Study On Improving The Strength Of Paper With PVA Fiber And Chemical Additives

Plant fiber is the main component of traditional paper.The basic properties of plant fiber determine the paper index.With the development of production and life,the paper index of some pure plant fiber has been difficult to meet the requirements.At present,the birth and development of various kinds of man-made fibers provide fiber sources for paper raw materials,and various kinds of chemical fibers and inorganic fibers have been widely used in the fields of industry,agriculture,aviation and aerospace.In this paper,water-soluble PVA fiber as the research object,through the preparation with plant fiber,and assisted by traditional papermaking wet end additives,the paper discusses the application effect of water-soluble PVA fiber in papermaking,which provides practical guidance for high-strength special paper.It is found that the addition of wet strength agent can significantly improve the dry tensile index,wet tensile index and folding strength of the paper with PVA fiber,and the tear index of the paper increases slightly.The dry tensile index,wet tensile index and folding strength were not significantly improved when the wet strength agent was added more than 2.00%.When the amount of wet strength agent is 2.00%,and then adding dry strength agent CMC into the mixed pulp,the dry and wet tensile index and folding strength of the paper will be further improved,and the tear index of the paper will also be slightly improved.When the CMC content is more than 0.9%,the paper strength index is no longer significantly improved.PAE wet strength agent and CMC have a good synergistic effect on the dry and wet tensile index and folding index of the paper with PVA fiber.Three kinds of water-soluble PVA fibers,sy-7(70 ?),sy-9(90 ?)and MQ-3(100 ?),were added into the paper.The dry and wet tensile index of the paper decreased with the increase of fiber content,while the folding resistance and tear index of the paper increased with the increase of fiber content The sy-9 fiber with hot melt temperature of 90 ? can improve the folding strength and tear index of the paper,and the dry and wet tensile index loss of the paper is the smallest.Under the experimental conditions,the paper added four kinds of surface sizing agent to the paper with PVA fiber,and the dry and wet tensile index of the paper decreased with the increase of fiber content.When the waterborne polyurethane emulsion with solid content of 20% was used for surface sizing,the dry and wet tensile index loss of paper was the smallest.The folding resistance and tear index of paper increase with the increase of fiber content.Under the same surface sizing condition,the folding resistance and tear index of paper reach the maximum when the fiber content is the maximum;the folding resistance of paper with 25% PVA fiber and 20%solid content waterborne polyurethane surface sizing is the maximum;the combination of PVA fiber and polyurethane surface sizing agent can better improve the folding resistance of paper The folding strength and tear index of the paper,dry and wet tensile index of the paper will be slightly reduced.When the content of PVA fiber is more than15%,the dry and wet tensile index of the paper will lose a lot.Taking the label paper with high strength requirements as the pilot test object,the addition of low melting point water-soluble PVA fiber(melting point less than 100 ?)can obviously improve the paper strength.When the proportion is less than 20%,it can meet the continuous and stable production.If the addition is too high,it is easy to cause problems such as sticking net and dirty wool cloth.