Method for manufacturing E0 level wood veneer

A technology of plywood and preparation steps, applied in the direction of joining of wooden veneers, chemical instruments and methods, adhesives, etc., to achieve the effect of strengthening the bonding performance, improving the structure, and improving the water resistance

Inactive Publication Date: 2008-08-20
INST OF CHEM IND OF FOREST PROD CHINESE ACAD OF FORESTRY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This patented technology describes a new type of urethane (urea) -melanium formaldehydrone resinate). These compositions have improved properties such as reduced shrinkage upon curing, increased hardness, decreased residual formaldeyloxy group concentration, better moistur balance, longer life span, higher heat capacity, greater impact force binding ability, stronger adhesion, more elongated crystal structures, shorter covalently bound times, fewer formaldezols per unit volume when combined together, reducing volatile organics emissions, maintaining solvent characteristics, preventing decomposition or degraded products that could harm health hazard compounds like benzyl ethers. Additionally, these materials exhibited enhanced thermal conductivity compared to other types of bindings agents, allowing it to actively participate at room temperatures while minimizing energy consumption. Overall, they provide technical benefits including improved physical property values, reduced environmental pollution levels, simplified manufacturing processes, safer use overcomes issues associated with current methods, and provides superior durability and weldable qualities.

Problems solved by technology

This patented describes different methods for producing strong yet flexible wooden plates called urethane resin foams. These products were developed over time due to their superior properties such as durability against environmental factors like moisture, heat stability, and flammability. They also had improved water repelling characteristics compared to traditional binders. To achieve these goals, various modifications including addition of specific ingredients and adding formaldehydrogenase activators may help increase binding intensity and eliminate formaldelectrodes. Overall, these improvements resulted in better performance qualities and reduced costs associated with urethanilame resin binder compositions.

Method used

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  • Method for manufacturing E0 level wood veneer
  • Method for manufacturing E0 level wood veneer
  • Method for manufacturing E0 level wood veneer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1 (Preparation of three plywood)

[0016] The first step: Add 320g of formaldehyde solution, the first batch of melamine 7g, and the first batch of urea 108g into the reactor in a 500ml four-necked flask, adjust the pH to 7.5 with triethanolamine, heat up to 85°C, and react for 40 minutes.

[0017] Step 2: Adjust the pH to 4.8 with 50% formic acid, and react to the desired viscosity at 90°C.

[0018] The third step: adjust the pH to 6.5 with triethanolamine, add 7 g of the second batch of melamine and 42 g of the second batch of urea, and react at 90°C for 50 min.

[0019] The fourth step: adjust the pH value to 7.5 with triethanolamine, add 35g of the third batch of melamine, and react at 80°C for 40 minutes.

[0020] Step 5: Cool down to 70°C, add 55g of the third batch of urea, continue the reaction at 50°C for 30 minutes, and cool and discharge. Test its performance separately, and the results are listed in Table 1.

[0021] The sixth step: take 60g of the prepa...

Embodiment 2

[0023] Example 2 (Preparation of three plywood)

[0024] The first step: add 320g formaldehyde solution, the first batch of melamine 8g, and the first batch of urea 108g into the reactor in a 500ml four-necked flask, adjust the pH value to 8.0 with triethanolamine, raise the temperature to 85°C, and react for 50min.

[0025] Step 2: Adjust the pH to 5.2 with 50% formic acid, and react to the desired viscosity at 90°C.

[0026] The third step: adjust the pH to 6.7 with triethanolamine, add 8 g of the second batch of melamine and 42 g of the second batch of urea, and react at 90°C for 50 min.

[0027] The fourth step: adjust the pH value to 8.0 with triethanolamine, add 33 g of the third batch of melamine, and react at 90°C for 40 minutes.

[0028] Step 5: Cool down to 70°C, add 60g of the third batch of urea, continue to react at 55°C for 30 minutes, and cool the material to discharge. Test its performance separately, and the results are listed in Table 1.

[0029] The sixth step: ...

Embodiment 3

[0031] Example 3 (Preparation of three plywood)

[0032] Step 1: Add 320g of formaldehyde solution, 9g of first batch of melamine, and 108g of first batch of urea into the reactor in a 500ml four-necked flask, adjust pH to 8.5 with triethanolamine, heat up to 90°C, and react for 40-50min.

[0033] Step 2: Adjust the pH to 5.5 with 50% formic acid, and react to the desired viscosity at 90°C.

[0034] The third step: adjust the pH value to 6.2 with triethanolamine, add the second batch of melamine and 42 g of the second batch of urea with the same quality as the first batch, and react at 90°C for 50 minutes.

[0035] The fourth step: adjust the pH value to 8.0 with triethanolamine, add 32 g of the third batch of melamine, and react at 90°C for 40 minutes.

[0036] Step 5: Cool down to 70°C, add 63g of the third batch of urea, continue the reaction at 60°C for 20 minutes, and cool and discharge. Test its performance separately, and the results are listed in Table 1.

[0037] The sixt...

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PUM

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Abstract

The invention provides a preparation method of plywood of E0 grade. The urea formaldehyde resin adhesive has an advantage of simple preparation technology, good reproducibility, lower cost and long store time. By using the urea formaldehyde resin adhesive, the plywood/three-ply board/overlaying panel/multilayer board accord with the requirements of plywood of E0 in terms of the bonding strength and the formaldehyde emission. The method in the invention has the advantages that: the preparation of the urea formaldehyde resin adopts the alkali-acid-alkali traditional craft; the urea and the melamine are added in three times; the urea is added in three times which adjusts the quality of the resin molecule; especially, the urea, which is added in the second time, not only degrades and resets the large molecules but also decreases the content of the ether linkage and reduces the release of the formaldehyde; during the composite process, the pH value in the condensation polymerization is rigidly controlled; by the two-step condensation polymerization, the condensation polymerization can rapidly proceed in good order.

Description

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Claims

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Application Information

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Owner INST OF CHEM IND OF FOREST PROD CHINESE ACAD OF FORESTRY
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