US3508891A - Heat treatment of insulating unwoven products formed of vitreous fibers - Google Patents

Heat treatment of insulating unwoven products formed of vitreous fibers Download PDF

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US3508891A
US3508891A US558762A US3508891DA US3508891A US 3508891 A US3508891 A US 3508891A US 558762 A US558762 A US 558762A US 3508891D A US3508891D A US 3508891DA US 3508891 A US3508891 A US 3508891A
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United States
Prior art keywords
mat
temperature
thickness
fibers
glass
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Expired - Lifetime
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US558762A
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English (en)
Inventor
Jean Paymal
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Compagnie de Saint Gobain SA
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Compagnie de Saint Gobain SA
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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4209—Inorganic fibres
    • D04H1/4218—Glass fibres
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/24—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
    • C04B28/26—Silicates of the alkali metals
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/0072—Heat treatment
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/60—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only artificial stone
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
    • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
    • D04H1/645—Impregnation followed by a solidification process
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/2964—Artificial fiber or filament

Definitions

  • Fibrous insulating products are generally manufactured by drawing out a molten substance at high temperature which is divided into filaments and is rapidly cooled. The internal structure of the material thus obtained is different from that which the same material acquires during slow cooling.
  • the process in accordance with the invention consists in subjecting the pad or mat of fibers of materials in the vitreous state, through its entire mass, to the action of a homogeneous heat treatment Which imparts to the fibers a condition approximating a stable state at the high temperatures which the pad or mat is called upon to encounter in use.
  • the starting temperature of the plastic zone is higher for a material which has been treated in accordance with the invention, corresponding to a condition close to the stable state, than for the same material which is rapidly cooled after the temperature of fiberizing.
  • Another characteristic of the invention which has been determined, is that a prolonged action of treatment does not lead to obtaining clearly superior results over a treatment for a reduced time period, for example, of the order of one minute.
  • the process of the invention therefore, lends itself very well to a continuous execution and procedure, and consequently to the production of a continuous pad capable of experiencing a high temperature before the plastic zone or state sets in.
  • the mat or wadding at the same time as the heat treatment, such as described above, is applied to the mat or wadding, the latter is subjected to a compression.
  • a mat is obtained whose thickness can be much less than that of a mat which has not undergone compression, and whose thermo-mechanical resistance is improved.
  • FIGS. 1 to 7 show graphical curves representing the results of tests on the products of the invention to determine their improved thermo-mechanical properties.
  • FIG. 1 is a graph showing the reduction in thickness of a mat as a function of the temperature to which it is subjected, which varies in dilferent samples with the heat treatment imposed upon the mat in the course of its fabrication.
  • the ordinate axis of the graph T:/ T is the ratio in percent of the final thickness of themat to its initial thickness, and the abscissa axis represents the intensity of heat in the degrees centigrade as the temperature of the mat is increased linearly with time.
  • FIG. 2 is a graph similar to FIG. 1 showing comparative tests on mats formed from fibers of the same glass composition as in FIG. 1, three of which mats corresponding to curves B, C and D" having been heat treated at the same temperature of 540 C. but for different durations, namely, one minute, five minutes and sixty minutes, respectively.
  • FIGS. 3, 4 and 5 are graphs similar to FIG. 1 showing comparative curves of test results on mats formed from fibers of different vitreous materials, each indicating a higher temperature stability when the mats are subjected to a heat treatment in accordance with the invention in the course of their manufacture.
  • FIG. 3 shows comparative curves for mats formed from a hard glass composition having an annealing point of approximately 660 (3.; FIG. 4, for a windowpane glass composition; and FIG. 5 for a rock wool glass composition.
  • FIG. 6 is a graph showing the collapse of a fibrous mat which is treated in accordance with the invention, and which is subjected to a substantially uniform high temperature for an extended period of time.
  • FIG. 7 is a graph similar to FIG. 6, showing comparative curves indicating the diiference in behavior between 3 treated and untreated mats when both are subjected to the same temperature over an extended period of time.
  • thermomechanical characteristics In order to measure the improvement of these thermomechanical characteristics in a practical way, one may proceed as follows:
  • a sample specimen is cut out of a mat of fibrous material and is placed in an apparatus which imposes on it a definite load, which may be between 50 kg./m. and 200 kg./m.
  • the sample is subjected to a variable temperature, increasingly linearly with time, and the change in thickness of the sample is recorded.
  • the beginning of the sinking or collapse of the product treated takes place at a temperature all the higher corresponding to the higher temperature at which the sample specimen had been subjected during its heat treatment in the course of its fabrication in accordance with the invention.
  • FIG. 1 represents the loss in thickness of the samples subjected to a load of 100 kg./m. placed in an oven whose temperature rises 5 C. per minute.
  • These samples consist of fibers manufactured from a glass whose annealing temperature is about 540 C. (glass No. 1).
  • the curve A of FIG. 1 relates to a raw product such as is usually used, without special treatment; curves B, C and D correspond to the same product after a treatment of 60 minutes at respective temperatures of 420 C., 480 C. and 540 C., respectively. It will be noted that settling occurs at very high temperatures for treated products B, C and D. It is quite diificult to indicate precisely the beginning of settling of the samples. Therefore, one can take as reference datum of the thermomechanical properties, the temperatures corresponding to 5% to 10% of reduction of thickness.
  • the length of treatment must be short.
  • the fibrous mats generally leave the production machines at high speeds, of the order of 10 to 50 meters per minute; and the unit of thermal treatment would attain prohibitive proportions if the time period were of the order of an hour or a half-hour.
  • FIG. 2 shows comparative curves of specimens heated at 540 C. for different periods of time.
  • Curve A portrays the behavior of a mat which has not been subjected to a heat treatment and corresponds to curve A in FIG. 1.
  • Curve B illustrates the characteristics of a mat which has been heated for one minute, curve C, for five minutes, and curve D for sixty minutes. The decrease in thickness of 5% is obtained at temperatures of 495 C., 470C., and 450 C., respectively, for treatments lasting sixty minutes, five minutes, and one minute (Table III).
  • the gain is still 140 for a treatment limited to one minute.
  • An industrial embodiment of the process can be attained easily with the aid of a belt conveyor device permitting continuous treatment. If the mat is thin, it is not necessary to circulate hot air across the mat; if the thickness of the mat is more than a few centimeters, obtaining quickly the temperature at the center of the mat requires a circulation of air across the product.
  • the treating procedure applies to all fibrous products having a base of vitreous material. It is suitable to adapt the treating temperatures to the characteristics of the materials. In a general way, for glass, a temperature near the annealing point is selected, slightly lower than this, if the time of treatment can be longslightly higher, in the contrary caseto obtain more rapidly the desired structural evolution or change. This point corresponds to a viscosity of 2.5 10 poises. For mineral fibers, a temperature will be selected corresponding substantially to this viscosity value.
  • FIG. 3 shows comparative curves E and F.
  • Curve E portrays the behavior of glass No. 2 in Table 11 above, having an annealing point of 660 C. without heat treat ment
  • curve F portrays the characteristics of the same glass mat which has undergone a heat treatment.
  • FIG. 4 shows comparative curves G and H.
  • Curve G (glass No. 3) portrays the behavior of window glass having an annealing point of 550 C., without heat treatment
  • curve H portrays the characteristics of the same glass fibers which have undergone a heat treatment.
  • FIG. 5 shows comparative curves I and J for mats of rock wool formed of lime feldspar minerals.
  • Curve I depicts the behavior of a mat which has not been subjected to a heat treatment while the mat represented by Curve I experienced a heat treatment.
  • the improvement in temperature stability obtained by the treatment in accordance with the invention is preserved when the products are maintained for a long time at high temperatures.
  • temperatures below the annealing point centered at about 150 C. below this point, there appears a very marked difference between the raw or untreated product and a heat-treated product.
  • the crushing or collapse of a raw product under a given load is greater than that of a treated product.
  • a mat of fibers of glass No. 1 having a mean diameter of 6 microns, which has been heat-treated 2 minutes at 540 C., and having a thickness of 100% under a load of 100 kg./m.
  • curve K in FIG. 6 when the mat is brought to a temperature of 400 C.
  • This final thickness is much less than that of the mat of fibers which has been heat-treated and which is represented by curve M thereabove.
  • the latter corresponds to curve K in FIG. 6, representing the behavior of a treated mat formed of fibers from glass No. l.
  • the curves in FIG. 7 are plotted on a logarithmic scale on the axis of the abscissas.
  • the two types of tests described above i.e., tests with progressive elevation of temperature (FIGS. 1 to 5), and tests with uniform temperature (FIGS. 6 and 7), evidence a reduction in thickness of the test samples under the effect of a definite load.
  • Another type of test can be visualized in which the thickness would be maintained constant between two parallel plates and in which the reaction of the sample compressed between these two plates would be measured.
  • the relaxation effect thus experienced by the mat is the same as that which is reproduced in the most ordinary conditions of utilization of insulator panels held between two fixed walls.
  • the temperature may be homogeneous at every point of the samples, or, on the contrary, the temperature may be non-uniform and variable as a function of the distance between the point under consideration and to the confining walls. The latter condition corresponds to the temperature variation which is established naturally in an insulator panel during the performance of its heat-insulating function.
  • the general form of the relaxation curves thus obtained representing the variation of the reaction of the product initially compressed between the two walls as a function of time, is substantially similar to that of the preceding curves giving the variation in thickness of the mat under constant load as a function of time.
  • the decrease in reaction on the walls is less in the case of a mat of fibers, which is heat-treated beforehand in accordance with the invention, than in the case of a mat of untreated fibers. This difference in loss of reaction remain small at any moment, in particular, when temperature stabilization is attained.
  • the fibers which have been previously treated have a higher viscosity, much farther from the value of equilibrium at temperature T; therefore, these fibers during the same time period, will undergo less deformation or relaxation.
  • the treated pads will maintain a thickness under load greater than the raw mats, or will exert at constant thickness a greater reaction on the walls.
  • Another very interesting advantage of the process according to the invention concerns the obtaining of a mat of fibers of desired thickness for a given density.
  • the fibers are lapped one over the other which gives a certain cohesion to the fibrous mat.
  • a product is obtained having a certain natural density. Often, this density is too low for the mat to have good insulating properties for a small thickness. It is sought, therefore, to increase the density of the mat by calendering or rolling it.
  • the pad or mat of fibers having, for example, a weight of 2.5 kg. per square meter is obtained with a natural thickness of formation of 25 cm., presenting initially a density of 10 kg./.m.
  • a stress of compression capable of reducing its thickness to 4 cm. may be exerted at the start, which will make the density rise to 62 kg./m.
  • This solution has several disadvantages.
  • the initial product is very cumbersome, it is often difficult to exert at the start the compression necessary for a strong decrease in natural thickness and, finally, a too strong initial reaction of the insulator panel on the walls, due to this application under compression, can sometimes be difficult to maintain.
  • a process according to the invention consists in bringing the pad, within a suitable time, to the temperature selected for treatment, and simultaneously maintaining it at a reduced thickness, slightly under the desired thickness.
  • the time durations and temperatures are such as indicated previously.
  • a much weaker pressure of the order of 10 kg./m. to 30 kg./m. according to the value of the excess thickness of the pad, which may amount to only a few percent, this excess thickness being necessary in order for the pad to accommodate itself satisfactorily to the shape of the walls which are to be insulated, so as to leave no empty space where movements of air convection currents might develop which would be harmful to the insulation effect
  • a binding agent resistant to high temperatures which may be, for example, a mineral binder such as silicate of soda.
  • the mats and pads obtained by the process in accordance with the invention may be used particularly in every case where an apparatus, such as for example a boiler, oven, etc., is raised to a high temperature and is to be insulated thermally by means of mats or pads subjected to compression in order to form an insulating body without a break in continuity.
  • an apparatus such as for example a boiler, oven, etc.
  • the method of treating a resilient thermal insulating unwoven mat of fibers of vitreous material of substantial thickness with the fibers in freely interlaced condition which consists of (a) heating the mat uniformly through its entire thickness at a temperature in the vicinity of the annealing temperature, and Well below the softening temperature, of any of the viterous material in the mat, for a short period of time of the order of one to five minutes to increase the heat resistance and stability of the fibers at elevated temperatures while maintaining the integrity of the fibers and their disposition in the mat, and

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Structural Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Textile Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Nonwoven Fabrics (AREA)
  • Thermal Insulation (AREA)
  • Inorganic Fibers (AREA)
US558762A 1965-07-13 1966-06-20 Heat treatment of insulating unwoven products formed of vitreous fibers Expired - Lifetime US3508891A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR24486A FR1468740A (fr) 1965-07-13 1965-07-13 Perfectionnements aux produits isolants constitués de fibres de matériaux à l'état vitreux

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US3508891A true US3508891A (en) 1970-04-28

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US558762A Expired - Lifetime US3508891A (en) 1965-07-13 1966-06-20 Heat treatment of insulating unwoven products formed of vitreous fibers

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US (1) US3508891A (enrdf_load_stackoverflow)
BE (1) BE683925A (enrdf_load_stackoverflow)
CH (1) CH443580A (enrdf_load_stackoverflow)
DE (1) DE1596370B2 (enrdf_load_stackoverflow)
ES (1) ES328768A1 (enrdf_load_stackoverflow)
FI (1) FI45075C (enrdf_load_stackoverflow)
FR (1) FR1468740A (enrdf_load_stackoverflow)
GB (1) GB1112465A (enrdf_load_stackoverflow)
NL (1) NL6609303A (enrdf_load_stackoverflow)
SE (1) SE320624B (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113529269A (zh) * 2021-09-16 2021-10-22 青岛诺亚方舟环境工程有限公司潍坊分公司 一种利用污泥生产保温材料的方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1899056A (en) * 1928-08-24 1933-02-28 Banner Rock Corp Process of making felted mineral fiber
US3002857A (en) * 1955-11-14 1961-10-03 Owens Corning Fiberglass Corp High temperature inorganic binder and products produced with same
US3328230A (en) * 1956-04-03 1967-06-27 Saint Gobain Fiber glass product and method of making it

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1899056A (en) * 1928-08-24 1933-02-28 Banner Rock Corp Process of making felted mineral fiber
US3002857A (en) * 1955-11-14 1961-10-03 Owens Corning Fiberglass Corp High temperature inorganic binder and products produced with same
US3328230A (en) * 1956-04-03 1967-06-27 Saint Gobain Fiber glass product and method of making it

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113529269A (zh) * 2021-09-16 2021-10-22 青岛诺亚方舟环境工程有限公司潍坊分公司 一种利用污泥生产保温材料的方法
CN113529269B (zh) * 2021-09-16 2021-12-10 青岛诺亚方舟环境工程有限公司潍坊分公司 一种利用污泥生产保温材料的方法

Also Published As

Publication number Publication date
ES328768A1 (es) 1967-05-01
BE683925A (enrdf_load_stackoverflow) 1967-01-11
NL6609303A (enrdf_load_stackoverflow) 1967-01-16
SE320624B (enrdf_load_stackoverflow) 1970-02-09
DE1596370B2 (de) 1971-09-09
FR1468740A (fr) 1967-02-10
FI45075B (enrdf_load_stackoverflow) 1971-11-30
GB1112465A (en) 1968-05-08
CH443580A (fr) 1967-09-15
FI45075C (fi) 1972-03-10
DE1596370A1 (de) 1971-04-08

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