SU1232479A1 - Method of producing particle-board - Google Patents

Description

The invention relates to the production of laminated materials based on shredded wood and a binder, and can be used in the wood industry in the manufacture of chipboard, plywood and lining of furniture panels.

The purpose of the invention is to intensify the pressing, increasing strength and reducing the toxicity of the plates.

The binder is made as follows.

A certain amount of amide resin and hardener is weighed into the mixing tank. Mass i is thoroughly mixed for 1–2 minutes.

The press stock is prepared as follows.

The bonded mass is introduced into the chipboard by means of an air diffuser and the chipboard is then formed, and by hot pressing, a slab is obtained. The plates are pressed at 60-} L5 C, specific pressure of 2 MPa and exposure in a hot press 0.4 min / mm, moisture content of the outer layers of chips 5.7%, internal 5%. Plates are pressed with three-layer thickness of 16 mm, density of 650 kg / m. The consumption of the binder (by the mass of absolutely dry wood) is 10% for the inner layer, and 12% for the outer layer.

As a hardener, technical homoserine is used, which has the following characteristics: liquid from yellow to dark brown color (the presence of sulphate precipitate is allowed, by weight,%: homoserine P-1 6.5-7; methane 2.3- 2.6; ammonium sulfate 37-

Urea-formaldehyde resin 60% concentration

Water

20% ammonium chloride solution

S

0

0

50

five

38; dimethyl sulfide 0.05-0.1; hydromethylmethionine oxide 0.5-1.0; methanol 0.05-0.1.

The aqueous concentrate of homo: erin is non-flammable, non-hazardous, non-toxic.

Table 1 shows the composition of the binder.

Physico-mechanical properties of the plates are given in table 2. .

The content of free formaldehyde during curing of the binder is given in table 3.

The effect of the hardener on the curing time, the viability of the binder and adhesiveness according to GOST are given in Table 4.

With the introduction of technical homoserine into the adhesive composition in an amount greater than 4 May, h, per 100 May, h, resin, the adhesive capacity of the composition deteriorates, and the toxicity slightly decreases.

The data in Table 2 confirm that the use of technical homoserine as a hardener increases the tensile strength in static bending by 3–10%. The tensile strength perpendicular to l 1 (but the layer increases by 5–26%. Toxicity decreases by 1, 1-13.6 1X0- per.

The efficiency of the proposed method is achieved by reducing the pressing time, improving the strength and reducing the toxicity of the plates both during their pressing and operation, as well as by reducing the cost of the hardener.

Table 1

100 100 100 100 100

Components I ma.h.

vesno-T 1 2 G 1 -5

the famous

Technical homoserine

The density of the plates

kg / m

Strength at static bending, MPa

Strength at stretching perpendicular to the surface, MPa

0,370,390,470,470,45

Water absorption after being in the water for 24 hours,

%

Swelling by

tollute%

Examples

The composition of the compositions

Known;

New 100 ma.ch. carbamide resin "

Continued tabl.J /

Content of components, ma.ch. by examples

0.5

table 2

650

650

650650

650

15,015,715,8 15.6

15.3

0.42

68,367,366,766,9

67,8

20,019,519,18,9

19.0

Table 3

The content of free formaldehyde, mg / l, in the method

known

proposed

Examples

The composition of the compositions

 5 ml of 20% ammonium chloride

100 ma.ch. carbamide resin 0.5% technical homoserine

100 wt.h, carbamide resin + 1% Technical Homo-serine

100 wt.h. carbamide resin + 2% of technical homoseries.

I

100 ma.ch, karmabidny smo.- ly + 3% of technical homoserine

00 wt.h. carbamide resin 4% technical homoserine

100 carbamide resin + 5 ml of 20% ammonium chloride solution 65 30 I, 34

100 carbamide resin +0.5

technical homoserine 55 28 1.68

100 carbamide resin + 1

Continuation of table.3.

The content of free formaldehyde, mg / l, in the method

known

proposed

0.068

0.062 0.059

0.020 0.012

0,005

Table 4,

zi

technical gog oserina 50 24

 karmabid resin +2

technical homoserine 40 24 1.82

4100 carbamide resin +3

technical homoserine 38 24 I, 64

5100 carbamide resin +4

technical homoserine 30 24 I, 60

Editor A. Shandor Order 2733/17

Compiled by E. Savostikova

Tehred O. Gortvay Proofreader A, 0 {hand.

Circulation 501 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab. 4/5

Production and printing company, Uzhgorod, st. Project, 4

12324798

Continued table. four

: zTz: ii: iz:

Claims (1)

METHOD FOR PRODUCING WOOD-; ' NO-STOVE BOILERS by mixing crushed wood with urea-formaldehyde resin and hardener and their subsequent hot pressing, characterized in that., With the aim of intensification. * pressing, increasing strength and reducing the toxicity of plates, as a hardener use technical homoserine in an amount of 0.5 to 4 wt.h., per 100 wt.h. urea-formaldehyde resin. Bf 00 bf m C0