DE3342685A1 - ITEMS FROM TIED, HEATED AND PRESSED WOOD FIBERS - Google Patents

Description

The invention relates to objects made of wood wool, which are bound with various binders, dried and hot-pressed is to make flat plates or other desired shapes.

It is known to manufacture objects obtained by bringing chip material together by hot pressing will. The material is appropriately crushed and compacted by adding large amounts of binding agents, for example Urea resin can be used.

However, the articles have poor flexural strength and employ very significant amounts of binders in advance.

In addition, they are not manufactured in thicknesses less than 2.5 mm as their mechanical strength is not allows it to be used expediently under heavy loads.

It is noteworthy that this type of article has a high percentage of water absorption that is only can be partially eliminated by treatment with water-repellent substances.

The main object of the invention consists in the production of objects from bonded and compressed material, which overcome the aforementioned problems, i.e. excellent mechanical strength and very low water repellency

ensure absorption without losing its properties, even if they are immersed and saturated with water and then dried. In addition, the items should only require relatively small amounts of binders.

To achieve this goal the invention provides one. Item available, which is characterized by that it consists of an intimate union of wood wool, which is brought together by a binder and then was pressed and heated, the wood wool is essentially cut from wooden blocks, residues from Planing and edging and similar operations.

The structural and functional features and advantages of an article of the invention are set out below Description demonstrated in greater detail. Reference is made to the attached figures to represent a plate:

Fig. 1 is a plan view of a plate according to the invention

and
Figure 2 is a schematic cross-section along the line

II-II of the plate according to FIG. 1.

Referring to the figures, a plate 11 is made of an intimate union of so-called wood wool 12 composed by binding with binders or resins.

The wood wool is cut from wooden blocks, residues from Planes and edges received, which are processed into thin elongated plates of the desired sizes in special devices xverden.

The platelets produced in this way have good individual strength, since they are along the direction of the Wood fibers are formed lying flat by processes that are similar to planing processes.

The wood wool obtained is bound with suitable synthetic resins, for example phenolic resins, to form a so-called Form mat (mattress).

During the production of the platelets, the differently stretched platelets are fed in and straightened in batches spontaneously essentially evenly, transversely and longitudinally, and in this way form the previously mentioned one Fiber mat.

This mat is then passed into a drying device, where it contains a large proportion of the wood wool and the binder contained water loses.

The mat pre-treated in this way is pre-pressed and fed into a hot plate press, where they combined one Exposure to pressure and heat for a set time, which depends on the desired strength, is subjected.

What matters is the fact that the aforementioned Drying process is carried out at temperatures a few degrees above room temperature, as well as that due to the fact that the wood wool surface areas are much smaller than those of chipboard, the quantities very little binding agent required.

The arrangement and in particular the elongated shape of the platelets ensure mechanical strength and flexural strength in all different directions.

The properties mean that both flat objects and objects of a variety of other shapes can be punched out directly from the mat according to the description and thus finished and prefabricated Articles of remarkable strength and in the desired dimensions can be obtained. Another very An important feature of the objects produced by the process according to the invention is that they are excellent Water resistance, which is expressed in the fact that they have absorption properties when immersed in water, the are practically the same as those of the wood from which they are obtained, the density being the same.

Also noteworthy is the fact that the articles made with relatively low density are also excellent have thermal conductivity coefficient.

To the above-mentioned features and advantages of objects made from wood wool over objects made from To illustrate chipboard material more clearly, the following two comparison tables show the results of one Series of laboratory tests performed on plates.

Physical and mechanical properties of chipboard panels on the market

; strength
density

Flexural strength:

- longitudinal

- transversal

modulus of elasticity

Water absorption

- after 2 h

- after 24 h

swelling

Kg / mc.

M / mm '
M / mm '
N / mm '

750

18th

18th

2500

47 65

10

758

23

22nd

2650

48
59

11th

12th

770

22nd

21 2700

47 58

14th

r-o co oo cn

Starch density

Flexural strength:

- longitudinal

- transversal

modulus of elasticity

ι. ■; Water absorption without

>! Water repellent treatment

J ^; 2 h

24 hours

swelling

Water absorption after water repellent treatment

2 h

H

swelling

Thermal conductivity coefficient at + 10 ° C

\ ■ -

! mm

Kg./mc

H / mm '

N / mm '

N / mm '

Kcal
mh ° C

12 450

28

28

40

60 13

32

0.045

ι 55 2 1 12th 700 800 5 52
52 ι
I.
70 y
70;
j 3 : 30 5800 7400
I. 650 12th
j 38 35 46 I 5300
I. 0.050 ^;
t 52 . -. . .
48 38 - ■
11.5 11th 5 4th 29 22nd 11th 10.5

900

80

80

8200

0.8

1,100

110 110

11800

30th

46 11

20th

10.5

20th

40 10.5

2.5

18 9.5

CT) OO

The preceding tables clearly show that with plates of the two types with the same density in the case of the invention Boards have a much higher strength and the percentage of water absorption is much lower.

It is also noteworthy that if the density is greater than than 800 kg / sqm objects, in this special case panels of very low thickness, even less than 1 mm “In any case, these objects have excellent mechanical properties, polygamous ones of fiberboard and are equal to those of synthetic resins such as Bakelite.

ORIGINAL

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Claims (4)

Attorney's file: 33 161 _{25> November 1983} Faesite S.p.A. Padova / Italy Objects made from bound, heated and compressed wood fibers Claims 1J object, characterized in that it consists of an intimate combination of wood wool which has been produced by a binding agent, subsequent pressing and heating, the wood wool being composed essentially of trimmed wooden blocks, residues from planing and edging and similar operations. 2. Articles according to claim 1, characterized in that the wood wool is composed of thin elongated platelets which are formed along the direction of the wood fibers. V / DW / Hy - 2 - * (089) 98 82 72-74 Telex. 5 24 560 BERG d Bank accounts: Bayer Vereinsbank Munich 453100 (BLZ 700 202 70) lelegramme (cable) Telekopierei (089) 983049 Hypo-Bank Munich 4410122850 (BLZ 70020011) Swift Code HYPODE BtRGSTAPFPATENl Munich KaIIp Intotec 6350 Gi Il -i Hl Postscheck Munich 65343-808 (BLZ 70010080) 3. Objects according to claim 1, characterized in that they are in the form of plates of different thickness and density. 4. Objects according to claim 1, characterized in that they are punched out in any shape or form.