The Research On Relational Producing Technology Of High Performance Fruit Nursery Paper

Fruit nursery paper is a protective technical paper used in agriculture to improve fruit qualified rate and the fruit’s exterior qualities, such as the smooth surface finish and fruit color,and it’s very popular for consumers,which brings more considerable economic benefits for orchardist. But in recent years, due to the cost of fruit nursery paper is increasing, as well as the flavor of apple using the fruit nursery paper become lighter, the attitude of people on the prospects of fruit nursery paper are mixed, and even there is an argument on " fruit nursery paper will be phased out soon ".In this background, this thesis started from the primary research on Shaanxi Provincial Fruit Bureau, fruit nursery paper mills and growers, carried out an analysis on the development trend of fruit nursery paper and the actual production application problems. The results showed that:(1) In terms of the status of apple production in our country, consumer still can’t accept “the apple without fruit nursery paper”, the prerequisite of achieving the goal “ no bag production” is that the supervision system of Chinese pesticide market and fruits safety are regular;(2)for a lot of waste fruit nursery paper produced in the orchards annually, there still has no any re-use technologies, resulting in waste of resources and land pollution;(3) In pursuit of fruit nursery paper of high water resistance, fruit nursery paper on the market has a very low air permeability index, which affects the taste and flavor of the fruit greatly;(4) owing to the lack of national standards for the characterization of fruit nursery paper shading property, and Shaanxi Province local standard based on the opacity as the shading property. Based on the practical application, results showed it is unreasonable. To solve the above problems, this paper carried out the research from the following three aspects.Firstly, the study identified the re-pulping process of fruit nursery paper, clarified effect of process conditions such as the pretreatment, pulping time, grinding rotation, and adding different additives on the pulp morphological parameters, and the performance of paper. Optimum conditions were as following: under weak acidic conditions, adding Al2(SO4)3 at 100℃ for pretreatment, pretreating time for paper bags was 15 min, pulping time 20~25 min, refining by PFI with 3000 r, and then got the best overall performance of fruit nursery paper. The tensile index of handsheets was 46.8N·m·g-1, tear index 6.7m N·m2·g-1, burst index was 2.2 k Pa·m2·g-1,s permeability of 2.9μm·(Pa·s)-1,and product quality could be accepted by the standards. In addition, the results of different additives affect on the properties of secondary fibers from fruit nursery paper were: wet strength agent dissociation agents> Sodium hypochlorite> aluminum sulfate. Compared with the blank, adding 2% of wet strength agent dissociation agents, the tensile of paper increased by 22.5%, while the tear strength increased by 12.3%. This would not only make use of a lot of fiber resources, but also reduce the amount of carbon black, and wastewater treatment was easier, reducing the cost and improving the production environment.Secondly, on the one hand, the air permeability of the paper was improved by adjusting the structure of raw materials. When the ratio of OFNP, OCC, softwood pulp, binata pulp was 3:4:1:2, it had obvious advantages in terms of strength and air permeability of fruit nursery paper, while reducing part of the production costs. On the other hand, with the increase of the amount of filler, the air permeability of the paper could be improved. The effect of FACS was the most obvious. However, the strength of the paper would be the cost of improving the air permeability. Therefore, to consider the comprehensive performance of paper, the final choice was 10% FACS. When the filler of inside layer and outside layer ratio was 7: 3, the degree of water resistance and air permeability were balanced, meeting wth the performance of imported products.Thirdly, by testing three indexes, such as transmittance, opacity, and evenness of fruit nursery paper, the result indicated: the opacity index was not accurate to characterize fruit nursery paper shading performance, and from the theoretical and experimental comparison research it was proved that Shaanxi apple bagging paper opacity standard was unreasonable, and the quality credibility problem of fruit nursery paper mills caused by the error detection should be avoided.