RU2373248C1 - Glue method of timber-based material - Google Patents

Abstract

FIELD: woodworking industry.

SUBSTANCE: in method of gluing of timber-based materials, including operation of glue application on glued surfaces, connection of glued surfaces up to total hardening of glue, according to the invention, glue is pretreated in magnetic field with intensity 3-24·10⁴ A/m during 30 minutes.

EFFECT: solidity increasing of glued connection of timber-based materials and speed enhancing of hardening of glue line.

4 tbl

Description

The invention relates to a technology for performing adhesive joints and can be used for gluing wood materials.

A known method of bonding wood materials, selected as a prototype, including the operation of applying glue to the surfaces to be bonded, open exposure and connection of surfaces until the glue is completely cured under the influence of a constant magnetic field with a strength of 3 ... 24 * 10 ⁴ A / m (RF Patent No. 229857.4 C09J 5/00, 05/10/2007, Bull. No. 13).

Studies have shown that despite the high adhesive strength of the processed glued products, not all of them can be placed between the plates of the electromagnet. This gluing method requires small parts.

The invention solves the problem of reducing the consumption of glue while increasing the strength of the adhesive joints of wood materials.

This is achieved by the fact that in the method of bonding wood materials, including the operation of applying glue to the surfaces to be glued, joining the surfaces to be glued until the adhesive is completely cured, according to the invention, the adhesive is pre-treated in a magnetic field with a strength of 3 ... 24 · 10 ⁴ A / m for 30 minutes . KFZh, PVA glue or SUPRATERM 436 glue (supertherm 436) is applied to the glued surfaces.

The method is as follows. A container with glue is placed between the poles of the electromagnet, the amount of which is equal to the consumption per shift, and subjected to magnetic treatment for 30 minutes. On the surface of parts made of wood materials, a layer of treated glue is applied, the consumption of which is 180 ... 250 g / m ² , and glued surfaces are connected.

As a result of exposure to the adhesive of a constant magnetic field with a strength of 3 ... 24 * 10 ⁴ A / m, the strength of the adhesive joint increases significantly. For example, the strength of glued oak samples increases by 25% (using KFZh resin and PVA glue) and by 95.6% when gluing supertherms 436 compared to conventional gluing. The increase in tension above 24 · 10 ⁴ A / m does not lead to a significant increase in tensile strength.

It has also been experimentally proved that there is a change in the viscosity of the adhesive composition, as a result, the adhesive consumption decreases by 10% when gluing solid wood with treated adhesive compared to untreated. Experimentally established such a fact as acceleration of the curing of the adhesive layer by 30% in the case of using treated adhesive as an adhesive.

The proposed method for gluing wood materials can be applied to a number of adhesives, for example:

- KFZh GOST 14231-88 (urea-formaldehyde resin of increased viability) is used for the production of plywood, furniture, building and joinery products, etc. The mass fraction of free formaldehyde is 0.5 ... 0.9%, the concentration of hydrogen ions is pH 7.5-8.7 , mass fraction of solids 67 ± 2%;

- PVA DF 50 / 5N GOST 18992-80 (PVA - dispersion polyvinyl acetate homopolymer coarsely dispersed, D - dispersion, F - dibutyl phthalate or diisobutyl phthalate, 50 - minimum solids content of 50%, 5 - plasticizer content in terms of dry residue in percent - 5 %, N - low viscosity) is recommended for use in household chemicals, construction and woodworking industries, textile industry, packaging production, etc .;

- SUPRATERM 436 glue (aqueous polyurethane dispersion), density about 1.05 g / cm ³ , pH 7, used for 3-dimensional gluing of thermoplastic furniture film on MDF boards or other materials with a finely porous structure.

Table 1 c shows the test results using KFZH resin (carbamide-formaldehyde increased viability), table 2 using PVA glue (polyvinyl acetate), and in table 3 supertherm 436 (polyurethane solution). The tests were carried out using samples made of oak, table 4 shows the results of the experiment on the influence of the magnetic field on the consumption of resin CFG when bonding solid wood. From these data it is seen that when processing the resin in a magnetic field there is a decrease in glue consumption by 10% while increasing the strength of the adhesive joint.

Table 1 Glue Type of test Field strength, A / m Tensile strength, MPa Number of samples Strength increase,% CFJ chipping - 8.20 10 0 3 9.20 12 6 10.40 22 9 10.70 23.6 12 10.70 23.8 fifteen 10.80 24.7 eighteen 10.82 24.7 21 10.83 24.7 24 10.83 24.7

table 2 Glue Type of test Field strength, A / m Tensile strength, MPa Number of samples Strength increase,% PVA chipping - 7.90 10 0 3 8.53 7 6 10.01 twenty 9 10.26 22.4 12 10.51 24.4 fifteen 10.60 25 eighteen 10.59 25 21 10.60 25 24 10.59 25

Table 3 Glue Type of test Field strength, A / m Tensile strength, MPa Number of samples Strength increase,% Super-
term
436 chipping - 2.5 10 0 3 2.95 18.0 6 3.33 33,2 9 3.65 46.0 12 4.00 60.0 fifteen 4.39 75.6 eighteen 4.73 89.2 21 4.89 95.6 24 4.94 97.6

Table 4 Glue Type of test Field strength, A / m Tensile strength, MPa Number of samples Adhesive viscosity, at 20 ° С, according to ВЗ-4, s Glue consumption, g / m ² CFJ chipping - 8.20 10 120 180 3 9.20 120 180 6 10.40 80 180 9 10.70 80 175 12 10.70 80 175 fifteen 10.80 80 170 eighteen 10.82 80 165 21 10.83 80 160 24 10.83 80 160

Claims (2)

1. The method of gluing wood materials, including the operation of applying glue to the glued surfaces, joining the glued surfaces until the glue is completely cured, characterized in that the glue is pre-treated in a magnetic field with a strength of 3-24 · 10 ⁴ A / m for 30 minutes 2. The method according to claim 1, characterized in that glue KFZH, PVA or supertherms 436 are applied to the glued surfaces.