US 3016582 A
Description (OCR text may contain errors)
Jan" 16, 1962 c. G. JOA
BATT OR MAT FORMING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 14, 1957 INVENTOR. C'UQT 6 Jan Afro/eve" v5 Jan. 16, 1962 c. G. JOA 3,016,582
BATT OR MAT FORMING APPARATUS Filed Feb. 14, 1957 2 Sheets-Sheet 2 2/3 INVENTOR. f9' 6 60m" 6. Jan
BY M I M4 A rraew v! United States Patent Qiifice 3,016,582 Patented Jan. 16, 1982 3,016,582 BATT R MAT FORMING APPARATUS Curt George .Ioa, Sheboygan Falls, Wis., assignor to Falls Paper 8; Power Company, Chester, Pa., a corporation of Wisconsin Filed Feb. 14, 1957, Ser. No. 640,277 1 Claim. (Cl. 19-156) This invention relates to a batt or mat forming method and apparatus.
In the past, pulp sheets from the wood pulping mills have been disintegrated in a hammer mill and the resulting fluff has been conveyed by blowers and pipe systems to the point of use and deposited by various elaborate mechanisms on conveyors or drums to make batts. Not only have these installations been relatively expensive, but considerable difficulty in their use has been encountcred because of irregularities in flow of the convection currents of air or the like and, more particularly, because of the generation of static electricity in the duct work which will interfere with the regularity of flow of the finely divided particles of wood fiber.
The present invention eliminates these problems substantially in their entirety by combining batt forming means directly with the hammer mill so that there is no intervening duct work or convection circuit. The pulp sheet is disintegrated in the hammer mill in the usual manner and the particles sufficiently finely divided to flow through the hammer mill screen are deposited directly upon a moving conveyor belt (or transferred thereto by a forming screen wheel). In either case, the deposit is substantially direct from the hammer mill screen to the batt and it is found that the relative movement between the forming screen and the hammer mill screen is such that the fibers are given the desired orientation in the batt.
In one embodiment herein disclosed, a portion of the deposit is used to make up one relatively narrow batt and another portion of the deposit makes up another relatively narrow batt, the two batts being subsequently laminated together to make up a batt of double thickness.
In the drawings:
*IG. 1 is a view in transverse section through a hammer mill and batt forming device embodying the invention.
FIG. 2 is a fragmentary detail view showing a slight modification in which a batt leveling wheel is substituted for an adjustable seal to determine batt thickness.
FIG. 3 is a View somewhat similar to FIG. 1 showing a modified embodiment in which the batt forming screen is on the periphery of a wheel from which the formed batt is transferred to a conveyor.
FIG. 4 is a view in transverse section through a modified embodiment for making a laminated batt.
FIG. 5 is a section on line 55 of FIG. 4.
FIG. 6 is a diagrammatic plan view showing the lateral shifting of one component preliminary to its lamination with the other component of the laminated batt.
The hammer mill casing S, rotor 9, swing hammers 1t), hopper 11 and knurled infeed roller 12 and 13 are all generally conventional. The pulp sheet 15 introduced into the hopper is forced by the feed rolls into the path of movement of the swing hammers and supported by the shear plate 16 for disintegration by the hammers. The disintegrated fluff material 17 passes about the path of the hammers 10 as these rotate clockwise with rotor 9. When the material is ground sufiiciently fine, it passes through the foraminous hammer mill screen 20 and falls onto the forming screen 21 which here comprises a conveyor belt trained about drive pulley 22 and idler 23.
A portion of the forming screen which is traversing the hammer mill housing passes across a high vacuum suction box at 24 which desirably has at least two discharge ports at 25 and 26 through which air is evacuated.
The suction causes air to be drawn through the hammer mill. The makeup air enters the hopper 11 and holds the fibers to the hammer mill screen 20, thereby assisting in the comminuting operation of the mill. The air passing through the batt which is in continuous formation on the forming screen 21 holds the newly arrived fiber in place. The movement of the batt relative to the hammer mill screen tends to lay the fibers with their longitudinal dimensions parallel to the path of conveyor movement, thus giving fiber orientation in the deposited batt 30.
For compacting the batt and making it uniform in thickness, a wiper 33 is adjustably mounted on hopper 11 across the port 34 through which the batt issues. The wiper may be made of somewhat flexible heavy rubber attached to a plate 35 adjustably bolted to the side wall 36 of the hopper. The width of the wiper exceeds the height of the opening 34 so that the wiper extends along the top surface of the batt as clearly shown in FIG. 1, holding in the hopper such material as is loose on the surface of the batt.
As an alternative embodiment, I may provide a relatively fixed seal at 339 to exclude atmospheric air, this seal encircling a paddle wheel type leveling rotor 38, the vanes of which throw the loose fiber on the upper surface of the batt rearwardly into the hammer mill casing where it is redeposited.
It is still desirable to hold the batt to the conveyor by vacuum even after it leaves the housing 8 and I may use a vacuum box 39 for this purpose. However, I do not use as high a degree of suction on the vacuum box 39 as is employed in the vacuum box 24 which aids in depositing the fibers that form the batt.
The forming screen may comprise the periphery 211 of a suction wheel 40 such as that shown in FIG. 3. There a pair of seals 331 and 332 guide the material from the hammer mill screen 26 onto the periphery of the suction wheel. The suction wheel as shown in FIG. 3 rotates counterclockwise in order that the batt formed thereon may be deposited onto the conveyor 212 which has a suction box 392 of its own. In order to facilitate the transfer from the wheel to the conveyor, a portion of the wheel is relieved of vacuum by an arcuate baffle 42 supported from the shaft 43 about which the wheel rotates. The operation is essentially as above described, the high degree of vacuum being drawn on the interior of the wheel by means of withdrawal of air through port 252.
The construction shown in FIGS. 4 to 6 differs from those above described only in that a divider or dividers at 45 in the bottom of the hammer mill housing 8 guides the pulp onto two separate forming screen belts 213 and 214. The top runs of both belts are at the same level and a single vacuum box as above described may serve both beneath the hammer mill. However, in the exemplification disclosed, the belts operate in opposite directions, the belt 213 operating to the right as viewed in FIG. 4, and the belt 214 to the left. The batt 304, formed on screen 214, is transferred to conveyor 47 and shifted laterally as shown in FIG. 6 and ultimately laminated with batt 303 as shown in FIG. 4.
The webs of batt material made according to any of the embodiments herein disclosed are adapted for such use as sanitary napkin pad manufacture, as well as for the manufacture of packing material, and many other purposes. The invention is not to be regarded as limited to the use of pulp sheet as the starting material, since excelsior, hair felt and other materials may also be disintegrated in a hammer mill and used to form a batt in the manner herein contemplated.
The combination with a hammer mill comprising a rotor having hammers, a housing for the rotor and a :3 1B foraminous screen within the housing partially encircling 1,691,585 the path of hammer movement, of a plurality of form- 1,973,074 ing screen means movable side by side across the housing 2,078,355 beyond the forarninous screen from the path of hammer 2,105,759 movement and provided With suction box means for 5 2,478,148 drawing to themselves material disintegrated by the ,5 ,7 5 hammers and passing through the foraminous screen, 2,581,069 together with means for laminating together material 2,665,453 deposited on a plurality of said forming screen means. 2,689,985 10 2,698,271 References Cited in the file of this patent UNITED STATES PATENTS 2,726,423 561,689 Patterson June 9, 1896 2,731,679 1,336,403 Weiss Apr. 6, 1920 5 2,807,054
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