RU2339503C1 - Method of wood materials adhesion - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: synthetic glue is applied on the surface of parts from wood materials, glued surfaces are joined until glue hardens completely, at that glued parts are located between plates of electrostatic field capacitor so that power lines of electrostatic field are directed perpendicular to glue line and treated in electrostatic field with intensity of 2.16-9.5·10² V/cm, and glue applied on glued surfaces is polyvinyl acetate PVAC or epoxy K-153.

EFFECT: higher strength of glued connections of wood materials and higher speed of glue line hardening.

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Description

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

A known method for gluing wood materials, selected as a prototype, including the operation of applying glue to the surfaces to be glued, open exposure and joining the 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 (Patent RF No. 2298574, C09J 5/00, 05/10/2007, Bull. No. 13).

Studies have shown that despite the high adhesive ability of phenol-formaldehyde resins, not all of them can be used for high-speed bonding of wood in a magnetic field. This bonding method requires adhesives having a high cure rate and a high dielectric loss factor.

The invention solves the problem of increasing the strength of the adhesive joints of wood materials and increasing the speed of curing of the adhesive joint.

This is achieved by the fact that in the method of bonding wood materials, including the operation of applying synthetic glue to the surfaces to be bonded, joining the surfaces to be glued until completely cured, according to the invention, the parts to be bonded are placed between the capacitor plates of a constant electric field so that the lines of force of the constant electric field are directed perpendicular to the adhesive the seam, and is subjected to processing in a constant electric field with a strength of 2.16-9.5 · 10 ² V / cm PVA glue (polyvinyl acetate) or K-153 (epoxy glue) is applied to the glued surfaces.

The method is as follows. A glue layer is applied on the surface of parts made of wood materials, the consumption of which is 180 ... 250 g / m ² , the glued surfaces are connected and placed between the plates of the capacitor of a constant electric field so that the lines of force are directed perpendicular to the glue line.

The exposure of parts in a constant electric field should not exceed the curing time of the adhesive joint.

As a result of exposure to the adhesive layer of a constant electric field with a strength of 2.16-9.5 · 10 ² V / cm, the strength of the adhesive joint increases significantly. For example, the strength of glued oak samples increases by 25-30% compared with conventional gluing (table), the acceleration of the curing of the adhesive layer by 30%. The increase in tension above 9.5 · 10 ² V / cm does not lead to a significant increase in tensile strength.

Table 1 shows the test results using glue K-153, in table 2 - using glue PVA. The tests were carried out using samples made of oak.

Table 1 Chipping Adhesive K-153 Test Results Field strength, 10 ² V / cm Tensile strength, MPa Strength increase,% - 11.17 0 2.16 11.19 0.18 3.17 11.43 2,33 4.17 12.5 11.9 4.83 12.81 14.68 5.33 13.33 19.34 6.33 13.83 23.8 7.33 13.92 24.62 8.33 13.92 24.62 9.5 13.92 24.62

table 2 Chipping PVA Adhesive Test Results Field strength, 10 ² V / cm Tensile strength, MPa Strength increase,% - 6.2 0 2.16 6.23 0.48 3.17 9.29 1.45 4.17 6.3 1,6 4.83 7.4 19.35 5.33 10 61.29 6.33 10.5 69.35 7.33 10.7 72.58 8.33 10.7 72.58 9.5 10.7 72.58

Claims (2)

1. A method of bonding wood materials, including the operation of applying synthetic glue to the surface of wood parts, bonding the surfaces to completely cure the glue, characterized in that the parts to be bonded are placed between the capacitor plates of a constant electric field so that the lines of force of the constant electric field are directed perpendicular to the glue line, and subjected to processing in a constant electric field with a strength of 2.16-9.5 · 10 ² V / cm 2. The method according to claim 1, characterized in that polyvinyl acetate PVA or epoxy K-153 is applied to the surfaces to be glued.