DE1900649A1 - Article containing asbestos fiber and process for its manufacture - Google Patents

Description

JOHUS-MAfHTILLE CORPORA! · ΙΟΙ ' 22 Bast 40t'-ι Street, Sew York 16, New York, U. S. A.

Asbestos fiber holder subject matter and method of its

Manufacturing

For your convenience, the priority is the corresponding t. USA-A time IdUn ₁ -; Ser. No. t> y9 2 ^ 5 dated January 2, 19 whether claimed.

The invention relates to the production of objects containing asbestos fibers and relates in particular to objects and products formed by a conventional wet process by filtering out: before particulate material from a pulp or after a conventional dry process by squeezing out excess water. The invention provides a system for considerable Increase in the number of production and speed at which these articles are manufactured. Although more specific embodiments of the invention are predominantly based on the manufacture of Aebeet cement products by air filtration of particulate material from a slurry in which asbestos fibers, water cement and silica ) are included, and in particular to the

. ♦. / 2

909835 / 02U

Manufacture of M> est cement pipe material if used of chrysotile (a Canadian asbestos) as the main one Fiber of a solr.-hen pulp are directed is It is understood that the other forms of the invention include the manufacture of any product with them. Include asbestos fibers.

For many years, the manufacturers of after a wet or a dry process containing asbestos fibers Products are steadily treading paths and using resources, to get the best products at the highest production rates to manufacture. In the manufacture of these products, and particularly in the case of asbestos-cement articles, a satisfactory quality of the molded asbestos-cement articles has now been achieved, so that now in the production of these objects of high quality the main effort Aimed at the best possible output There are numerous systems and plants for manufacturing Clay Aabest cement products directed patents, from which in particular the ü! Patents 2,220,386 (Badollet) and 3,095,346 (Sfiechko) on the EKr method of increasing the production ■ numbers directed by influencing the filtering characteristics of the pulp in a painting process

909135/0244

BAD ORIQfNAL

US Patent 2 220 3βό has never achieved a success wirtschaftlic while SiOF _1, the system _f remäß the US Patent 3 C95 34h extensive commercial use; pleased. Despite this -economic- success, the constant competitive pressure makes constant efforts to discover new and improved ways and means for the most useful and economical production of this object necessary.

The invention relates to a method for improving the Production steel or speed at which asbestos fiber or asbestos fiber Zemert products either by an Iiaß or a dry process by means of use a non-foaming anionic dispersant permit.

The underlying the invention The object is to provide a system for influencing the Filteru-.smwrkmale a non-asbestos fiber-containing slurry, namely in such a way that d ⁴ e Produktionscahl the usual technical means used in the production of these bo -htiualitativen products by filtering out the particulate material is increased considerably from such a pulp,

Another object of the invention is a system for key positioning of asbestos-cement ore ufniaseti of high quality and

909835/0244

high strength, such as asbestos-cement-pipe-material, at increased production numbers with the help of the asbestos-cement pipe material used to manufacture such as this so far Technical equipment used - ^.

Another object of the invention is a system for manufacturing of asbestos-cement products of high quality and high strength, such as asbestos-cement-E-ear material, with the help of cheaper materials, but with normal production figures and with the help of the manufacture such asbestos-cement products previously used technical equipment.

Another object of the invention is a. System for the production of asbestos-cement products of high quality and high strength in the manner that the production number the conventional one used by a dry process to produce these high quality products Plant is increased considerably.

The aforementioned objects are achieved with the aid of the invention in connection with the normal manufacturing facilities, how they are used in the manufacture of such items and in particular in the system in which

909835/0244

BATHROOM ORIGINAL

Parts of the toilet material present in a slurry are deposited on the slurry on a surface in order to bind a continuous sheet or sheet of partial sheet material, on which sheet or sheet is then used to form objects will. According to the invention, a non-foaming anionic dispersant is included in the slurry, which is normally used to disperse the finished materials in the slurry in recommended amounts which, where filtering affects the output, reduce the rate of production, are advantageous Results of the invention are achieved by using these non-foaming anionic dispersants in amounts which are considerably less than the amounts recommended by the manufacturers for dispersion purposes. In particular before the production. Significant benefits have been obtained from asbestos-cement tubing by adding an agent consisting of a sulfonic acid derivative, namely a liatric salt of condensed naphthalenesulfonic acid, to the slurry. It has also been found that when the dispersants according to the invention are combined with the high molecular weight polyacrylamides of the type described in US Pat. No. 3,095,346, a synergistic effect occurs. The invention makes it possible, with the aid of the existing technical equipment previously used for the production of Aebest cement pipe material, to increase production

909835/0244 BATH

pay to manufacture an asbestos-cement pipe material of high quality and high strength. In addition, considerable increases in production times were achieved because, in a conventional drying process, a non-foaming anionic dispersant was added as one of the components.

The invention is detailed below with reference to FIG Description of one of their preferred Dur-, hführungsformeπ

explained in more detail.

Manufacturers of asbestos-cement products. numerous Prüfveryuche (Tests) have developed 'over the years, which will enable them to determine in the laboratory rasoh as the most diverse substances or processes work if they are turned on _r in the actual P oduktionsvorgang. In view of the importance of the filtering speed of the asbestos-cement slurry for the manufacture of Aebest cement products, special methods have been developed to determine the effect on its piling characteristics when various changes are made to the slurry. In the Sfiscko patent specification, Sapte 4, line 1, to column 5, line 44, a method for the production of test samples for the purpose of determining the filtering inaccuracy is an Aebest cement

0O983S / OI44

. £ - 'BADORlQrNAL

- Ί -

broadly described. Table II of this part of Sfiscko-Patet: tschrift shows a comparison of the various substances and their A _and swirkur.g the filtering speed of the asbestos-cement grouts ?, in which they are installed. This part of the Sfiscko patent is to be addressed as part of the present description

In pursuing the Sfiscko application, it was accidentally discovered that the description of the Badollet patent contained an error regarding the amount of freeness-increasing agent to be used. This error is evident from the results of Table A, below, in which the test cakes prepared according to the procedures of the Sfisckc patent using a Turkish red oil proposed by Badollet, such as that proposed by "Apex Chemical Company, Inc." is brought under the trade name "turkey Ito. 75" on the market _r erzielteri times are recorded. In Table A, the percentages of Turkish red oil used are expressed as a percentage of total solids so that a direct comparison can be made with the results in Table III of the Sfiscko patent. The percentages of total solids expressed in Table A as 0.02, 0.04, 0.06, 0.08 <f>

909835/01 * 4 BA0Ofl. _QWAL

the percentages of 0.2 to 1.0 9 & of the mean to the weight of the asbestos fibers as expressed on page 1, column 2, lines 48-49 of the Badollet patent is.

TABLE A

$> Turkish-

red oil (der 0.00 0.02 0.04, 0.06 0.08 0.0 0.2 0.4 0.6 0.8 Total solids)

Filter time 8? 100 101 102 105 86 83 81 63 60 (in seconds)

The results in Table A show that with the help of the substances proposed in the Badollet patent then advantages are achieved if an amount amounting to about ten times the amount proposed by Badollet is used. Even then, the benefit to be achieved is small and at the expense of quality and strength of the formed products. It is entirely possible that the results recorded in Table A the Show reasons why the substances suggested by Badollet have not found any economic use.

In the process of looking for improvements · in overall production A theory has been developed of asbestos-cement products according to which commercially available as a dispersant designated means in the production of

909835/0244

Asbestos-cement objects, but in considerably smaller quantities than those required to achieve complete dispersion recommended amounts, could be used to minimize and minimize filtering problems nevertheless a certain dispersing effect of the cement and the ultrafine particulate material for better filling of matrix cavities and thus create a denser product. Research in this area led to the conclusion that although these substances were classified in the dispersant class, with them some benefits could be obtained by treating them as a. Means for improving the filtering characteristics tried an asbestos-cement slurry. Accordingly, according to the procedures described in the Sfiscko patent Experimental cake made using one of these dispersants. As illustrated in Table B, in which the amount of dispersant used is expressed as a percentage of total solids is, the results have been daunting. In addition, the attempt with this dispersant was because of use of the substances proposed by Bedollet in ten times the amount normally used Improvement had been achieved at this tenfold amount carried out with disastrous results.

... / 1O

909835/0244

- · ιο -

TABLE B. 0.02 0, 04 0.08 0.01 81 81 96 7 83 0.4 ο, 6th - 0.2 155 21 2 8 90

ia Tamol 'in wet mix (based on total solids)

Filter time (SeJc) i i> Tamol in wet mix (based on total solids) Filter time (sec) £

The dispersant used according to Table B was a sodium salt of condensed naphthalenesulfonic acid marketed by the company "Röhm and Haas" under the trade name ^w Tamol ^n.

In accordance with common practice, the results recorded in Table B would indicate that no further efforts should be made to use dispersants to improve the filtration characteristics of an asbestos-cement slurry. However, it was decided to make an experiment on a small wet machine in order to run a wet machine in actual production. ^r ; to enable observation of these dispersants and thereby determine whether, according to the original theory of the manufacture of a

... / 11

909835/0244

denser product would produce advantageous results. The small room machine is a common machine for making paperboard with a mixing container in which a slurry is made which contains asbestos fibers, water cement and silicate as particulate material. The pulp is usually prepared to have a pesticide content of about 7 fd , after which it is placed in a bottle. The pesticides forming the pulp are filtered out in the vat on a drum (cylinder mold) and transferred as a continuous layer or filter system to a mushroom, which carries the layer to a collecting roller on which it is rolled together into several layers. When the required number of layers has formed on the collecting roller, a cut is made in the longitudinal direction, whereupon the layers consisting of individual layers are removed from the collecting or winding roller as a single sheet, which is then subjected to the usual asbestos-cement hardening processes.

A series of experiments to produce A3best-Zement-Tafein carried out, with each of the In individual experiments, the only variable that could be changed was the amount of dispersant used. With every attempt

90983S / Q244

a pulp with a 7 %> solids content was used, in which the pesticides contained 20 $> Chfysotil asbestos fibers processed once in an impact mill and 80 # · of a mixture of water zemint and flint in the ratio ν about 6: 4. The chrysotile Aebest fibers were asbestos fibers marketed by the applicant under the trade name "4T30", while the water cement contained a Protland cement marketed by the company "National Pioneer Company" under the trade name "Portland Cement Type A", the Silex consisted of a powdered silica marketed by the company "South River Sand Company ¹¹ under the trade name" Pulverized Silica ¹¹ , and the dispersant contained the above-described tamol. Each panel produced with the aid of the wet machine had a size of 355 »6 x 635 mm and was cut into ten test pieces, each 76.2 x 203» 2 mm. The results of these runs are expressed in Table C below.

... / 13

909835/0244

TABLE G.

Properties of change # change

Fixed pieces of fabric used (with an average of 10 pieces for dry additive amount of material) weight base material ■ (T- ^ iIe per dice thickness dry density million) (mm) weight (g / g / cm3

piece

Control
le
Tamol nothing
10 6.6 "
6.9 6.5
6.5 180
175 Tamol 50 7.0 8.3 232 Tamol 150 6.3 12.5 337

1.88 base

1.86 -2.5

1.88 +29

1.85 +87

In. Considering these results, i.e. no density changes, however, production improvements, it was decided to use a number of particularly suitable for checking "the production figures." Attempts to carry out using the various means that can be used to improve the filtering characteristics of a Asbestos-cement slurries had been recommended. As a result, a number of tests were carried out on the small wet machine, where the only variable that could be changed was the type and amount of agent used. The pulp was basically the same as used to obtain the results of Table G. was used. The results of these tests are given in Table D below.

9Q983S / Q244

- control Additive - 14th - 1900649 referred to in more detail rma "Marathon ⁸¹ , a department St. 1x Separan Base of the Ge
velvet solids TABEL D. is in through the ii ... / 15 2x Separan no .
Additive Additive 1x Separan + 0.015 1 " Per" bion number io change
the production gate 1x tamol 0.030 io De ? width) ⁺ IX Tamol 0.015 i> 294 1.48816 °) Core value 2x tamol 0.05 # 330 1.48816 + 12.0 1Ox Tamol 0.05? 6 381 1.48816 + 29.6 1x Turkish
Red oil
2x » 0.10 io 506 1.48816 + 72.1 10x » 0.05 i> 2x marasperse
N-22 0.2 io
9.4 io 464, 1.48816 + 57.5 2.0 pounds 513, 1.48816 + 74.3 0.1 io 320, 1.48816 + 8.9 165,
141, 1.48816
1.48816 -43.8
- 52.0 197 1.48816 - 33.1 362, 1.48816 + 22.9 o) 1.48816 is the conversion factor for lb / ft in kg / m luk ^J
pr ( χ «the optimal utility value (i m I ise level) from 14.326 m / min (47 ft per , 6. ⁺ even felting speed > o. min). ,8th . Separan - is specified in the Sfiscko patent , 9 . Tamol - is in the foregoing Merasperse - ,1 . 6th 8th . 5.
4th 1 . 1 .

309335/024 ^

the American Can Company, under the name Marasperse N-22 Sodium lignosulfonate launched on the market.

The results according to Table D show that a synergistic effect is achieved when an agent such as Tamol is used in conjunction with a high molecular weight polyacrylamide of the type described in the Sfiscko patent. Therefore a number of actual production tests were carried out in an Aebest factory in which Tamol was added to the materials that make up the pulp from which asbestos-cement pipe material is made. The equipment used to make the asbestos-cement tubing was of the type described in U.S. Patent No. 2,24-6,537. In all production tests of the difference between the solid contained substantial ^ 100 i * solids), and the total fiber percentage solids water cement and gravel (silica) in an approximate ratio of 6 to 4. The waeser cement contained one made by the Atlas Cement Company; A marketed Portland cement, Type A, with a cement sag designation of 0.026 (empirical laboratory control tests where wekcgeb buedruge values are highly desirable) and the pebble contained a marketed powdered pebble. The results of the various production runs are given in Table E below.

909835/0244

HA O O

■ Ρ CQ

Control Run No.

to

O (O 00

«N

O ft *

Λ3

ο ω

O 03

Tamol Run No.

cd:

co

% TUBOl

Solution Us «!

- 16 -

TABLE E

———

WI A-25 S-IT S%%

(ZN THE PIBER BLEND) I (in the fiber mixture)

% Total Fiber

Solids

Prod.Rate

Cont.Run

Tons / hr

A "HÜ-

Q) M H CU

β I OrH • Η Ο

IJ

O · Η

U 03

Prod.Rate Tamol Run Tons / hr

• H ■ P

tJ CD O «3D

CU -P

Jh cq O) H

S Improve.in Prod. Rate Tons / hr

15-2 15-3

16-2 16-3

.05 .10

.05 •

10 10

10 10

15 10

10 10

90

90 O

17.8 18.6

18.6 18.6

5.85 6.60

7-9 7.9

9.1 10.0

♦ 18 ♦ 50

♦ 55 ♦ 51

CD O O

(JD

17-2 17-3

.05 .10

10 10

10 10

90 90

18.6 18.6

5.55 5.55

7.6 7.6

♦ 37 ♦ 37

The pipe made during runs 15- (1,2,3, and H) was 6 "Class 150 asbestos-cement pipe in 13 ft lengths. The pipe made during runs 16- (1,2,3, and 4) and 17 - (1,2,3, and H) was 10 * 'Class 150 asbestos'cement pipe in 13 ft lengths.

I The pipe material produced in tests 15-0,2,3 and 4) was a "6" asbestos ί, I Cement pipe material (Class 150) in lengths of 3962 mm (13 ft)

ι The pipe I produced in experiments 16-0,2,3 and 4 and 17-0,2,3 and 4) material was 10 "asbestos-cement tubing (Class 150} in lengths of 3962 mm (13 ft)

In the production tests according to Table E, the asbestos fiber designated W-1 is a blue crocidolite manufactured by the company "Puttens Asbestos, Ltd." and sold by the company "John Phillips &Son" under the trade name "W-1". The S4T is a chrysotile asbestos fiber brought onto the market under the trade name "S4T". The A-25 is a by the applicant under the trade name "A-25 ¹¹ placed on the raking Ohrysotil-asbestos fiber in all aforementioned production trials the porridge Nalco was one of the company" National aluminates Inc. ^M under the trade name "Na ^ -CO 633 "high molecular weight plyacrylamide, added to the market. The results of these production trials clearly demonstrate the benefits achieved by incorporating a non-foaming anionic dispersant such as Tamol in the slurry used to make Asbeet cement tubing.

Another from the use of a non-foaming anionic Dispersant in the slurry for the manufacture of asbestos cement tubing derived beneficial The result was found after the production tests given in Table E had been carried out. The one with these

... / 18

. 9Q9835 ~ / O2 <U - ~~ ————

The water cement used in the production trials was a low sag water cement (0.026). A separate series of production tests was carried out to determine whether the addition of a non-foaming anionic dispersant would allow the use of a water cement with high shrinkage (0.154) for the production of asbestos-cement pipe material. Accordingly, a control test was run using a low shrinkage water cement (0.026) of the type used in the tests to establish Table E to determine whether the plant was operating at normal production rates. Because it was known that the use of any water cement with high shrinkage was not possible. was "an attempt was durchgtführt, wherein the Wasserjsement from a mixture of 50 i" of the hydraulic cement referred to in the foregoing in more detail with low loss (0.026), and 50 1 · a through i ^ RMA "Penn-Dixie Oement Company" on the market The water cement that was brought in passed with high shrinkage (0.154), but the usual production rate could not be maintained. Then using dee mixture ^ of 50 #Water cement with high shrinkage and 50 f> Water cement added with low shrinkage Tamol what asbestos-cement pipe material was prepared in the usual ProduktIqas "number or speed. Then it was

... / 19 ——— 309835/0144 ~ '"

the mixture of $ 50 high shrinkage water cement and $ 50 Water cement with low shrinkage completely replaced by water cement with high shrinkage (0.154), while the slurry Tamol in was added in an amount equal to $ 0.05 of the total solids. In this experiment, only water cement was used with high shrinkage (0.154) and Tamol asbestos-cement pipe material of high quality and high strength in one production number produced that is equal to that in the easben part of the experiment when only water cement with low shrinkage (0.026) was used, the production rate was. An essential economic one The advantage is that for the production of the usual pipe material of high quality and high strength the use of water cement with high shrinkage is possible. Although the specific reasons for this are not exhaustive are known, show de results clearly by incorporating a non-foaming anionic dispersant, such as Tamol, in the slurry of the usual machine for Manufacture of an asbestos-cement product such as asbestos-cement tubing achieved advantages.

In another type of business, it is common to by means of a device similar to the small wet machine described above, asbestos-cement boards with a

90983S / Q24A

Thickness of about ^f j.35 mm and a dry density of 1, bO2 g / cm (100 lbs per cubic foot). These bars have a size of 127 x 254 cm before they are cut - and are normally produced with an output of around bars per hour. In a series of comparative tests on the same machine, on the same day and with the same pesticide material in the slurry, but using no additives other than those described in the Sfiscko patent, searches were made of those in which a non-foaming anionic dispersant, for example, Tamol ¹¹ K ", was added in an amount of from 0.05 fo of Peststoffgehalts, such tablets produces at an output rate of between 70 and 75 panels per hour.

In consideration of the addition of a non-foaming anior.ischen dispersant to the asbestos pulp A number of trials have been carried out to achieve the advantages achieved in the manufacture of asbestos-cement products when adding a non-foams tide η anionic dispersion: = means to the asbestos fiber slurry in a wet process working. Machine for the production of Abesbpapier

... / 21

909835/0244

to determine the results achieved. These results were so encouraging that it was decided to use the non-foaming anionic dispersant, ie Tamol, the slurry for the entire productions of a factory for the manufacture of asbestos-fiber roofing felts and asbestos-fiber piping sheets by the applicant under the designation "9 -1/1 roofing felt »,» 10 roofing felt »," 10 TRANSHIEED ⁿ , "i / 8" commercial "and" 1/16 "commercial" and "1/16" commer-lal "to be added as standard material. Using the monthly average tons per hour worked for the month prior to the addition of Tamol as a basis, the average tons per hour worked for the two months following the addition of TamoJ increased by an average of $ 20.

909835/0244

It has also been found that significant advantages can be obtained by incorporating a non-foaming anionic dispersant, such as tamol, into the mixture of desiccants used in a conventional drying process for the manufacture of asbestos products. In a conventional drying process, the drying substances such as asbestos, KitiSei (silica), cement and dye are mixed with one another and _c ebilaet to weight batches. Each Uh & rge is ausrexchenc water added to form a flowable paste which is passed into the bed of a press, after which they ater for removing excess // and subjected to form the desired article hydraul Ie cn em .üruck and then the normal ASBEs t- Cement, hardening processes are subjected to. In the production of νυη ü.sbest cement products by means of a üoj.ichen dry process, in which there were about 35? Έ asbestos fibers, d "5.5p silicic acid (silica), 39, ί? J & cement and ZyO dye by adding dry, fexnpulverized Tamoi as an egg dry matter in an amount of about 0.05% of the dry matter, an increase in the production figure of at least 15% is achieved Part of the water is added.

... / 23

90 9-8 35/0244

As a matter of fact it is clear that non-foaming anionic dispersants have quite a unique effect on the manufacture of asbestos fiber-containing articles from a slurry containing asbestos fiber-infused particulate matter by depositing portions of the particulate matter on a surface to form a panel subsequently used to form the article. It will also be appreciated that the beneficial results obtained with these dispersants were not readily apparent from their normal prior art classification as dispersants and from the results obtained using these sample test programs to analyze their filtering characteristics. At uei. The above experiments listed in Tables (J, D and E) gave particular advantages by incorporating two specially designated dispersants, namely Tamol and Marsperse, into a jisbest cement paste. It was also found that similar advantages result from use Related products made from a sulfinic acid derivative, such as, for example , sulfonated by the company "Oiba Chemical and Dye Company, Inc." under the name "Ultravon WC", is a benzimidazole derivative of a higher fatty acid, a by the company Jfiake States Yeast & Chemical Division, St. Ittgis Paper Company "under the trade name" Toranil B "on the

... / 24

909835 / 02A4

Sugar-free calcium lignosulfonate marketed by the National Aniline Division, Allied Chemical Corporation under the trade name Naccosol A sodium alkylnaphthalene sulfonate marketed by the National Aniline Division, Allied Chemical Corporation "Naccotan A" marketed alkylaryl sodium sulfonate, a sodium salt of condensed mononaphthalene sulfonate marketed by "Jacques Wolf and Company, Division of Nopco Chemical Company" under the trade name "Lomar PW", a sodium salt of condensed mononaphthalene sulfonate sold by "Jacques Wolf and Company, Division of Nopco Chemical Company "under the trade name" Nopcosant "marketed sodium salt of a condensed naphthalene sulfonate, a by the company" Dewey and Almy Chemical Division, W.fi. Grace and Company "under the trade name" Darvan 1 " marketed sodium salt of polymerized alkylnaphthalene sulfonic acid, marketed by the company "Dewey and Almy Chemical Division, WR Grace and Company" under the trade name "Darvan 2 ¹¹ " sodium salts of polymerized substituted benzoid alkylsulfonic acid, by the company "Dewey and Almy Chemical

Division, W.H. Grace and Company "under the trade name "Darvan 15" marketed sodium salts of polymerized alkylnaphthalene sulfonic acid, a by

... / 25

909835/0244

the company "Dewey and Almy Chemical Division, W.fi. Grace and Company "under the trade name" Daxad 21 " Mono-Calciumaiz brought to the market from polymerized Alkylarylsulfonic acids, by the company "Dewey and Almy Chemical Division, W.fi. Grace and Company "under the trade name" Daxed 23 " Nfctrxum salts from polymer & substituted benzoid alkyl sulfonic acids, by the company "Dewey and Almy Chemical Division, W.R. Grace and Company" under the trade designation "Daxad 27" marketed sodium salts of substituted beoid alkyl sulfonic acids and suspending agent Group and a sulfonated naphthalene-formaldehyde polymer such as one by the company "New York.Color and Chemical Company, Division of American Dyewood, Inc. "under the trade name" Syntan Mc " -sulfonated condensate from naphthalene formaldehyde, a by the company "Dyestuff and Chemicals Division, General Aniline and Film Corporation "· under the Sodium eel of a sulfonated naphthalene-formaldehyde condensate marketed under the trade name "Blancol" and one by the company "Deyestuff and Chemicals Division, General Aniline and Film Corporation?" under the trade name "Blancol N" Bred sodium salt of a sulfonated naphthalene-formaldehyde condensate, comprehensive group.

909835/024

The non-foaming anionic dispersants after of the invention are in achieving the beneficial results in very low concentrations of about 0.01 to 0.2 wt. Based on the dry weight of the solids contained in the slurry. It can use larger amounts of the non-foaming anionic Dispersants can be used, however, the additional use is superfluous as they do not result in any additional benefits. Further, when the amount of the dispersant is increased, it starts normally intended way to act as a dispersant with detrimental effects on the production rate or speed at which the articles getting produced. It should also be noted that the necessary to achieve the desired results Amount of dispersants with the percentage of solids present in the slurry and with the type of changes the solid part of the pulp forming material.

... / 27

909835/0244

Claims (1)

1. Process for the production of asbestos fiber-containing Objects from a one with asbestos fibers Slurry containing particulate matter duroh deposition of parts of the particulate material B on one Area for the purpose of forming a wet plate, which is then dried to shape the respective object made of particulate material, characterized in that the production number at which the panels and that of them resulting objects are produced, by incorporating a non-foaming anionic Dispersant in the slurry is increased. 2. The method according to claim 1, characterized in that the particulate material contains water cement and that the the item made from the panel is an asbestos-cement item. 3. The method according to claim 1, characterized in that the panel consists essentially of asbestos and that the object produced is an asbestos paper. ... / 28 909835/0244 4. The method according to any one of claims 1 to 3, characterized in that the dispersant is a sulfonic acid derivative or a sulfonated naphthalene-formaldehyde polymer or a sodium salt of condensed Is naphthalenesulfonic acid. - 5. The method according to any one of the claims Ibis 4 »thereby characterized in that, based on the dry weight of the particulate material, 0.01 to 0.2 wt. # des anionic dispersants can be used. "B. The method according to any one of claims 1 to 5, characterized in that characterized in that in addition to the slurry, based on the weight of the particulate material, 0.005 to 0.1 wt. a water-soluble high molecular weight polymer of an amide from IOrmel CH ₂ = G-OON-R ₃ are added, where R ^ is a radical selected from the group consisting of hydrogen and methyl, and H ₂ and R- are radicals selected from the group consisting of hydrogen, alkyl having 1 to 4 carbon atoms and hydroxylalkyl having 1 to 4 carbon atoms . 909836/0244 7. Aaheatgegenatand, characterized in that ea according to one of claims 1 to 6 produced iat. Patent attorneys Seiler and Pfenning 90983570244