US2023019A - Apparatus for saturating sheet material - Google Patents

Description

Dec. 3, 1935. G. P. HEPPEs APPARATUSA FOR SATURATING SHEET MATERIAL Original Filed Feb. 5, 1927 2 Sheets-Sheet l Dec. 3, 1935. G. P, HEPPEs APPARATUS FOR SATURATING SHEET MATERIAL Original Filed Feb. 3, 1927 2 Sheets-Sheet 2 Aw m y e fw@H a;

Patented Dec. 3, 1935 UNITED STATES APPARATUS FOR SATURATING SHEET MATERIAL George P; Heppes, Chicago, Ill., assignor, by mesne assignments, to The Patent and Licensing Corporation, Boston, Mass., a. corporation of Massachusetts Originalsapplication February 3, 1927, Serial No. 165,558. Divided and this application May 20, '1930, Serial No. 453,976. In Canada December Claims. (Cl. 91-55) This application is a division of my application Serial No. 165,558, filed February 3, 1927. The invention relates to apparatus for saturating absorbent material particularly in sheet form 5 and has for its objects not only to saturate the material to a higher degree than has been-possible with apparatus heretofore in use for that purpose, but also to control the saturation so as to produce definite degrees 'of saturation less than '10 complete if so desired. My invention finds a particular practical exemplication in the problem of saturating sheets of feltecl fibrous stock commonly used as a foundation or base for fabricated roofing. Such stock is commonly made of rag or asbestos fibers or mixtures of these or other fibers,

the sheetsbeing formed on a paper-making machine so that the fibrous material is interfelted into a bibulous structure capable of absorbing a considerable quantity of suitable saturants. In

the manufacture of roofing elements from raw felt, it is customary to saturate the felt Witha suitable waterprooiing material so as to make the sheetwater repellent. For this purpose a low melting-point asphalt is customarily used-since asphalt of this kind can readily be heated to a relai tively 4high degree of fluidity Without raising the temperature so high as to char or injure the fibrous material of the sheet when immersed in a bath of the molten saturant for a sufficient time to effect approximately the maximum degree of saturation possible from a single immersion of the sheet. It has been found that a sheet of raw roong felt when immersed in a bath of asphalt having a melting point of from 120 to 150 F. heated to a temperature of approximately 300 F'. is quickly saturated to about 70 per cent. of itstheoretical capacity, after which no more saturant enters the sheet, no matter how long the sheet may be left in the bath. The saturation of roof- 40 ing felt in the manufacture of roofing units according to general practice thus rarely reaches 80 per cent. of the theoretical maximum. Felt` 50 felt with saturant obviously reduces pro tanto the' moisture absorbing capabilities of the felt and thus affords the roofing elements made therefrom additional protection against deterioration. If, after a thorough immersion, the sheet is removed from the bath and is allowed to cool with 5 excess saturant on the faces thereof, the con traction of the asphalt in the pores and voids of the sheet together with whatever residual gases and vapors may be entrapped in such pores and voids, sucks some of the excess asphalt from the 10 surface into the sheet so that a sheet thus saturated and cooled is found to have absorbed saturant to very nearly 100 per cent. of its theoretical capacity. I have found moreover that a saturation very close to the theoretical maxi 16 mum can be obtained by cooling the sheet with an excess of saturant on one face only of the sheet. This is believed to be due to the fact that the face from which the excess is substantially entirely removed when the sheet leaves the bath 20 starts to cool immediately, causing the asphalt in the pore spaces at the surface of the felt to become sluggish and thereby to prevent air from being sucked into the sheet through that face. On the other hand, the surface on which an ex- 25 cess of hot asphalt is allowed to remain does not begin to cool at once since it is kept heated for a time by the presence of the layer of excess as- -phalt on the face. 'I'he cooling therefore of the asphalt in the sheet proceeds from the uncoated 30 face of the felt and asthe saturant and gases Within the sheet contract, they suckin more particularly the excess from the coated face, suction of air from thev uncoated face being practically prevented by the initial chilling of asphalt in. the superficial pore spaces thereof. In this manner, satisfactory results have been obtained in the saturation of roofing felt by excess being left on one face only of the felt as it emerges from the saturating bath. It has been customary heretofore to run the sheet of roofing felt which has passed throughthe saturating bath to a cooling device comprising a looping mechanism which receives the saturated felt in festoons and allows .it to cool byexposure tothe air. In feeding the saturated sheet from the saturating tank to the looper, it has heretol fore been found necessary as a practical matter to remove excess saturant from the faces of the Sheet, Unless this were done, diiculty has been experienced with traction of the feeding rolls, excess saturant on the sheet causing the sheet to q slip on the rolls. A further diiliculty has arisen from the presence of excess saturant on the lower face oi' the sheet due to the fact that such excess was liable to cause the sheet while cooling to stick to the looper bars over which it was festooned so Athat upon attempted removal of the sheet, it was 4liable to tear. By my invention, I provide means for squeezing and feeding the sheet from the saturating bath to the looper mechanism but leaving a' sumcient amount of excess saturant thereon without, however, losing traction. Moreover, the apparatus embodying my invention prevents the sticking of the saturated sheet to the looper bars. Y

An important feature of my invention is embodied in a special type of squeeze roll which engages the upper face of the sheet as it emerges from the saturating tank. This roll is providedl with recesses of desired number, size and .shape formed on the face of the roll, these recesses serving as temporary reservoirs to receive some of the excess saturant on the face of the sheet leaving the saturating tank and to permit such saturant to pass the squeeze rolls and to remain on the face of the sheet'during the subsequent cooling thereof. The amount of excess saturant remaining on the face of the sheet after passing the rolls may be accurately controlled by the Size and shape of the holes and the spacing of the rolls. Various other vadvantageous features v tives of rolls having recessed portions of various will be apparent to one skilled in the art from the following description and on the drawings, of

Figure 3 illustrates apparatus for use with a.

modified form of my invention.

Figure 4 indicates a fragment of sheet showing the pattern of excess asphalt left on a face thereof by a roll such as shown in Figure 5.

Figures 5, 6, and 7 are fragmentary perspeccongurations.

Figure 8 shows a roll with recesses of adjustable capacity.

Figure 9 is a fragmentary transverse section of a roll such as is shown in Figure 8. y

Figure 10 is a perspective of a serrated doctor used with the apparatus indicated in Figure 3.

Figures 11, 12, and 13 are fragmentary perspectives of looper bars having projections of various shapes thereon.

Referring to Figure 1, a roll of raw roofing felt is indicated at 2U. This felt maybe led by suitable -guide 'rolls into a saturating tank 2| which is customarily provided with means for maintaining a pool of saturant therein at any desired temperature. The sheet may be led over a series of rolls 22 in the tank to secure thorough contact with the saturant and to permit bubbles of air and vapor issuing from the sheet to escape therefrom. The sheet upon leaving the bath of molten asphalt in the container 2| may be led,

kdirectly to a pair of squeeze rolls 23, 24, or if desired, may have the excess saturant on its upper face doctored therefrom as at 25, after which a secondary application of waterproong material may be applied as by a suitable spout `ures 6, '7, and 8.

26. coating may be similar to that in the `container The material supplied for the secondaryy 2| or preferably may be an asphalt having a higher melting point such for example as is commonly used forv coating the saturated sheet.

Of the pair of squeeze rolls 23, 24, which draw the saturated sheet from the tank and feed it toward the looper mechanism, the lower ril 23 is adapted to contact with the upper face of the sheet, the upper roll 24 being adapted to engage excess asphalt on the face of the sheet and to pass vsuch excess through the nip/ of the mils. The lands between the recesses, i. e., the portions of the roll which come in contact with the sheet, press the sheet and squeeze from the areasA of contact substantially all the excess saturant thereon, the recesses permitting substantial quantities of lexcess saturant to remain on the portions of the surface not touched by the lands. In the normal operation of the machine, a slight excess will be left on the squeezed areas of the sheet, heavier excess being left on the remaining areas. 'I'hese recesses may be of any desired number, area, depth or shape. As exemplied in the form of roll shown in Figure 4, the recesses comprise a series of `longitudinal grooves intersected by a series of peripheralv grooves, these groovesJ being, by way of example, about onequarter of an inch apart and having a, width and depth of approximately one-eighth of an inch. The number, size and distribution of the grooves, however, will depend upon the characteristics of the saturant' and of the sheet as well as the degree of saturation desired. By regulating the size, number and distribution of the grooves in the face of the roll, the amount of excess saturant left thereon after the sheet has passed between the squeeze rolls may be accurately controlled, this control being not ysubject to tampering with by operators of the machine. If the excess saturant left on the sheet is low melting-point asphalt such as is used in the saturating bath, it is desirable that the amount of excess thereof left on the face of the sheet be carefully regulated, since a deficiency would result in an insufficient saturation of the sheet While an excesswould result in an inferior roofing element subject to slippage of the waterproof coat of high melting-point asphalt which is subsequently applied thereto, since an excess of low melting-point asphalt interposes a layer too readily aifected by solar heat. Such readily affected layer of low melting-point `asphalt remaining on a completely cooled sheet prevents a coating layer of high melting-point asphalt from direct engagement with and anchorage to the fibers of the foundation sheet. The roll illustrated in Figure 5 leaves excess saturant on the sheet in a checkered pattern such as shown in Figure 4, these crisscross lines of saturant quickly spreading to form a fairly uniform layer of asphalt which is sucked into the sheet during the cooling thereof. Other forms of roll surfaces may be employed, however, as found desirable or convenient, a few of these being illustrated in Fig- It is obvious, however, that many other patterns may be devised such for example as spiral grooves which may be arranged to leadfrom the center line of the roll face toward the ends thereof, such a pattern havcess coating from the face thereof. The roll 3| ing the additional function of tending to keep the sheet properly stretched laterally. In order to facilitate adjustment of the capacity of a roll to pass excess saturant, I may provide recesses of variable capacity, as shown in Figures and 9, wherein the recesses are shown as cylindrical in form, the bottoms being the heads of screws 21 which are threaded into suitable holes 28 in the roll. Any pattern of recesses. however, which provides a satisfactory distribution of excess asphalt on the face of the sheet coming in contact with the roll comes within the purview of my invention.

If desired, the upper roll 24 of the pair of squeeze rolls, which in the apparatus illustrated feed the sheet from the saturating tank, may also be provided with grooves in its face. This roll is adapted to contact the under face of the sheet and for reasons hereinbefore set forth, it is considered advantageous in order to avoid vcertain practical difilculties in handling the sheet to remove most, if not all, of the excess asphalt adherlng to the sheet as it leaves the saturating bath. For this reason, the grooves in the roll 24 are preferably smaller thanthose in the roll 23, and if desired, the roll 24 may have a plain ungrooved face. It is understood, however, in case the sheet should be fed to apparatus in which substantial excess saturant on the under face of the sheet would not be objectionable, it is possible to leave any desired quantity of excess saturant on the under face as well as on the upper face. The excess asphalt on the sheet after passing the rolls 23, 24 will in general be sufficiently fluid to spread under the action of gravity and surface tension to form a fairly uniform layer on the sheet, this spreading action being indicated in part in Figure 4. If desired, however, the spreading may be hastened by a, spreader such as a steam pipe 29 or bar 30 extending across the sheet and in light contact therewith. The spreader should preferably be heated to prolong the fluency of the excess asphalt, but this is not necessary.

Another arrangement of squeeze rolls may be employed involving the use of a third roll (not shown) located beneath the roll 23. With such a set of rolls, the upper and lower rolls being plain and the middle roll being recessed, the sheet would receive two squeezes so as to remove more of the saturant from the lower faces of the sheet While leaving a measured amount of excess on the upper face.

In the looping mechanism as indicated in Figure 1, a pair of feed rolls 3 I, 32 may be used to feed the sheet coming from the rolls 23, 24 into the looping apparatus. The sheet after leaving the squeeze rolls 23, 24 will, according tomy invention, have a predetermined or controlled excess of waterproofing material on the upper face thereof and if desired a lesser excess on the lower face thereof. Some of this excess will normally be upon the upper face of the sheet when it reaches the feed rolls 3|, 32. In order to avoid squeezing this unabsorbed excess from the face of the sheet, I preferably provide the face of the roll 3| with grooves or other recesses which may be similar to those in the roll 23 so that the sheet is carried through these feed rolls without loss of traction and also without removal of the exmay also be heated in order to prolong the uid condition of the excess saturant on the upper face of the sheet. -If substantial excess be left on the under face of the sheet, the roll 32 should be suitably'recessed to prevent squeezing such excess therefrom. The looping mechanism itself comprises essentially an endless carrier 33 composed of a pair of parallel chains supporting by their ends a series of looper bars 34. The chains of the carrier 33 pass over and are driven by suitable sprocket wheels as at 35, the progress of the bars 34 being continuous and relatively slow. The feed wheels 3|, 32 feed the flexible saturated sheet into festoons between successive looper bars 34. A suitable idle roll 36 is supported on a pair of rockable arms 31 pivoted as at 38 to permit the roll 36 to be raised. The progress of the looper bars 34 is so timed in relation to the speed of the feed rolls 3|, 32 that when a sufficient length of the sheet has been fed between a pair of successive looper bars to form a full festoon, thelooper bar comes in contact with the lower portion of the roll 36, the latter being of sufficient Weight to pinch the sheet between it and the looper bar and thus to prevent any more of the sheet being fed into the festoon ahead of such looper bar. This results in the beginning of the next festoon which immediately follows this looper bar and thus the looping process is repeated. In order to prevent the squeezing of excess asphalt from the face of the sheet which overlles the looper bars, I may also supply the roll 36 with recesses or grooves to receive temporarily such quantities of excess saturant as still remain on the upper surface of the sheet when the looper bar comes in contact with the pinching roll 36.

Instead of removing substantially all excess saturant from the bottom of the sheet as it leaves the saturating bath, I may if desired provide the face of the feed rolls 24 and 32 with grooves so as to permit the retention of a substantial excess yof saturant on the under face as well as upon the upper face of the sheet. avoid the well known difficulty usually arising from excess saturant on the under face of the sheet, namely, the liability of the sheet to stick to the looper bars, I may provide the looper bars with raised contact points (Figures 11, l2, and 13) which may be in the form of stars, knobs, or other spaced surfaces of small area to support the sheet and to hold the greater part of the area of the lower face of the sheet out of contact with the looper bar.

The exposure of the sheet to the atmosphere in the looper is preferably of sufficient duration to cool the sheet to approximately the melting point of the saturant in the sheet and at the same time to allow substantially complete absorption of the asphalt into the sheet, resulting from the sucking in of the excess asphalt left on one or both surfaces of the sheet. As hereinbefore set f orth, it is preferable to regulate the amount of excess of low melting-point asphalt left on the face or faces of the sheet by forming the recesses in the squeeze rolls of the proper size so that by the time the sheet is withdrawn from the looper, all of the excess on the faces thereof will have been drawn into the body of the sheet and will have become congealed within the pores and voids thereof. Upon leaving the looper, the sheet may be fed as by suitable feed rolls 39, 40 to a Acoating device generally indicated at 4| by which a protective coat of high melting-point asphalt is applied to the upper face of the sheet, this In order to coating being preferably surfaced with corn--` minuted material such as crushed slate or its equivalent, this slate or grit being applied as by apparatus conventionally shown at 42 and'rolled 'into intimate contact with the coating as by press rolls 43. The excess of coating material which may run oif the upper surface of the sheet may be caught in a receptacle 44 from which also may be picked up coating asphalt to be applied in a thin layer to the under side of the sheet as is customary in the roong industry.

In case the secondary application of asphalt by the spout 26 (Figure 1) in the process of saturating the sheet is of high melting-point asphalt rather than the low melting-point variety, I may provide a suitable receptacle 45 to catch any excess falling from the sheet, this excess being transferred by any suitable means to the receptacle 44 to supply additional asphalt for the under coat of the sheet.

In Figure 2 is illustrated a modified form of saturating apparatus with which I may use my improved squeeze roll. As shown this apparatus comprises a saturating tank 2| adapted to hold a bath of low melting-point asphalt. 'Ihe usual rolls 22 are provided to guide the sheet through the bath. Upon leaving the container 2|, the sheet is preferably fed between a set of squeezing rolls 46, 41, 48 which remove excess asphalt from both faces of the sheet and also tend to work some of the asphalt into the inmost portions of the sheet. The sheet may then be run directly to a second tank 49 containing a secondary saturating bath, or may flrst be cooled as by a looper conventionally indicated at 50, or by another suitable cooling means. After suitable immersion in the secondary saturating bath, the sheet may be then passed between squeeze rolls 23, 24, which are preferably similar to those shown in Figure 1, either or both of which may be recessed as hereinbefore described. From these rolls the sheet is taken to a. looping apparatus similar to that shown in Figure 1, after which the sheet is further operated on as desired. 'I'he use of a separate tank 49 for saturating permits greater control in the nature of the saturants applied to the sheet. If desired, the tanks 2| and 49 may contain the same kind of substance, in which case a connecting pipe may be used to facilitate circulation through the two tanks. I may, however, use a. higher' melting-point asphalt in the tank 49 than in the tank 2| so that a greater amount of excess may be left upon the face of the sheet than would be practicable in the case of the low meltingpoint asphalt commonly used as an initial saturant. If an excess of low melting-point asphalt, beyond what can be absorbed in the process of cooling the sheet, is left on the face of the sheet, this unabsorbed excess prevents a proper bonding of the subsequently applied coating of high melting-point asphalt with the fibers of the foundation sheet, so that the coating on the surface of the shingle, being ordinarily surfaced with a layer of slate, is liable to slip when warmed by the sun of a summer day. If, however, the secondary saturating step is carried out with high melting-point asphalt, some of this asphalt will be sucked into the sheet and will thus firmly anchor any excess which may be left upon the surface after the sheet has been cooled, this excess having a sufficiently high melting-point to prevent slippage of the surfacing layers in hot weather.

In Figure `3 is illustrated another means for carrying out my invention. According to this form, the vsheet is passed between the usual squeeze rolls 23, 24 upon leaving the saturating tank, which remove substantially all the excess saturant from the face `oi the sheet. Additional waterproofing material which may or may not be similar to that in the tank 2| is applied at cznsice to the upper face of the sheet as by a spout having a notched or serrated edge as shown in Figure 10. A guide roll 53 may be placed opposite to the doctor to support the sheet against the edge of the latter. 'Ihe quantity of asphalt left on the sheet to be absorbed may be con- 1o trolled by the number and size of the notches in the doctor 52. It is obvious that such a doctor may be used on the under side of the sheet in conjunction with suitable means for applying excess asphalt to that side. l5

Having thus described certain embodiments of my invention, it should be evident to those skilled in the art that various changes and modications might be made therein without departing from its spirit or scope as defined by the appended claims.

I claim:

1. Apparatus of the class described, comprising means for supplying a sheet of roofing felt saturated with molten asphalt and covered with excess molten asphalt, means for feeding the saturated sheet with excess asphalt on its surface, and means for forming the fed sheet into loops to cool, said looping means comprising a. plurality of looper bars having raised contact points on their surfaces and arranged to engage a face of said sheet having excess asphaltthereon.

2. Apparatus of the class described, comprising means for supplying a sheet of roofing felt saturated with molten asphalt and covered with excess asphalt on both faces, means for feeding said sheet along with regulated quantities of excess asphalt on both faces, and means for forming said sheet into loops to cool, said looping means including a plurality of looper bars each having raised contact points on its surface to receive and support said sheet.

3. Apparatus for impregnating an absorbent sheet, with a molten asphaltic saturant, comprising a tank for molten saturant, means for passing the sheet through the saturant in said tank, means forexposing the hot saturated sheet to the atmosphere to cool the saturant in the sheet, and means for feeding the hot saturated sheet from the tank to the exposing means without indenting the sheet, said feeding means including a pair of driven rolls spaced apart a distance approximately equal to the thickness of the sheet for frictional feeding engagement therewith, at least one of said rolls having indenta- 55 tions therein to carry through the nip of said rolls a measured quantity of excess hot saturant just sufficient to satisfy the absorptive requirements of the sheet during cooling.

4. Apparatus for impregnating an absorbent 00 sheet with a molten asphaltic saturant, comprising means for maintaining a bath of saturant molten, means for passing a sheet through said bath, means for exposing the hot saturated sheet to the atmosphere to cool the saturant therein, and means for frictionally feeding said sheet from said bath directly to said exposing means including means for leaving an excess of said molten saturant on the face of the sheet substantially equal to the amount the sheet can absorb in cooling.

5. Apparatus for impregnating an absorbent sheet with a molten asphaltic saturant, comprising means for maintaining a bath of saturant The sheet then passes under a doctor 52 5 molten, means for passing a sheet through said bath, means for exposing the hot saturated sheet to the atmosphere to cool the saturant therein, and means for frictionally feeding said sheet from said bath directly to said exposing means, said feeding means including a. pair of driven rolls having opposing surface portions of substantial area spaced to squeeze the sheet without indenting it, at least one of said rolls having surface indentations adapted to pass substantial quantities of saturant through the nip between the rolls.

GEORGE P. HEPPES.

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