DE3138969A1 - FIRE-RETARDANT HEAT INSULATION PLATE AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Description

HOFFMANN · ΚΙΤΙ, Κ & PARTNER

PATENT LAWYERS

DR. ING. E. HOFFMANN (1930-1976) DI PL.-ING. W. EITLE · D R. RER. NAT. K.HOFFMAN N. DI PL.-1N G. W. LEHN

DIPL.-ING. K. FPCHSLE. DR. RER. NAT. B. HANSEN ARABELLA STREET 4. D-8000 MD NCHEN 81. TELEPHONE (089) 911087 TELEX 05-29619 (PATHE)

35 603 m / wa

GREFCO, INC., LOS ANGELES, CALIF. / UNITED STATES

Fire retardant thermal insulation panel and process for its manufacture

The invention relates to a fire-retardant insulating panel and a method for their production. In particular, the invention relates to an insulating plate, which consists essentially of expanded perlite, fibers, binders and fire-resistant substances composed.

Inert materials such as perlite or vermiculite have been used as insulating materials for years. Such Materials serve a variety of uses including loose insulation and as a component together with binders and fillers: .. for production of panels with insulating properties. Perlite is

a generic name for certain volcanic glasses, which are available in ground form and which are sudden when heated to a controlled temperature expand to form lightweight particles which are excellent heat and noise insulating Have properties.

Insulation panels, which are made up of large amounts of perlite with relatively small amounts of other fillers and binders have been used primarily as thermal insulation panels that are dimensionally stable. However, these plates have low strength properties and, depending on the one used Binders, can be quite brittle.

Products of this type can be processed by a "wet" process •getting produced. This process includes the following steps: Prepare an aqueous slurry of the plate components and evenly suspending the solids throughout the slurry by mechanical means Agitation, dewatering the slurry over a sieve, forming a wet plate, and then gently compress the wet plate to form a uniform thickness and finally dry it the plate.

Insulating panels of this type have many uses; for use as roof insulation, however, are missing the required qualities for some types of such panels, that are required of a good product.

For roof insulation, it is desirable in

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to be water-repellent to a high degree is a bad one To have thermal conductivity, to have good strength factors and to be strong enough to support them Withstands handling and traffic to a certain extent. In order to also comply with the building regulations of various countries, it is important to that the material is fire retardant and that it is not a great deal more toxic under combustion conditions Gives off gases.

The insulation panels according to the prior art lack or lack one or more of the required properties for a superior roofing sheet. Certain panels that have the required strength and brittleness properties, achieve these qualities by using fibers or fire-resistant Substances that are expensive or that add to the amount of toxic gases that are emitted, if they are subject to combustion conditions. Other panels designed to have a low Giving off amount of toxic gases, the fiber materials and certain types of binders eliminate the such gases result on combustion, and thus sacrifice flexibility.

The object of the invention is to provide a fire-retardant insulating board or cardboard or sheet to provide, which are produced in a relatively cost-saving manner and which have sufficient insulating capacity, strength and flexibility for use as a roof insulation panel and which also

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Performs well in certain standard toxicity tests. Such a plate can be produced by a wet process, for example by means of a Fourdrinier machine.
.

The above task is made by a fire retardant

Thermal insulation panel solved, which is characterized in that it is essentially 50 to 80% expanded perlite, 3 to 30% clay, 5 to 15% newsprint fiber, 1 to 6% B2O3, up to 25% one non-combustible fiber material, a binder and a waterproofing material, and which in a continuous process by removing a liquid vehicle from a slurry of Solids is produced, the liquid in the slurry boron compounds in a sufficient Concentration contains to give the plate a B ^ O ^ content of 1 to 6% after drying. Such a plate has both insulating and fire-retardant properties and also has have sufficient strength and flexibility to be used as a roof insulation panel. This Material emits relatively low levels of toxic gases under combustion conditions. Gases such as

Carbon monoxide is given off in such low concentrations that the material is subject to building inspections Test procedures, such as the CIN 4102 A2 tests, does well. A thermal insulation panel that passes a less stringent test, such as the DIN 4102 B1 tests, can be made by the same process using 50 to 80%

expanded perlite / 3 to 30% clay, 5 to 30% newsprint fibers, 1 to 6% B ₃ O ₃ , up to 25% of a non-combustible fiber material, a binder and a waterproofing material. 5

Insulating panels according to the invention have properties achieved by balancing a number of controversial specification requirements e.g. with regard to toxicity, strength, fragility and water absorption. To create optimal areas for each To achieve these characteristics, the properties of the various materials must be used for formation the 'press plate and their interaction · must be observed. For example · Starch is added to give strength to be awarded; too much concentration of strength however, reduces the fire-retardant property.

Materials such as boron compounds can be used to make the insulation panels fire retardant; however, these compounds contribute to brittleness or Brittleness if they are used in too great a concentration.

Clay is used in the panels to bind the perlite particles together. It also increases the Jorand-inhibiting property. However, in high concentrations it can reduce the rate of dewatering of the liquid from the slurry. It can also contribute to the brittleness in the plate.
30th

Asphalt can be used to make an insulating mat

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to impart the water-repellent property. On the other hand, asphalt is toxic when burned
Gases off; if the concentration is too high, plates become
that fail standard toxicity tests.

Newsprint fiber is used as a binding component and prevents the board from becoming too brittle.
In large concentrations it steers towards the organic
Matter that releases toxic gases when burned, which is detrimental to toxicity tests.

The combination of these materials in a wet process within the ranges according to the invention provides an insulating panel which is inexpensive, fire retardant and "of low toxicity, has good thermal insulation properties and has sufficient strength and
Flexibility for use as a roof insulation panel. 20th

The insulating plate according to the invention, as it is here
is carried out and described, has improved
fire-retardant properties. According to a preferred embodiment, this plate is composed of expanded perlite, newsprint fiber, clay, starch, polyboron and a silicone compound. The plate can
also include small amounts of asphalt, though
the inclusion of asphalt is somewhat detrimental to the toxicity tests. · <X

.: = ■ - ■

Perlite is a non-combustible mineral, which

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in its expanded form serves as an insulating material. As such, it is the main component of the insulation panel Because of its non-flammability, it contributes to the fire-retardant properties of the panel. When incorporated into the insulating panel in amounts less than about 50% by weight, based on the finished panel, the plate has a reduced insulation value; in amounts that are below approx. 30% the formed plate, does not have a sufficient-. · High insulation value to its intended purpose to meet. In amounts above approx. 80% by weight, perlite becomes such a main component of the insulation panel that certain properties of the plate suffer. For example, the strength and flexibility of the Plate reduced as it is unable to incorporate sufficient amounts of newsprint fiber and clay. "For use as a roof insulation panel, it is preferred that pearlite is incorporated in a range of 40 to 75% by weight.

Newsprint fiber is used in amounts of 5 to 30% by weight incorporated into the plate to give it strength. Tests on plates made according to the invention Procedures have been produced that show that the modulus of rupture · (MOR) flexural strength is at an unacceptable level lower level drops when the percentage of newsprint fiber or a similar material such as e.g. Kraft fiber, is below approx. 5% by weight. Tests for The modulus of rupture (MOR) was determined according to ASTM method C203; however, there were samples 2 "χ 6" (5.08 cm χ 15.24 cm) with

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a 10.6cm (4 ") span instead of 7.62cra χ 30.48cm (3 "χ 12"). Samples with a 2540 cm (10 ") span used, as prescribed by the ASTM procedure is. Newsprint fiber or another organic fiber in quantities above approx. 30% are too large The percentage of combustible material in the panel indicates that it can be considered fire retardant. Also, newsprint contributes to the amount of toxic Gases that are formed when the plate burns. It was found that the insulating plate does well in the German A2 toxicity test if the amount of newsprint fiber is less than 15% by weight amounts to; the insulating plate consists of up to 30% by weight Newsprint fiber passed the German BI test. For control of toxic gases and to give the plate sufficient strength is a range from 5 to 10 ■% by weight of newsprint fibers preferred.

Components must be added to the insulating plate in order to improve its MOR resistance. Both sound like e.g. bentonite clay and starch are suitable binders and add to the strength of the insulation panel at. These components improve the modulus of rupture determinations when they are in certain ranges. However, clay in amounts of more than approx. 30% by weight makes the insulating plate so brittle that it can be used for purposes in which there is any traffic above it takes place, such as with roof insulation, is not suitable. In addition, such high concentrations that the plate is difficult to manufacture and to handle without breaking. as otherwise stated,

at least 3% clay must be added to the composition to add strength to the panel. There Clay is an inorganic substance, it is not flammable and contributes to the fire-retardant property of the panel at. When dispersed, clay physically covers the newsprint fiber and protects it from burning. In order to contribute sufficiently to fire retardancy and to bind other components together, should be the clay in the entire slurry mixture and be well dispersed in the dry plate.

Strength contributes to the strength of the plate and also represents a binding agent. Corn starch (corn-starch) has been found in various Plate compositions proved suitable. Starch is most effective as a binder and also shows a high modulus of rupture strength factor. For example, raw corn starch has been used with success was gelatinized in the drying process during molding. Starch is flammable and carries in high concentrations contributes to the amount of toxic gases emitted under combustion conditions; thus reduced the fire-retardant properties of the panel. So that an insulating plate can be used under burn conditions To maintain its shape, the board also contains a non-combustible binder such as clay. If perlite and other components would only be bound together with the help of a flammable binding agent, such as starch, the panel would completely disintegrate once the binder was substantially burned off. The amount the strength in the panel composition should be large enough for it to act as a binder, however

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not so high that this is used in a significant way Flammability of the plate contributes. It has been found that it can be used with good effect in concentrations of up to approx. 4% by weight. 5

To the branding property of the insulating battens further To improve, the addition of boron compounds is preferred. These can be the slurry from which the Plate is made, are added so that they mix with the combustible components.

They can come in forms such as polyboron, one of which is commercially available boron-containing compound, or by in-situ addition of acid to borax.

Amounts of less than about 1% by weight of B ₀ O- do not result in a significant increase in the fire-retardant property. Since it was found that in this composition boron in the form of polyboron, for example, significantly contributes to the brittleness of the plate, amounts above about 6% by weight of B ^ O- should not be used. In concentrations above 6% by weight B ₃ O ₃ , the insulation panel is brittle and difficult to install as roof insulation. Such a high concentration also makes the plate difficult to manufacture or handle without undue breakage.

Another means to improve the fire retardant property is - as mentioned above - the use of perlite and clay to reduce the amount of combustible material Reduce material in the plate.

For use as roof insulation or for another

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For outdoor use, it is advisable that the insulation panels are water-repellent. This can be achieved by adding a waterproofing agent to the Slurry is added. Both silicone and asphalt compounds are suitable for the production of water-repellent panels. Silicone can be in much smaller sizes Weight concentrations used as asphalt to get the desired results. For example obtained with 0.1 to 0.3 wt.% silicone compounds, such as RE-28 or Y-9106 from Union Carbide, acceptable water-repellent behavior. When using silicone compounds this area is preserved an insulating plate that absorbs 2% by volume of water when immersed in water for 2 hours and 5.6% for one Immersion time of 24 hours. To get similar results, 3 wt.% Or more of asphalt-> Compounds are used. The use of silicone is due to its ability to work in low concentrations to give water-repellent properties, as well as due to the fact that asphalt compounds to a large extent, even if they are present in small quantities. are essential to those given off under incineration conditions Contributing gases, preferred.

'Further materials can be added to the insulating plate in order to improve the flexibility. Rock wool and fiberglass fibers of short length, which are incorporated into the panel increase the proportion of non-combustible materials in the panel, they increase the flexural strength or reduce the brittleness of the same. However, they increase in a certain Measure the cost of the plate.

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In addition to the production of a fire-retardant insulating panel, it is possible to produce a non-toxic panel with the aid of the material compositions within the areas listed above. The toxicity can using a standard tests, such as according to DIN 4102-A2, a test that is applied in West Germany, and determines the quantities are determined of toxic gases produced upon combustion of the products. To do well in the A2 toxicity test, a product sample 60 cm in length is placed in an oven heated to 400 C at 1 cm / min. The burned samples must not result in deaths in rats exposed to the gases formed; in addition, the CO level of the rat blood must be below 35%.

Insulation panels that fail the A2 toxicity tests may pass the less stringent DIN 4102-B1 test. The B1 test to determine the branding property is carried out by exposing four 190 mm 1000 samples to the conditions of an oven heated ^{to 750 ° C. for 10 minutes.} The samples must have an "undestroyed" mean value of at least 150 mm, whereby none of the samples may be completely destroyed.

In addition, the gas temperature in the center of the hood of the test apparatus must not exceed 250 ⁰ C.

The production of fire-retardant insulation panels according to the invention can be made by a continuous process by removing a liquid vehicle a slurry of solids and boron compounds

• ·

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and subsequent drying of the felt obtained. The board components starch, clay, newsprint fiber and boron compound are mixed with water combined in a mixing apparatus such as a Dutchman. If the components are in sufficient quantities are mixed, a waterproofing material and the expanded perlite are added. All the slurry is then a conventional filter device, such as a Fourdrinier machine for dewatering admitted. This machine produces a mat or felt of uniform thickness, which is then made to the desired Thickness is pressed; The mat is then placed in a drying oven to form the dry sheet fed.

If a non-flammable fibrous material such as rock wool is added, care must be taken that the fibers are in the intermingling step not to be broken open. If stronger fibers, such as fiberglass, are used, such precautions are taken unnecessary.

To different embodiments of the invention in more detail To explain, the following examples are given:

Example I.
30th

A fire-retardant insulation panel is produced using:

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525 kg of newsprint 360 kg of bentonite clay
210 kg pre-cooked starch 150 kg polybor

'' 780 kg of rock wool

10,000 l of water

These materials are mixed in the following way: 5,000 liters of water are added to a hollander and the newsprint, bentonite, starch and polyboron were added. The Dutchman was operated until that Newsprint was made into pulp; then the rock wool was added. The rock wool was only mixed in for about 3 minutes, with 2 minutes for breaking up and moistening the rock wool Were available and about 1 minute for mixing. "During this time interval, the remaining 5,000 liters of water were added. The Dutchman's load was then tipped into a mixing vat in which 100 kg Asphalt emulsion was added together with a further 10,000 liters of water. This mixture was then converted into a Machine chest and then transferred to a mixer in which perlite was continuously added. the entire slurry was then collected using a headbox added to a Fourdrinier and after dewatering a drying oven and a method for Completion or equipment supplied.

The perlite used in this example had a density of 0.048 to 0.096 g / cm ³ (3 to 6 lb / ft ³ ); the bentonite clay provided one

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Calcium bentonite from Chamacid, Brussels / Belgium, which is referred to as bentonite A. The starch was a pregelatinized corn starch manufactured by Marigel in France and encoded with AC. The rock wool used was basalt wool, manufactured by Isola, Hasslinghausen, Federal Republic of Germany, and polyboron was a mixture of boric acid and borax with the approximate composition Na ₂ BgO ₁₃ -4H ₂ O and was obtained from US Borax. The asphalt emulsion used was the Shell 205 product and was obtained from Ghent, Belgium.

Since the polyboron is water soluble, the polyboron is only present in the water of the mat and not as part of the mat solids. It does not set until the water is removed. Because additional water is added with the perlite and doing so at various stages of the process, the amount of polyboron added to the slurry must be "this" Take dilution into account. To increase the amount of polyboron To calculate that must be added during the molding process, the following calculation can be used Find:

desired

added weight of polyboron

water water

Solids 7 solids

Slurry mat

theor.% polyboron

χ Plate χ in the dry weight plate 100

In this calculation, the weight added represents the amount of polyboron added to the mixture of the slurry should be admitted. The amount of water is-

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that amount of water that is in the mixture of the original Slurry is used and the amount of solids are those in the original mixture solids present in the slurry. This is divided by the water and the amount of solids, which are present in the plate after pressing. The theoretical plate weight is determined on the basis of the Weight of solids in the slurry mixture. The percentage of additive that is desired in the dry plate is determined by preselection the desired amount of polyboron.

The amount of solids and water in the slurry mixture is known when the formulation is chosen will. The ratio of water'.solids in the wet Press plate is not known before a plate is made; an approximation is therefore made, to be able to calculate the polyboron weight.

In a continuous process, the return water is saturated with polyboron and the amount added to the hollander can be reduced.

The weight percentages of the materials in the dry plate made according to this example, are the following:

Parts by weight of ingredients 30

58.0 Perlite 9.2 Newsprint (newsprint) 1/8 asphalt 7.4 Bentonite

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3, 7th strength 15-, 2 Rock wool 4r 7th Polyboron.

The plate had the following properties:

Density: 0.192 g / cm ³ (12 pcf)

Water absorption (2 hours): 4% by volume; Modulus of rupture (MOR): 4.50 kg / cm ² (64 psi) ΓΙΝ 4102: rated as passed: A2

Example II

A fire-retardant insulating panel was produced using the same method as in Example I, wherein the weight percent of the materials in the dry plate were as follows:

Parts by weight of ingredients

65 Perlite 15th Newspaper 10 Rock wool 2 pregelatinized starch (Marigel AC) (Jl Asp / holding emulsion (Shell 205) 4th Bentonite clay 2 Polyboron

This plate had the following properties:

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Density ^: 0.176 g / cm ³ (11 pcf) Rupture modulus (MOR): _{5f34 kg / cm} 2 _{(76 psi)}

Although this plate was not actually tested, it could be expected to pass the PIN 4102 test would pass and receive a B1 rating.

Example III

To produce a fire-retardant insulation panel, the following components were placed in a 20 liter container:
15th

113 g perlite (expanded from No Agua, New Mexico ore

to a density of 3.6); 60 grams of pulp newsprint (25% pesticides);
1.5 g uncooked corn starch;

10 grams of CTS-1 clay (Kentucke Tennessee Clay Company);

1.1 g RE-28 silicone emulsion (Union Carbide); 27 grams of polyboron;

1.7 1 water
25th

These ingredients were mixed using a high speed clover blade mixer mixed; after sufficient mixing, perlite was added and mixing continued until the perlite is dispersed. The slurry was then placed in a Tappi record maker where most of the water was removed

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Formed mat, which was then pressed by means of a hydraulic press. The plate was then dried for 16 hours at 121.1 ⁰ C (250 ⁰ F) in a convection oven. The plate contained:

Weight point Components 75 Perlite 10 Newsprint 1 strength 6.8 volume 4.8 Polybör 0.3 silicone

The plate had the following properties: 15

Density: 0.176 g / cm ³ (11 pcf)

Rupture modulus (MOR): 4.22 kg / cm ² (60 psi) Water absorption (2 hours): 2 vol.%

The conditions under which a board is dried have an effect on the flexural strength (MOR strength) of the resulting board. When using a high temperature cycle, as is normally the case in a production, higher MOR strengths can than when be achieved, a constant drying cycle of 121.1 ° C (250 ⁰ F). For example, plates are obtained with a significantly higher bending strength than that of a drying at 121.1 ⁰ C (250 ⁰ F) with the following cycle: 1 hour at 216 ⁰ C (420 ⁰ F), reduced to 160 ⁰ G ⁽⁰ 320 F) for 2 hours, "then 110 ⁰ C (230 ⁰ F) for 1 hour and a final reduction to room temperature.

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* ft * »

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Example IV

Insulating panels were again produced as in Example III, with the exception that glass fibers were added during processing to the pulp with the newsprint. The additional ingredients were 111 g perlite with a density of 0.051 g / cm ³ (3.2 pcf); 48.5 grams of pulp containing 14.5 grams of newsprint and 1.5 grams of G.63cm (1/4 ") chopped roving; 5 grams of Flintkote 205 asphalt emulsion (60% solids); 10.2 grams of bentonite clay; 6 g uncooked corn starch; 0.4 g RE-28 silicone emulsion (Union Carbide); 30 g polyboron and 1.7 l water.

The dry plate consisted of:

Parts by weight of ingredients

74 Perlite 9.5 Newsprint 1 Glass fibers 0.63 cm (1/4 ") 2 Asphalt (solids) 7th volume 4th strength 0.1 silicone 4.7 Polyboron

The plate had the following properties:

Density: 0.176 g / cm ³ "(11 pcf)

Rupture modulus (MOR): 6.33 kg / cm ² (90 psi) Water absorption (2 hours): 2.3% by volume

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Other methods can be used to assemble the components, e.g. perlite can be used with . a spray of dilute asphalt emulsion and then dried to give the perlite particles To give a waterproof coating instead of adding the asphalt to the slurry. This allows advantageous results in terms of an improvement in the water-repellent properties of the obtained Plate can be achieved. In addition, a mixture of acid and borax can be used instead of polyboron, to bring boron into the insulating plate. This has the advantage that you get a higher percentage of Boron compound achieved in the insulating plate instead of in the reflux water.

It has also been found to be effective in dispersing fine clay particles, starch granules and emulsified asphalt particles, as well as an aid for drainage without loss of solid materials of the slab, an organic polymeric polyelectrolyte, e.g.

Lufax 295, is suitable for incorporation. Plates made with about 0.5% Lufax showed less Stratification of the particles and a more homogeneous distribution within the entire plate.

For the person skilled in the art, it is readily apparent that the above embodiments are within the The scope of the invention as defined in the claims and the equivalents defined, modified and varied.

Claims (7)

HOFFMANN · EITLE & PARTNER * * '* J' ° Ö d Ö U PATENTANWÄLTE DR. ING. E. HOFFMANN (1930-1970). DIPL.-1NG. W. EITLE DR.RER. NAT. K.HOFFMANN. DIPL.-ING. W. LEH N DIPL1-INCK-FJJCHSLe · DR. RER. NAT. B. HANSEN ARABELLASTRASSE 4 D-8000 MÖNCHEN 81 TELEPHONE (089) 911087 TELEX 05-29619 (PATHE) 35 603 m / wa GREFCO, INC., LOS ANGELES, CALIF. / USA firefighters. Thermal insulation panels and process for their production ■ f ~ PATENT CLAIMS "- | 1. Fire-retardant Wärxneisolierplatte, characterized in that it consists essentially of 50 to 80% expanded perlite, 3 to 30% clay, 5 to 30% newspaper _{fibers, 1 to 6% B n} O. ,, bis'zu 25% of a non- combustible fiber material, a binder and a waterproofing material, the panel being made in a continuous process by removing a liquid vehicle from a slurry of solids, and the liquid in the slurry is sufficient boron compounds -2 - to M * Concentration to add 1 to 6% B ₂ O ₃ to the plate after drying. 2. Insulating plate according to claim 1, characterized in that g e - indicates that the non-flammable fiber material from the group stone wool and glass fiber is chosen. 3. Insulating plate according to claim 1, characterized in that the said Includes sheet up to 8% thickness, up to 6% asphalt and up to 2% silicone. 4. Insulating plate according to claim 1, characterized in that g e that said boron compound comprises a mixture of boric acid and sodium borate. 5. Insulation plate according to claim 1, characterized in that g e that the plate through Removing said liquid formed in the slurry by a Fourdrinier process and then the plate is dried by applying heat. 25th 6. Insulating plate according to claim 1, characterized in that it is essentially is non-toxic. 7. Insulation panel according to claim 6, characterized in that it is 5 to 15% Newsprint fiber includes. • η ft η > <Γ. Process for the production of the insulating plate according to Claim 1, characterized in that the plate by removing a liquid Vehicle from the sludging of solids, pressing out further liquid and then Drying is formed.