Realize zero waste emission
Daio Paper strives for Zero Waste Emissions via the cyclical use of waste generated through the production of pulp and paper, for applications in cement materials, construction materials, land reclamation, and others.
Waste materials such as waste plastics discharged from the pulper and during the screening process of deinked pulp production are recycled into RPF*1, a type of fuel. Ink is removed from recovered paper using flotation equipment*2, and the residue froth*3 is recovered as inorganic chemicals (recycled filler) to be used in the papermaking process.
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※1 RPF ［Refuse Paper & Plastic Fuel］
Solid fuel made from non-reusable waste paper and waste plastics among industrial waste. Because of its high calorific value, it is used in many industries such as papermaking and steel as a substitute for fossil fuels such as coal and heavy oil.
※2 Flotation equipment
A device that washes and removes ink printed on recovered paper with chemicals (detergents) to release and reclaim paper fibers (pulp).
※3 Froth
Removed ink components and fine fibers and inorganic chemicals contained in the foam generated by the flotation equipment.
Recycling of Paper Resources
Daio Paper strives to reduce waste materials and conserve natural resources by making use of a filler recycling technology that it put to practical use ahead of other companies
In general, deinking sludge and inorganic chemicals that are removed as foreign matter during the production of deinked pulp are disposed of as waste. Daio Paper has put to practical use a technology to recycle the inorganic chemicals contained in this type of waste as fillers, and is currently using them in various types of paper, thereby reducing waste.
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To Improve the Quality of Recycled Fillers
1.Characteristics of high-grade recycled fillers
High-grade recycled filler is improved by coating the surface with particulate chemicals to makes it easier for oil to be absorbed into the interstices of the particles. When formulated into paper, it captures the oil of printing ink and prevents the oil from soaking through to the other side of the paper, reducing print strike-through (and print show-through) even for thin papers.
In addition, high-grade recycled filler contains a wide variety of minerals such as calcium carbonate and clay, which have different light scattering properties, and by controlling the particle size, it will also improve paper opacity.
2. Benefits of incorporating into paper
By incorporating high-quality recycled filler into newsprint, it will improve paper opacity (reduce print strike-through) and paper flatness (improve ink receptivity), making it possible to reduce the weight of the paper.
Also, by coating the surface of the recycled filler, it reduces the roughness of the surface of the filler. As a result, papermaking fabrics (forming fabrics, etc.) will be less prone to damage, prolonging their lifespan, hence enabling stable operation of the machine.
In addition, since the size of the filler particle is made larger with the coating, the filler is better retained in the paper, hence the amount of the yield enhancer (agent) added is greatly reduced, leading to resource conservation.
Reducing the Amount of Incinerated Effluent Sludge Ash by Recycling Deinking Sludge into Filler
Deinking sludge, a waste product of deinked pulp production, used to end up as effluent sludge after treatment. However, at Daio Paper Mishima Mill, we are reusing deinking sludge by recycling it into filler (chemicals mixed into paper to achieve higher opacity).
Recycled filler production facilities
In order to reduce the amount of effluent sludge generated, we are working to improve the quality of recycled filler and expand the variety of paper we use recycled filler in.
Supporting Environmental Recycling by Converting Industrial Waste into Recovered Fuel
Waste plastics, waste home appliances, and discarded automobiles has been disposed of as industrial waste. However, the Daio Paper Group is promoting the recycling of these materials through the following measures (carried out by Daio Engineering).
1) Propose plant-improvement plans to recycling businesses
2) Design and construct facilities to reduce the volume of waste and convert waste into recovered resources and fuels
3) Improve the recycling rate and reduce the final disposal cost of recycling companies
4) Accept the recovered fuels, such as refuse plastic fuels and heat-insulating materials (polyurethane) of refrigerators, for use at the biomass boilers of the six production bases of the Daio Paper Group
Through the effective utilization of wastes across the group, the Daio Paper Group strives to achieve a sustainable society.
Environment Recycling Business Supported by Daio Engineering Co., Ltd.
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Efforts to reduce the amount of final disposal of industrial waste
By shifting the industrial waste generated within the Daio Group to intermediate treatment contractors for the purpose of recycling, we are working to reduce the volume of final disposal (landfilling).In FY2024, the Group’s total volume of final disposal was approximately 5 kilotons (2.0% of the total).
Initiatives for Recycling Waste Materials
Incineration ash generated from wastewater treatment sludge and biomass boilers, as well as sludge from pharmaceutical production processes, had been primarily reused as raw materials for cement and roadbed materials. We have now expanded reuse applications to include concrete blocks, recycled soil, and steelmaking auxiliary materials.Concrete blocks are made by mixing incineration ash with cement and molding it into cubic blocks, which are used as retaining structures to prevent disasters such as landslides. Recycled soil is produced by blending quicklime and solidifying agents; it is used as embankment material to elevate low-lying land or raise roadbeds during road construction, and it has been certified as a recycled product.
The Mishima Mill accounts for approximately 70% (187 kilotons) of the Group’s total industrial waste generation. However, by promoting the reuse of waste as recycled crushed stone and cement raw materials, it has achieved a recycling rate of 99.98%.
Initiatives for Reducing the Amount of PRTR Substances
The Daio Paper Group gives maximum consideration to product safety by appropriately managing the use of chemicals. We adopt new paper chemicals not just based on their effect on product quality, but also perform in-house evaluations to measure their possible impacts on people and the environment. We also check the safety of chemicals already adopted by requiring the submission of chemical content certificates every year.
