阅读说明：本技术 一种环保型密度板及其制作方法 (Environment-friendly density board and manufacturing method thereof ) 是由 施晓旦 侯立军 郑璐 于 2018-09-12 设计创作，主要内容包括：本发明公开了一种环保型密度板,包括如下重量份的组分：木纤维35-55份,造纸废弃物20-25份,胶5-20份。其制作方法,是将木材和造纸废弃物削片、破碎后混合,经热磨、喷胶、干燥、铺装、热压、后处理后得到所述环保型密度板。本发明充分利用造纸过程中的剩余物--造纸废弃物,节省木材的使用量,同时由于造纸废弃物加入到木纤维中,提高了密度板的整体力学性能和产品质量,提高了木材的利用率,促进了人造板的产品技术创新和工艺创新。(The invention discloses an environment-friendly density board which comprises the following components in parts by weight: 35-55 parts of wood fiber, 20-25 parts of papermaking waste and 5-20 parts of glue. The manufacturing method comprises the steps of chipping and crushing the wood and the papermaking waste, mixing, hot grinding, glue spraying, drying, paving, hot pressing and post-processing to obtain the environment-friendly density board. The invention fully utilizes the residue in the paper making process, namely the paper making waste, saves the using amount of wood, improves the overall mechanical property and the product quality of the density board, improves the utilization rate of the wood and promotes the product technical innovation and the process innovation of the artificial board because the paper making waste is added into the wood fiber.)

1. The environment-friendly density board is characterized by comprising the following components in parts by weight: 35-55 parts of wood fiber, 20-25 parts of papermaking waste and 5-20 parts of glue.

2. The environmentally friendly density board of claim 1, wherein the paper-making waste contains aromatic high polymer containing phenolic hydroxyl group, and is selected from at least one of sapropel, pulp residue, wood bark, pulp waste liquid extract, and siliceous white mud.

3. The environmentally friendly density board of claim 1, wherein the glue is selected from urea-formaldehyde glue, phenolic glue, or a modified glue thereof.

4. The method for manufacturing the environment-friendly density board is characterized in that the environment-friendly density board is obtained by chipping and crushing wood and papermaking waste, mixing the chipped and crushed wood and papermaking waste, and performing hot grinding, glue spraying, drying, paving, hot pressing and post-treatment on the mixture.

5. The method according to claim 4, comprising in particular the steps of:

cutting and crushing wood into wood chips, performing thermal cooking, and performing mechanical separation to obtain wood fiber;

step two, crushing the papermaking waste into particles with the particle size not larger than 5cm, mixing the particles with the wood fiber in proportion, adding the mixture into a hot mill, controlling the grinding disc gap to be 0.6-0.85mm and the steam pressure to be 0.65-0.75MPa, and mechanically separating to obtain a mixture of the wood fiber and the papermaking waste;

spraying glue to the mixture of the wood fiber and the papermaking waste by using steam, so that the glue is uniformly sprayed on the surface of the mixture of the wood fiber and the papermaking waste;

step four, after drying at 165-188 ℃, paving in a paving machine, and prepressing;

step five, sending the mixture into a hot press for hot pressing, wherein the hot pressing temperature is controlled to be 185-195 ℃, the pressure is 2.5-4.5mpa, and the hot pressing time is controlled to be 15-30s/mm of plate thickness;

step six, carrying out post-treatment after hot pressing to obtain the environment-friendly density board;

the components in parts by weight are respectively as follows: 60-70 parts of wood, 20-25 parts of papermaking waste and 5-20 parts of glue.

6. The method of claim 4, wherein the paper-making waste is selected from at least one of a slime, a sludge, a wood bark, a pulp waste liquor extract, and a siliceous white mud.

7. The method of claim 4, wherein the glue is a urea-formaldehyde glue.

8. The method of claim 5, wherein the wood pieces are of the specification: the length is 6-30mm, the width is 5-25mm, and the thickness is 3-5 mm.

9. The method as claimed in claim 5, wherein the temperature of the thermal cooking in the first step is 135-175 ℃ and the cooking time is 3-6 minutes.

10. The method as claimed in claim 5, wherein in the fourth step, the drying is primary formal air flow drying, the heat is guided by a blower to dry the material, so that the material obtains heat in the pipeline and the moisture is vaporized, the drying inlet temperature is 175 ℃ and 180 ℃, and the outlet temperature is 60-65 ℃; the prepressing pressure is 1.0-2.0MPa, and the prepressing time is 30-60 s.

Technical Field

The invention relates to the technical field of density board manufacturing, in particular to an environment-friendly density board and a manufacturing method thereof.

Background

The artificial board industry is an important industry for efficiently utilizing wood resources and is an important means for realizing a sustainable development strategy. Under the condition that the current forest resources are increasingly reduced, forestry 'residues' are fully utilized to replace large-diameter-grade wood products, and irreplaceable effects are achieved on reasonable utilization of forest resources, environmental protection and meeting of requirements of economic and social development on forestry.

China is a large country in the paper making industry, most of papermaking wastes, which are a large amount of residues in the paper making process, are used as fuels to be burnt or enter a sewage system, so that the papermaking wastes cannot be efficiently utilized, and the ecological environment is greatly damaged. Therefore, the conversion of papermaking waste into building materials for recycling is an important economic and social item.

Disclosure of Invention

The invention aims to provide an environment-friendly density board and a manufacturing method thereof, which aim to overcome the defects in the prior art.

The invention is realized by the following technical scheme:

an environment-friendly density board comprises the following components in parts by weight: 35-55 parts of wood fiber, 20-25 parts of papermaking waste and 5-20 parts of glue.

The wood fiber is obtained by thermal cooking and mechanical separation of wood. Typically, the fiber content of wood is about 60-80% by weight of the wood.

The wood may be a conventional choice in the art, including but not limited to: one or more of pine, poplar, birch, wheat straw, reed, bagasse, jute, flax, mulberry bark, etc.

The papermaking waste contains aromatic high polymer containing phenolic hydroxyl.

Preferably, the papermaking waste is at least one selected from the group consisting of sapropel, pulp residue, wood bark, pulp waste liquid extract and siliceous white mud.

The glue may be selected from those commonly used in the art, including but not limited to: urea-formaldehyde glue, phenol-formaldehyde glue, etc., or modified glues thereof. When urea-formaldehyde glue is used, the adhesion between wood fibres and paper waste is optimal.

The invention also discloses a manufacturing method of the environment-friendly density board, which comprises the steps of chipping and crushing the wood and the papermaking waste, mixing, hot grinding, glue spraying, drying, paving, hot pressing and post-processing to obtain the environment-friendly density board. The method specifically comprises the following steps:

cutting and crushing wood into wood chips, performing thermal cooking, and performing mechanical separation to obtain wood fiber;

step two, crushing the papermaking waste into particles with the particle size not larger than 5cm, mixing the particles with the wood fiber in proportion, adding the mixture into a hot mill, controlling the grinding disc gap to be 0.6-0.85mm and the steam pressure to be 0.65-0.75MPa, and mechanically separating to obtain a mixture of the wood fiber and the papermaking waste;

spraying glue to the mixture of the wood fiber and the papermaking waste by using steam, so that the glue is uniformly sprayed on the surface of the mixture of the wood fiber and the papermaking waste;

step four, after drying at 165-188 ℃, paving in a paving machine, and prepressing;

fifthly, the mixture is sent into a hot press for hot pressing, the hot pressing temperature is controlled to be 190 +/-5 ℃, the pressure is controlled to be 2.5-4.5mpa, and the hot pressing time is controlled to be 15-30s/mm of plate thickness;

step six, after hot pressing, carrying out post-treatment such as edge sawing and sanding to obtain the environment-friendly density board;

the components in parts by weight are respectively as follows: 60-70 parts of wood, 20-25 parts of papermaking waste and 5-20 parts of glue.

Preferably, the wood chips have the following specifications: the length is 6-30mm, the width is 5-25mm, and the thickness is 3-5 mm.

Preferably, the temperature of the thermal cooking in the step one is 135-175 ℃, and the cooking time is 3-6 minutes; the mechanical separation is referred to as a thermomechanical process.

Preferably, in the fourth step, the drying adopts primary formal airflow drying, the heat is guided by a blower to dry the materials, so that the materials obtain heat in a pipeline and vaporize moisture, the temperature of a drying inlet is 175-180 ℃, the temperature of an outlet is 60-65 ℃, and the drying explanation adopts oil and gas to heat a heat exchange plate set so as to achieve the purpose of rapidly heating and drying air; the pre-pressing pressure is 1.0MPa-2.0MPa, and the pre-pressing time is 30s-60 s. The purpose of pre-pressing is to preliminarily compress the paved raw materials by a compressor so as to preliminarily compress the plate blank, and the blank scattering phenomenon cannot occur in the transportation and hot pressing processes; compressed into a mat while passing through a prepress.

Because the mixture of the wood fiber and the papermaking waste has poor heat transfer performance, the hot pressing process in the step five strictly controls the hot pressing time and the hot pressing temperature, and in the manufacturing process of a thick density board, a plurality of pre-pressed board blanks are stacked to reach the preset thickness.

The invention fully utilizes the residue in the papermaking process, namely papermaking waste, saves the using amount of wood, and simultaneously improves the overall mechanical property and the product quality of the density board because the papermaking waste is added into wood fiber.

Detailed Description

The invention is illustrated below by means of specific examples, without being restricted thereto.