FR2459323A1 - IMPROVED PROCESS FOR BITUMEN IMPREGNATION OF FIBROUS MATERIALS PROFILES AND IMPREGNATED MATERIALS THUS OBTAINED - Google Patents

Abstract

PROCESS FOR IMPREGNATION WITH HOT BITUMEN OF FIBROUS MATERIALS, IN PARTICULAR CELLULOSIC MATERIALS, PROFILES. IT BASICALLY INCLUDES A VACUUM IMPREGNATION OF PROFILED ELEMENTS OF THIS MATERIAL, ADVANTAGEOUSLY GROUPED IN A COMPACT BURDEN CONSTITUTING A UNIT CHARGE, WITH, IF DESIRED, RECYCLING OF THE HOT BITUMEN FOR A CERTAIN TIME, AND POSSIBLE COOLING OF THIS BY SOAKING IN HOT WATER, ITSELF POSSIBLY FOLLOWED BY A NEW VACUUM OF THE LOAD OF IMPREGNATED PROFILE ELEMENTS. APPLICATION TO THE MANUFACTURING OF IMPROVED COVERING, SIDING OR SEALING ELEMENTS.

Description

The present invention relates to the obtaining of

  fibrous, especially cellulosic, profiled and impregnated

  bitumen; the invention also relates to the obtaining of

  fibrous, and in particular cellulosic, profiled,

  and impregnated into the mass by hot bitumen.

  Classically, to impregnate with bitumen

  For the preparation of roofing materials and cladding, the previously formed cellulosic materials are quenched in a bath of hot bitumen.

  either continuously or discontinuously.

  This conventional technique, however, has several disadvantages. First of all, the impregnation thus carried out is slow, because the hot bitumen hardly flushes the air

  and water still contained at this stage in the thickness of materials

  cellulosic products subjected to impregnation. This results in a noticeable deterioration of the cellulosic fibers and, consequently, a clear reduction in the mechanical strength (tensile strength, bursting force, impact resistance, ...) of the

  end materials, including profiled plates or

  Thus, at the impregnation temperature, which is greater than 150 ° C., the degradation of the cellulose is rapid and all the more important as the soaking time in the hot bitumen is long. In addition, this technique often leaves, at the bottom of the materials emerging from the hot bitumen bath being substantially vertically, an unsightly bitumen bead, dirty and representing an unnecessary additional consumption of impregnating product, this bead resulting from the excess of bitumen flowing by gravity along the impregnated materials,

  cellulose being unable to absorb it.

  Moreover, such a technique requires

  large size and requires maintenance at a temperature of

  high amount of bitumen, so investment

  heavy and time-consuming investments and significant energy consumption, because each element of the material to be impregnated must be clearly separated from the next so that it

  can be good contact between cellulose and bath of bitu-

me.

  Another impregnating technique is also known

  cellulosic materials, which consists in applying,

* -2 2459323

  in an impregnation tank where the elements of cellular material

  The impregnated impellers are embedded in hot bitumen and suitably spaced between them, one or more overpressures forcing the bitumen to penetrate the interior of the cellulosic network of each element. This second known technique, although it allows

  to reduce the duration of impregnation, however,

its disadvantages.

  First of all, acting by pressure, she

  not in the cellulose material (cardboard) a mattress of air and water vapor which makes the impregnation at heart very difficult; we often see in elements, especially

  plates, whether profiled or not, of cellulosic material

  According to this technique, a central zone "white", no

  impregnated, therefore unprotected and easily putrescible.

  Moreover, this technique does not solve the problem.

  sticky bitumen, which appears and again constitutes a gene. In addition, such a technique, involving an overpressure, involves a discontinuous operation and requires leaving, between the successive elements of material to be impregnated grouped by unitary charges, a sufficient space for the penetration of viscous bitumen, hot, and Therefore

  requires a very large volume of vats (or number of vats)

  carrying, dTo again heavy investments and the obli-

  to maintain at high temperature significant quantities of

bitumen.

  However, it has now been found, unexpectedly, that a substantially better impregnation of profiled fibrous materials in all respects by hot bitumen can be achieved by means of a method essentially comprising the step

  vacuum impregnation, advantageously on

  impregnated material impregnated in a compact burden, and possibly the cooling of the impregnated elements by dipping in hot water, itself possibly also followed by a new evacuation of the profiled elements

  impregnated collected after this soaking.

  In its most general aspect, the present invention therefore relates to a process for impregnating with hot bitumen fibrous materials, in particular cellulose materials, profiled, characterized in that it basically comprises a

  vacuum impregnation of profiled elements of this material,

  tagged into a compact burden

  unit, if desired, recycling the hot bitumen for a certain duration, and optionally (and advantageously) the cooling of this impregnated charge by soaking in hot water, itself possibly followed by a new setting empty of the load of impregnated profiled elements. In another essential aspect, the invention relates to profiled elements of cellulosic material impregnated with

  by a method as described above.

  It is remarkable and unexpected that

  operating in this way, not only is there a marked improvement in the

  mechanical properties of the impregnated profiled elements obtained,

  but also the presentation and the cost of manufacturing are improved.

  cation of these. This is indeed how easily

  impregnation of the bitumen, if desired until saturated

  in a remarkably homogeneous manner, both

  the whole mass of the same element as between different elements

ent.

  In the present context, the term "elements pro-

  spun fibrous materials "any element made from a

  fibrous material and in particular elements of cellular material

  for example of cardboard, and which has been conferred

  wire, simple or complex, making it no longer entirely planar. The elements thus referred to are, for example, corrugated plates, advantageously monolayer corrugated plates, or

  fat plates, advantageously monolayer; these last

  res are simply called "fats" in the sequel.

  The method according to the invention comprises the implementation

  of a fairly high vacuum, preferably leaving a

  residual pressure of not more than 1/3 atmosphere and advantageously

  about 1/5 atmosphere (1 atmosphere e 105 pascals).

  The aforementioned vacuum impregnation step firstly comprises the introduction of elements to be impregnated into an enclosure which can be sealed and which resists a vacuum, and in which a high vacuum is then made, preferably up to at the pressures above. Once this vacuum is reached, which has evacuated most of the air contained in the fibrous structure, it gradually increases the level of hot bitumen in the chamber, while maintaining the vacuum in it substantially at the same value, which causes a very rapid evaporation of the residual water contained in the fibrous elements. It has also been found that resistance to the penetration of bitumen into the interior of fibrous elements

  is very weak and the impregnation is very fast.

  An advantageous variant of impregnation furthermore comprises a step of breaking the vacuum, partial or total, while the impregnated fibrous elements are always in the hot bitumen. More advantageously still, such a breakage

  partial or total vacuum, followed by a return to a vacuum

  the previous value, is itself part of a

  pe recycling hot bitumen, stage of which it constitutes an intermediate phase or the final phase; it has been possible to establish

  that still considerably increases the speed of the opera-

  impregnation. Alternatively, it is also possible to make again in the enclosure a vacuum as indicated above, either before or during the removal of the hot bitumen after the impregnation time that has been set (after possibly tests

  for its prior determination in each case); se-

variant

  Particularly advantageous, even if the

  The treated fibrous elements also comprise, after removal of the bitumen, a bituminous bead, the total breaking of the vacuum and the return to atmospheric pressure before the chamber is opened ensure the resorption of the bitumen raked on the surface and the disappearance of this excess, which is then pumped to

  inside the fibrous structure.

  Another original and advantageous characteristic of the process according to the invention, which is certainly only optional

  but it is none the less a carrier of results of the highest

  tér t, consists of the impregnation of grouped profiled elements

  in a compact burden constituting a unitary load.

  Indeed, in the conventional technique which comprises an impregnation under atmospheric pressure, it is imperative to maintain between the profiled elements, in practice arranged vertically, a sufficient space so that the bitumen can freely circulate around these elements and that the impregnation

  not be hindered by the slow release of air and heat.

  afraid of water contained in the fibrous network. When against

  they had sought to overcome this gap between

  In such an operation, so far only a very weak impregnation had been obtained, leaving above all substantially vertical fibrous elements "white" spots of non-impregnated material. Now, the realization and the

  maintaining such minimum spacings representing an aster-

  which increases the impregnation operation, makes the preparation more cumbersome and necessarily makes it longer to put into operation

  artwork. Orson has now found quite unexpectedly

  that the process according to the invention comprises an impregnated

  Under vacuum conditions, provided that the elements to be treated are not only planar but are profiled, it is possible to group any number, even a very large number, of unitary profiled elements of the fibrous material to be impregnated,

  against others and without any spacing other than that

  natural variations, even small ones, between the specifications of each element and the one

  precedes and / or follows in the burden thus formed.

  It is even possible to prepare groupings which, by pre-bundling, with possibly a prior palletization, constitute a unitary unit representing a unit marketable in the state once it has been submitted to

the impregnation according to the invention.

  Moreover, it is quite certain that the process as described above is absolutely not limited to the case of a

  fibrous material which has not been pre-treated and

  that particularly well in the case of materials, including roofing materials, cladding or profiled sealing,

  stained or colored according to the process described in

  patent applications FR 76.16263 and first certificate of addition 78.14039 attached to this patent in the name of the same applicant, and to which we can usefully refer, before being

  subjected to impregnation according to the present invention.

  According to an advantageous form of implementation of this

  the pigment is applied in the form of a pigment preparation containing a thermoplastic or thermosetting binder, in amounts as low as 0.1%

  and up to 25% of the total weight of the pigments

  these values being expressed as resin solids content of the binder, and preferably of the order of 2 to 3%, also

counted in dry extract.

  The method according to the invention furthermore comprises

  As described above, a tagging step of cooling the impregnated elements by dipping in

  hot water, which may itself be followed by a new

  evacuation of impregnated profiled elements collected

after this soaking.

  This cooling with hot water must be such that it quickly returns to a temperature of about 1000C the elements of hot impregnated fibrous material, that is to say in practice being before soaking to a nearby temperature

  -180oC, knowing that the impregnation is carried out in the practice

  most commonly with bitumen at 180-190oC.

  This step constitutes another original characteristic of the process according to the invention and it cooperates with the other aforementioned steps to provide impregnated products.

virtually without defects.

  Cooling of bundled fibrous material elements emerging from the vacuum impregnation could indeed

  to be a source of problems that are difficult to solve industrially.

  Leaving these hot elements together effectively

  quickly, if we are not careful, a phenomenon of self-

  combustion or, at best, a degradation of the mechanical properties

streets of these impregnated elements.

  Only two solutions appeared then economically

  practically exploitable: air cooling or

water cooling.

  No. Wh 50 Air cooling has several drawbacks

  the most important is that it is difficult to control

  ler the cooling temperature and that it is therefore not very reproducible and inhomogeneous, both between successive charges

  that even within a unit load of fibrous elements

Kg 3 strips, impregnated and warm.

  We then obviously thought of cooling with cold water

  of. However, it resulted in too much moisture recovery

  fibrous material elements. The residual moisture represents

  felt 10 to 15% of the weight of the impregnated elements and was such t.1

  that the storage of these produced distortions of the

  son, in particular deformations of the corrugations of

  corrugated bituminous cardboard, which could even be called

then soft plates.

  Unexpectedly, it is on the contrary a cooling with hot water, and preferably in water at 92-1000C,

  which has proved to be the near ideal solution for ob-

  retention of unaltered impregnated elements. In practice, it suffices

  made a short soak, of the order of, for example, 1 minute

  approximately, or even fewer, elements coming out of the impregnating step.

  tion at about 160-1800C in water at 92-1000C, so that they take up only a reasonable amount of moisture, of the order of only 5 to 7% of the weight of the impregnated elements. The plates are then only 1000C, or less, at the end of soaking and there is more to fear that they

degrade by auto-combustion.

  Nevertheless, yet another optional variant of the method according to the invention further comprises a new evacuation of the impregnated profiled elements collected after this soaking. In practice, the vacuum that is appropriate then is a vacuum

  not more than approximately 600 mm of mercury, that is, a vacuum

  leaving a residual pressure of about 1/5

  atmosphere (0.2 x 105 pascals), under which the temperature

  The boiling point of the water is only about 600C.

  The theory indicates that moist impregnated elements

  at 1000C thus lose, by placing under a vacuum of 600 mm of

  3% of their wet weight by evaporation of water and

  in fact a temperature close to 60C. Practice has confirmed that they actually lose 2 to 3% of their

weight.

  These most advantageous variants of the invention

  lead to impregnated fibrous material elements,

  which are "cold" (about 600C) and have a

  good hygrometry (2 to 4% residual moisture, by weight).

  The impregnated fibrous elements thus obtained are original and are also part of the present invention;

  they are fibrous elements impregnated with bitumen and possibly

  previously colored, profiled, with a normal internal moisture (2 to 4% by weight of residual moisture) as soon as they come out of production and able to be stored or even delivered as they are without being subjected thereafter alteration

  .notable ... DTD: The invention also relates to assemblies comprising

  a group of fibrous material elements impregnated with bitumen, profiles and juxtaposed to form a burden without

  spacing elements, and possibly joined together by a

  and, if necessary, pre-palletisation, so as to

  a commercial whole that can be stored and even delivered "as is, with no other operation than control operations! i and / or identification, as a labeling, usual. fibrous cellulose-based profiles, prepared by known methods, come out very dry impregnation and risk, if their storage is brief, not to take enough moisture and to be used and: i. The moisture recovery during use is then accompanied by a dilation of the material already fixed and a deformation detrimental to its aesthetics and behavior.The invention is illustrated more concretely in the

  examples below, which do not limit it in any way.

:. EXAMPLE 1-

  For the impregnation of cellulosic cardboard

  corrugated monolayer with a density of 0.57 and a unit average

  3.15 kg, each comprising 10 waves, an installation consisting basically of the following elements was implemented: - 1 impregnation tank (capacity 5 m 3 and diameter 1.3 m) fSS - - 1 melter with walls and bottom double (2.5 m diameter, 12 m3 capacity), - 1 bitumen pump with variable speed motor (1.5 to ... 6 HP, 500 to 2000 rpm, - 1 vacuum pump with liquid ring 140 m3 / h to 700 mm Hg, i -: .. - 1 asphalt feed valve with pneumatic control and adjustable opening,.: -1 air operated bitumen drain valve with adjustable opening, -1 valve Pneumatic vacuum breaker, pneumatic control valve, vacuum separator between tank and melter, -1 recorder for supply temperature, temperature, return temperature and the vacuum, - 1 electric level on the overflow of the tank, and

- 2 Vacuum adjustment manostats.

  This installation operating automatically, we operated as follows: we put the plates, contiguous to each other, and arranged vertically in a metal cage

  in the tank, which was then closed.

  and the vacuum pump was started. Once reached

  prefixed value of 600 mm Hg vacuum (ie a pressure of

  1 / 5th atmosphere, or 0.2x105 pascals, approximately in the tank), the feed valve is opened and the bitumen is mounted by gravity in the tank, to the overflow and,

  at this time, the bitumen pump and the recycling timer

  clage went off. The latter, after the pre-set time has elapsed, closed the supply valve and opened the drain valve and activated the bleed timer. Finally, once the prefixed bleeding time has passed, the cycle has

  stopped and the vacuum was broken manually and opened the tank.

  Tests have established that - with 80/100 road bitumen, the temperature of this one

  must be at least 1750C, and is advantageously approximately

  1800C, under the conditions of impregnation.

  - with an automated cycle comprising 5 minutes to evacuate (a value of 500 to 600 mm of Hg approximately), 5 minutes to fill the tank, 12 minutes to perform a bitumen recycling, 6 minutes to perform the emptying of the bitumen and minutes to allow bitumen bleeding

  plates, plates having all an

  similar to that of plates of the same type impregnated according to the first of the conventional techniques mentioned above, but these plates had moreover perfectly surfaces surfaces, their lower edge being perfectly clean, to such a point that one no longer recognized the top of the bottom plates

after unloading.

  Example 2. In the same installation as that described in Example 1, impregnated with 80/100 road bitumen at an average temperature of 1820C (under the impregnation conditions)

  corrugated plates, as defined in Example 1,

  in a burden without spacers arranged, for its introduc-

  in the tank, in a suitable metal cage.

  The impregnation cycle involved this time a vacuum breaking and was then the following: - 3 minutes to evacuate (a value of 500 mm of Hg approximately), - 3 minutes to get up bitumen in the tank , to the overflow, while continuing to accentuate the vacuum to bring it to approximately 600 mm Hg), - 12 minutes to recirculate the hot bitumen, under the vacuum then reached, that is to say under residual pressure

  about 1 / 5th of atmosphere), but with, at the end of the first 10

  After a few minutes, break the vacuum to a value of A P (in mm of Hg) and restore the empty mass immediately before, followed by recirculation (or recycle) under this vacuum for the remaining 2 minutes, - then 6 minutes. to empty the tank and 10 minutes to achieve a bleed under vacuum, after which the tank was put back

at atmospheric pressure.

  The results obtained were as follows: ## EQU2 #

  top of the plates at the bottom of the means of

plates

after

  1 0 103 103 103 EXCELLENT 2 200 112 116 114 GOOD 3 300 116. 116 116 GOOD 4 600 122 122 122 Poor Operating the same, but setting the P to partial vacuum breaking at 200 mm Hg and doing this time vary the duration of recycling (variable t, in minutes), we obtained the following results:

  n t Imim rate of tax rate of tax

  test (enmiiius) pregnation prégnation prégnation face pla-

  at the top of the bottom of the means after plates plates bleeding 1 10 112 116 114 Good 2 8 106 112 109 Good 3 5 100 106 103 Almost perfect

4 2 100 106 103.. I

  j? ii :: y il 2459323 It is clear that a compromise must be sought between

  the surface state of the plates after bleeding and the rate of

  prégnation. EXAMPLE 3 The procedure was as in Example 1, but using corrugated plates previously dyed in the mass in accordance with the process of the patent application FR 76 16263 and the application for the first certificate of addition 78.14039, respectively. to it (and to which we can refer, usefully for more detail), and each time we obtained results quite similar to those

mentioned in Example 1.

  EXAMPLE 4 In the same plant as that described in Example 1, grouped slabs were impregnated in accordance with the procedure of this example and immediately soaked in hot water and, alternatively, then

under vacuum.

  For example, 8 cellulose cardboard

  The thickness of the corrugated monolayer (10 waves per plate) was as follows: No. of plates 1 2 3 4 5 6 7 8 Weight of carton (g) 3160 3190 3180 3170 3170 3250 3140 3120 Weight after print 6300 6300 6290 6290 6280 6300 6230 6300 gnation (g) Impregnation rate 99.4 97.5 97.8 98.4 98.1 93.8 98.4 101.9 Pyrometric measurements showed that the grouped plates came out of the bath. substantially impregnating

  same temperature as that of this bath, that is to say 1800C.

  The burden of plates was plunged to this temperature.

  re for 1 minute in water at 98-100oC.

  The moisture recovery from the center plate was

about c (w / w).

  In order to carry out other tests, samples of corrugated board of 18x18 were made from some of the plates referenced 1 to 8 above.

  cm. One plate could provide 30 samples.

  We operated on plates coming out of

  and not yet absorbed moisture.

  The samples to be tested were heated in an oven at 1800 ° C. to a constant temperature and then soaked as quickly as possible and for exactly 1 minute.

in water at 98-1000c.

  The experiments (referenced a, b, etc.) were carried out

  grouped plates, the groups of plates being

  referenced Gn (n = number of plates).

  Dry weight Ps at 1801C and Ph were evaluated for wet plates (after soaking for 1 minute in

  water at 98-1000c and natural draining for 1 minute).

  For a time t (in minutes), each group of Gn plates was enclosed in the vacuum tank where a vacuum of 600 mm Hg (ie a residual pressure of 175 mm Hg (or 1/5 d atmosphere), the atmospheric pressure being,

  the day of these experiences is 775 mm H &).

  The weights (Pv, in g) of the samples were measured and the moisture recoveries RH1: after cooling with boiling water and draining,

RH2: after vacuum delivery.

  Three series of experiments were carried out: two sets (a and b) of 10 samples Gl0 from the same plate underwent a vacuum of 600 min of Hg for 15 minutes, -two sets (a and b) of 10 samples Gl0 from another plate have undergone the same tests, and -three sets (a, b and c) of 9 G9 samples from

  third plate suffered the same vacuum during each

  vein 5 minutes, 10 minutes and 15 minutes.

  The following results were obtained

  ____ ____ _____ ______ ________ __________ __________ _____ _____ +

  where 9 9 8 8 8 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1? L9q ç: 9q 6'e6 c 'frc 9e' T 9 r'817 C'81r 9'6I o'Lz o'Lz o'Lz where

O '22L

  THE OTTAWA O'LOY IS THE 91IQ 'LiTiI

19'0911

  TILI ú'5 c'g 2 "9 The 9 The 9 6 'qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqr

The LI86

9611,

* 8 '100T

9 '966

Z '766

9'ZIIT

8'LIII

  This is the case of Oloogo; OIDq [(hMW UGa) (9 {(2) (2) (sg-) (^ T-qd) (Mfi2 xWuaI) (2) a (ue2se (1) JodeA1 (5) (sci-11) (2) (9) as a percentage, the percentage of calcium hydroxide is not higher than that of

14 2459323

Claims (16)

  1. Impregnation process with hot bitumen   fibrous materials, especially cellulosic materials,   spunbond, characterized in that it basically comprises a vacuum impregnation of profiled elements of this material, advantageously grouped into a compact burden constituting a unitary charge, with if desired recycling hot bitumen for a certain period, and vented. the cooling of this impregnated filler by soaking in hot water, itself possibly followed by a further evacuation of   the load of impregnated profiled elements.   2. Method according to claim 1, characterized in   what it includes the implementation of a vacuum leaving   a residual pressure of not more than 1/3 atmospheric,   Preferably about 1/5 of atmosphere (1 atmosphere - 5 pascals).   3. Method according to claim 1, characterized in that it further comprises a vacuum breaking step, partial   total, while the Impregnated fibrous elements are always days in the hot bitumen.   4. Method according to claim 3, characterized in that the breaking of the vacuum is itself part of a hot bitumen recycling step, step of which it constitutes an intermediate phase or the final phase, and that it is him - same follow up   Â a return to a vacuum having substantially the previous value.   5. Process according to any one of the claims   1 to 4, characterized in that then a vacuum is again made as above, either before or during evacuation.   the hot bitumen after the impregnation time that has been fixed.   6. Process according to any one of the claims   1 to 5, characterized in that it comprises the impregnation of ele-   sections grouped into a compact burden constituting a unitary charge.   7. Process according to any one of the claims   1 to 6, characterized in that it comprises the treatment of materials   previously colored or tinted '.   8. Process according to claim 7, characterized in   what the pigment used for this prior coloring   is applied in the form of a pigment preparation con-   holding a thermoplastic or thermosetting binder, in amounts which may be as low as 0.1% and up to 25% of the total weight of the pigment composition, these values being expressed as resin solids content of the binder, and preferably of the order of 2 to 3%, also counted in dry extract.   9. Process according to any one of the claims   1 to 8, characterized in that it comprises a cooling step   elements impregnated by soaking in hot water   quickly bringing the temperature back to around 1000C   impregnated fibrous material parts, hot.   The method of claim 9, characterized in   that is used cooling water at 92-1000C.   11. Method according to one of claims 9 or 10,   characterized in that it then comprises a new setting   empty impregnated profiled elements collected after the trem-   page, the emptiness realized leaving then a pressure   residual of about 1/5 atmosphere (1 atmosphere, 105pascals).   12. Products, characterized in that they constitute   of fibrous elements impregnated with bitumen and possibly pre-colored beforehand, provided with an internal moisture of   2 to 7% and advantageously from 2 to 4%, by weight of residual moisture.   duel approximately as soon as they are out of production and capable of being   stored or delivered in the same state without any subsequent significant reduction.   13. Products, characterized in that they constitute   killed fiber elements impregnated by a method according to one   any of claims 1 to 11.   14. Products according to claim 13, characterized in that they have an internal humidity of about 5 to 7%   3o the weight of the impregnated elements.   15.Products according to any of the claims   12 to 14, characterized in that they constitute materials   roofing, cladding or waterproofing.   16. Sets, characterized in that they comprise   a group of fibrous material elements impregnated with bitumen se-   any one of claims 12 to 15, juxtaposed with   to form a burden without spacers, and possibly   combined by pre-furbishing and, if necessary, palletizing.