Document evqa1LvBGBO3wQEg2dj7kBR6m

FILE NAME: Keene (KNE) DATE: 1956 Jan 24 DOC#: KNE003 DOCUMENT DESCRIPTION: US Patent - Method of Making Mineral Wool Insulation United States Patent Office 2,732,295 Patented Jan. 24 1956 2,732^95 . METHOD OF MAKING MINERAL WOOL INSULATION ation la the intefdted web ix converted by beat to the farfnmhle, insoluble atape. Since tbe bentonite b in corporated m the inorganic fibrous material in the presence cf as aquroos metinan, the water will swell the bentonite and the final product will contain bentonite in its twoDe* Frederick H. HoDenberg, i r . Maple H dghti, Ohio, as signor to XUIdwin-Httl Compawy, Trmlon, N. J , a cor poratios cf New Jersey ,, . , , In die preferred embodiment of the invention, the sheet of insulating material which b objected to heat to convert tbe resin a formed from an aqueous suspension of tbe 22,1952, Serial No. 310^23 9 Ctafans. ( 0 .9 2 --21) 10 ****** B attdal ^ the me of a screen to remove water therefrom. Preferably, the thermosetting resin and beotonite are mixed with the aqueous suspension of the inorganic fibres, for example, in tbe beater or the mixing cr agttatisg tank or tbe bead box, but if desired a soluble Tbe present invention relates to ax inorganic fibre 16 liquid resin and tbs bentonite may be added to the inter i,ilaring material of unusual and improved properties, felted web, for example, to the wet fibre on tbe sbeetand to a wet process of producing the tame, and more prodcriag eaten or subsequently. If desired, instead particularly, it relates to an ?nltng sheet material which of forming the interfelted web from an aqueous suspension is characterized by its nre-resistance. In addition, tbe by the use of a screen. a smaller amount of water may be inventior relates to an aqueous resinous composition SO employed aad tbe resulting suspension may then be de- which is available for use in tbe production of inorganic fibrous insulating material possessing water- and fire-re posited e~ither contn~roocsly on s conveyi'ng system or batch-wise into forms. As will hereinafter appear, other sistant properties. The present application is a division of application Serial Number 665,807 filed May 2, 1946, additives, rich as a supplemental fire-rcifirdant, a defearn ing agent, a bentonite-viscosity reducing agent or both now Patent Number 2,633,433. _ *8 may advantageously be added at a suitable point in the One object of this invention is to provide an inorganic process. By inorganic fibres is meant what is generally fibre insulating material, which, while relatively light, known in tbe industry as glass wool, mineral (rock or possesses high flexural strength, is waterproof, fireproof, slag) wool, cad asbestos fibres and all these will be re and has high electrical and thermal insulating values. ferred to generally herein as fibres. Any one of these Another object is to furnish an insulating material which 90 gijjojjj materials may be used advantageously in the possesses, in addition to other desirable properties, fire- process, the use of mineral wool being generally preferred, resistance and which, if raised at one portion to tbe com and mixmres of any two or all of them in varying pro bustion temperature of the resin, will provide a barrier portions assy be utilized. For example, portions of long preventing propagation of thermal decomposition in ad fibre asbestos, such as amosite, may be advantageously jacent portions of the product. . mixed with gt* s o d or rock wool, or both, to provide A further object is to provide an economic and com additional strength to tbe finished board. mercially practical method of producing an insulating In the case of the use of the glass or rock wool, either material comprising inorganic fibrous material, a syn long-fibre or loose wool, or what is knows in the trade thetic resin binder, and bentonite, die latter ingredient not as granulated or nodulized wool may be used. The only imparting fire-resistance and other desirable proper- *0 granulated or nodulized wool is prepared by nodulizisg ties to the product but also facilitating the practice of the the wool em a rotary screen which aiso removes the major process. Still another object of the invention is to provide s portion of the shot, that is tbe glass-like granules of doufiberized material. When long-fibre wool is used, a large method of producing an insulating material by which various t.y/tp--es --of t--he--r-m- -o-s-e--t-ti-n-g -r-e-s-i-n-s-,. i-n--c-l-u--d-i-n,,g -a--s-o--l-u-b-le- percentage of the shot is advantageously removed in the process, for example, by a riffle box. The removal of the resin even in &very dilute solution, may be used and in 40 major portion of the shot is important since, obviously. which the white water may be utilized to make up new substantial quantities of it will seriously alter the weight stock solutions. _ of the board without changing the volume appre Still another object is to provide a resinous composition ciably. comprising a soluble thermosetting resin in solution in an aqueous medium and a fire-retardant in suspension therein, 60 In the preferred embodiment of the invention, granu lated or nodulized word is employed since the finished which composition is avafial !e for use in tbe production product wifi have lower thermal conductivity, lower of Insulating material of im;: roved properties. Other objects will be apparent from a consideration of density, greater strength, and better handling properties, as compared to a product made from long-fine;ed wool. thi specification and the claims. Mixtures of long-fibered and nodulized wool may be used " The insulating material of the present invention com if desired. prises an interfelted web of inorganic fibrous material and By "thermosetting resin" is meant any synthetic re n t a synthetic resin in its resoluble, infusible stage and in an initial stage of polymerization which is convertible bentonite incorporated in said interfelted web, the resin by heat to the insoluble, infusible state. Such resins and bentonite providing water-resistance and fire-resist 63 may be used in any one of the three following forms: ance, respectively, to tbe product cs will hereinafter be dis ( 1) as an aqueous solution of a water-soluble liquid cussed. In one preferred embediment, the train and thermosetting resin: (2) as an aqueous emulsion of a bentonite are distributed throughout the interfelted web water-insoluble thermosetting resin in liquid form; and substantially uniformly, but, if desired, the product may (3) as an aqueous dispersion of a water-insoluble ther- have more resin in the outer sections than in the center section and the resin may even be substantially confined * * * * * **** * to th e outer Tr^ony. Mixtures thereof may also be used if desired. The first Tbe product may be prepared t y any process in which two forms contain liquid resins as distinguished from the a thermosetting resin and bentonite in the presence of powdered resin of the third form. . # an aqueous medium is Incorporated in Inorganic fibrous ' While any of the thermosetting resins, or mixtures rwi-r,t.). the fibres of which are in an aqueous thereof, may be employed, for example, phenol-farmal- suspension thereof and in which tbe resin after its associ- defayde, reacrdnobformaklchydc. urea-formaldehyde, and thdr inactivity with the reain, for example, sine hotate n a y he used "with % powdered resin ta t not with the liquid resin due to its reactivity with the latter. _ The proportions of inorganic fibre, resin, and bentonite examples tf fa n n a B e M * * * * * * m b so eca are form aldehyde, parafonualdtoyde, *aa,, beI*" .thyle^ f tTa; mine- Tile a a a l aieo d k a 1 m o fifi w * ts ^ 10*01 rtx n ? which 8 a llm a cpiMHr. ^ o c a b a w i ^ u b l e resin derived from pine-wood, c o n t e u ^ phenA alde hyde and ether groups; T Jresfa**"*** n a wdium or potassium aoap of rosm, aod * Bee may be eluded in the resinous anpodooa. ___ ., , . Bentonite is a generic tern w*enng colloidal day that have an affinity for water and swell a toe presence thereof, and any of toe varicw grades of bentonite, sucn as sodi'im-, potassium-. taJemm-. o r magcesom-contam. ing h*n^"te may be c a d la me production erf the product of the invention. Atentageocriy, a bentonite wwiitthh a high waler-absorpS*e capacity b employ! and, in the finished product may vary widely but lince these three ingredient* hr associated tfc die presence of water, the relative amounts thereof fit depend upon the par ticular type of proedtt (feed fa thfe preparation of the product Generally, the finished material will contaim 10 from 'bout 55% to abdht 57% of inorganic fibre, from abtfut 1% to about 30% of the heat-converted rOdn, and from about 2% to about 25% of bentonite. Insulating material havfeg particularly advantageous properties toay fcbhUfa frb& about 70% to about 97% of inorganic Id fibre, from about 1% to abend 10% of the heat-converted resin, and from about 2% to about 18% ot bentonite, for instance, from 85% to 90% fibre, 4% to 6% reds, and 6% to 8% bentonite. _l a a typical example, the in sulating materia! emtiia 87% rode wool fibre, 5% of a * phenol-formaldehyde resa converted to its infusible, in stated, the soluble state, and 8% of bentoniittee;;, in another example., a swollen state. Regardless of toe type of rosm em the finished product contained 92% of rock wool fibre, ployed, the presence of bcatouim, cither akme or with 3% of a heat-converted phenol-formaldehyde resin, and h er fire reta. rda..nts in toe f,in_is_he5d%toosnflabtemngtonmitaet.eri'aWl hen a supplemental fire-retardara sertvveess ttoo rreeonddCerTtthhee pprroodu^ctf cfiiMMje^ii^stnanut. . u u mduded in the product, the amount hereof may vaiy ^ smaU^amount, Tor example, a few te n te o f t-tfd to high temperatures, even when the resin is tn a percent up to 5% o t even more, based on toe weigfa o t toe resin, and toe amount employed in any particular torporated with The inorganic .fibroos material in toe finished product. T bi inorganic fibres m the finished case will be determined by the degree of supplements! product form an fasoUtmg blanket over the resin particles 80 fire-retarding action desired. . ... preventing the beat of combustion from bee* dissipated, The insulating material of the present invention fa characterized not only by fire-resistance and water-prool- and, due to the presence of toe fibres, air can breathe ness, bi s by high electrical and thermal insulation through tie material to support cortesticn. It can be Values, ft is further characterized by high flexural Seen therefore, that 2 tajr portion of the binder is raised 35 strength, sound absorbing properties, and resistance tn to the combustion tem pers* of toe resre, tnennal de vibration. Referring to water-resistance, a sample of the composition will spread throughout the entire product insulating material f th invention was found to have unless some means fa provided to prevent Spch action. absorbed less than t% water in an atmosphere of 55% The presence bf the bentonite in the finished product relative humidity at a temperature of 120* F. Even stheervrmesalasdethcoemmpoeasintsionfotrhrporeuvgehnttihneg pthroedcperLopagBaetniotonniotef 40 winhgebwathter,miat tedriidalnvot idseutebrmioerragteedainnd caofldte,rhtoote, owrebt oidn acu as an excellent fire-retardant for *U the various types sulating material was dried, th original strength was re of thermosetting resins that may be used in toe production tained. Tests bf th product by toe Columbm liine- of the insulating material since the beetoche provides a temperature method Showed h6 evidence of burning. mechanical bharirier between thoe portion of toe product fjo a tn o o tt, tot product Is characterized by its kase of which has been raised to the combustion point of toe resin and toe adjacent portions. In toe evert toe product is subjected to a temperature sufficiently high to cause fusion of the bentonite, toe toed bentonite then serves as the barrier. This contorna occurs during the appli cation of toe insulating matenil to * mera! surface by metili pira, since fa sneh a n o c e * toe pins hre arcweldefl to toc metal Surface. Thus, if toe material is ignited at one portion, the combustion wifi not spread to h er portions fine to toe hairier provided by toe ben haUnUd3Uli1*Uu*ldiUmAaily/ bWe utilized w"it*h*-*a" minim-u-m-- 7o-f du.sti'n--g* knd -bre*akage and, th- ere-fore, w-it-h---p-ract-i-c-a-l-l-y- no ifioi- trial health hazard. Th product may, therefore, be used fa .a application Vfar Such properties are de ed kirabl. ' . ^ The wfcight p tr cubit fobt bf th product may tfay over a wide range, depending upon toe process steps em ployed fa hs production, is will hereinafter b described, fcnd Ufailly the weight per fcubic foot Will be between 55 about and IS pounds. When toe product is to b used tonite. _ fa an insulating material to t Ships or fa bther applied The bentonite fa used, fa any p a r tia te Cie, fa ih lions where i light weight product fa desired, the weight amount to provide toe desired fire-resistance to tire prod per cubic fo rt is advantageously between about 6 and u c t The amount employed will be dependent on the 10 pounds. . quantity of resin in toe product When optimum fire- 66 As previously stated, Varkwi proefcstes taa be used resistance fa desired, the amount of bentonite will usually in tb preparation f th product, and the particular proo- exceed toe resin content, for example, web a product fesl depends Oh whether fa aquous solution, an emulsion, containing 5% trai*, abort 8% bentonite may be present, Of S dfapnrsion is itili employtd. Furtheirtiort, when whereas With a item content o f 3%. the bentonite content ab fcquofcai Solution b> fcmployed, th procs depends may only be about 5%. 03 ! whthf th resin Still remain in solution When toe As previously stated* if desired, the fire-relardant chat Solution Is brought Into Contact with toe Water em acteristics of the bentonite may be supplemented by th ployed fa the proce or whthr th resin will precipitate presence fa the product of another fire-retardant. While ndrsdi conditions, these two typtt of faitiii atfaeom various chemicals having fire-retardant properties may be solutions toe ttsrtfcd *hi6o-itsifl;predpit&tabie" tan used with the bentonite, zinc ammonium phosphate ha* urtsfaip felp teteb U tespectivtiy. When bhtohit U been found to be parC'cularty effective. The choice of included fa toe aqueous solution Of this resin, toe the particular supplemental fise-Rtardact employed will depend upon its ability lo be used fa the process without dtbfiity Of too lOlfaiOfi WitoOut precipitation of toe fsifi U fiiiidl IntOi, s that solution which a undesirable reaction with toe icon and to be retained fa the flhifJibd material. Cfcfttfa Subitene iteviiifc fire- hfmll fiiln-prcipilfabifc ctey bcm pon .the m- reterdfat propelle* ate fifa n ib b le fa r nib due to 76 ftiion m to bentonite ih hn-fesin-precipittble type. 8,783,38 . In a typical c u e where it it desired to employ a nos- _ u 1 interfelted web after h i foemstioa, tor instance, on the i ' resin-predpitatabic solution ta d to provide a solution, web-forming screen or after removal therefrom either - l after dilation with the water employed in the process, of before or after drying may bs treated with an aqueous " 5% by weight of rests solids, an initial solution con raedunn containing the resin and bentonite, ffltvr the 1 taining 70% resin solids end having a dOntafelity of at g web is formed from a water-suspension of the inorganic ' I least 14 (water) to 1 (solution) by weight is employed. fibrous materiaL it h a "water-laid web," and as is usual In a typical case where it is denied to employ a resin- in water-laid web* the major portion of the fibres there prcdpitatable solution and to provide a suspension con in are oriented in a plane substantially parallel to the ' taining 5% by weight of precipitated m in solids after plane of the web at sheet. If the dried sheet is treated, j , dilution with the water employed in the process, an io ft may or may not be re-wet prior to the application of initial solution containing 70% resin solids and having the resuwarrym* medium, but, of coarse, if a precipi- a dfluiabQity of less than 14 (water) to 1 (solution) by tated resin is desired, the product must contain sufficient . weight is used. Dlnstradve of the effect of bentonite, if water to cause a precipitation of the resin when a rrsir>- a solution containing 5% to 10% by weight of bentonite preciphatable solution is employed. Furthermore, if particles in suspension and 5% by weight of resin solids 15 desired, instead of treating the interfelted web with an . in solution, after dilation with die water employed in aqueotn medium containing both the resin and the . the process, if desired!, it Is not necessary to use an bentonite, foe bentonite may be incorporated with the initial resin solution having a notability of at lu s t 14 fibres prior to the mterfefting step or subsequently there to 1, but a solution of a dflutabflity ratio oi less than to and after drying, the product may be treated with an 14 to 1 may be employed provided the notability ratio go aqueous solution or emulsion, for example, by spraying, is greater than about 4 to 1. Thus, the bentonite will dipping, or passing the solution or emulsion through the serve to convert a resin-prccipitatable solution into a product. non-rcsm-predpitatable solution. When a resin-predpitalable solution fa applied to the It is to be understood that the resin content of the interfelted web, whether it be on the forming device or solution or suspension after the dilation by the water in 25 subsequently, the water associated with the web and the the process may vary widely, for example, from about displaced water fa drawn through the web as filtrate. IV4% to about 20% by weight of resin sclids, and that Since the presence of tise water in the web raises the an initial resin solution to provide such resin content will amount of water in the resin solution above the critical be employed. This is also the case when a resin emul dilution ratio, the resin fa precipitated from the solu sioLnikoerwdisisep, etrhseiobnenistounsietde.content of the resin-water medi 20 tioTnhaendifnatedrisfepletresdedwtherbouogfhoiuntotrhgeanwiect wfiebbro. us material, ' & um after the dilution by the water in the process may whether the resin be associated with the fibres prior to vary widely, for example, from about 1% to 18% by the formation of the web or thereafter, is advantageously weight of bentonite, and an initial amount of bentonite formed on the screen of an Oliver filter or other type to p rovide such quantity will be employed. The bentonite 55 of revolving screen equipped with vacuum compartments, is preferably moistened with sufficient water to swell it but. if desired, the web may be formed on the usual cylin v.v before it is incorporated with the resin-water medium. der type of paper machine or on the screen of a Four- When bentonite is employed in the upper portion of the drinier machine. Thereafter, die web fa subjected to range, for example, about 6% and above, the viscosity the action of a pressure roll or rolls in order to compact . of the medium is high and, with relatively thick prod- 40 ft to some extent and to smooth the surface and, after . E->: ucts, difficulty may be encountered in removing excess the treatment with the bentonite and resin as described, ; izz liquid horn the interfelted web when a screen is used the interfelted web fa dried and heated to convert the resin Yd in the formation thereof. In order to decrease the to the insoluble, infusible state. In the preferred cm- viscosity of the medium, particularly when more than bodiment of the invention, the interfelted web is formed about 6% bentonite is present, it has been found that by the process described in Patent No. 1,865,049, except this may be accomplished by the inclusion in the resin- 45 when granulated or nodulized wool is employed, the riffle wain: medium of a small amount of a soluble polyphos box may be omitted. As stated, the use of pressure rolls phate; tat example, sodium or potassium hexameta- fa recommended since they serve to exablish the thick phospbatr, tetraphosphate, or pyrophosphate, sodium ness of the product at a predetermined point For ex TS.- tetraphosphate being preferably employed. When a ample, in the preparation of a one inch board, the suc soluble polyphosphate is employed, some of it at least will 60 tion may be applied so that the stock will build up an be present in the finished heat-converted product. The interfelted web of approximately one and one-eighth amount employed may vary from a few of a per inches and by passing under the pressure rolls the thick cent up to 3% or more based on the weight of the ness may be reduced to one inch. '. bentonite. The preferred range is from about 0.5% to When the stock solution delivered to the screen con about 1.5%. Thus, in a typir-l cast, where an 8% sus- 65 tains the resin and bentonite, as well as the inorganic pension of bentonite (after dilution by the water in the process) was used, and 1% of sodium tetraphosphate fibrous materiaL the solution may foam and, if this con dition fa encountered, a suitable foam-reducing agent was present, the viscosity was reduced approximately to may be added. - I- that of a 5% bentonite concentration. In the case where the saspension of fibre, benicnitc, and resin is sufficiently The interfelted web is subsequently healed to dry the web and convert the resin to the infusible, insoluble state concentrated so that it is n<)t necessary to remove ex cess water by a screen, the use of a polyphosphate is and the product may be cut to the desired size, for ex ample, by means at circular discs revolving at high speed, usually not required since a hi >h viscosity is an advantage. The process is preferably arried out by mixing the either before or after the drying and heat treatment. The interfelted material may be heated by any suitable means retin and the bentonite with the inorganic fibrous ina- terial before the interfelted w.'b is formed, and in this and the temperature of the heat-treatment will depend type of process, the non-rcsin-;<redphating solution, the upon the particular resin preseat in the interfelted struc resm emulsion or resin dispersion may be added to the ture. Advantageously, the wet interfelted web fa placed beater, mixing, or agitating task or head or delivery upon pallets which support it in a flat form and are de box to the screen used to form the web. If desired, in signed to impart to the web a smooth flat surface. The stead of using a screed to form the web, a conveyor or pallets are placed on can and the care in turn are placed stationary form may beVemployrd. In this case, the use in a drying tnnneL The drying tunnel fa usually kept of granulated mineral wool is advantageous. " at a temperature of between 250* F. and 550* F , a pre In the case a non-resia-precipitaring solution, a resin- ferred range being between 300* F. to 350* F. At this precipitating solution, or a resjt emulsion is used, the W temperature, the water is evaporated and the resin is Il Od*verted to t e `Wfo.ftte. fate** Stfafc THt fc*th of time trf heat-freetroe fa * fanction f t e BUpenare embayed end te3aBy -require three boon r are. Whs* the interfeited web mwteim e tram whidi ft 6 each other are assochted, are felted into it thick shdet; drying and beating said c e t to convert the condensation product therein into th insoluble, infusible, state. 2. The procs of claim ! wherein a soluble alkali fcfci !J soluble fa die rdudttd w*ttx i f a iir t M ft c Web, 6 polyphosphate is p resents thetupesstoa. . i! there fe a Undencjt during tbb drying cyde far Such rean 3. The process o f daim 1 wherein said condensation ! to migrate to the outer surface. H n migitehm reanlts product comprises a phenol-formaldehyde condensation in a prfahte th has a treat ttte r o w t a t a after product ' U bmer core. While trtch a prodad fa at ties desirable, 4. The process for prododng mineral wool inmlatk die tee of bentonite has the farther edvagttge. heat a 10 in board form possessing a low density of between abodt product haying a substantially anSbrm terooboe of 6 and 25 pounds per cubic foot, high strength, fire r resin is desired, since hen mag sock oinHe resin, A t sistance and waterproofnesS which comprises ir-lxing, with bentonite reduces A t amount Of migration so that T ran water, nodulized mineral wool, asbestos fibres, bentonite _a pr_a_c_t_ic_a_l_S_t_a_nd_p_o_i_nt ver_y bttie oeam , afthnag_h there and a synthetic thermosetting condensation product select- u.s_ua+l*ly is s. lai*gh,t imi cr_ea_s*a", fLa. ^n_s-- -r *brnvlran on t e* 15 ed from the group consisting of phenol-formaldehyde, r- outer sariace. This *6& t far fa sfac L soranci-tormaldehyde, me-formaldcbyde and furfuraf- bes iatfae pafticltt tff fibre Very ccrapktcly asd prvf e . formaldehyde condensidcm products to provide a snspeh- a finished rod* which fa to faawf e . fa fa ct toc in which the concentration of bentonite is between io c a ie where (he product bi been cal to c before about 196 and about 1896, by weight, and of coadensS- ooveha of the stefa, lhdi the sfigbf Trpyration p*6 - to tkm product between 1V496 and about 20%, by weight; vides a product fa which the surfaces thereof nefadmg continuously feeding said suspension to a continuously the edges and ends are neatly sealed. moving screen; drawing water from said suspense* Rtfeatcless o f the particular form i f faoeor r through said screen whereby the mineral wool fibres and fafedwm ifapteyeri, ft will be desrabfc te rerircubte th asbestos fibres, with which bentonite and condensation :::: water removed through the t e t en. This partksaziy 85 product in intimate misture with each other re ass- important when a fion-resrn-predps-tati-ng sc-m-ori &- em- dated, are felted into a thick sheet; drying and hating ployed since the resin and bentonite contra cf A c Wbise said sheet to convert the condensation product thofcfa Water remains Substantially constant Snrii a sufaoon is into the insoluble, infusible state. normally relatively unstable and these fa a tendency for 5. The process of clami 4 wherein a soluble aBcafi the resin upon standing to sefarate from she solution. SO metal polyphosphate is present in the suspension. The Use of bentonite in such a solution, however, makes 6. The process of claim 4 wherein said condensation ft possible to obtain resin sotntkns stable ovtxa period of product comprises a phenol formaldehyde condensation months and, in fact, the stability of such a solution in product. ............................. . , ^ creases upon aging. The sfsbiliry imparted to such a 7. Th _1 t_!__ f *_pr-o-c-e--ss---i--f- *p. rodu*c-in_g ninnerai w\iootl11.immiin. iaaktA.imvri solution by the bentonite, therefore, makes it posable to 84 fa board form possessing a low density of between about recover and re-use th white water. _ _ 6 and 25 pounds per cubic foot, high strength, fire re As stated previously, ooe object of the favcotka fa to sistance and waterproofness which comprises mixing, With I provide a rsinons composition coniprirfag & soluble water, nodulized miueral wool, bentonite and a synthetic t= thermosetting' resin fa solution in an aqneaes medium thermosetting condensation product selected o c a the and bedtonite suspended therein, wMefc composition fa *9 group consisting of phenoWonraidehyde, resorcinol-form useable in th production of insulating saxerfaL fa making such a composition, fa wifi b desfrahie to first aldehyde, urea-formaldehyde asd furfural-formaldehyde condensation products to provide a suspension in which suspend the bentonite in water to swefi fa and then to the concentration of bentonite is between about 196 an<l i_n_co_rp_o_ra_t_e__It__W_i_th__th_e__re_s_in__r_o_ta_t_io_n_. T ie coocentia- about 1896, by weight, and of condensation product tiohs^bf bentonite and resin in flic aofctioa may doir- 45 tween lVi96 and about 20%, by weight; continuously I spond to those Of the solution to be wed ia the prdduc- tiort of die insulating material such, for example as those given above, but it fa advantageous to make a feeding said suspension to a continuously moving screen: drawing water containing bentonite and condensation product from said suspension through said screen whereb inore concentrated solution, for example, a srfution con- the mineral wool fibres, with which bentonite and con taining from 20% to 5096 of retin and from 1096 to 60 densation product in intimate mixture with each other are 40% of bentonite and then to State this scfcmoo at the tim of its usd. The presence of the tenfmge stabilizes associated, are felted into a thick sheet; drying and beat ing said, sheet to convert the condensation product therein ihe fesin as hcreiblbre described. _ v _ , into the insolnble, infusible state, and recirculating a id Considerable modification is postte fa t e proportions drawn water for re-use in the process. . i. ., of the 'constituents to! the matmg mlcrjd f t e j n - 65 8. The process of claim 7 wherein a soluble alkali metal ventio, as well as in the steps of preducaas without departing from tb t essential fosares f t e polyphosphate is present fa the suspension. .. 9. The process of claim 7 wherein said condensation invention. . product comprises a phenol-formaldehyde condensation I claim: . h e prtocesS for producing mineral wuel . . mstdition M product. iti bbard form possessing tow density cf beewsen bowt References Oled fa the file of this patent 6 and 25 pounds {seb cubic fool, high strength, fire fasslahbS kd wtefprfuss vdtich comprises caring; with water, nodulized mineral wool, bentonite ccd sysihetic thermOsctting condensation pttoduct Sdctted from fisc 5 group consisting erf phenol-forrildeiiyde, icvscinol-focni- aldehydj ure-fotmaldehyd and fmfonl-fbcnaldehyde coadehsatiton products to provide a wapenwan a which the concentretion of bentonite is between about 1% and about 1896 by Weight, and faf oeadensaties product fa 70 between about 1Vi 96 and about 20%, by we&u; continu ously feeding said suspeasioe to a contturniady moving screen; drawing water.from said Kpcatiou.-tough said 737,099 951,183 1,160,365 1,841,678 1,887,726 1,972,453 2,011,915 2,067,876 2,151,357 2,195,272 UNITED STATES PATENTS kafi. Gaari -______ Aug.2i,'l? 8S - Mar. 8.1910 Baekeland______________Nov. 16,1915 Russell ---------------- Jan. 19,1532 Weber______ _________Nov. 15,1932 jpoweQ c _ i_____ u---------- Sept A 1934 Seigle ,, t____ --------------- Aug. 20,1??5 CampbeD -. Jan. 12, 19?? Reitzel Mar. 21,1939 Ehlers sa_^-:cs.-s.-- - Mar. 26,1940 creen whereby, the mineral wool fibres, w te ahidt besi toaite and condensatiou product ia ftninwte aixtara with 76 (Cihti references on foliowing page) . . 2383,066 2, 407,376 2,4s 8,186 2,485,458 2367,559 2,633,453 9 TOOTED STATES PATENTS 8,788,805 __ . 10 OTBRB BPFPBBJffW Gerity May 16,1944 McDermott______----------Ans- 21.1945 MaxweQ Sept 10, 194$ Miller A rs. 31,1948 Quinaet L Oc:. 18,1949 Glieder - Sept 11,1951 Mannfartnre o f Palp ad Paper, 3rd cd. toL V, aec. L pp. 17, 107. Boehm: Piper Trade J. May 2,1940 pp. 35- 36. H olien b ets..... --.. . Mar. 31,1953 \ \ \\ ' \ \ \ i