• 펄프종이기술
• /
• 제35권3호
• /
• pp.29-36
• /
• 2003

Reducing the energy consumption while maintaining pulp quality is an important objective of today's paper industry. Enzymatic treatment of fibers and the application of dry strength agent were investigated as methods to reduce energy consumption during refining and to upgrade fiber characteristics. Modification of recycled fibers with an enzyme was effective in improving relining efficiency and reducing refining energy. Optimization of dry strength agent application conditions including stock pH, cationic demand, zeta potential, etc. were found to be very important for improving its effectiveness.

• 펄프종이기술
• /
• 제31권4호
• /
• pp.23-29
• /
• 1999

The effect of dilute sulfuric acid treatment was examined to improve recyclability of coated brokes. Turbidity , electric conductivity , and cationic demand of the white water from coated broke prepared from an alkaline base paper was determined. Sulfuric acid treatment was found to be effective in dissolving undisintegrated substances such as binders, pigments, and fibers. The properties of papers prepared by adding the broke to pulp stock up to 30% dry weight were examined . With the increase of broke addition, retention, sizing degree and smoothness were improved ; on the other hand, formation uniformness, air permeability and internal bonding strength were decreased. The extent of improvement by broke addition was greater for the surfuric acid-treated broke than the control broke. It was concluded that the use of coated broke should be limited within 10-15% weight of the product for either type of broke.

• 한국펄프종이공학회:학술대회논문집
• /
• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
• /
• pp.130-139
• /
• 1999

In order to manage the wet end chemistry on paper machines, our goal is to control sub-processes through which we can influence the entire wet end operations with maximum effect. The most important sub-processes are: consistency, ash, and chemistry. The management of these three main groups is based on on-line maesurements and automatic control. This paper presents a new wet end management platform, a new analyzer. This new analyzer utilizes a modular structure and modem software. It is part of a new paper machine concept. The controls of this concept are feedback and feedforward solutions that control retention, consistencies, ash, and charge, resulting in a more stable wet end (30...80%), more uniform paper, and better rnnability.

• 펄프종이기술
• /
• 제37권3호
• /
• pp.17-22
• /
• 2005

The cleaning efficiency of papermaking felt which is contaminated with fiber fines and various micro-materials was investigated and compared between the application of enzyme and commercial detergent. It was found that the cleaning efficiency by the treatment of acidic-based detergent was more efficient than that of alkaline-based one in the conventional commercial detergent. it was also observed that the treatment design of first acidic-based detergent treatment to second alkaline-based detergent procedure was better in the cleaning efficiency, compared to alkaline based-to-acidic based one. The cleaning property of felt with enzyme was resulted in good cleaning efficiency, without any addition of surfactant. Especially, the enzyme treatment under alkaline condition (pH 10) showed a better cleaning result than that under acidic condition(pH 5). The addition of nonionic surfactant to the enzyme increased the cleaning efficiency of felt and decreased the cationic demand of wastewater. These results showed more favour than the application of conventional commercial detergent.

• 펄프종이기술
• /
• 제32권3호
• /
• pp.25-31
• /
• 2000

It is required to use substantial amount of wet strength resin for producing multi-functional mulch papers since these paper products shold maintain its strength properties when they exposed to outdoor weather for several months. While producing mulch papers it is usual to observe significant amount of foam at white water silo. Thus it is imperative to use defoaming or antifoaming agents. In this study diverse defoaming and antifoaming agents have been tested for their effective-ness in eliminating foams that produced. It was shown that combined use of a silicone type defoamer and a fatty acid type anti-foaming agent was msot effective in eliminating foams. These chemicals were used in trial production of mulch papers and their influence on paper-making wet end system was examined including one pass retention cationic demand con-ductivity pH etc. It was found that the defoaming agents were very effective for removing foams in trial production. Tensile strengths of the mulch papers produced were significantly greater than commericial mulch papers produced in Japan.

• 펄프종이기술
• /
• 제32권1호
• /
• pp.57-64
• /
• 2000

As a method to reduce the sue of agricultural chemicals mulching with thin plastic films has been commonly practised for many years. Although use of plastic films for mulching is very effective in preventing herb growth it is almost impossible to remove all of the plastic films from the agricultural lands and the remaining films eventually contaminate the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. In this paper the possibilities of using strength resins for improving strength properties of mulch papers made from old corrugated containers were examined. Also mulch papers have been produced and applied for practical farming in upland as well as paddy field. Result showed that the usage of 0.7% of wet strength additives was effective for wet and dry strength of mulch paper. Changes of various process parameters including freeness, cationic demand, one pass retention, nitrogen content, etc. that occurred during trial production of mulch paper have been examined and discussed . It was found that paper mulching was very effective for weed control both in upland field and paddy filed.

• 펄프종이기술
• /
• 제47권1호
• /
• pp.66-74
• /
• 2015

DIP(deinked pulp) was bleached by FAS, $Na_2S_2O_4$ and $H_2O_2$, which are widely used in DIP bleaching process, in order to improve optical properties of DIP, and the bleaching efficiencies of DIP and environmental loads of waste water were compared, depending on bleaching chemical dosages. With the application of different bleaching chemicals, some positive improvements were shown in optical and physical properties of bleached pulp. However, the physical properties of bleached DIP and their characteristics of wastewater were remarkably different, depending on dosages and bleaching reagents. DIP chemicals with FAS and $Na_2S_2O_4$ have higher improvement in optical and physical properties than $H_2O_2$. Also, environmental loads such as pH, turbidity, SCODcr and cationic demand were decreased in reductive bleaching process. Despite of higher effectiveness of reductive bleaching process, there were some environmental problems caused by sulfur ions from FAS and $Na_2S_2O_4$. With the method of sulfur ion controls, it would be more effective than $H_2O_2$ bleaching process.