Method for preparing pulp for making natural-color packaging paperboards by using corn straw raw material

Abstract

The invention relates to a method for preparing pulp for making natural-color packaging paperboards by using a corn straw raw material. The corn straw raw material is pretreated to separate most leaves and piths of corn straw and then is pulped by adopting a chemical mechanical method, and prepared paper pulp can replace waste paper pulp to be used for making corrugated raw paper or cardboard paper and other natural-color packaging paperboards. The method is characterized in that the structural characteristics of different components such as leaves, piths and straw skin in the corn straw raw material are fully utilized, the leaves and piths with smaller fiber contents are turned into powder or granules and the straw with higher fiber content is turned into dense sheets in the pretreatmentprocess, and then the extruded powder or granular leaves and piths are separated through screening for preparation of fodders or bio-organic fertilizers; the straw skin raw material without leaves andpiths is pulped by adopting the chemical mechanical method, and the organic waste generated in the preparation and pulping process can be used for preparing the fodders or bio-organic fertilizers.

Description

technical field [0001] The invention belongs to the field of high-efficiency utilization of agricultural stalks, and in particular relates to a method for preparing natural-color packaging cardboard compounding pulp by using corn stalks as raw materials. Background technique [0002] my country is a big corn planting country, and a large amount of corn stalks are produced every year. In 2016, my country's corn production was 219.6 million tons. According to the ratio of 1:1.6 of corn seeds and corn stalks produced by a plant of corn, the corn stalks produced reached more than 350 million tons. At present, only a small amount of such a huge amount of corn stalks is used as feed, biomass fuel or directly returned to the field. Waste, and a large amount of dense smog produced not only pollutes the environment, but also easily causes fires and traffic accidents, seriously threatening the safety of people's lives and property. On the other hand, there is a serious shortage of p...

AI Technical Summary

Problems solved by technology

This method uses manual removal of leaves and ears, which is not conducive to large-scale application, and chemical pulping is performed on straw raw materials that have not been separated from bark and husk. The utilization rate of raw materials is low, and the waste liquid generated cannot be treated, so it is difficult to carry out large-scale Industrial application; patent CN201710160032.1 discloses a method for preparing high-yield corrugated base paper pulp from corn stalks under normal pressure. First, corn stalks are sent to a pulverizer and crushed to a particle size of 1-2 cm. The crushed straw is sent to a high-speed vibrating screen to keep the material in a suspended or semi-suspended state, and then the skin and pith are separated by means of a cyclone separator. Although this method considers the separation of the skin and pulp, the corn stalk is cut too finely (1~ 2cm), the production efficiency is low and it is also unfavorable for the separation of bark and husk, so it is not suitable for large-scale application; the patent No. CN00113771.9 discloses a grass plant (wheat straw, corn stalk, rice straw, miscanthus stalk) Mechanical pulping process, the raw materials are prepared by cutting grass, pond soaking, thickening, preheating, refining, centrifugal sieve separation and other processes to prepare pulp

Since this method has not undergone pulp removal and dust removal treatment, the quality of pulp is poor, and it is only suitable for small and medium-sized paper mills, and cannot be used for large-scale production; the patent with publication number CN105386350A introduces a method for biopulping of corn stalks , the corn stalks are naturally air-dried, crushed and sieved to obtain 30-40 mesh particles, and then the particles are subjected to microwave, fermentation, filtration, sterilization, centrifugal concentration and grinding, and finally xylanase treatment

This method requires repeated low-concentration and high-concentration treatments on the material. Not only is the process complicated, the production cost is high, and the water consumption is large, it is not suitable for large-scale production applications.

It can be seen that the above-mentioned existing corn stalk preparation and pulping technologies have relatively large defects, and it is impossible to realize large-scale comprehensive and efficient utilization of corn stalks in pulping and papermaking.