Analysis of property of SCDP Raw material and it’s origin.
- Selection of the SCDP
- ease of pulp : using L&W pulp fiber standard ease control gets the SCDP eased fully. The easing condition : pulp consistence 2%, easing time 5 min.
- the stage 1 screening of the SCDP : using L&W screening machine for filtering to remove the larger particles of impurities (main rice hulls), selecting 0.30mm of slit screen. Thickening the filtered dregs pulp to 20% of consistence for backup.
- Refining the high consistence of SCDP
- refining the SCDP : get the above backup pulp filtered by 0.30 mm slit screen into KRK refiner for refining the pulp, the stage of refining is 2, refiner gap is 0.15mm, the consistence of pulp is 18%.
- the stage 2 screening of the SCDP : using L&W screening machine selects the pulp refined through KRK high consistence refiner, selecting 0.20mm of slit screen.
According to the data of fiber analysis, the content of small components in SCDP is rather high 37.6%, which is much higher than normal papermaking pulp; the component of longer fiber, their average width are 49.6µm (whereas, the fiber width of softwood pulp is about 30µm), therefor, we can see that the state of SCDP through high consistence refining is similar to wood dregs, and can’t fully be changed into pulp. So, we can conclude that SCDP is not suitable for papermaking by itself.
Determination of The Physical Properties of Paper Sheet
Get the 44˚SR of beaten SCDP mixed with OCC pulp, then eased in L&W standard pulp-easing machine or pulp-easing control, and make handsheets of the basic weight on standard sheet former being 110g/m2.
All the handsheets, after two stages of press, adopt quickly heating and drying then transfer them to the room of relative humidity (50±2)% and temperature (23±1) ˚C to balance their moisture, finally, checking their tightness (GB/T 451.3-1989), tensile strength (GB/T453-1989), tear resistance (GB/T 451.3-1989 GB/T 455.1-1989) and ring crush strength (GB?T 2679.8-1995) etc. according to state standard.
According to the above result, we can conclude that:
- it can’t make paper by SCDP itself, the reason are : (1) there are rather high content of small components in pulp; some starch residues get filtration of pulp very difficult; (2) the binding force between fibers is small, which gets the strength of finished paper very low and poor quality paper.
- the highest adding percentage of SCDP is 60%, if the adding percentage is more than 60%, the filtration of mixed pulp is very difficult, and the mixed pulp can’t from paper of good quality.
By : Gunawan Surya