US2252157A - Insulating bat - Google Patents

Description

l atented Aug. 12, 1941 INSULATING BAT William M. Bergin, Granville, and Allen L. Simison, Newark, Ohio, assignors, by mesne assignments, to Owens-Corning Fiberglas Corporation, a corporation of Delaware v No Drawing. Application July 26; 1938 Serial No. 221,460

8 Claims.

The present invention relates to mineral wool bats, especially those comprising glass wool, slag wool, rock wool or the like, thickened with a binding material to produce an unusually'light weight, strong, self-sustaining, resilient bat having fixed dimensions. The invention has special application to glass wool, heat or sound insulating bats made in accordance with the teachings of the British. patent to Triggs 428,720 or United States Patent 2,133,236.

An object of the present invention is to provide a fibrous bat having the aforementioned properties of strength, high resilience and fixed dimensions, combined with unusually light densities of about 1 lb. per cubic ft, and ranging up to any density, such, for example, 3 /2 or 9 lbs. per cubic it, according to the particular purposes to which the bat is to be put. Ordinarily, for house insulation material, a light density of about 1 /2 lbs. per cubic ft. is desirable. Such bat may have sufiicient structural rigidity so that the bats may'be' handled, assembled into place without reenforcing memberssuch asa cardboard core, or outer wrappings of paper, or reenforcing stitchings.

For better heat insulating qualities desirable for use in refrigerators, stoves, bottle coolers and the like, a 3% lb. density, more or less, is generally desirable. Higher densities of about 5 to '7 lbs. per cubic ft. are preferable for boiler insulation, industrial ovens, board or sheet type of material or the like.

The present invention is particularly suitable for railroad insulation where the lightest density possible is desired coupled with high structural strength capable of withstanding the jolting and vibration incident to railroad car use. A bat incorporating the present invention may have an extremely light density of about 1 /2 lbs. per cubic ft., and sufiicient structural strength that it may be mounted inside the railroad car wall panel and not settle or gradually break up due to the destructive vibration of the train.

Another object of the present invention is to provide a heat and sound insulating body having the foregoing properties while using a minimum amount of binding or stiffening material to accomplishthe same.

Another object is to provide a bat having a stifiening or binding material which will maintain its properties through wide temperature ranges, and will not sag or become brittle as the temperature rises or falls.

Another object of the invention is to provide a bat which is self-sustaining, fluffy, and yet suiiiciently resilient and pliable that it will fill out all contours of a heat insulating panel, and then permit the bat to be stiffened to permanent form after installation in the cavity. This enables strong vibration resistant insulation to be applied to a panel which may have irregular shapes or contours and yet distributed in such a way to fill all the space in the said panel.

Heretofore numerous binders have been suggested and used for bonding together mineral wool fibers into bats. Most generally such materials as asphalt, gypsum, starch, rosin, linseed oil, glue, sodium silicate, pitch or the like have been attempted. These binders generally are Water soluble or thermoplastic. If water soluble, they have for that reason proved unsatisfactory when subjectedto moisture conditions. If thermoplastic, they are unsatisfactory when subjected to certain temperature conditions.v Various other disadvantages have attended the use of these materials as, for example, the rosin is subjected to oxidation and embrittlement after only a short period during the life of the bat; sodium silicate attacked the fibrous material particularly if it contained an alkaline constituent.

using a very small amount of thermosetting, condensation product. This may be and preferably is combined with an incompatible oleaginous lubricant such as oil, fatty material, or the tempering oil emulsion patented and described in the Williams and Bone Patent No. 2,083,132, or their Patent No. 2,107,284.

Various ther'mosetting condensation products may be used, as, for example, phenol formaldehyde, urea formaldehyde, or various modifications and variations of these synthetic materials which may be made by one skilled in the art to produce a resin originally in a liquid state, and finally in a hard, strong, solid mass. For ordinary purposes Bakelite, originally as water soluble material has been found very satisfactory for use in the present invention.

A small amount of the thermosetting stiffening agent may be added to the tempering oil or lubricating mixture and applied directly to the blasted fibers. Preferably, however, the combination is first emulsified with water and then sprayed on the glass fibers as they are building up to mat formation upon a conveyor.

Various proportions of materials may be used, although it has been found that a small proportion of only about A;% to 1 4% of Bakelite per weight of wool is sufficient for ordinary purposes.

When minute amounts of about /2 to A of a percent are used, the bat has materially increased stiffness and vresilience, and reduced limpness, but it is not rigid or stifi. With increased amounts, the bat assumes a semi-rigid form, and with the higher amounts, 2. fair amount of rigidity and strength are attained. The bat is still resilient and tough and can withstand considerable bending or compression stress without destroying its properties.

The finished bat may thus have about /2 to 2 /2% thermosetting stiffening agent, about an equal amount of stearic acid, oleic acid or other fatty acid, generally'about 1%, acting as an emulsifier if desired, and a suitable amount of oil incompatible-with the thermoset stiffening agent, such as "hydrocarbon oil, for instance, bright stock hydrocarbon oil, mineral oil, paraffin oil, petroleum oil or the like in amounts of about 2% or so, as desired. Metallic soap, waxes, fats, ammonia or the like may also be added to increase water repellancy of the bat if desired. Bentonite or the like may be added to act as an emulsifier, and to increase the heat insulating properties of the bat.

The method of applying the emulsion or mixture of lubricant and binder may be similar to any of those now in use. Ordinarily it is preferable to spray the mixture onto the fibers as they build up into mat formation and are con tinuously withdrawn in mat formation. It is desirable to accomplish this process over the fiber deposition zone in order to control the deposition and preferably to apply sufficient heat to evaporate the aqueous phase of the emulsion, leaving the lubricant and binder or stifiening agent distributed over the fibers. After removal from the deposition zone, it is desirable to heat treat the stiffening agent and cause it to polymerize into a final set, thus adding stiffness and a controlled amount of rigidity and resilience to the bat. This may be accomplished by any of the usual methods as, for example, by passing the material between rollers or between caterpillar belts having hot air or the like passing continuously therethrough in order to impart suflicient heat to polymeriz'e the thermosetting agent. The caterpillar belt will also hold the bat down to a predetermined fixed dimension as the thermosetting binder hardens.

It is also possible and at times desirable when insulating closed panels, such as refrigerators, stoves or the like, to insert the bat in a loose, fiuffy state prior to polymerization of the stiffening agent, and after it has been inserted into the cavity, apply heat and thermally set the binder in position.

The reason Why such a small amount of binder, as, for example, an amount less than or about 1% can efiect such striking increases in strength and stifiness of the bat is not fully understood,

although several reasons have been advanced to explain the phenomenon. From observations under a microscope, it was noted that at a large number of intersections of fibers, it appeared that the stiffening agent congregated in very small amounts and coated the intersections with rounded smooth concave surfaces in a manner similar to a fillet, thus imparting high structural strength with a minimum quantity of mahardened, however, it tends to retain this form and thus structurally assume an ideal contour with respect to the adjacent fibers. The small amount involved, however, avoids rigidity to a point of brittleness, and permits the product to achieve a certain amount of flexibility and yieldabilityunder stress.

It is also considered possible that the oleaginous lubricant would form a uniform, homogeneous coating over the individual fibers, and that an incompatible thermosetting resin acts as a binder or stiffener independently. The lubricant over the fibers, however, would provide a sufiicient amount of yieldability so that the bat would attain a high degree of resilience and strength without causing excessiverigidity and embrittlement of the individual fibers.

Various modifications and variations may be resorted to within the spirit and scope of the present invention as defined in the appended claims.

We claim:

l. A strong, semi-rigid, resilient, light weight bat comprising an unfelted mass of glass wool fibers, and a treating material disposed over the fibers, said treating material including a hydrocarbon oil as a lubricant and polymerized urea formaldehyde as a binding and stiffening agent.

2. A light weight, tough, resilient bat comprising a loosely felted mass of glass wool fibers, and a treating material disposed over the fibers, said treating material including a petroleum lubricant coating the individual fibers, a thermosetting aldehyde condensation product bonding said fibers together, and a fatty acid.

3. As an' article of manufacture, a mass of mineral 'wool fibers bonded into an integral resilient insulating bat with polymerized phenol formaldehyde dispersed throughout the bat at spaced apart junctures of the fibers to bond the same together, and a lubricant incompatible with said phenol formaldehyde and coating the individual fibers, said lubricant being a hydrocarbon oil.

' 4. A light weight, stiff, resilient bat comprising an interfelted mass of mineral wool fibers, and a treating material distributed over and between adjacent fibers which comprises a hydrocarbon lubricant serving to coat the fibers and impart flexibility to the bat, and a stiffening agent incompatible with said lubricant and consisting of the residue of a thermosetting aldehyde condensation product bonding the fibers together at their junctures.

5. As a product of manufacture, a mat of inorganic fibers, the individual fibers thereof having been treated with a plurality of immiscible substances, at least one of said substances being petroleum oil having afiinity for the fibers and at least one other of said substances being a polymerized thermosetting aldehyde condensation product originally in aqueous solution.

6. As an article of manufacture, a bat comprising a light-weight 'mass of felted mineral fibers, a residue of a thermosetting condensation product in percentages of from to 2 and disposed at intersections of the fibers serving to bond the same together, and a lubricant incompatible and immiscible with the said condensation product comprising a hydrocarbon oil coating the fibers and imparting increased flexibility to the bonded bat.

7. As an article of manufacture, a mass of glass wool fibers bonded into an integral resilient insulating bat with polymerized origstices between fibers open, said treating ma- 2,2o2,157 a p 3 terial including petroleum oil in percentages of about 2% of the finished bat coating the fibers and serving to lubricate the same and impart -yieldability to the mass, and a stiffening agent of heat-polymerized phenol formaldehyde in percentages of from 70 to 2 of the finished bat disposed at junctures of the fibers serving to bond the same together.

10 WILLIAM M. BERGIN.

ALLEN L, SIMISON',