-- 211~66 1
~,~O~ OF AND APPARA~U~ FOR INJ~CTlNG TREATIN~-LIQUID INTO
~OOD HAT~RIAL AND ~GRGu~ I~ORaANIC MA~RIAL, AND h~.~OD FOR
D~ AO~lNG RAY PAR~NCRYMA C~LL ~AL~B AND A~PIRAT~D PIT PAIR
The prQsent invention relates to a method of and
apparatus for in~ecting treating liquid such as resin into
wood material and stone material. More particularly, the
present invention relates to a method of injecting a treating
liquid which gives the wood material high rot resistance,
insect resistance, ant resi6tance, mold resistance, flame
resi6tance, dimenslonal st~bility, and increased strength, and
which gives the stone material increased acid resistance. The
present invention also relates to a method of destroying ray
parenchyma cell walls and aspirated pit-pairs.
Hitherto, various methods have been used such as
injecting treating liquids into the wood material, as heat-
treating and applying pressure on it, as pouring liquids into
it after boiling, for making it highly flame resistant, rot
resistant and insect resistant, and for giving it high
dimensional stability and increased strength.
The treating liguids have been injected into the wood
material by applying thereupon pressure right up to a
specified pressure in a short time while maintaining that
pressure for a long period of time. In this case, though
dep~Aing on the kind of wood material used, the injection of
the treating liquid has been generally carried out at a
pressure not more than 15 kg/cm2 because injection carried out
above this pressure causes the wood material to deform such as
to warp, bend, or to ~e~ - ~h~nner.
~A
211366 1 ''
As such a treatment method, there i6 known a wood
treating process di6closed in USP 4,194,033 (Motai). With
this disclosed process, wood i8 heat-treated and boiled so
that film holes are opened by pressure and temperature. Also,
as described in USP 3,693,584 (Barnett), there is a proposed
method by which pressure is slowly intermittently raised for
injecting treating liquid. Note that USP 3,693,584 (Barnett)
discloses an apparatus by which pulse pressure is applied to
open and close wall holes for in~ecting treating liquid,
aiming to, e.g., shorten the treatment time and inject the
treating liquid into the wood core 6ufficiently. Further,
typical one of treating-liquid in~ecting apparatus is
disclosed in USP 3,895,138 (Sewell).
In recent years, deterioration of h~ ngs made of stone
material caused by acid rain has become a problem in Europe.
Various measures have been taken to protect the stone material
from acid rain, such as applying the treating liquid to the
stone material, and taking advantage of the properties of the
stone material itself, such as the property of marble to
neutralize acid water which comes in contact with its surface.
The wood material generally has many groups of cells as
shown in Fig. 8. Between each cell is a 6tructure consisting
of a wall pit-pair 1 scattered about forming wall pit 2 as
shown in Fig. 9(a). At the center of the wall hole 2 i6 a
hyperplnstic portion, called a torus 3. The torus 3 is
~uL~unded by a thin mesh-like pattern (margo). In the wood
material having this kind of 6tructure, in the process of
processing the wood material into heart wood and the like, the
wall pit wall i8 drawn toward one of the pit opPn~ngs, so that
the torus 3 blocks the pit opening. The wood material in this
condition is said to have an aspirated pit-pair (Fig. 9(b)).
When the wood material has an aspirated pit-pair, which is
seen in the heart wood in many cases, the torus 3 blocks the
- 2 -
~,
,
'- 211366 1
pit 2. The wall plt 2 in the heart wood as well a6 those in
the sap wood are al60 ~locked by the toru6 3. For thls
reason, in order to spread the treating liquid thLGUyhOUt the
wood material, lt is necessAry to de~L,vy the torus 3 whlch
blocks the pit op~n~ of an aspirated pit-pair, or to de~LL~y
the cell wall itself, 80 that the treating liquid can permeate
into ad~acent cells.
In order to ~e~ y the torus 3 to those at the center of
the material, an applled p~e6~u~e of 30 kg/cm2 has been
requlred using the ~n~el.L~QnAl treating-liquld in~ectlng
methods. u~we~e~ as descrlbed above the materlal hAs been
deformed at an Appl~e~ ~L~F_ ~rê of 15 kg/cm2 or more. As a
result, it has been nece~-ry to carry out the in~ection at a
low pressure whlch does not cause deformatlon Or the ~aterlal.
Con-equently, there has not been ~ oUJ~ pressure to de~L,vy
the torus 3 adequately and in~ect sufficiênt treating liquid
into the interior of the wood matêrial.
The wood treating ploce6s using heating and boiling as
A1~clo~~' ln USP 4,194,033 (Motal) remarkably deteriorates the
~L en~Lh of wood. Also, hecAl~e the pre~sure for
pressurization is as low as 1.5 kg/cm2 to 2 kg/cm2, the
external pressure is in bAlAnce with gases in the treated
material and hence the treating liquid cannot be in~ected into
the wood core (for a JArA.~se red pine of 250 x 250 x 2000 mm,
a maximum a~ e value of the penetration depth i6 85 mm: see
Table 1).
Further, while USP 3,693,584 (Barnett) describes
pressurization, the ~aximum raised p~e~Duhê i6 generally on
the order of ~5 kg/cm2 ~6 ~entloned above and, therefore, the
treating liquid cannot be in~ected into the wood core even if
the pressure is slowly intermittently rai6ed. Thi6 is also
apparent from the fact that one ob~ect of USP 3,693,584
(Barnett) i6 to 6ufficiently in~ect the treating liquid into
A~-
~- 21 1366 1
the wood core. USP 3,693,584 (Barnett) intends to inject the
treating liquid by increa~ing and decreasing the presgure-
applying force with a short period, i.e., to improve quality
of the injection treatment from the different stAn~roint from
that of the present invention.
on the other hand, particularly for broadleaf trees,
pres~ure i~ applied to the wood material to a predetermined
pressure. For this reason, impuritie~ such as tylose get
clogged in the ve66el~ ng it extremely difficult to
in~ect the treating liquid to the central portion of the
material.
In addition, the ~tone material has been only protected
at the ~urface because the treating liquid has only been
applied to the surface thereof, and because of the nature of
the ~tone material $tself. As the ~tone material was exposed
to acid rain over a long period of time, its acid resi6tance
decreased, so that the -AF~res taken against the acid rain
hec~ - ineffective. As a result, the acid rain permeated to
the interior, and the stone material was eaten away from the
interior, resulting in a powdered interior and the like.
The present invention i6 intenAe~- to overcome the above-
de~cribed problems and has as its ob~ect the provision of a
method of and an apparatus for in~ecting a treating liquid
into wood material and porous inorganic material so that the
treating liquid ~preads throughout the interior thereof,
without deforming the wood material, stone material, and other
material~ to be treated. The present invention has as another
ob~ect the provision of a method of destroying ray parenchyma
cell wall~ and aspirated pit-pairs.
A
..
2 1 1 3 6 6 1
.. .
To achieve the _bove ob~ects, the present invention
provides a method of destroying ray parenchyma cell w_lls ~nd
aspirated pit-pair6 of conifer6, and in~ecting treating liguid
into conifers, the method compri6ing ~n initial pressure-
applying/in~ecting step of liguid-pressurizing the treated
wood material at the normal temperature under pLe~ure in the
range of 1 to 10 kg/cm2, and holding the r_ised pressure for
at least 10 minutes to in~ect the treating liguid into the
tr~Ache~ of the treAted material a treating-liquid in~ecting
step of, after QlAr~e of the time holding the above ralsed
pressure, stepwisQly pressurizing the treated material at the
normal temperature up to the ~inal applied ~ E-~re having a
maxlmum value of 50 kg/cm2 with intervals of 5 to 10 kg/cm2,
And holding the rai6ed pr~5~UL2 in each of the pressure-
applying stages for at lea6t 10 minutes to in~ect the treating
liguid under pres6ure into the treated wood while dissolving
the gases remnining in the treated wood in the treating
liquid, and a pressure-removing 6tep of depre66urizing the
treated wood from the fin_l applied pressure to the
atmospheric pre66ure for a period exten~e~ to at least 20 or
more minutes to ~eve~ the treated wood from being broken due
to abrupt ~YpAn~on of the gases di6solved in the treating
liquid in~ected into the material. Preferably, a ~Le6DULe
re~c~ n~ 6tep of de~res~Lizing the treated wood down to at
least the atrr ~eric preF--~re or below, and holding the
~ c~ eFF-~re for at least 20 minutes to purge gases out of
the treated wood may be inter~z_e~ before the initial
~i e~DUL a applying/in~ecting step.
Al60, in a method of de6troying ray parenchyma cell wall6
and aspirated pit-pairs of broadleaf trees, and in~ecting
treating liquid into conifers, the method compri6es a
pre6~u.e .~ -c~n~ 6tep of dep,e~u~izing the treated wood
material down to at least the al -.p'-~ric pre66ure or below,
A
21 1366 1
,
and holding the .e~ ceA pre66ure for at lea6t 30 minutes to
purge ga6e6 out of the treated material, an initial pressure-
applying/in~ecting step of llquid-pres6urizing the treated
wood at the normal temperature under pressure in the range of
1 to 10 kg/cm2, and holding the rai6ed pressure for at least
20 minute6 to in~ect the treating liguid into the tr~h~ A of
the treated ~aterial, a treatlng-liquid in~ecting 6tep of,
after el~p-e of the time holding the raised pressure,
6tepwi~ely pre66urizing the treated wood at the normal
temperature up to the final applied ~,eg~u,e having a maximum
value of 50 kg/cm2 with interval6 of 5 to 20 kg/cm2, and
holding the rai6ed ~Le~u'~e in each of the presDu.e applying
6tage6 for at lea6t 10 minute6 to in~ect the treating liquid
under pres6ure into the treated wood while dis601ving the
gases remaining in the treated wood in the treating liquid,
and a pres6ure-removing 6tep of depre66urizing the treated
material from the final applied pre66ure to the at ~ ric
pre66ure for a period extenAeA to at lea6t 20 or more minutes
to ~e~ht the treated wood from being broken due to abrupt
p~n~ion of the ga6e6 dissolved in the treating liquid
in~ected into the treated wood.
Further, co~cerning a method of in~ecting treating liquid
into 6tone material6 in the pro~~ t invention, the method
compri6es a pre6~u,e ,~uc~ng 6tep of depre66urizing a treated
material down to at lea6t the atmcE~-ric pres6ure or below,
and holding the re~uce~ ~e~u~a for at least 60 minute6 to
purge ga6e6 out of the treated material, an initial pre66ure-
app~ying/in~ecting 6tep of liquid-pre66urizing the treated
~aterial at the nor~al tem~eL~Lu~e under ~r~_E-~re in the range
of 1 to 10 kg/cm2, and holding the rai6ed pre66ure for at
lea6t 60 minute6 to in~ect the treating liquid into crack6
insidQ the treated material, a treating-liquid in~ecting 6tep
of, after el~rEe of the timQ holding the rai6ed pre66ure,
--- 2 1 1 3 6 6 1
pres6urizing the treated material ~t the normal temperature up
to final applied pre66ure having a maximum value of 50 kg/cm2
at one time, and holding the final applied pre66ure for at
least 30 mlnutes to in~ect the treating liquid under pre66ure
into the treated materlal while dl6solving the ga6e6 remaining
in the treated material in the treating liquid, and a
pres~u a ,~moving 6tep of depre6~urizing the treated material
from the final applied pLe~u a to the atmo_,~?ric pre6sure
for a period ext~nAeA to at lea6t 20 or more minutes to
r.L the treated material from being broken due to abrupt
eYrAn~ion of the ga6e6 di¢601ved in the treating liquid
in~ected into the treated ~aterial.
Preferably, the treated material i6 pre66urized under
dynamic pre66ure by using a pres~u,e applying pump of delivery
constant type. When treating wood material6, the treating
liquid may be a cation-ba6e treating liquid prepared by
emul6ifying plant oil or mineral oil with a cationic
6urfactant. On the othèr hand, when treating 6tone materials,
the treating liquid may be one cont~A~n~ng 6ilane monomer6 a6 a
main com~onenL.
According to the method of in~ecting treating liquid
rel~ted to the present invention, e6tabl~ ng an initial
pre6~ù~e applying/in~ecting 6tep not only to facilitate the6e
operation6 later but al60 to remove the p~_Q-~re to that of
the atr~ e th~ougl. a ~Y-~a ~ ~lng tank at the maximum
of 50 kg/cm2 without bre~ng the wood material in ac¢ordance
with the type of material treated and it6 interior 6tructure,
is e~fective in making po~6ible the treatment of in~ection at
the high pre66ure of 50 kg/cm2. Therefore, in~ecting treating
liquid into the raw wood materials up to the heart wood, which
wa6 very difficult u6ing the cor~r~ n~l method6, and
in~ecting treating liquid sufficiently to the Ce.~L~1 portion
of the 6tone material, which in~ection it6elf wa6 not carried
~A
- 2 1 1 3 6 6 1
out u6ing the cor.~el.~lonal methods, become posslble.
Furthel -~e, in ln~ectlng treatlng-llquld lnto the mnterlal,
the treatment i8 possible at the normal temperature (0 to
40~C). As a result, this is also effectlve in the efficiency
of work, becau6e such extra work can be omitted, as creosote
treatment that treating liguids are in~ected after heat-
treated up to about 90~C, or making the in~ection easy
beforehand by heat-treating and boiling the material.
Accordingly, the wood material has greatly increased rot
re6istance, insect re6istance, ant resi6tance, and mold
resistance increasing the lifQ Or the wood. In addltion,
in~ecting treating liquid, having no possibility of ~ -ng,
to the cenL.al portion ~e~en~8 crack~ng from o~a~Ling for a
long period of time, allowing a hlgh ~ onal stablllty to
be ob~A~ns~. Further, uslng a flame-resi6tant treating liquid
therewith in~ects the treating liquid thG~ouyhly to the
central portion, 80 that the wood material treated by the
present method has high flame resistance and dimensional
stablli~y, allowing it to be u6ed in a variety of
applicatlons- In addltlon, by the ~P~nt method, the
posslbllity of in~ecting treating liquid is w~ene~ even to
many kind6 Or wood which had been regarded as difflcult to
in~ect and therefore which could not be treated, and thu6 the
use of whi d had been limited. M~eo~e" the increased life
of the wood material and the increa6e in kinds of wdod which
can be treated help stop the unpl~nne~ cutting of tropical
forests, a problem in ~ecLI.L years, thereby making the method
extremely useful from the viewpoint of forest protection.
The stone materlal can also be protected from damage
caused by acld rain, 80 that its yL~c~ ~les are not
deteriorated. The outside walls of h~ ng8 can be protected
from destructlon c~a~ by acid rain, a seriou6 problem ln the
reglons, 6uch a6 ~u.ope, whlch have many bull~ngs bullt of
- 8 -
'A
,
211366 1 ~
stone material. In other word6, according to the present
invention it will not be necessAry to prohibit the use of
marble and other 6tone materials for the out6ide walls of
b~ ngs. The invention not only y~e~er.~6 ~ -ge6 to the
stone material from oc~uL,ing, but al60 i6 very useful for
preservlng a nation' 8 culture and for environmental
protection.
According to another a6pect, the pre6ent invention al60
provides an apparatu6 for in~ecting treating liquid into wood
m~terial6 and po.~s inorganic materials, the apparatus
comprising a pre~6urQ ves6Ql for accommodating a trested
material in a rE~l~ 6tate, a ~1 a6~ùLizer for deprcEs~rizing
the pressure vessQl, a liquid pressurizer of delivery constant
type for pres6urizing the pressure vessel under dynamic
p~L~6uLe, and a ~L~g6uLe ,. ~ing apparatu6 con~ected to the
pres6ure vessel and cont~n~ng a ga6 pressurized to the 6ame
pressure as the treating liguid in the ple~6uLe ves6el, ~or
relea6ing the ga6 to the a~ -~yhere to thereby L.--~ve the
yLC65u~ e in the p~e66uLe ve6sel. Preferably, the pre66ure-
removing apparatu6 may compri6e a pre66ure-removing tank which
is ccr.r.e_~ed to the pressure vessel and is cont~n~g a gas
pressurized to the same pre66ure a6 the treating liquid in the
yL~ 6~re ve66el, and a pre6su~a ~e~oving valve which i6
ccr~eYLed to the pre66ure-removing tank and is ~ye..ed and
closed to ,. -~ the y~C~u~ in the yLc~.uLe ves6el thl~u~l-
the ~Le6DU~e removing tank.
Further, according to the present invention, in a method
of in~ecting treating liquid into wood material6 and porou6
inorganic material6 by u6ing a treating-liquid in~ecting
apparatus which compri6es a pre66ure ve66el for accommodating
~ treated material in ~ re-le~ 6tate, a dep~e6~u,izer for
depre66urizing the pre66ure ve66el, a liquid pre66urizer of
delivery con6tant type for pre66urizing the pre66ure ve6sel
21 1366 1
under dynamic pressure, and a pressure-removing apparatus
which is connected to the pressure vessel and containing a
gas pressurized to the same pressure as the treating liquid
in the pressure vessel, and is releasing the gas to the
atmosphere to thereby remove the pressure in the pressure
vessel, an expansion speed of the gases which are dissolved
in the treating liquid inside the treated material
accommodated in the pressure vessel is suppressed by
controlling the pressure-removing apparatus so as to remove
the pressure in the pressure vessel down to the atmospheric
pressure for a period extended to at least 20 minutes,
making the gas which has a smaller molecular structure than
the treating liquid discharged from the treated material
earlier than the treating liquid. Preferably, the
pressure-removing apparatus may comprise a pressure-
removing tank which is connected to the pressure vessel and
containing a gas pressurized to the same pressure as the
treating liquid in the pressure vessel, and a pressure-
removing valve which is connected to the pressure-removing
tank and is opened and closed to remove the pressure in the
pressure vessel through the pressure-removing tank. In
this case, an opening degree of the pressure-removing valve
is controlled so that the pressure in the pressure vessel
is removed down to the atmospheric pressure for a period
extended to at least 20 minutes.
The apparatus prevents air expansion from breaking the
material while pressure is being removed, allowing the
treating liquid to be injected into the central portion of
the material.
Having thus described the invention, reference will
now be made to the accompanying drawings illustrating
preferred embodiments and in which:
Figs. l(a) through l(c) illustrate graphs showing the
reduction and application of pressure when the treating-
- 10 -
~'A ~
2 1 1 3 6 6 1 ~
liquid injecting method of the present invention is appliedto conifers (lodge-pole pine);
Figs. 2(a) through 2(c) illustrate graphs showing the
reduction and application of pressure when the treating-
liquid injecting method of the present invention is applied
to broadleaf trees (red oak);
Figs. 3(a) through 3(c) illustrate graphs showing the
reduction and application of pressure when the treating-
liquid injecting method of the present invention is applied
to stone material (marble made in Italy);
Fig. 4 illustrates the internal structure of the
conifer;
Fig. 5 illustrates the internal structure of the
conifer;
Fig. 6 is a cross-section illustrating the condition
of the wood material after it has been treated with the
treating-liquid injecting method of the present invention,
and that after it has been treated with a conventional
treating-liquid injecting method;
Fig. 7 is a block diagram illustrating the arrangement
of the treating apparatus for implementing the method of
the present invention;
Fig. 8 is an enlarged sectional perspective view
illustrating the structure of the wood material;
Figs. 9(a) and 9(b) are cross-section of the wall pits
in the wood material structure;
Figs. lO(a) through lO(d) illustrate the injection
depth of the treating liquid when the treating-liquid
injecting method of the present invention is applied;
Figs. ll(a) through ll(c) are tables illustrating the
test data in the cases of Fig. 1 to 3; and
~A '
211~66 1 -~
Figs. 12(a) through 12(d) illustrate cells of the wood
material before and after the treatment of the present
invention is carried out.
Similar numerals in the Figures denote similar
elements.
Fig. 1 shows graphs showing the reduction, application
and removal of pressure in the first embodiment of the
present invention when the method is used to inject the
treating liquid into the conifer. Further, Fig. 1 is the
illustration of the lodge-pole pine treated with injection.
Figs. 4 and 5 each illustrate the structure of the
conifers. Fig. 6 compares the condition of the wood
material after it has been treated using the treating-
liquid injecting method of the present invention, and after
it has been treated using a conventional treating-liquid
injecting method. Fig. 7 is a block diagram showing the
arrangement of the apparatus used for implementing the
present method. Fig. 10 illustrates the injection depth of
the treating liquid when the present invention is applied.
In the present invention, the treated material 11 which is
stored in a pressure vessel 12 is treated as follows:
first, the pressure is reduced by a pressure-reducing
vacuum pump 13; next, from a treating-liquid reservoir 16
via a treating-liquid measuring reservoir 14, the treating
liquid is injected with the application of pressure by a
liquid pressure-applying pump 15 of delivery constant type.
Then, the pressure is removed from the inside of the
pressure vessel 12 via a pressure-removing valve 19 and a
pressure-removing tank 18.
The conifers generally have the structures shown in
Figs. 4 and 5. For this reason, it is necessary to destroy
the ray parenchyma cell walls and aspirated pit-pairs to
inject the treating liquid to the central portion. In the
present
- 12 -
iA ~
2 1 1 3 6 6 1
method, the pressure 18 gra~ally applied from a low pressure
to the material to be treated, so that the pressure difference
beL~een the internal and external portions of the wood
material is mainta1ne~A~ which is large enough to desL~oy the
torus 3, but not too large to deform the wood material. Each
toru6 3 i6 then A - F L,oy~d by the pres6urQ of the treating
liquid, allowing the liquid to permeate sufflciently to the
internal portion of the wood matQrial.
First, after the treating liquid is in~ected into the
surface cells (both cells whose cross-section is ~YpoEe~A. to
the 6urface _nd which are near the surface), the ray
paLenc~.yma cell walls at the outermost portion and the
aspirated pit-pairs are desL~o~cd, and then the pressure in
the trache~A 21a i6 made equal with the external pressure.
The pressure in the tra~-he~ 21b, 21c, and the like is m_de
egual with the external ~.es6u~e as each torus 18 surce66ively
de~L,v~ed to those in the heart wood. In this case, the
pressure is transmitted t~uyl- very narrow gap6 or small
holes. Accordingly, it i~ ~ecess-ry to increase the pre6sure
for h~gh~r efficiency, but a suAAPn increA6e in pressure
Ça~ the material to hec- - th~nn~r and become deformed.
Con~esuently, in the present invention the pLe6~u~ e is
increasQd ~u~ eFs~vely in ~teps 60 a6 not to thin and deform
the material.
In the pres~u~a ~ c~ng step of the present invention, _
treated material 11 is stored and se-leA in a pressure vessel
12 comprising the apparatus illustrated in Fig. 7 (step 1 of
Fig. 1, whlch will be abbreviated to S1 hereafter). Then as
shown in Fig. 1, the p~2F ~re of the material is temporarily
re~A.~ce~A to 760 mmHg by a ~Le6~u~e reA~c~ng vacuum pump 13,
with the material mainta~ne~A~ at thi6 ~Le6~uLe for about 20
minutes, in order to L~'-Ve as mu¢h air ~rom the material as
possible. -
- 13 -
A
21 1~66 1
The depressurizlng process i6 not limited to the pressure
of - 760 mmHg, but may be performed under the atmospheric
pressure or below. For conifers, the pressure-reA~o~g
plocess itself is not neces6~rily required. Alt~ol~qh the
pre6sure level ~ay be at the atmospheric pressure or below, a
very long treatment time which is in ~YcesF of the practical
range would be neeAe~ lln~P6s the treated material i6
depressurized down to - 600 mmHg or below. on the other hand,
if the treated material i~ depres6urized down to - 600 mm~g or
below, the treatment time would be shortened, but it would be
reguired to ~ a a F~~l~ng ability or the eq~ nt and the
performance of the vacuum pump, resulting in poor economy. If
no pre55 ~e ~e~ clnq ~YOCCS8 is performed, it would be
required to take a longer time for each of r~h-eguent steps
l~c~ce of the effect of gases existing in the treated
material. From the bal~nce bcL~etr. the treatment time and the
n~ceS~ry equipment, therefore, thi6 embo~ ~ employs the
pres~u~e ,el.~ nq ~ocass under - 760 m~Hg as the pressure-
reA~Cl ng step.
The next step is the pressu~e applying step. In the
initi~l pres~u,e applying/in~ecting step, pressure is applied
on the ~aterial at be~eO 0 kg/cm2 and 10 kg/cm2 by a liquid
pressuLe applying pump 15 of delivery constant type (S2).
BesidQs, in the present embodiment, this step is done at
beL~L~r. 0 and 5 kg/cm2. In this case, each portion of the
material in the pressure ve6sel 12 is 6ub~ected to the same
pre66ure in aacordance w~th Pa6Ca1'~ law. The materlal is
maint~lneA at this pressure for about 20 minutes. Unlike a
pump of pressure c~n~ant type which has been convcl,Lionally
used for in~ection under pressure, this liguid pressure-
applying pu~p 15 of delivery constant type operates in such a
manner that if the setting pressure is set to 5 kg/cm2, for
example, the pump cont~nuo~ly supplies the treating liguid at
<A -''
21 1366 1
a cert~in flow rnte under pressure in the range of O kg/cm2 to
5 kg/cm2 to the pressure vessel 12. When the interior of the
pre6sure vessel 12 reaches the setting pre6sure, the pump
throttles the delivery rate 60 as to maintain the setting
pressure. The llquid pres~uLc applying pump 15 of delivery
constant type is also different from the pump of pressure
constant type in that a ~Lu,.. pipe for ~eLu~..ing the treating
liguid from the pump to the tank to remove the pressure
cefifiively applied i6 not provided.
In this embodiment, when the pressure vessel 12 is filled
with the treating liguid and the liguid pres~e applying pump
15 of delivery con~Lant type still further cont~ n~8 to supply
the treating liguid, the ~L2 ~-~re in the pressure vessel 12 is
raised because the treating liguid supplied to the pressure
vessel 12 has no exit to ese~re thereth~Guyl.. As the pressure
rises, the treating liguid is in~ected into the treated wood
materi 1. At the same time, ray parenchyma cell walls and
wall pits of the treated material ~re broken. The in~ection
of the treating liguid and the destruction of the ray
parenchyma cell walls mean that the volume of the pressure
v~FFe~ 12 is e5~ Lially increa6ed, and hence the pressure in
the pressure vessel 12 is re~ure~. In ~r~yc.r.Fe to a pressure
drop, the treating liguid is further in~ected into the treated
wood and the pressure is further raised. This pressure rise
cAur-~ another in~ection of the treating liquid and another
destruction of the ray pa~e,.~ ma cell walls. Thereafter, the
pLoces8 is cont~ue while the pressure is re~U~e~ and then
raised. Thus, in this . hg~ -nt, the pressure for
pressurization is gr~ y raised with repeated up and down
of the pressure. When the y,e&~u~e for pressurization re~rh~s
the setting pres6ure, the delivery rate of the treating liquid
is throttled 80 as to maintain that ~L~F !~re. Upon no further
in~ection being ~ d under that pre66ure, the treating
- 15 -
~A
21 13 6 6 1 ~
~.
liquid 6top6 m~v.- -nt toward the pre6sure ve66el 12 and the
pre66ure for pressurization ce~s~F to risé. The process is no
longer ~o~L666ed in such a condition and, therefore, the
pre66ure for pressurlzation is rai6ed to a next 6tage. Stated
otherwise, in this embodiment, the treating li~uid i6 moving
in the pressure ve66el 12 at all times to create dynamic
pressure therein, and the treating liquid is in~ected into the
treated material under 6uch dynamic pres6urQ,
By col.LLa6t, in the convention~l pump of pres6ure
con6tant type, when the 6etting pres6ure of 5 kg/cm2, for
example, i6 reached, movement o~ the treating liquid from the
pump to the pressure ve6sel is 6toppe~, creating static
pressure in the pressure vessel. In other words, the pressure
i6 linearly raised and comes to a 6tandstill at the setting
pres6ure. Accordingly, the in~ection of the treating liguid
is harder to develop than the in~ectlon thereof under dynamic
pres6ure like this embodlment. Furthermore, when the interior
of the pressure vessel reaches the setting pressure,- the valve
i6 6witched to ~e~UL~ the treating liquid from the pump to the
tank thlu~yl. the ~eL~L~I pipe for removing the pressure
~Yce6~ively applied. Because of this valve switching
operation, it i6 difficult to make conLLol to 6upply the
treating liquid again to the pressure vessel 12 immedi~tely in
~DpOn~9 to a 6m~11 pres6ure ohange in the ~,~sF-~re ves6el 12.
On the conL,ary, in this embodiment u6ing the pu~p of delivery
constant type, since the ~e~u,e vessel 12 has no exit to
e~c~pe theret~Iu~gh and the pump i6 operating at all ti~es,
urging the treating liquid to be delivered, the treating
liquid can be ,e u~plied i~mediately in ,~v~o~re to pressure
change. A pressure of O to 10 kg/cm2 is large ~nongh to
destroy each torus 3 and the like. As a result, although when
the material is maint~ned at this pre66ure with the treating
liquid being in~ected into the 6urface cells, not ~11 of the
- 16 -
A
21 13 6 6 1 -
ray parenchyma cell w_118 and aspirated pit-pairs are
de~L,oyed, a portion of them is de~oyed, allowing pressure
to be transmitted to the cenL,al portion. At this relatively
low pressure of a maximum of 10 ~g/cm2, the wood materlal
itself is not deformed. The lnitlal pre66ure-
applying/in~ect$ng step which uses the pump of delivery
conOLant type i8 one of ma~or features of the present
invention. By carefully performing thi6 step for an extenAeA
tlme, the treating liquid penetrate6 lnto the wood core, and
the applled pres6ure is also transmitted to the wood core,
en~h~ ~ ng the treatlng liguid to be effectlvely in~ected in the
F~h~equent treating-liguid in~ecting step. Thus, this step i6
not ~ust a fir~t ~tage of the r'b~P,~ent stepwlse pressure
applic_tion, but has a meaning as a p~e ~oc~s for the
~equent stepwi6e pressure Arpl~cAtion under high pressure.
on the other hand, thl6 step is required to be carrled
out under such a level of pressure as the treated material
will not be de~L,vyed. Theoretically, therefore, the pre6sure
applied in thls step c_n be ral6ed up to the limit pressure
until which the treated material is not desL,oyed, i.e., 15
kg/cm2. However, this step is carried out below 10 kg/cm2,
i.e., lower than the limlt ~La~6u~e, ln the present invention.
The reason is as follows. 15 kg/cm2 ,e~ ent6 the limit
pressure at which de6truction of the treated wood i6 v~ ly
conrirmed. T~o~ng at the material on a microscopic scale,
there o~ul~ collApFe of the wood when in ~'C~vG of 10 kg/cm2.
If the wood i6 collApse~, the treating liquid is not in~ected
into the cell6 of the col 1A~P6~ region, and conrequently the
portions not filled with the treating liquid are left in the
material. If the ~Loce68 comes into the 6~hsequent treating-
liquid in~ecting step under such a condition, the non-in~ected
portions of the materi_l cannot withstand the high pressure
applied in the treating-liquid in~ecting step and thus the
- 17 -
i ~ ''~
21 1366 1
wood would be destroyed, because the non-in~ected portlons are
not s~en~h~n~ by the treating liquid and the appl$ed
pre88Ure i8 not transmitted to the lnterior of the m~terial.
In the present invention, therefore, a maximum vslue of this
step is set to 10 kg/cm2. Particularly, in thi6 embodiment,
the maximum value is set to 5 kg/cm2 with a sufficient
allowance.
The next step is the treating-liguid in~ecting step. In
the present embodiment, as 6hown in Fig. 1, the pressure is
increased stepwise from a pressure of 0 to 5 kg/cm2 of the
initial pressule applying/in~ecting step until the final
45 kg/cm2 stage of pre~6ure application (83-S6). In this
embodiment, the y.ess~se is increased to 15 kg/cm2, 25 kg/cm2,
and 45 kg/cm2. The final applied pressure can be set to
50 kg/cm2 at -Y~ . Depen~1nq on an imy~ nt of the
pressure resisting eq~ - ~, the final applied pressure can
be set to h~qh~r pressure, e.g., 70 kg/cm2. HOWeV~L,
according to the method of the present invention, since the
treating liquid can be in~ected into the center for al ~ ~ all
kinds of trees under the pressure of up to 50 kgjcm2, applying
h ~ qh~r pressure than 50 kg/cmi is meaningless. Note that the
maximum value of 50 kg/cm2 represents the pump setting
pressure and of course includes an error of about 10%.
Accordingly, when the final applied ~LC~u~e of 45 kg/cm2 is
applied in this embodiment, the ~ e~8~Lc of approxlmately
50 kg/cm2 may be in fact applied to the treated wood.
Further, the maximum applied pressure is changed to an
ayyLGp~iate value der~n~nq on the kind of the wood material.
Specifically, for lodye ~ole pine into which it is hard to
in~ect the treating liquid, the maximu~ applied pressure i8
set to 45 kg/cm2 like this embodi~ent, but for Japan cedar
into which the treating liquid is easily in~ected, the maximum
applied pressure of 30 kg/cm2 is sufficient.
- 18 -
A
21 1366 1
First, the pressure i6 increa6ed 6 to 15 kg/¢m2 (S3).
Since a pressure Or 5 kg/cm2 has been applied in the initial
pressu,e applylng/in~ecting step (S2), there i8 a relative
pres6ure dlffe~nce of 1 to 10 kg/cm2 beL~ee,. the internal and
external portions of the wood material at the time when the
pre88ure i8 inGreased to 15 kg/cm2. Tho~lgh Aepe~ g on the
type of wood ~aterial, the torus 3 is ~r~ y destroyed when a
pressure of 2 to 5 kg/cm2 is applied to it. Accordingly, in
the first stage of the treatlng-liquid in~ecting 6tep, a
greater number of aspirated pit-pairs, mainly those near the
outer portion of the wood material, are de~L~oyed. The
mater$al is again maint~ neA at 6 to 15 kg/¢m2 for about 20
minutes. ~ere the pressure ~n~lAp the pressure vessel 12
rises with up and down beL~eel. 6 and lS kg/cm2 to 15 kg/cm2
which is provided, keep~ng the ~n~Ae of the vessel unfixed in
pressure. For this reason, in the same way as it is described
abovej the pressure is transmitted th~u~l- destroyed ray
parenchyma cell walls and aspirated pit-pairs, allowing the
wood material to be sub~ected to a pressure of 15 kg/cm2 to
its inner portion.
In the treating-liguid in~ecting step, the pressure is
further increased when a~pLv~Liate while in each pressure-
applying stage the material is main~ P~A at a part1rl~lAr
e~u~e for a certain period of ti~e. That is, in the
~Frnt step pressure is further applied to the wood material
at 16 to 25 kg/cm2, 26 to 35 kg/cm2, and 36 to 45 kg/cm2, each
for 20 minutes untll the rinal ~tage of pre6sure application
(S4-S6). The relative yL~_s~re difference which oc~u~
between the internal and external portions of the wood
material in each 6tage fi~cc~6~ively de6Lloy~ the ray
parenchym~ cell walls and the aspirated pit-pairs.
Fig. 10 show6 s~ce~sive changes in in~ection depth of
the treating liguid resulted when the pressure is 6tepwisely
-- 19 --
~A ~
21 1366 1
raised a6 mentioned nbove. Fig. lO(a) shows the in~ection
depth of the treating llquid in the initial pre6sure-
applying/in~ecting step. For the conifer, the treating liquid
is first in~ected into cell6 exi6ting in the wood surface.
The re~n~ are that cell section6 are eYro~e~ to the surface
of the conifer, enabling the treating liquid to be in~ected
into the surface cells, and that the cell6 to which the
treating liquid has been in~ected have h ~ gh~r ~ .e
resistance than the cells to which the treating liquid has not
yet been in~ected. The latter fact i6 attributable to that
the volume of liquid is less changed than the volume of ga6
with ~e~pecL to pressure. Therefore, the cells to which the
treating liquid ha~ been in~ected are not bLOUy21t into cell
Lu~u,e even when pressure i~ applied thereto externally,
because a volume change of the in~ected liquid is small. On
the other hand, for the cells to which the treating liquid has
not yet been in;ected, gases in the cells are compressed upon
the pres6ure applied thereto externally to such an extent that
cell wall6 can no longer resist a change in the volumes of
s- ~es~ed gases, and the cells are lu~L~,ed even with the
6ame pressure applied. Stated otherwise, to apply pres6ure
not lower than 15 kg/cm2 in the ~h~squent treating-liquid
in~ecting step, it i6 required to in~ect the treating liquid
into the surface cells 80 that tho6e cells have sufficient
pressure resistance. Thus, the initial pressure-
applying/in~ecting step in the present invention i6 not ~ust a
fir6t 6tage of the stepwise ~e~u,e application, but an
~ ant step for enabling the F-~h-equent high-pressure
proce6s to be achieved. Under the pres6ure applied in the
initial step, once a certain amount of treating liquid is
in~ected, the treating liquid cannot he in~ected in the amount
ceeding the above one, even if the in~ection is cont~n~le~
- 20 -
~A
21 1366 1
. .
for an exten~e~ time. Therefore, the p~oce86 i8 Advanced to a
next 6tep for raising the pressure by one stage.
Fig. lO(b) shows the first stage of the treating-liquid
in~ecting step in which the ~e~u,e i6 raised to in~ect the
treating-liquid into a ~eep~r region than in the previous
step. But, ~ec~re the pressure re~-hos a limit in thi6 stage
too, the pressure is further rai6ed by one stage.
Likewise, in Fig. 10(c), the treating liquid is in~ected
into an ever ~ee ~r region than in the previous stage, but the
pressure reA~h~ a limit. Then, the interior of the pressure
vessel is pressurized to the final applied pressure.
Under the final applied pressure, the treating liguid i8
in~ected into the wood core tFig. 10(d)). Whether the
treating liquid has been in~ected into the wood core or not is
~udged by comparing the amount by which the treating liguid
can be in~ected on calculations with the amount by which the
treating liquid has been actually in~ected. On this occasion,
the amount by which the treating liquid can be injected on
CAIclllAtions i6 determined by subtracting the volume of wood
portion and the volume of contA~ne~ water from the total
volume of the wood material.
A6 described above, wood materials are ~ lly deformed
when a pressure of 15 kg/cm2 i8 applied thereto. The
materials are, hcwe~_~, deformed due to shock ari~ing from a
pressure difference which iB caused by a cn~n application of
pressure from no pressure to 15 kg/cm2. Accordingly, if the
pressure is applied in steps to the wood material a6 it i8 in
the present invention, the wood material is not easily
deformed even when the final pressure applied thereto eYcee~
15 kg/cm2.
In the present invention, in each 6tage ~e~ e i6
applied for a predetermined time 80 that the internal portion
of the wood material is sub~ected to the pressure of a
- 21 -
21 13661
,
part$cular pressure-applying st_ge. Therefore, even if, for
example, a pre6sure of 25 kg/cm2 i6 _pplied, the pre6sure
increase during pre66ure appllc_tion i8 merely the relative
pressure difference between the internal and extern_l portions
of the wood materiAl. That is, the pres6ure which the wood
material exper1ences i6 merely lO kg/cm2 (25 kg/cm2 minus the
previou6 applied ~eD~ura of 15 kg/cm2), cau6ing no
deformation.
Accordingly, according to the pre6ent invention the
treating-liquid in~ecting 6tep carried out 6tepwise allows the
aspirated pit-pairs and the like to be de~.oyed to those at
the internal portion of the wood material, without deformlng
the wood materlal ltself.
In each pressure stage, lt 18 preferable that for the
first few pressure appllcation stages of up to _bout 15 kg/cm2
the material is malntA~ne~ at a part1c~Ar pressure ~or a
relatively long period of time of lO minutes or more, while
the length of time can be shortened thereafter.
Pressures in the initial pres~u~e applying/in~ecting step
and the treating-liguid ~n~ecting step, the pressure
difference for each stage, and the length of time the material
is maintA~e~ at A cert_in pres6ure are naturally set at
different values in accordance with the kind, type _nd
dimensions Or the wood mater~al. For exa~ple, the pres6ure
difference i6 made large when a large p~e~u~e is required to
de~oy the torus 3, and the material is mainta~e~ at a
certain pressure for a longer period of time when time i6
reguired to equalize the pressure to the inner portion of the
wood material.
In the treatlng-llquld in~ecting 6tep, the treating
liquid i6 in~ected into the material to be treated with a
liquld pres6~e applying pump lS of dellvery constant type and
_llowed to spread th~o~Jl,~ the materlal under a cert_in
- 22 -
~,
-- 21 13661
pre66ure. At thi~ time, the g~se6 L~ -1ning in the tracheid
21 of the material and the g~es ~ n~ ng in wood cell6 _re
first compres6ed to minimum volumes. Then, ba6ed on the
Henry ~ 8 law, those gase6 finally dis601ve in the treating
liguid. In the prior art p~oce66, ~ince the applied pre6sure
is 6et to an insufricient level from the relation to
destruction of the wood material, pool6 of gases are pro~l~ce~
in the treated wood. At the time the pressure applied
externally is in h~ 1 Ance with the pressure in6ide the treated
wood, there G~ 6 a condition in which the pools of gases
function like air spring6. Accordingly, these air springs
p~evenL in~ection Or the treating liquid, making it difficult
for the treating liguid to penetrate into the core of the
treated wood. In the present invention, however, the problem
of des~Luo~ion of the material iB solved and the high-pressure
o~e6s can be performed at the final applied pressure of
5 kg/cm2. The high ~Le~8u~e pLoca88 ~nAhl~q the ga6es in the
treated wood to be dissolved in the treating liquid based on
the-Henry's law, and hence the treating liquid can be in~ected
into the core of the treated material.
on the other hand, after in~ecting the treating liguid by
applying pres6ure a6 de6cribed above, the treated wood must bQ
released from the pLas~uLi~ed state. H~we~" if the rai6ed
pressure i6 rlddenly removed, the ga6es dissolved in the
treating liquid based on the Henry' 6 law may be abruptly
eYrAnA~d~ cau6ing the wood material itsQlf to be de_L-oyed.
More 6pec~fically, since the volume change of liquid i6 much
smaller than the volume change of gas with re6pect to
pres6ure, the pre66ure in the ~e5D~LL vessel 12 would be
6~dA~n~y d~Gpped if the treating liquid i6 ~e~u~..ed at a time
from the pressure ve66el 12 filled with the treating liquid to
the treating-liquid reservoir 16. Co~.e~on~ngly, the gase6
dissolved-in the treating liquid inside the treated material
- 23 -
A~
~- 2 1 1 3 6 6 1are so _bruptly ~YpAn~d a8 to de~troy the m_terial. For
conifers cGr.L.ary to that the wood is thinned or deformed if
6u~nly sub~ect to the externally applied pre6sure of
15 kg/cm2 or h~gh~, the wood i~ des~oyed upon a sudden
pre66ure ~.~ î v~l~ In this embodiment, the treating liquid
inside the treated wood contains the gases dissolved therein
under the pre6sure Or 45 kg/cm2. Accordingly, if the treated
material i6 ~Ae~ly ~c~u~ed to the atmospheric pressure, it
would be de6troyed from the inside by forces cGrLes~onA~ng to
45 kg/cm2. In thi6 embodiment, therefore, it i6 required to
con~ol the eYpAn~on 6peed of the ga6es di6~01ved in the
treating liquid for ~ra~t--~ing the wood material from being
de~L.o~ed.
For that reason, the present invention particularly
includes a pre6sure-removing 6tep (S7) and a pressure-removing
tank 18 in the treating apparatus. The pressure-removing tank
18 is previously rilled with a ~o~inflammable gas which is
supplied from, e.g., a gas pump or a nitrogen or carbon
dioxide gas bomb and i8 pressurized to the same level as that
in the pressure vessel 12. Then, the gas is Al ~hArged little
by little from the pressure-removing tank 18 through a
pressure-L~ -~ing valve 19 80 that the pre66ure in the
pre66ure ves6el 12 i6 gra~ lly lowe~ad. At thi6 time, the
p. ~ 6 F"re in the pre66u~a l_~oving tank 18 i6 lowe-ed at the
same rate a6 that at which the pre66urQ in the pressure ve66el
12 i~ ed. Accordingly, the eYr~n~ion 6peed of the
di6601ved ga6e6 in the treated wood can be con~.olled
~p~n~g on an op~n1ng degree of the pre6Du~e .emoving valve
19. With the con~.ol of the pres~ure reduction rate, it is
po66ible to expel the ga6 which has a 6maller molec~lar
6tructure than the treating liquid out of the treated wood
earlier than the treating liquid, and to leave the treating
liquid 6ufficiently in the treated wood.
- 24 -
A'
-
21 1366 1
The condltion of the wood mnter$al treated using the
trent~ng-liquid in~ectlng method o~ the pre6ent --hoA~ -nt,
and that treated using a conventional treating-liquid
in~ecting method are 6hown in Fig. 6 for comparison. A water-
soluble dye wa6 in~ectQd using the pre6ent method and a
conventional method, and then each treated wood material wa6
cut for comparison (J~r~ne~e cedar and radiator pine heart
wood h~ving a water content of 55S and mea6ur$ng 20 x 20 x 100
cm were used). As i6 apparent from Fig. 6, the wQod material
treated by a convcr.~Qn~l method only permits a 6mall r L
of treating liquid to enter from the cut end face, and almo6t
no treatinq-liquid is in~ected from the other face6. That i6,
in 6pite of the in~ection from the cut end face, the portion
near the 6urface 13 alone was deeply colored, and as regard6
the interior, only the ve66~l~ were colored within 5 cm or 60
from the 6urface, or with the color becom~ng thin gradually.
On the other hand, ~ccording to the ~e~ont method the
treating liquid i6 in~ected from any direction, from the
cros6-grain, 6traight-grain, and the like, and besides, tho~gh
the surface wa6 a little deep, the light and shade of the
color wa6 hardly 6een in the interior. That i6, according to
the ~LP çnt method the ray pa,encl,~ma cell wall6 and the
a6pirated pit-pair6 in the material are ~ ~,oyed for
in~ecting the treating liquid, 60 that the treating liqu$d i6
con6i6tently in~ected not only into the materi~l~6 6urface but
to it6 ce.,~al portion, thereby po6ing no problems when heart
wood i8 used as the material to be treated.
Fig. 12 shows the condition6 of cells of the treated wood
material before and after the in~ect~n of the treating liquid
in the present invention. Fig6. 12~a) and 12(b) 6how the
condition6 of wall plts before the in~ection, wherea6 Figs.
12(c) and 12(d) 6how the condition6 of wall pit6 after the
in~ection. Fig6. 12(a) and 12(c) show the condition6 of cell6
- 25 -
~.~
- 21 1~661
of sap wood, whereas Figs. 12(b) and 12(d) shoW the condltion6
of cells of heart wood. Wlth the in~e¢tion, the conditions
are changed from Fig. 12(a) to Fig. 12(c), from Fig. 12(b) to
Fig. 12(d). Note that Figs. 12(a) and 12(b) c~L.e~pond
.e~e~ively to the ~tates of Figs. 9(a) and 9(b) when viewed
from the outer side. A6 seen from Figs. 12(c) and 12(d), the
wall pit~ are bro~n in all wood region up to the core, by
uging the method of the present invention. It is thus shown
that the treating liquid peneL,ates into the heart wood.
In this r ~o~ , the amount by which the treating
liquid can be in~ected is calculated beforehand from the water
content, the vacancy rate, the weight and the volume of wood.
Taking into accoun~ the errors due to impurities, 70 to 80S of
the calculated in~ectable amount is set a8 the amount by which
the treating liquid can be pract~c~l~y in~ected. Fig. 11
shows experimental results including data such as the specific
weight before and after the treatment. In Fig. 11, (a)
represents in~ection data for lo~go ~ole pine, (b) for red
oak, and (c) for marble.
Here, the water content U can be ex~essed by:
GU - G0
U ' x 100
G0
where GU - weight of wood, and G0 - volume of wood x
total dry ~pec~ ric weight of wood
The vacancy rate C can be ex~e6sed by:
ro
C -- 1 - X 100
l.S (true rpec~ic weight)
where ro - total dry specific weiqht of wood, and
1.5 - true specific weight of wood
The weight A of water cont~e~ in the wood can be ex~.e66ed
by:
100 - C
A c GU - (GV x x l.S)
100
- 26 -
~'A ~
21 13661 ~
Therefore, the in~ectable amount B c~n be determined below
using the weiqht A of water that i6 converted into volume:
B - (GV x C) - A
where GV - volume Or wood
In consideration of an effect of impurities su¢h as rosin and
tylo6is,
B x (70 to 80%)
i6 set as the practical in~ectable amount.
The treating liquid can be in~ected until rea~-h~ng the
practical in~ectable amount thus calculated. While confirming
a reduction of the tre~ting liguid in the in~ected-r -u..L
calculating tank 17, the treating liquid i6 in~ected until
reaching the practical in~ectable amount. At'thi6 time, if
the in~ected amount does not reach the ~L ~ ' ~ amount, the
pressure-applying time at the final applied pressure is
exten~e~ 80 that the treating liquid i6 in~ected into the wood
core.
To describe it in more detail with reference to Fig.
ll(a), since the calculated in~ectable amount i~ 52.5 1, the
practical in~ectable amount is about 37 1. On the other hand,
the actual injectable amount is 31 1. This value of 31 1 i8
within the range where it can be tho~ght that in~ection of the
treating liquid has been completed 6ubstantially to 100%,
ta~ng into acco~ .L different wood ~LvpcL~ies (heart wood or
sap wood) and variations in individual wood material6.
Particularly, 6ince this embodiment employ6 heart wood for
which in~ection of the treating liquid i6 hard, it i~
rea~onahle to think that the treating liquid ha6 been
6ufficiently in~ected into the wood core, al~ho~gh the actual
in~ected amount i6 about 6 l le66 than the practical
in~ectable amount. For comparison, in the ¢on~cn~Qnal 6imple
pressing method, the treating liquid only les6 than 5 1 could
be in~ected into lodge-pole pine under the same wood
A~ - 27 -
''~
21 1366 1
. .
conditions even with a heating process applied. According to
the present invention, the treatlng liquid can be in~ected in
the amount 6 or more times as much as the conventional method
at the normal temperature as described above.
A return of the treating liguid after the pressure
removal in Fig. 1 i6 presumably ascribed to that some treating
liquid is pushed out by the dissolved gases, and that the wood
compressed under pressure increases its volume when returned
to the atmospheric pressure.
Usable liquids to be in~ected include vegetable oil and
mineral oil emulsified and made water-soluble by cationic
surfactants to which are mixed antiseptics, insecticides, ant
killer substances, and mold retarders. The treating liguids
to be in~ected, which are cationic, combine ionically with the
anionic wood material to prevent leakage from the wood
material, making them suitable treating liquids.
Further, cation-base pharmaceuticals have a strong sterilization
effect as well known, and di-decile di-methyl ammonium chloride (DDAC) as
one kind of cation-base pharmaceuticals is used as a wood preservative
over the world. It is also known that oil has an effect of
preventing cracks or distortions of wood. By using oil and
any of cation-base pharmaceuticals in a combined manner, it is
possible not only to develop a preservation effect, but also
prevent cracks or distortions as defects of wood, thereby
enabling wood to be more effectively utilized. In addition,
an oil component which has become water-soluble due to the
combined use is advantageous in that its emulsified state is
broken with drying of wood, allowing only moisture to
evaporate, and the remained oil component develops a water
repellent effect and also contributes to a preservation
elfect. In this case, the remained oil component is less
dissolved in water again, beca~se it is cationic and ha6 been
once separated from the emulsified state. Furthermore, a
- 28 -
. ~ .
21 1~66 1
treating liquid prepared by emulsifying oil in a cation-base
surfactant has a small grain slze and hen¢e can be easily
in~ected into wood. Compared to water-601uble glycol6 used a6
treating liquids, the6e treating liquid6 ~ ever.~ leakages from
G~L~ ing and have better dimen6ional 6tability and the like
over a longer period of t$me. In addition, emul6ifying them
by non-ionic and A~1Qn~c surractants and A~dtng ant~re~Lics
thereto allow the same effects to be obtA~ned. Further, 6ince
in the pre6ent method the treating liquid can be in~ected to
the central portion of the wood material, a treated material
having a h1gh~r flame resistance than the con~el.~ional treated
materials can be obt~A~ne~ by the in~ection of flame rQtarders.
A ~e_~n~ embodiment of the treating-liquid in~ecting
method related to the present invention will be herel~nd~r
described. The 8eCQ~ : ho~ ~ent is a method for in~ecting
the treating liquid into broadleaf trees (red oak). Fig. 2
illu6trates graphs showing the reduction and application of
pre6sure during the treatment.
Compared with the aforement1one~ ¢onifers, broA~lenf
trees IlF~lal~y have many thick ve~Fel~ which pass water.
Therefore, it may be seen that these veFrel~ can be used to
ea6ily in~ect the treating Iiquid. Pcwe~er, these vefireJ~
actually contain a large amount of impuritie6 such as tylo6e.
Accordingly, applying pre66ure all at once cal~r~F the
impuritie~ to get clogged in the veFFel~, pLe~an~ing in~ection
of the treating liquid. For thi6 reason, a6 regard6 the
pre6ent invention, in the initial pres6u.e applying/in~ecting
step, to make the treating liguid go through the ve66el~ and
conrequently to transmit equal pres6ure of the liquid are
followed by to in~ect the treating liquid to the central
portion of the material, by applying a relatively low pre6sure
which doe6 not cause the impuritie6 to get clogged in the
Ve68eJ 6 over a long period of time. Thus here too, the
- 29 -
A~
211366 1 ~i
initial pres6ure-applyinq/in~ecting 6tep of the pre6ent
invention i6 of different ~ignif1c~e from a mere fir6t step
of the stepwise p~e~u~e application.
The present method 6et6 the pre66ure-reducing time at
more than 30 minute~ at lea6t, preferably 60 minutes which i8
longer than that set for the conifers as 6hown ln Fig. 2, in
view of the fact that the bro~le~ trees contain more
elements in their vesEel~ compared to the conifers, which
makes it neces~ry to minimize the influence of the gas in the
ve~eJ F Oc~U~ L ing during pre~ure application by removing as
much gas in the ves6el as possible (Sl).
Even in the following pres~Le applying step, a
relatively low pressure of about 0 to 10 kg/cm2 is applied, 80
that the clogging ln the v~6~el~ does not occur. The
pressure-applying time is set at 30 minutes, which is longer
than i~ is for the conifers (refer to S2). In thi6
~-ho~ , the treatment i6 carried out under o to 5 kg/cm2
in the same manner as the above described case for conifer6.
Thi6 is, in addition to the foregoing re~o~, because
tracheids are more apt to be clogged in the case of broadleaf
trees. Accordingly, it i6 ~ e~Lant in the case of broadleaf
trees to perform this step under low pLa~uLe for a long time.
Accordingly, the treating liguid being made through the
vesFels in advance, the ve~Fel~ can be set at a certain
ple~ULe, without being hampered by ~_~Eol clogging. After a
low pressure is applied for a long period o~ time, the
pressure is applied in step6 at 6 to 15 kg/cm2 rOr 10 to 20
minutes, 16 to 30 kg/cm2 for 20 to 30 minutes, 31 to 45 kg/cm2
for 30 minutes and 80 on (S3-S5). Beside6, concel..ing the
final pre6sure ~pplication, a6 mentioned above, it doe6 not
matter whether pre66ure i6 applied until 50 kg/cm2 or at lower
values than 45 kg/cm2 according to the kind of the wood
material. In thi6 ca6e, the pre6sure on the broadleaf tree6
- 30 -
~A ~'
- 211366 1 .
can be increa6ed in a fewer 1- h~r of steps than for the
conifers, 6ince they have larger number of ve6sel element6.
In the ca6e of broadleaf trees therefore, the treatment i6
generally ~r6~,L6sed like the following; a6 indicated by a dot
line in Fig. 2, the time during which the low pres6ure is
applied i6 long and, thereAfter, the ~s~ re is relatively
quickly raised. Similarly, Alth~lgh the amount of treating
liquid in~ected is moderately increAsed at the beglnn~ng, its
gradient is quickly increased with a rise of the pre6sure. By
oGI.LLast, in the case of conifer6, the pressure and the amount
of treating liquid in~ected are genc~ally increased at a
substantially uniform gradient, a6 ~n~cAted by a dot line in
Fig. 1. After the treating liquid has been in~ected, the
pres6ure is gr~ Ally ~. -ved using the pressure-removing
valve 19 a6 de6cribed above (S6).
Obta 1 ne~ was the sa~e re6ult a6 those of the conifer6
that the treating liquid wa6 in~ected to the cen~ral portion
of the treated material. Fig. ll(b) 6hows the6e data.
Furthermore,- in the case of broadleaf trees as well as
conifer6, the pre~sure, the pressure difference, and the
length of time the material i6 maintA~ne~ at a certain
pres6ure can be set at different values for each step in
_ccordance with the kind, type and ~ ion6 of the wood
material.
Fig. 3 illu6tr_te6 gr_ph6 6howing the reduction and
application of pres6ure during material treatment in the third
embodiment of the treating-liquid in~ecting method related to
- the pre~ent invention. The present embodi~ent i6 a method for
in~ecting the treating liquid into ~or~us inorganic materials
such a6 6tone material. In the pre6ent method, the time for
reducing the pre6sure and the time for applying low pres6ure
are made long. After the pres6ure is red~ce~ and low pre66ure
i6 ~pplied, the pres6ure i6 increa6ed at once to a high
~ ,,,
2 1 ~ ~ 6 6 1
pres6ure, which allows in~ection of the treating liquid to the
internal portion of the 6tone material.
Porous inorganic materials 6uch a6 marble contain a large
quantity of ga6 in the$r interior due to their structure.
Accordingly, in the pre6ent method 6ufficient pre6sure-
red~c~ng time i6 taken 80 that the gas in the interior can be
sufficiently removed (81). In this case, it is desirable that
the pressure-reducing time i6 longer than it i8 for the
aforementioned broadleaf trees, tnerefore about 120 minutes.
Stone mater1al6 al60 contain a large A - L of fine
impurities or ~ine pOwaer in t~eir interior. Accordingly, a6
an in$tial pre6~u~e applying/in~ecting 6tep, in order to
prevent clogging by these entitie6 from oc~uL~ing, a
relatively low pressure of about 5 kg/cm2 is applied for a
longer period of time than for the wood material, for example
for about 60 minutes (S2). Thi6 allows the material'6
interior to be at a certain pressure as is the case for the
broadle_f tree6. After low pre6sure i6 applied for a long
period of time, the treating-liquid in~ecting 6tep is carried
out. In the pre6ent emhoA~ ?nt, ~nlike in the c_se of the
wood material, a high pressure of 45 kg/cm2 i6 applied at
once, becA-~e the 6tone material i8 not ea6ily deformed by
pres6ure application (S3).
On the other hand, after in~ecting the treating liquid
under high ~le6~u~e, the pres~uLe ~moving valve 19 i6 used to
gradually remove the pressure a6 de6cribed above (S4).
Accordingly, according to the methods of the pre6ent
invention, the treating liquid i6 in~ected to the ce~
portion of the material. A piece of 70 x 30 x 3 cm-marble
(made in Italy) used a6 6tone material was in~ected with a
water-601uble dye and then cut. It wa6 found that the marble
wa6 uniformly dyed to it6 central portion, thereby verifying
that the in~ected treating liquid doe6 reach the material'6
- 32 -
i ~
21 1366 1
central portion. It goes without saying that in this case
too, conditions of treatment are changeable according to
the type of the material.
In the present method, using, for example, a Toa
Kagaku's "Alone Water Shut" (trade name) whose major
component is silane monomer further increases the treated
stone material's resistance to acid rain. That is, the
silane monomer in the base material chemically combines
with the silanol and forms a layer highly effective in
preventing water absorption, thereby protecting the stone
material from damage caused by acid rain and the like. In
addition, since the hair net pits in the stone material,
particularly the marble, are not embedded, the stone
material can be treated by taking advantage of its
characteristics, without deteriorating the respiratory
action of the marble.
Although embodiments of the invention have been
described above, it is not limited thereto and it will be
apparent to those skilled in the art that numerous
modifications form part of the present invention insofar as
they do not depart from the spirit, nature and scope of the
claimed and described invention.
A '~'
