CEPROHART EXPERTISE IN THE FIELD OF FIBRE SUSPENSION FLOW. FUTURE CHALLENGES

Petronela Nechita

Pulp and Paper Research and Development Institute – CEPROHART SA Braila, Romania

Cost Action FP1005Fibre suspension flow modelling - a key for

innovation and competitiveness in the pulp & paper industry

MC and WG Meeting, Nancy 13-14 October 2011 INPL

CITY of Brăila Geographical position on the continent,

country and county

PULP and PAPER RESEARCH AND DEVELOPMENT INSTITUTE –

CEPROHART BRĂILA, ROMANIA

Has been founded in 1956

Having experience in qualified research and development services for pulp and paper industry.

Produces speciality paper grades: filtering composites for alimentary liquids, foods packaging papers, security papers for documents, pre-coated papers and boards, composites with specialty uses.

THE MAINS ACTIVITIES

• Fundamental and applied research in the field of pulp and paper industry;

• Design and Technological Development activity for the pulp and paper industry;

• Production (at pilot plant level) of special paper grades (filtering composites for alimentary liquids, security papers for documents, food packaging papers, filter paper, composite materias for the automotive industry and speciality uses)

SC CEPROHART SA BRĂILAROMANIA

Paper machine - Pilot plant

Capacity: 1500 t/yearWorking width: 1600 mmSpeed: 7 - 10 m/min for composite materials (700 - 1650 g/sqm) 100 m/min for paper grades (from 35 g/sqm )

Composite materials

Structural composition consists of mixtures of different type of raw materials

Multi – phase systems involving at least one material whose flow behaviour is nenewtonian

Forming at high consistency

OUR Case Study1. Composites board with application in

automotive industry (for sealing materials used in internal combustion engines)

• High contents of fillers (until 70% - colloidal graphite and talc)

• Mixture of three type of fibrous materials (virgin cellulose fibres, mineral fibres and Polyparafenilen – tereftal – amide) and butadiene - acrylonitrile carboxylate latex

Composites board with application in automotive industry

- grammage: 700 1250 g/sqm- forming consistency: 3 4,75 %- pilot plant speed: 8 m/min- consumption of electricity: 2400 kwh/t- heat consumption (steam): 4.5 Gcal/t

• High level of foam (air bubbles) leads to additional problems in pulp stock flow;

• The mixing tanks of pulp stock are equipped with recirculation systems to avoid a “flocculation” phenomena

• High turbulence

2. Filtering composite based on cellulose fibres intended to separate the disturbing and/or

contaminant colloidal components in the alimentary liquids

Composition:- Virgin cellulose fibres : 50%- Filler: 50%Forming parameters:- Consistency: 1.35 2.5 %- Thickness of fibrous suspension layer on forming wire: 2 – 5 cm - Grammage ( 1200 – 1650 g/sqm)- Speed: 1,1 m/min consumption of electricity: 2650 kwh/t heat consumption (steam): 4.5 Gcal/t

A strict control should be assigned to forming consistency and fibrous suspension flow aiming to assure fibres orientation and obtaining a proper fibrous network with all components of composite matrix

3. Composite materials for seedling manufacturing

Composition:- Peat – 70%- Recycled cellulose fibres : 30%Forming: Formation and dewatering system through die molding

Die vacuum formation

Die dewatering Upper die dewatering

Formation consistency: 0.8 – 1 %

Composite materials for seedling manufacturing

Control parameters:

- Dewatering rate - Vacuum level- Water viscosity- Forming consistency, level of turbulence and flocculation

Disturbances:

The peat consists of fibrous structure based long fibres, with high capacity of flocculation during forming process and with lower drainage rate.

Flocculation degree and flocs distribution depend on the fibrous suspension consistency and level of turbulence

Regardless of working speed, increasing of fibrous suspensions consistency have a negative influence of fibrous network formation. Increasing of consistency results in flocculation enhancement while increasing of flocks resistance and energy consumption for their re-dispersing.

Together with Technical University of Iasi we have some contribution to study concerning electrokinetic's, rheologic, hydrodynamic and physico-mechanical characteristics of some fibre suspensions obtained from cellulose recycled fibres.

Also, we completed some doctoral thesis in the field of fibrous pulp and paper rheology

FUTURE Challenges FP 1005 COST Action give us an opportunity

to learn and understanding the fibre suspension flow phenomena and solving well defined disturbances that we meet during composite materials manufacturing.

FP 1005 COST Action offers the frame to identify advanced techniques and methods used for fibre suspension analysis and flow modelling

Analytical tools and techniques for fibrous suspension preparing and paper materials characterising

Preparative techniques: sheets and mould forming

Characterization tools:

Isolation and treatments techniques:

Contact:petronela.nechita@ceprohart.ro

Al. I. Cuza Street, no.3, Braila, 810019, ROMANIA

Tel: +40239 619 741Fax: +40239 680 280

www.ceprohart.ro