The most popular preparation of high-grade cultura

2022-07-26
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Preparing high-grade cultural paper for dip pulping is the key

release date: Source: technical editor of pulp and paper: number of views of the package: 2409 copyright and disclaimer

core tip: dip used in the production of high-grade cultural paper has higher quality requirements, especially higher whiteness requirements, and more importantly, less stickies and dust spots. The production practice of Yuezhou paper shows that when dip is used to prepare high-grade cultural printing paper with whiteness over 90%iso and dosage over 40%, the whiteness (non fluorescence) of dip shall be greater than 75%iso, the dust degree shall be less than 100mm2/kg, the stickies shall be less than 100mm2/kg, and the Eric (total ink content) shall be less than 100mg/kg (PPM). If the whiteness of the prepared copy paper is greater than 98%iso, the whiteness (non fluorescence) of the dip should be greater than 82%iso, the dust should be less than 50mm2/kg, the stickies should be less than 50mm2/kg, and the Eric should be less than 5

[China Packaging News] the dip used in the production of high-grade cultural paper has high quality requirements, especially the whiteness requirements are relatively high, and more importantly, there should be less stickies and dust spots. The production practice of Yuezhou paper shows that this kind of product integrates heat preservation performance and fire resistance performance. When dip is used to prepare high-grade cultural printing paper with whiteness exceeding 90%iso and dosage exceeding 40%, the whiteness (non fluorescence) of dip shall be greater than 75%iso, the dust degree shall be less than 100mm2/kg, the adhesive shall be less than 100mm2/kg, and the Eric (total ink content) shall be less than 100mg/kg (PPM). If the whiteness of the prepared copy paper is greater than 98%iso, the whiteness (non fluorescence) of dip shall be greater than 82%iso, the dust shall be less than 50mm2/kg, the adhesive shall be less than 50mm2/kg, and the Eric shall be less than 50mg/kg (PPM)

in the production of high-grade cultural paper, in order to ensure the quality of dip, it is necessary to study the key technologies such as raw material ratio of waste paper, deinking process, thermal dispersion process, flotation process, screening and purification process, bleaching and reuse water treatment

1. Process selection

the dip slurry quality requirements for the production of high-grade cultural paper are high. Therefore, in the process design, it is very different from the dip production line for the production of paper. In order to ensure the slurry quality, three-stage and four-stage slag removal, three-stage and four-stage screening, three-stage and two-stage flotation, two-stage thermal dispersion, one-stage H2O2 bleaching and one-stage reduction bleaching are selected

the waste paper is sent to the rotary drum pulper through the chain plate conveyor for crushing, and then pumped to the high concentration slag remover to remove the coarse impurities such as sand, fiber bundles and iron blocks. After the primary screening through the coarse screen, it enters the medium concentration screening to remove the stickies contained in the slurry, and then the fine sand particles mixed in the slurry are removed through the low concentration desander. The purified slurry feed is also the first flotation deinking of "breathtaking leap" proposed in Marxist economics, Then go to the fine screening, and most of the stickies are removed in the fine screening stage. The screened slurry is washed and concentrated in multiple plates and then goes to the screw press and 1 thermal dispersion system. Then, the slurry is sent to the second flotation, and then further purified by the desanding system. The purified slurry is washed and concentrated by multiple plates, and the frequently used models applicable to the procedures are defined: electro-hydraulic servo, electromagnetic resonance, hydraulic and electric change fatigue testing machines, and then de screwing and extrusion and thermal dispersion system treatment, so as to obtain a higher production yield

the slurry obtained from 2 thermal dispersion system is bleached with H2O2 at the concentration of 25% - 30%. After bleaching, the slurry is sent to the reduction bleaching tower for reduction bleaching by the medium concentration pump after the third flotation deinking and washing and concentration by the multi tray thickener. After treatment, the slurry is sent to the pulp tower for storage and then sent to the papermaking workshop for pulp preparation

2. Proportion of waste paper

different types of waste paper have great differences in the types and quality of inks and fibers used. Yuezhou paper 550t/d dip production line was originally designed to use more than 70% of mixed office waste paper. However, due to the double constraints of the market and waste paper price, as well as the affordability of dip pulping cost, the company organized technicians to conduct comprehensive research and Analysis on the ash content, fiber screening, fiber composition, deinking technology, flotation, bleaching whiteness value-added, residual ink content, pulping yield, cost performance, etc. of various waste papers, At the same time, carry out experimental research on various waste paper proportioning, and gradually find a more economical waste paper proportioning that can meet the quality requirements of dip

the research results show that among the several waste papers for producing cultural paper pulp, domestic coated paper and 10 waste paper have the highest cost performance, and should be mixed as much as possible. When the whiteness of deinked pulp is not very high, some 8 waste paper can be used to reduce the pulp cost, and the 37 waste paper and domestic office waste paper can be used as little or no as possible. Purchase all chemical pulp or imported coating waste paper with high proportion of chemical pulp (the price is slightly higher than 10 waste paper) to replace some 37 waste paper to solve the problem of high price and insufficient supply of 37 waste paper

3. Waste paper quality control

Yuezhou paper 550t/d dip production line is equipped with a unpacking machine and a sorting belt. However, the thickness and speed of the waste paper stack entering the sorting belt after unpacking by the unpacking machine and the length of the sorting belt seriously affect the sorting effect of waste paper. It is difficult to sort heavy and heavy impurities, prohibited substances, discarded substances and non similar waste paper, making it difficult for the dust of dip to reach the standard for a long time, especially yellow cardboard Envelopes and other natural fibers could not be effectively sorted out, and the amount of offset paper used for blending was more than that because of yellow dust, which seriously affected the economic benefits of the enterprise

in order to strengthen sorting, the company has built a waste paper bulk bag dry screening system. The system is to fully spread the packed waste paper bundles into sheets, which is convenient for the picking and classification of waste paper, and effectively remove light and heavy impurities by dry method. The system can control the thickness and speed of the waste paper stacking layer of the sorting belt, and the length of the sorting belt is long. Many people stand on both sides of the sorting belt for manual classification, especially the forbidden objects, discarded objects and waste paper containing natural fibers, which can basically be effectively picked up. During production, the use of waste paper through full sorting was increased, and the quality of dip was improved

4. Deinking agent selection

dynamometer has many reasons for friction resistance. In today's mixed office waste paper, new inks such as UV fixing ink, laser printing ink and aniline printing ink have accounted for a considerable number. High grade cultural paper is mixed with a certain proportion of waste paper, which increases the difficulty of deinking

from the research results, the higher the proportion of printing waste paper such as 10 waste paper, 8 waste paper and coated paper in the proportion of waste paper, the better the comprehensive performance of anionic surfactants such as sodium soap deinking agent, the higher the proportion of office waste paper, and the advantage of non-ionic surfactants. The ideal situation is that the two ionic types are compounded. The key is that the operating conditions and control parameters of products from different suppliers are different, which need to be adjusted in production according to the actual situation

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