阅读说明：本技术 一种木质纤维发泡型包装纸板及制备方法 (Wood fiber foaming type packaging paperboard and preparation method thereof ) 是由 曾军堂 陈庆 司文彬 陈涛 于 2020-05-25 设计创作，主要内容包括：本发明涉及包装材料领域,公开了一种木质纤维发泡型包装纸板及制备方法。包括如下制备过程：(1)将木质纤维加入稀硫酸浸泡后利用双氧水溶液漂白,制得预处理木质纤维；(2)将淀粉、交联剂、氢氧化钠加入水中搅拌糊化,制得稀浆状糊化淀粉；(3)将硅藻土吸附碳酸氢铵后喷覆交联聚乙烯醇胶液,制得发泡助剂；(4)将预处理木质纤维、无机纤维、发泡助剂加入稀浆状糊化淀粉中,制得膏状料；(5)将膏状料刮涂在基纸表面后夹在两基纸间辊压平整,高温发泡,裁切,即得木质纤维发泡型包装纸板。本发明制得的包装纸板具有良好的支撑性和轻质性,并且工艺简单易控,材料成本低,可以直接回收,本发明的方法为批量制备包装纸板提供了技术支撑。(The invention relates to the field of packaging materials, and discloses a wood fiber foamed packaging paperboard and a preparation method thereof. The preparation method comprises the following preparation processes: (1) soaking wood fiber in dilute sulfuric acid, and bleaching with hydrogen peroxide solution to obtain pretreated wood fiber; (2) adding starch, a cross-linking agent and sodium hydroxide into water, stirring and pasting to prepare paste-like thin starch; (3) adsorbing ammonium bicarbonate by diatomite, and spraying a crosslinked polyvinyl alcohol glue solution to prepare a foaming auxiliary agent; (4) adding the pretreated wood fiber, the inorganic fiber and the foaming auxiliary agent into the pasty gelatinized starch to prepare a pasty material; (5) and scraping the paste material on the surface of base paper, clamping the base paper between two pieces of base paper, rolling and flattening, foaming at high temperature, and cutting to obtain the wood fiber foamed packaging paper board. The packaging paperboard prepared by the method has good support and light weight, the process is simple and easy to control, the material cost is low, the packaging paperboard can be directly recycled, and the method provides technical support for batch preparation of the packaging paperboard.)

1. A preparation method of a wood fiber foaming type packaging paperboard is characterized by comprising the following specific preparation processes:

(1) firstly, adding wood fiber into dilute sulfuric acid with the mass concentration of 10-15%, soaking and stirring for 1-2 h, then filtering out sulfuric acid, filtering, washing with water, adding hydrogen peroxide solution with the mass concentration of 30-35% for bleaching, and finally cleaning to obtain pretreated wood fiber;

(2) adding starch, a cross-linking agent and sodium hydroxide into water, heating, stirring and gelatinizing to obtain pasty gelatinized starch; the raw materials comprise, by weight, 5-10 parts of starch, 0.1-0.2 part of a cross-linking agent, 0.1-0.2 part of sodium hydroxide and 120-150 parts of water;

(3) firstly, soaking diatomite into an ammonium bicarbonate saturated solution for 1-3 hours to enable the diatomite to fully adsorb ammonium bicarbonate, then filtering, spraying a crosslinked polyvinyl alcohol glue solution on the surfaces of diatomite particles, and finally air-drying at a high speed to prepare a foaming auxiliary agent; the raw materials comprise, by weight, 50-60 parts of diatomite and 8-15 parts of cross-linked polyvinyl alcohol glue solution;

(4) adding the pretreated wood fiber and inorganic fiber prepared in the step (1) and the foaming auxiliary agent prepared in the step (3) into the slurry gelatinized starch prepared in the step (2), and kneading uniformly to prepare a paste material; the raw materials comprise, by weight, 5-10 parts of pretreated wood fiber, 1-3 parts of inorganic fiber, 0.5-1 part of foaming auxiliary agent and 80-100 parts of slurry gelatinized starch;

(5) the method comprises the steps of coating a paste material on the surface of base paper in a scraping mode, controlling the thickness to be 1-3 mm, clamping the paste material between two pieces of base paper, rolling and flattening, carrying out high-temperature foaming treatment, and finally cutting according to requirements to obtain the wood fiber foaming type packaging paper board.

2. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (3) the starch in the step (2) is at least one of cassava starch and sweet potato starch.

3. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (3) the cross-linking agent in the step (2) is epichlorohydrin.

4. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (3) heating, stirring and pasting in the step (2) at the temperature of 80-85 ℃, at the stirring speed of 500-600 r/min and for 1-2 h.

5. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (3) the cross-linked polyvinyl alcohol glue solution in the step (3) is borax cross-linked polyvinyl alcohol solution with the mass concentration of 11-14%.

6. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (4) the inorganic fiber is at least one of glass fiber and wollastonite fiber.

7. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: the base paper in the step (5) is 120g/m²The kraft paper of (1).

8. The method of manufacturing a lignocellulosic foamed packaging board as claimed in claim 1, wherein: and (5) performing high-temperature foaming treatment between fixed heating flat plates, wherein the heating temperature is 100-120 ℃, and the heating foaming time is 3-5 min.

9. A wood fiber foamed packaging board prepared by the method of any one of claims 1 to 8.

Technical Field

The invention relates to the field of packaging materials, and discloses a wood fiber foamed packaging paperboard and a preparation method thereof.

Background

The cardboard is also called as paperboard, and is made of various kinds of paper pulp, and the thick paper sheets made of interwoven fiber are usually made of various kinds of plant fiber as raw material and non-plant fiber added on a paperboard machine. Some special paperboards are also mixed with animal fibers such as wool and mineral fibers such as asbestos. The paperboard is often used as a packaging material, and as a cheap and excellent packaging material, the packaging paperboard is widely applied, and particularly, with the rapid development of the logistics industry, the demand of the packaging paperboard is increased rapidly, and the packaging paperboard is generally concerned by people.

Packaging board is a generic term for board for packaging. Including white board, yellow board, kraft board, corrugated board, etc. The packaging paper board is required to have strong folding strength and good bending property, and is generally made from wood, rice and wheat straws and the like serving as raw materials by pulping by different methods and papermaking on a paper board machine. The packaging board is mainly used for making packaging cartons, and is also used as a packaging material or a printing material and the like.

Among the applications of packaging board, corrugated board is currently the most common. Corrugated board is a multi-layer adhesive body, which is composed of at least one wave-shaped core paper interlayer and one layer of paper board. The corrugated paper box can be subjected to multi-layer compounding according to needs, so that the high mechanical strength can be obtained, the corrugated paper can resist collision and falling in the carrying process and mainly plays a role in storage and protection in the transportation process, compared with metal, plastic and glass packaging products, the corrugated paper box has less waste and is easy to recycle, and the printing process mainly adopts non-toxic and easily-degradable environment-friendly water-based ink which is a well-known green packaging product. In addition, in order to further develop the packaging buffer material, the honeycomb paperboard liquid with high strength support is widely used. The honeycomb paper is made by applying the honeycomb paper to a paperboard according to the principle that human beings imitate a hexagonal honeycomb constructed by bees in the nature. The honeycomb paper core has strong compression resistance and bending resistance due to the unique mechanical structure. However, the laminating manufacturing process of corrugated paper and honeycomb paper is complex, needs multiple times of bonding and compounding, and influences the development of packaging paper boards.

The Chinese patent application No. 201810907774.0 discloses a novel shock-absorbing corrugated board, which comprises a corrugated board body, wherein the corrugated board body comprises a lower paper board, a buffer layer and an upper paper board, the lower paper board is positioned at the top of the buffer layer, the buffer layer is positioned at the top of the upper paper board, the buffer layer comprises a polyester resin layer, a film-turning resin layer and a composite silicate layer, and a waterproof layer is arranged at the top of the corrugated board body.

The Chinese patent application No. 201810439668.4 discloses a honeycomb paperboard for packaging, which comprises a honeycomb column layer, wherein surface paper layers are arranged above and below the honeycomb column layer, and a sandwich layer is arranged between the honeycomb column layer and the surface paper layers; the longitudinal section of the sandwich layer is triangular, trapezoidal or wavy, and an air channel is formed between the honeycomb column layer and the sandwich layer; and a closed structure is formed between the sandwich layer and the surface paper layer, and a moisture absorbent is arranged in the closed structure.

Chinese patent application No. 201711420665.8 discloses a method for producing artificial fiber paper foamed paperboard. The method comprises the following steps: (1) mixing an auxiliary agent, inorganic powder and polymer powder for spinning according to a proportion, and then carrying out mixing and kneading treatment at the temperature of 150-230 ℃ to obtain a molten material; (2) carrying out fiber drawing treatment on the molten material to form a cloth-shaped fiber material; (3) and adding foaming glue between the two groups of cloth-shaped fiber materials in proportion for compounding to obtain composite paper-shaped fibers, and foaming and shaping the composite paper-shaped fibers to obtain the artificial fiber foamed paperboard.

According to the above, the process for preparing the paperboard for the packaging material in the prior art by laminating corrugated paper and honeycomb paper with good lightening and buffering effects is complex, and the method for using the polyolefin material and the foaming agent for the foaming paperboard is difficult to degrade because polyolefin is a polymer and is difficult to recover because polyolefin is retained in the paper.

Disclosure of Invention

At present, in widely applied packaging paper boards, the gluing process of corrugated paper, honeycomb paper and the like with good lightening and buffering effects is complex, and in the prior art, when polyolefin materials and foaming agents are used for foaming paper boards, polyolefin is difficult to degrade and is retained in the paper, so that the problem of difficult paper board recovery is solved, and the development of the packaging paper boards is influenced.

The invention solves the problems through the following technical scheme:

a preparation method of wood fiber foaming type packaging paperboard comprises the following specific steps:

(1) firstly, adding wood fiber into dilute sulfuric acid with the mass concentration of 10-15%, soaking and stirring for 1-2 h, then filtering out sulfuric acid, filtering, washing with water, adding hydrogen peroxide solution with the mass concentration of 30-35% for bleaching, and finally cleaning to obtain pretreated wood fiber;

(2) adding starch, a cross-linking agent and sodium hydroxide into water, heating, stirring and gelatinizing to obtain pasty gelatinized starch; the raw materials comprise, by weight, 5-10 parts of starch, 0.1-0.2 part of a cross-linking agent, 0.1-0.2 part of sodium hydroxide and 120-150 parts of water;

(3) firstly, soaking diatomite into an ammonium bicarbonate saturated solution for 1-3 hours to enable the diatomite to fully adsorb ammonium bicarbonate, then filtering, spraying a crosslinked polyvinyl alcohol glue solution on the surfaces of diatomite particles, and finally air-drying at a high speed to prepare a foaming auxiliary agent; the raw materials comprise, by weight, 50-60 parts of diatomite and 8-15 parts of cross-linked polyvinyl alcohol glue solution;

(4) adding the pretreated wood fiber and inorganic fiber prepared in the step (1) and the foaming auxiliary agent prepared in the step (3) into the slurry gelatinized starch prepared in the step (2), and kneading uniformly to prepare a paste material; the raw materials comprise, by weight, 5-10 parts of pretreated wood fiber, 1-3 parts of inorganic fiber, 0.5-1 part of foaming auxiliary agent and 80-100 parts of slurry gelatinized starch;

(5) the method comprises the steps of coating a paste material on the surface of base paper in a scraping mode, controlling the thickness to be 1-3 mm, clamping the paste material between two pieces of base paper, rolling and flattening, carrying out high-temperature foaming treatment, and finally cutting according to requirements to obtain the wood fiber foaming type packaging paper board.

The wood fiber is an organic flocculent fiber substance obtained by chemical treatment and mechanical processing of natural renewable wood, is widely used in the fields of concrete mortar, gypsum products, wood pulp sponge, asphalt roads and the like, can be used for manufacturing medium density fiberboard and is used in the household building material industry. The conventional wood fiber which is commercially available at present is selected. In the selection of starch, in order to ensure sustainable development, the use of grain starch such as corn starch, wheat starch and the like is not recommended, while cassava starch and sweet potato starch are preferably selected, and especially the cassava starch has low cost and high yield and is very suitable for the starch of the invention. Preferably, the starch in the step (2) is at least one of tapioca starch and sweet potato starch; as a further preferred aspect of the present invention, the starch is tapioca starch.

The cross-linking agent is selected from conventional starch cross-linking agents, and the strength, water resistance, viscosity and the like of the gelatinized starch are improved by adding the starch cross-linking agent. Preferably, the crosslinking agent in the step (2) is epichlorohydrin.

Preferably, the temperature for heating, stirring and pasting in the step (2) is 80-85 ℃, the stirring speed is 500-600 r/min, and the time is 1-2 h.

According to the invention, the diatomite is immersed into the ammonium bicarbonate saturated solution, and the excessive liquid is filtered out through natural filtration, so that the diatomite fully adsorbs the ammonium bicarbonate, and the ammonium bicarbonate as a foaming agent has the advantages of high foaming times, good foam stability, low bleeding amount and the like. Further spraying cross-linked polyvinyl alcohol liquid (borax cross-linked polyvinyl alcohol liquid) on the surface of the diatomite adsorbing ammonium bicarbonate, forming a film on the surface of the cross-linked polyvinyl alcohol liquid, wherein the obtained film layer has certain water resistance and can relatively protect ammonium bicarbonate to be fixed in micropores of the diatomite; when heating and foaming are carried out in the later period, the film is gradually enlarged by the gas generated by the ammonium bicarbonate, a bubble supporting body similar to a sphere is formed after the gelatinized starch is solidified, and the foaming and the solidification are carried out simultaneously, and the cross-linked polyvinyl alcohol envelope prevents the gas from overflowing rapidly, so that the foamed bubble is similar to a sphere, and the bubble similar to a sphere and better in buffering and supporting performance is obtained. Preferably, the cross-linked polyvinyl alcohol glue solution in the step (3) is borax cross-linked polyvinyl alcohol solution with the mass concentration of 11-14%.

The method takes pretreated wood fibers, inorganic fibers, foaming aids and slurry gelatinized starch as raw materials to knead the raw materials to obtain uniform paste materials, and the paste materials are in a state of difficult flowing, are easy to form, are easy to stably blade-coat and fix on base paper to a required thickness, and are controlled to be 1-3 mm, preferably 2 mm.

In the present invention, the inorganic fiber in the step (4) is preferably at least one of a glass fiber and a wollastonite fiber.

Preferably, the base paper in step (5) is 120g/m²The kraft paper of (1).

The high-temperature foaming treatment process is carried out between fixed heating flat plates, wood fibers and inorganic fibers in the paste on the surface of the base paper have certain fluidity under the plasticity of gelatinized starch, foaming is carried out through a foaming auxiliary agent, sodium bicarbonate adsorbed by diatomite releases gas, a cross-linked polyvinyl alcohol coating is spread to form approximately spherical bubbles taking the diatomite as a core, meanwhile, the gelatinized starch adhesive fibers are cured under heating, and the uniform foaming thickness can be ensured through the fixed flat plate spacing, so that the composite packaging paperboard with excellent foaming effect is obtained. Preferably, the high-temperature foaming treatment in the step (5) is performed between fixed heating flat plates, the heating temperature is 100-120 ℃, and the heating foaming time is 3-5 min.

The wood fiber foamed packaging paperboard prepared by the method not only has good lightweight property and supporting property, but also has simple preparation process, and the paperboard is convenient to directly recycle.

The invention provides a wood fiber foaming type packaging paperboard and a preparation method thereof.A wood fiber is added with dilute sulfuric acid for soaking and stirring, inorganic acid is filtered out, the filtering and the washing are carried out, and hydrogen peroxide solution is further added for bleaching and washing to obtain a pretreated wood fiber; adding starch, a cross-linking agent and sodium hydroxide into water, stirring and gelatinizing to obtain slurry gelatinized starch; soaking diatomite in saturated ammonium bicarbonate solution, and filtering to make diatomite fully adsorb ammonium bicarbonate; then spraying the crosslinked polyvinyl alcohol glue solution on the surfaces of the diatomite particles, and carrying out high-speed airflow air drying to obtain a foaming auxiliary agent; adding the pretreated wood fiber, the inorganic fiber and the foaming auxiliary agent into the pasty gelatinized starch, and kneading uniformly to obtain a paste material; and (3) coating the paste material on base paper according to the required thickness, clamping the paste material between two pieces of base paper, rolling and flattening, foaming at high temperature, and cutting.

The invention provides a wood fiber foaming type packaging paperboard and a preparation method thereof, compared with the prior art, the outstanding characteristics and excellent effects are as follows:

1. provides a method for preparing a wood fiber foaming type packaging paperboard by absorbing a foaming agent with diatomite and crosslinking polyvinyl alcohol through a film.

2. The foaming agent is adsorbed by diatomite, and the polyvinyl alcohol is crosslinked by a film, so that when the subsequent heating foaming is carried out, the envelope is expanded by gas released by the foaming agent to form foaming holes similar to a sphere, and the foaming packaging paper board with good support property and light weight is obtained; and wood fiber and inorganic fiber are further dispersed under the assistance of gelatinized starch to form buffering, so that the supporting performance of the foaming paperboard is remarkably improved.

3. The process for preparing the foamed paperboard is simple and easy to control, the material cost is low, the paperboard can be directly recycled, and the problem that the paperboard is difficult to recycle due to the fact that polyolefin is used as a foaming material is solved; meanwhile, the technology of the invention provides technical support for batch preparation of packaging paperboards.

Drawings

FIG. 1 is a schematic process flow diagram of the method of the present invention for making packaging board; wherein: 1-base paper; 2-scraping the coated paste material; 3, rolling and flattening; 4-a foam; 5-heating the flat plate;

fig. 2 is a schematic structural view of the wood fiber foamed packaging board manufactured by the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, but it should not be construed that the scope of the present invention is limited to the following examples. Various substitutions and alterations can be made by those skilled in the art and by conventional means without departing from the spirit of the method of the invention described above.