CN112945788A - Method for preparing wood block with specified water content - Google Patents
Method for preparing wood block with specified water content Download PDFInfo
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- CN112945788A CN112945788A CN202110154207.4A CN202110154207A CN112945788A CN 112945788 A CN112945788 A CN 112945788A CN 202110154207 A CN202110154207 A CN 202110154207A CN 112945788 A CN112945788 A CN 112945788A
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 101
- 239000002023 wood Substances 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000008859 change Effects 0.000 claims abstract description 11
- 239000008367 deionised water Substances 0.000 claims abstract description 6
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 6
- 238000002791 soaking Methods 0.000 claims abstract description 5
- 238000005303 weighing Methods 0.000 claims description 11
- 241000218652 Larix Species 0.000 claims description 8
- 235000005590 Larix decidua Nutrition 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 241000218657 Picea Species 0.000 claims description 7
- 238000010521 absorption reaction Methods 0.000 claims description 7
- 238000012544 monitoring process Methods 0.000 claims description 6
- 238000001291 vacuum drying Methods 0.000 claims description 6
- 239000000428 dust Substances 0.000 claims description 4
- 230000004584 weight gain Effects 0.000 claims description 2
- 235000019786 weight gain Nutrition 0.000 claims description 2
- 241000894007 species Species 0.000 claims 1
- 238000005336 cracking Methods 0.000 abstract description 3
- 238000002360 preparation method Methods 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 238000001035 drying Methods 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 241000251556 Chordata Species 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007603 infrared drying Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000643 oven drying Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/02—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content
- G01N5/025—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by absorbing or adsorbing components of a material and determining change of weight of the adsorbent, e.g. determining moisture content for determining moisture content
Abstract
The invention discloses a method for preparing wood blocks with specified water content, which comprises the following steps: preparing a sample block with a preset size and treating the sample block to be absolutely dry; according to the specified water content, carrying out corresponding treatment on the oven-dried sample block; wherein: when the specified water content is in the low water content range, placing the completely dried sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%; when the specified water content is in the high water content range, firstly placing the completely dried sample block in deionized water for soaking for a preset time, taking out the sample block, wiping the sample block, recording the initial weight, and placing the sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%; the water content of the sample block is monitored by detecting the weight change of the sample block in the high-low temperature alternating tank, and the specified water content sample block can be obtained when the specified water content is reached. According to the method, the size of the sample block and the temperature and humidity of the high-low temperature alternating box are selected, so that the sample block can quickly reach the specified moisture content, and meanwhile, the sample block can be prevented from deforming and cracking.
Description
Technical Field
The invention belongs to the field of wood processing, and particularly relates to a method for preparing wood blocks with specified water content.
Background
The wood is the only renewable material in four major building materials, has the advantages of light weight, high strength-weight ratio, impact resistance, easy processing, rich texture and color tone, and the like, and is widely applied to the fields of buildings, furniture, interior decoration and the like. The moisture content is an important performance index of the wood, the performances such as the strength, the dry shrinkage and the wet swelling of the wood are closely related to the moisture content, and the research on the measurement of the moisture content of the wood and the influence of the moisture content of the wood on the performance of the wood is more and more abundant, so that the research on the process for quickly preparing the wood with the standard moisture content has very important practical significance.
The percentage of the weight of the moisture contained in the wood to the weight of the wood after the wood is absolutely dried is defined as the moisture content of the wood in China. The water content can be calculated by taking the weight of the oven-dried wood as a calculation reference, the calculated value is called absolute water content, which is called water content (W,%) for short, and the calculation formula is as follows:
W＝(Gs-Ggo)/Ggo×100％
where W represents the absolute moisture content of the wood, Gs represents the weight of the wet wood, and Ggo represents the weight of the oven-dried wood.
The prior art methods of preparing the wood block typically require lengthy storage procedures such that the moisture content of the wood block reaches a predetermined value. Some prior art techniques have used heated and dried wet wood blocks to produce wood blocks with standard moisture content, but this can cause the wood blocks to crack.
Disclosure of Invention
The invention aims to provide a method for preparing wood blocks with specified water content, which adopts specific step parameters to prepare the wood blocks with the specified water content, shortens the preparation time and avoids the deformation and cracking of the wood blocks.
The technical scheme of the invention is that the method for preparing the wood block with the specified water content comprises the following steps:
(S1) preparing sample blocks with the length of 315-325 mm, the width of 235-345 mm and the thickness of 9-11 mm, and treating the sample blocks until the sample blocks are completely dried;
(S2) according to the specified water content, carrying out corresponding treatment on the oven-dried sample block; wherein:
when the specified water content is in the low water content range, placing the completely dried sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%, monitoring the water content of the sample block by detecting the water absorption weight increment condition of the sample block, and obtaining the specified water content sample block when the water content of the sample block reaches the specified water content;
when the specified water content is in the high water content range, firstly placing the completely dried sample block in deionized water for soaking for a preset time, taking out the sample block, wiping the sample block, recording the initial weight, placing the sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%, monitoring the water content of the sample block by detecting the weight change condition of the sample block, and obtaining the specified water content sample block when the water content reaches the specified water content.
A further improvement of the invention is that the process of treating the swatches to absolute dryness comprises the steps of:
(S11) removing floating dust and burrs from the surface of the sample block using a wind gun and a brush;
(S12) putting the processed sample block into a vacuum drying oven with the temperature condition of 100 ℃ and the pressure condition of 0.1MPa, and recording the value after the weight of the sample block does not change any more, namely the oven-dry quality of the sample block.
In a further improvement of the invention, in the step (S2), the water absorption weight gain of the sample block is detected by taking the sample block out of the high-low temperature alternating box, weighing the sample block, and returning the sample block to the high-low temperature alternating box; and subtracting the absolute dry mass of the sample block from the weighed weight to obtain the weight of the absorbed moisture, and dividing the weight of the absorbed moisture by the absolute dry mass of the sample block to obtain the water content of the sample block during weighing.
The invention is further improved in that the low water content range is 0% -14%, and the high water content range is more than 14%.
The invention is further improved in that the wood used for preparing the sample block is larch or spruce.
A further development of the invention is that the predetermined period of time is greater than 24 hours.
The invention has the beneficial effects that: the method has a short whole manufacturing period of no more than three days at most, and the sample block can quickly reach the specified moisture content and simultaneously avoid deformation and cracking by selecting the size of the sample block and the temperature and humidity of the high-low temperature alternating box.
Drawings
FIG. 1 is a flow chart of a method of preparing a wood block of a specified moisture content;
FIG. 2 is a plot of water content versus time for a sample block during preparation of a never dried sample block;
FIG. 3 is a graph showing the change of water content with time in the process of preparing a sample block having a low water content range
FIG. 4 is a graph showing the change of water content with time in the process of preparing a sample block having a high water content range.
Detailed Description
As shown in fig. 1, an embodiment of the present invention provides a method of preparing a wood block having a designated water content, the method including the steps of:
(S1) preparing a sample block with a length of 315-325 mm, a width of 235-345 mm and a thickness of 9-11 mm, and treating the sample block to be absolutely dry.
In the process of preparing the sample block with the preset size, a chordate saw plate without decay, cracks and nodules is selected as a basic sample plate. In one embodiment, the dimensions of the pieces cut out of the base pattern are: 320mm long, 240mm wide and 10mm thick. In the process of drying the sample block completely, firstly, removing floating dust and burrs on the surface of the sample block by using an air gun and a brush, then, putting the processed sample block into a vacuum drying box with the temperature condition of 100 ℃ and the pressure condition of 0.1MPa, and recording the numerical value after the weight of the sample block is not changed, namely the drying quality of the sample block. The way of monitoring the weight change of the sample block is as follows: the weight of the block was quickly weighed every 2 hours with an electronic scale with an accuracy of 0.01g and recorded. After the sample block was treated to be absolutely dry, the dried state in the vacuum drying oven was maintained, and the temperature was returned to 25 ℃.
(S2) according to the specified water content, the dried sample blocks are processed correspondingly. In this embodiment, the specified moisture content is divided into two grades: the low water content range is 0-14%, and the high water content range is 14-40%.
When the specified water content is in the low water content range, the completely dried sample block is placed in a high-low temperature alternating box with the temperature of 40 ℃ and the humidity of 80%, the water content of the sample block is monitored by detecting the water absorption weight increasing condition of the sample block, and the specified water content sample block can be obtained when the water content of the sample block reaches the specified water content. The mode for detecting the water absorption weight increment condition of the sample block is as follows: and taking out the sample block every 1 hour, rapidly weighing the weight of the sample block by using an electronic scale with the precision of 0.01g, recording, and calculating by using a water content formula to obtain the water content of the current sample block.
When the specified water content is in the high water content range, firstly placing the completely dried sample block in deionized water for soaking for a preset time, taking out the sample block, wiping the sample block, recording the initial weight, placing the sample block in a high-low temperature alternating box with the temperature of 40 ℃ and the humidity of 80%, monitoring the water content of the sample block by detecting the weight change condition of the sample block, and obtaining the specified water content sample block when the water content reaches the specified water content.
The oven dried swatches were soaked in deionized water for greater than 24 hours. The water absorption weight increasing condition of the sample block is detected by taking the sample block out of the high-low temperature alternating box, weighing the sample block, and putting the sample block back into the high-low temperature alternating box; and subtracting the absolute dry mass of the sample block from the weighed weight to obtain the weight of the absorbed moisture, and dividing the weight of the absorbed moisture by the absolute dry mass of the sample block to obtain the water content of the sample block during weighing.
In one embodiment, larch and spruce-like pieces are prepared separately, which specifically comprises the steps of:
(1) selecting and preparing sample blocks: selecting parts without obvious defects such as decay, crack, nodule and the like from larch and spruce plates, cutting the parts into standard-size sample blocks with the length of 320mm, the width of 240mm and the thickness of 10mm, removing floating dust and burrs on the surfaces by using an air gun and a brush, and then quickly weighing the initial weight of the sample blocks by using an electronic scale with the precision of 0.01g, wherein the weight of the larch is 434.68g and the spruce is 352.82 g.
(2) Preparing a dried sample block: and (3) putting the processed sample block into a vacuum drying box with the temperature condition of 100 ℃ and the pressure condition of 0.1MPa, quickly weighing the weight of the sample block by using an electronic scale with the precision of 0.01g every 2 hours, and recording the weight until the weight of the wood is not changed any more, wherein the weight is the absolute dry mass of the sample block. The oven-dried quality of the three wood blocks obtained finally is as follows: larch 398.02g, spruce 317.05 g. The specific water content change curve is shown in FIG. 2.
(3) Preparing a sample block with low water content: putting the sample block in an oven-dry state at normal temperature into a high-low temperature alternating box with the temperature of 40 ℃ and the humidity of 80%, taking out the sample block every 1 hour, rapidly weighing the sample block by using an electronic scale with the precision of 0.01g, recording, calculating by using a water content formula to obtain the water content of the current sample block, and taking out the sample block when the water content reaches the specified water content and immediately using the sample block for calibrating a sensor. The specific water content of the sample pieces recorded within 20 hours was changed as shown in FIG. 3.
(4) Preparing a sample block with high water content: placing a sample block with known absolute dry mass into a closed container filled with deionized water, soaking for a certain time (not less than 24 hours), slightly absorbing surface water drops by using dust-free paper, recording the initial weight, then placing the sample block into a high-low temperature alternating box with the temperature of 40 ℃ and the humidity of 80%, taking out the sample block every 1 hour, rapidly weighing the weight of the sample block by using an electronic scale with the precision of 0.01g, recording, calculating by using a water content formula to obtain the water content of the current sample block, stopping processing the sample block when the water content reaches the specified water content, and immediately putting the sample block into application. The specific water content change of the sample pieces recorded within 20 hours is shown in FIG. 4.
In the process of oven drying the sample block, not only a vacuum drying mode but also conventional drying, infrared drying and high-frequency drying modes can be adopted. The wood of the sample block is not limited to spruce and larch
By adopting the steps, the preparation of the standard wood sample block with the water content of 0-30% of larch and the preparation of the standard wood sample block with the water content of 0-35% of spruce can be realized, the whole preparation period is determined according to the water content of the required sample block, and the maximum time is no more than three days. In this embodiment, through the size of selecting the appearance piece, the temperature and the humidity of high low temperature alternating case for the appearance piece can reach appointed moisture content fast, still can avoid simultaneously warping and fracture. The moisture content of the finally obtained sample block is not the balance moisture content, but the size of the sample block and the selection of the processing parameters enable the moisture content difference of different parts inside the sample block when the processing is finished to be extremely small, the sample block can be approximately uniform in moisture content, and the method can be used for accurately calibrating a microwave moisture content sensor. The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.
Claims (6)
1. A method of preparing a wood block of a specified moisture content comprising:
(S1) preparing sample blocks with the length of 315-325 mm, the width of 235-345 mm and the thickness of 9-11 mm, and treating the sample blocks until the sample blocks are completely dried;
(S2) according to the specified water content, carrying out corresponding treatment on the oven-dried sample block; wherein:
when the specified water content is in the low water content range, placing the completely dried sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%, monitoring the water content of the sample block by detecting the water absorption weight increment condition of the sample block, and obtaining the specified water content sample block when the water content of the sample block reaches the specified water content;
when the specified water content is in the high water content range, firstly placing the completely dried sample block in deionized water for soaking for a preset time, taking out the sample block, wiping the sample block, recording the initial weight, placing the sample block in a high-low temperature alternating box with the temperature of 38-42 ℃ and the humidity of 78-82%, monitoring the water content of the sample block by detecting the weight change condition of the sample block, and obtaining the specified water content sample block when the water content reaches the specified water content.
2. A method of preparing wood blocks of specified moisture content according to claim 1 wherein the process of treating the sample blocks to be oven dry includes the steps of:
(S11) removing floating dust and burrs from the surface of the sample block using a wind gun and a brush;
(S12) putting the processed sample block into a vacuum drying oven with the temperature condition of 100 ℃ and the pressure condition of 0.1MPa, and recording the value after the weight of the sample block does not change any more, namely the oven-dry quality of the sample block.
3. The method of claim 2, wherein in step (S2), the water absorption weight gain of the sample block is detected by taking the sample block out of the high and low temperature alternating box, weighing it, and returning it to the high and low temperature alternating box; and subtracting the absolute dry mass of the sample block from the weighed weight to obtain the weight of the absorbed moisture, and dividing the weight of the absorbed moisture by the absolute dry mass of the sample block to obtain the water content of the sample block during weighing.
4. The method of claim 1, wherein the low moisture content range is 0% to 14% and the high moisture content range is greater than 14%.
5. The method of claim 1, wherein the wood species used to make the wood pieces is larch or spruce.
6. A method of preparing a wood block with a specified moisture content according to claim 1, wherein the predetermined period of time is longer than 24 hours.
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| CN202110154207.4A CN112945788A (en) | 2021-02-04 | 2021-02-04 | Method for preparing wood block with specified water content |
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| CN202110154207.4A CN112945788A (en) | 2021-02-04 | 2021-02-04 | Method for preparing wood block with specified water content |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010015020A1 (en) * | 2000-02-04 | 2001-08-23 | Wood Drying Research | Method and apparatus for drying wood |
| CN103245539A (en) * | 2013-04-22 | 2013-08-14 | 河南理工大学 | Manufacturing method of coal samples with different water contents |
| CN103994908A (en) * | 2014-05-26 | 2014-08-20 | 中国矿业大学(北京) | Method for accurately preparing experiment test samples with different water contents |
| CN108802352A (en) * | 2017-07-28 | 2018-11-13 | 北京林业大学 | Measurement of water-content coefficient method and method for drying wood in timber drying |
| CN111487104A (en) * | 2020-05-29 | 2020-08-04 | 煤炭科学技术研究院有限公司 | Experimental device and method for manufacturing test pieces with different water contents |
-
2021
- 2021-02-04 CN CN202110154207.4A patent/CN112945788A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010015020A1 (en) * | 2000-02-04 | 2001-08-23 | Wood Drying Research | Method and apparatus for drying wood |
| CN103245539A (en) * | 2013-04-22 | 2013-08-14 | 河南理工大学 | Manufacturing method of coal samples with different water contents |
| CN103994908A (en) * | 2014-05-26 | 2014-08-20 | 中国矿业大学(北京) | Method for accurately preparing experiment test samples with different water contents |
| CN108802352A (en) * | 2017-07-28 | 2018-11-13 | 北京林业大学 | Measurement of water-content coefficient method and method for drying wood in timber drying |
| CN111487104A (en) * | 2020-05-29 | 2020-08-04 | 煤炭科学技术研究院有限公司 | Experimental device and method for manufacturing test pieces with different water contents |
Non-Patent Citations (2)
| Title |
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| 张彦娟: "丙烯酸酯_硅溶胶改性人工林木材与表面纹理强化的研究", 《中国优秀博硕士论文全文数据库（博士） 工程科技Ⅰ辑》 * |
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Application publication date: 20210611 |