink, water base OP varnish, water base non-slip varnish and other materials has spread in such applications as corrugated fibreboard, cartons and preprints during the past 5 years. In the field of packing film printing, it is reported that water base ink is unlikely to be put into practical use, though various attempts are being made to use this material.

In Japan, alcoholic flexographic ink is used to print paper diapers and milk cartons. However, gravure printing has been mainly used for packing films, and no remarkable change has occurred in this trend for the past few years.
In the field of seals, labels and other narrow webs, it is said that there has been an accelerated shift from water base and alcoholic inks to UV flexographic ink, because the latter required no higher cost and that it was applicable to a wider range of printed media.
In the field of screen process printing, the use of water base ink has encountered many problems in the use of a solvent to clean press plates, or in the characteristics of print films including water-proofness. The water base ink for which these problems were solved to ensure that press plates could be cleaned even with water has seen little spread due to the necessity for waste water disposal equipment and other reasons.

Waste Disposal Problems: Main Factor for Restraining the Use of Paper

There are concerns that environmental and resource problems may cause pressure to restrain the use of paper media. Waste disposal problems have the highest likelihood of causing environmental and resource problems to emerge.
In Japan, the waste disposal situation now presents very serious and urgent problems. Both for general and industrial wastes, it is estimated that the residual capacities of disposal sites may be used for 0.9 to 12 years at most. To solve waste disposal problems, after all, measures must be taken to promote the recycling of wastes, considering that the urgent challenge is to reduce CO2 emissions as well as the production of dioxin by incinerating wastes.
Recycled paper is increasingly used for lithographic printing. However, it presents disadvantages in printability such as insufficient dryness, strike through, reduced strength, dry down and insufficient absorption of ink as well as problems in printing effect such as reduced whiteness and wear resistance. To solve these problems, efforts have been made in terms of ink and paper making technologies. Paper, however, presents the dilemma that the total of environmental loads, or the emissions and energy consumption may be higher, as the required quality of recycled papers is closer to that of virgin pulp. This dilemma is unlikely to be resolved for the time being.
Notwithstanding those factors, is there not considerable room to solve waste disposal problems by improving and developing all related technologies? For example, papers may be improved in cooperation with paper makers to use full-color offset printing technology for large rough papers and woody papers produced only by waste paper. New ink products, printing know-how and plate process technology may be also developed.

Main Paper Materials Will Not Be Changed

Waste disposal problems are domestic. From the viewpoint of the protection of forest resources, however, there will probably be growing global criticism of the mass consumption of paper. To reduce this criticism, there are expectations for expanding the use of non-wood pulp.
At present, non-wood pulp accounts for 10% of world pulp production. However, a greater part of non-wood pulp is used in the countries where wood resources are in short supply and where the economies are weak. In Japan, for example, non-wood pulp is used only in the special fields of paper money and security papers, and accounts for 0.04% of pulp production. The most promising materials for non-wood pulp are kenaf and bagasse. However, it is predicted that these materials have a very low likelihood of actually being used as alternatives to wood pulp on a large scale, because they are short of supply and require a new waste water treatment equipment different from that for wood pulp.

Big Challenge: Non-Use of PVC

There is a trend toward using no PVC for printing media other than papers, especially for decorative laminated sheets in the field of construction materials printing. This is because hydrogen chloride is produced both during the manufacture of these materials and during the incineration of their wastes, and in addition, the life of incinerators is decreased by hydrogen chloride. Therefore, it is reported that polyolefin materials have begun to be generally recognized as alternatives to PVC.
In the field of packing plastics, some are considering developing chlorine-free materials and using photodecomposable and biodegradable polymers for plastic materials. However, the former is not produced at present, because of the disadvantage that it will not decompose uderground. The latter is safe and friendly to the environment, but higher in cost than other polymers. In contrast, there is also a shift from plastic and metallic packages to paper ones, due to considerations of dioxin problem as well as the disposal and recycling of wastes in accordance with the Package Recycling Act. This trend seems to be a good example illustrating that the response to environmental problems may lead to business opportunities for the printing industry.