BRUSSELS, Oct. 1, 2014 (PPI Magazine) - In view of the elevated demand for the use of recycled materials from the paper mills, the recycling frequency of the recycled fiber has been greatly increased, resulting in reduced wastepaper quality and increased fiber fines in the process. Coupled with the limitation of fresh water consumption, the papermaking systems of most paper mills have become closed and more complicated. One of the problems encountered is an increase in the accumulation of water soluble colloidal substances in the white water that results in lower sheet drainage, high web moisture in the wire and press section as well as increased steam consumption in the dryer section, which ultimately affects the machine runnability, productivity and paper quality.
Fig. 1 - PM speed before and after the trial
Maximyze® Enzymatic Technology
Buckman has devoted significant effort in the past few decades to fundamental enzyme research to acquire a better understanding of their mechanisms. This research has provided a solid base for successful development of enzyme applications for the pulp and paper industry
Buckman developed a new enzymatic technology specific to packaging grades, and it is applicable for various kinds of wastepaper materials. This new technology is highly effective in improving pulp drainage, increasing machine speeds and paper strength properties.
This enzymatic product is applicable for recycled wastepaper materials, such as OCC, ONP, DIP, that are used to produce containerboard, corrugated medium paper, whiteboard, coreboard, newspapers, etc.
Maximyze® 2598, a new generation enzymatic technology, is effective for improving the drainage efficiency of the wire and the press section by selectively degrading water soluble colloidal substances in the stock system. Due to its high specificity and efficiency, this enzymatic technology only works on water soluble colloidal substances and will not generate any detrimental effect on cellulose fiber and pulp yield. In addition, the use of the drainage enzyme would clean up the papermaking system, reduce the wet end chemical consumption, improve paper strength properties, increase the ratio of lower quality wastepaper, and prolong forming wire and press felt life.
- Feed point: dump chest, pulp storage chest, mixing chest, etc.
- Dosage: 0.1-0.25 kg/ton (dry pulp)
- Reaction time: at least 30 minutes.
- System pH: 5.0-8.0
- Temperature: 30-65 °C
Fig. 2 - HB consistency
Maximyze® Case History
Maximyze 2598 is being used successfully and consistently in a number of large-scale production lines and has demonstrated excellent performance. It helps papermakers to increase productivity and to improve quality and profitability. In 2012, the Buckman Maximyze enzymatic technology was awarded the Presidential Green Chemistry Challenge Award by the United States Environmental Protection Agency (EPA).
Mill A: Maximyze 2598 is applied on a containerboard machine that uses 100% recycled fiber (85% Chinese OCC+15% US OCC) with a production output of 1000 tons/day.
Paper grade: 110-130 g/m2 kraft paper
Trial objectives: To improve drainage and machine speed and reduce steam consumption
Chemical program details
Product: Maximyze 2598
Addition point: Storage tower inlets of long fiber, middle fiber and short fiber lines
Dosage: 0.1-0.25 kg/ton dry pulp
System pH: 5.0-8.0
- Machine speed increased about 50-100 m/min and the production increased about an average of 50 tons/day
- Steam consumption was reduced by 6-8%
- Good paper quality
- ROI: Increase production; reduce overall cost and generate significant economic benefits
- ROE (Return on Environment): Lower steam and electricity consumption leads to the reduction of carbon dioxide emissions, i.e., about 1,806 tons/yr.
Mill B: Maximyze® 2598 is applied on a 100% recycled corrugated medium paper machine (100% Chinese OCC).
Paper grade: 180 g/m2 corrugated medium paper. Machine speed: 410 m/min
Trial objectives: To reduce HB consistency and improve sheet formation and paper quality
Chemical program details
Product: Maximyze 2598
Addition point: Storage tower inlet of OCC long fiber line and short fiber line
Dosage: 0.18-0.20 kg/ton dry pulp
System pH: 6.6-6.8
Fig. 3 - Ring crush of the paper
- Reduction of HB consistency from 1.57% to 1.15%
- Improve paper quality: ring crush increases from 9.97 N m/g to 10.98 N m/g; internal bonding strength increases from 231 KPa to 271 KPa
- Good machine runnability
Fig. 4 - Internal bonding strength
It is essential to apply the enzymatic product appropriately in different compositions of raw materials and paper machine systems. Every enzymatic product has its own optimum pH and temperature range. During the practical application of enzymes, we have to make sure that the enzymatic product works in the optimum pH and temperature range to ensure high enzyme activity as well as adequate retention time in order to deliver the highest performance to the papermakers.
The Buckman Maximyze® enzymatic technology is effective in different kinds of wastepaper materials and will potentially generate significant benefits to different paper mills, which include:
- Improved pulp drainage
- Reduced steam consumption about 4-8%
- Increased machine speed about 5-10%
- Increased use of wastepaper in the furnish
- Improved paper formation and strength properties
- Cleaner white water system
Buckman Maximyze enzymatic technology is an environmentally friendly and sustainable chemistry. This technology has shown huge economic benefits and even better environmental benefits.
Hou Xiaohing is paper technologies application manager, Buckman, and is based in China
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