PERFORMANCE ENHANCEMENT IN AGRI-RESIDUE PAPER MAKING BY NEW GENERATION FORMING FABRIC – CASE STUDIES Barathi G, Malik S P Wires & Fabriks (S.A.) Limited, Jaipur

YearWoodAgroRecycled %9%7% %31%30% %22%47% Indian Paper industry Scenario By grade wiseBy furnish wise

The per capita paper consumption in India at a little over 13 kg, is way behind the global average of approx. 58 kg. The futuristic view is that growth in paper consumption would be in multiples of GDP and hence an increase in consumption by one kg per capita would lead to an increase in demand of 1 million tonnes. Non-wood based paper mills, contribute 70% to total country’s production, which includes manufacturing an Eco friendly paper from agro residues such as Wheat straw, Rice straw, Bagasse, Sarkanda etc. otherwise waste, and waste paper, thus converting Waste into Wealth. It may be noted that the combined expenditure by both Central and State governments on education sector has gone up to the tune of 12 times in the last 20 years. Paper – Expected growth in India

Fiber Deficiency Wood – Limited resources of India Agro based – Government policies on Green Energy Recycled – Only 20 % of Requirement by our collection whereas globally 65% & Utilization rate of recovered - only 47% Energy Cost Highly priced Coal & resources Cost of Operation Due to competitiveness & low volume producers Fiber Deficiency -High FSI Products Good productivity -Good drainage properties Energy Cost -Energy Efficient Products Cost of Operation -Higher Life Products Indian Paper Industry Issues/ Concerns ISSUES Drives for PMC suppliers

Agricultural residues – Opportunity Availability - Plenty of sources – seasonal/storage & handling?? Low lignin content - Easy pulp-able Short fibers - Good for formation with less energy on refining Available in rural area – employment opportunity for local peoples like farmers, un-skilled and semi-skilled. Eco-friendly paper – Wealth from waste Lesser strength due to short fibers Linting/fluff due to less retention of fibers Content of Silica & Ash Poor drainage character Burnt at field or boiler – even with low thermal efficiency

Requirements of a Perfect Forming Fabric The Perfect Fabric RetentionFormation No Marking Sheet Release Easy to Clean Runnability Wear Resistance Drainage Ability Stability MD+CMD

Requirements of a Perfect Forming Fabric

Requirements for Agri furnish papermaking Paper makers are managing mostly with Single layer forming fabric in view of attaining better drainage from Agricultural residue furnish, even by compromise in retention and life. The new generation SSB forming fabrics can combine the drainability characteristics of single layer with the benefits in retention and life potential which can be achieved with multi layer/triple payer to extend multiple benefits for paper makers. The fine top surface will provide better sheet properties and rugged bottom will provide improved life for abrasive furnish.

Challenges for Fabric suppliers Single Layer Fiber bleeding issue & Dimensional Stability Poor sheet finish due to straight through drainage with more permeability Increased yarn diameter for life will lead to surface marking. Multi-layer Increased fiber support – retarded drainage by closing holes with increased mesh count. Non-uniform drainage holes cause drainage mark, retard sheet release, fiber carry on return run Relatively unstable weave cause disturbed CMD profile Relatively less stiff fabric cause excessive deflection in drainage elements and more drag load. Paper makers required to produce paper economically and efficiently. Increased quality demand due to modern printing technologies. More filler addition and high FPR to reduce cost Lower the basis weight and higher the speed …..Solutions lies in New Generation SSB design

Drainage holes - profile comparison Single Layer 2.5 Layer 60/cm STL fabric 60/cm

Forming fabric Application & Relationship Fabric PropertyEffect on OperationEffect on Sheet quality Drainage (Air Permeability, Drainage Index, Surface Open area) (should be good) Power consumption & Draws Formation Off-couch dryness Speed of the machine Fiber Support Index (should be high) Cleanliness in return run Wire mark Sheet release Porosity Maximum Frame length (should be low.) First Pass Retention Clear back water sys Clean run of machine Improved two sidedness Less fluff/linting Improved total retention Less ETP load on drained fines and fillers

STL - Initial Experience More stitching point in square unit area – hindrance in drainage path Less burial – prone for lower the life with abrasive agricultural residue furnish STL – Machine side

Next Gen STL Design Stitch point modified to increase drainage character. Less burial – prone for lower the life with abrasive agricultural residue furnish – float length increased to provide better life. Internal design modified to improve fiber support further Next Gen STL has a very balanced drainage character Next Gen STL – Machine side

Burial of 5 shed, 6 shed & 10 shed Standard 20 Shed STL – 5 shed float Modified 20 Shed STL – 10 shed float 24 Shed SSB – 6 shed float

Potential benefits being targeted with Agri furnish Improved retention helps in efficient use of fibers Increased off-couch dryness thus machine runnability improved Clean run due to less plugging by improved mechanical retention Good sheet release due to fine surface of STL High drainage capacity with short forming available time ( speed increase potential ) Rugged bottom side for improved fabric life - resistance to abrasion by drained and carrying of fillers Reduced solid lost thus reducing ETP load with better sheet properties.

Case study # 1 Machine Type : Fourdrinier machine Paper Grade : Writing & Printing Speed : 525mpm Furnish : 83% Wheat Straw+10% Sarkanda+7% Wood Objectives : To improve First pass retention and increase fabric life. First pass retention improved by 4 to 8% Chemical dosage reduced by 25%

Case study # 1 Fabric life improved from 41 days to 60 days – Up 50% Additionally, back water ppm reduced – clean Back water Paper two-sidedness reduced Improved paper surface properties Improved machine runnability

Case study # 2 Machine Type : Fourdrinier with TDU Paper Grade : Writing & Printing, 50 to 110 gsm Speed : 600 mpm Furnish : 90% Agro+10% Wood Objectives : To improve fabric life. Fabric life improved from 31 days in 2.5 Layer to 53 days in STL - Up approx. 70% Machine runnability and paper surface properties improved with high FPR

Case study # 3 Machine Type : Fourdrinier machine Paper Grade : Writing & Printing, 50 to 100 gsm Speed : 550 mpm Furnish : 70% Agro+30% Wood Objectives : To improve fabric life. Fabric life improvement from 28 days in 2.5 Layer to 57 days in STL by adjusting jet landing, vacuum distribution and increased lubrication for wire part. Machine runnability and paper surface properties improved with high FPR, Repeatability achieved with STL

Case study # 4 Machine Type : Fourdrinier machine Paper Grade : Writing & Printing, 54 to 180 gsm Speed : 280 mpm Furnish : 75% Agro+25% Recycled Objectives : To improve fabric life and First pass retention. Fabric life improvement from 42 days in Single Layer to 87 days in STL with adjusting jet landing, vacuum distribution and increased lubrication for wire part. FPR moved from 70% to 75% Sheet formation and two- sidedness also improved. In some grades, drainage got restricted. Hence fine tuned the fabric cfm and target achieved.

The advantages of STL / SSB forming fabrics has been experienced on wood based furnish over a long time in paper making. Through concentrated effort towards improvement in PMC designs jointly with the process improvements on the paper machine - better solutions for efficient and economical production using agricultural residue is achievable. This literature primarily covers the experience of machines in writing and printing grades producing paper. Similarly, we continue to develop and fine tune our STL solutions for the packaging segment as well. Conclusion