SU1712148A1 - Method for cold glueing of the wood - Google Patents

Abstract

The invention relates to woodworking technology and can be used for gluing wood in the production of glued building structures, plywood, veneering furniture, in the production of musical instruments and other wood products. The invention makes it possible to shorten the gluing time by means of a method involving applying phenol-formaldehyde resin based on an adhesive based on phenol-formaldehyde resin mixed with para-formaldehyde and then applying a substance selected from the group of potassium carbonate, sodium carbonate, trisodium phosphate or Portland cement, in the amount of 2-10 wt.h. per 100 wt.h. resins, contacting surfaces and holding the surfaces to be glued under a pressure of 0.7 MPa for 6–8 hours. 2 tab.

Description

The invention relates to woodworking technology and can be used for gluing wood in the production of building structures, plywood, veneering furniture, in the production of musical instruments and other wood products.

Known methods of gluing drayusins include applying glue to the surfaces to be glued, connecting the surfaces to be glued and holding them under pressure.

However, these methods of squeezing are long, which reduces the productivity of the press ()

In order to speed up the bonding process and to improve adhesive joints, additional amounts of hardener are introduced into the adhesive during its preparation, which leads to a reduction in the viability of the adhesive and a deterioration of the bonding process. The introduction of an additional amount of hardener in the form of an aerosol on a previously applied layer of glue also leads to a deterioration in the process of gluing, which is caused by the uneven penetration of the hardener solution into the adhesive layer.

I

The closest to the present invention is a method of cold gluing wood, comprising applying to the surfaces to be glued adhesives based on phenol-formaldehyde resin mixed with paraform, and wood flour, the compound

glued surfaces and holding them under pressure.

However, this method of gluing is characterized by a considerable curing time,

The purpose of the invention is to reduce the gluing time.

The proposed method of gluing provides for an additional application of a substance selected from the group to the layer of glue: potassium carbonate, sodium carbonate, trisodium phosphate, and Portland cement.

The method is carried out as follows.

Adhesive based on phenol-formaldehyde resin (FGF-50K) with paraformaldehyde in the ratio of 100: 13.5 wt.h. respectively, and then the powder of a substance selected from the above group, which is an additional curing agent, is sprayed. The surfaces to be glued are joined and maintained at a pressure of 0.7 MPa for 6-8 hours. The glued samples are tested according to GOST 15613.1-77 immediately after the pressure is removed and three days after the pressure is removed.

Gluing strength of wood depending on the amount of added additional curing agent

The results of testing samples are given in Table. 1 and 2.

These data indicate that the bonding strength normalized according to GOST IOVBO-B for dry samples is achieved by holding the glued samples for 6–8 hours, which allows you to intend to consolidate the gluing process 1.5–3 times.

In addition, the high strength of the glued samples after boiling for three hours indicates the water resistance of adhesive joints.

Formula 8 invention

A method of cold gluing wood, including applying phenol-formaldehyde resin based glue mixed with paraformaldehyde to the glued surfaces, joining the glued surfaces and holding them under pressure, which also means that (cf. bonding, an additional powder of a substance selected from the group consisting of potassium carbonate, sodium carbonate, trisodium phosphate and portlandment in an amount of 2-10 parts by weight per 100 parts by weight of resin, is applied to the layer of glue, and pressure is applied at 0.7 MPa for 6-8 hours

Table 1

Continuation of table 1

The test results of the alkalinity of wood gluing when splicing according to GOST | 5 & 13.t-77 depending on the time of pressure pulling

T a b l and c a 2 Carbon dioxide - i cI LI, 10 ma.ch. 6.5 / 3.6 133 mas

Continuation of table 2 a and n. E. In the numerator is the strength of dry samples; . 3-hour KHni44eHMfl. The tests are carried out to establish the time of pressure under pressure necessary to achieve the transport strength of gluing. 6.6A, J2 6.6 L, 7 6.6 L, 8 in the denominator, the strength of the samples after

Claims (1)

Claim 15 A method of cold gluing wood, including applying phenol-formaldehyde resin-based glue to a mixture with paraformaldehyde on a glued surface, joining the glued surfaces and holding them under pressure, with the aim of reducing the bonding time , an additional powder of a substance selected from the group consisting of potassium carbonate, sodium carbonate, trisodium phosphate and Portland cement in an amount of 2-10 parts by weight is additionally applied to the adhesive layer. per 100 wt.h, resins, and holding under pressure is carried out at 0.7 MPa for 6-8 hours Table 1 Bonding strength of wood depending on the amount of added hardener Glue Additional hardener Shear strength, MPa Name Number of May. hours per 100 wt. parts of resin Resin FRF-50K Carbonic 2 7.4 / 4.8 with paraformal potassium 4 7.0 / 4.6 dehydrate 6 7.1 / 4.6 100: 13.5 Yu 6.9 / 4.5 May. h 12 5.9 / 3.0 Carbonic 3 6.9 / 4.8 * sodium 5 7.0 / 4.6 10 6.9 / 4.8 12 6.7 / 3.9 fifteen 5.3 / 3.0 T rinosodium phosphate .4 7.1 / 4.6 6 6.9 / 4.5 z- 10 · 6.8 / 4.2 12 6.5 / 3.8 fifteen 5.1 / 39 5 1712140 6 Continuation of table 1 Glue Additional hardener Shear strength, MPa Name Number of May. hours on May 100. parts of resin Portland cement 3 6.6 / 4.4 5 6.6 / 4.2 8 6.8 / 4.2 10 ’6.5 / 4.3 12 6.5 / 4.1 fifteen,, 5.4 / 3.1 - ¹ - - ' 6.9 / 4.6 • Table 2 The results of testing the bonding strength of wood during chipping according to GOST 15613.1-77, depending on the exposure time under pressure ' Glue Additional Test immediately after depressurization hardener, t deposited ** Tensile strength at chipping when time laziness on dressing 100 parts by weight pitches S "" Y ·> "· *" · · "··? · _ — ____ t—— - g——. • 3 G * 1 6 J ^{8 fifteen} 24 J - ““. “.“ “Before W -“ - - - - - “> ___ FRF-50 Carbonic acid from . Li, 10 parts by weight 3,7 4.7 .6.3 6.5 6.7 6.5 May 13.5 Carbon dioxide h · lara * formal _ri, 10 parts by weight 2,5 3.0 M 47 5.3 6.5 dehydrate Trisodium phosphate, 10 parts by weight 2.6 3.0 ' 3Λ 4* 5,0 6.6 Portland cement, 10 parts by weight 2.6 \ 2.7 3,5 4.3 5.8 6.5 1L 2.1 43 6.7 7 1712148 8 Continuation of Table 2 Glue Optional hardener sprayed onto Tests 3 days after depressurization ...... · .......... Strength at shearing, MPa, with holding under pressure, h 100 parts by weight pitches fifteen 1 24. FRF-50 from - Potassium carbonate, 10 parts by weight t 4.9 / 3.3 6.5 / 3.6 ' from 6.6 / 4.2 6.6 / 4.7 6.6 / 4.8 13) May 5. h. couple ·? formal Sodium carbonate, 10 m.h. 4.2 / 3.4 6.2 / 3.5 7.4 / 4.0 7.5 / 4.8 7.6 / 4.6 dehydrate Trisodium phosphate, Yu wt.h. 4.0 / 3.5 6.6 / 4.2 6.7 / 2.4 6.8 / 4.5 6.8 / 4.5 Portland cement, i10 parts by weight 6.0 / 3.8 ’ 6.6 / 4.0 6.8 / 4.2 6.9 / 4.8 6.9 / 4.8 · -. 4.6 / 35 5.4 / 4.0 6.9 / 4.5 g-s. N ote. In the numerator is the strength of dry samples; 'in the denominator is the strength of the samples after 3 hours of boiling. * Tests are carried out to establish the exposure time under pressure necessary to achieve * transport adhesive strength. Editor M. Bandura Compiled by E.Kazakova Tehred M. Morgenthal. Proofreader M. Demchik Order 497 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries under the State Committee for Science and Technology of the USSR 113035. Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.