US3330409A - Bale strap means and pulp bale combination - Google Patents

Description

July 11, 1967 M. B. JORGENSEN BALE STRAP MEANS AND PULP BALE COMBINATION 2 Sheets-Sheet 1 Filed Aug. 3, 1964 FIG. 4

FIG?) United States Patent 3,330,409 BALE STRAP MEANS l) PULP BALE C(BMBENATION Mark B. Eorgensen, Neenah, Wis, assignor to Kimberly- Clarir Corporation, Neenah, Wis., a corporation of Delaware Filed Aug. 3, 1964, Ser. No. 386,885 2 Claims. (Cl. 206--83.5)

My present invention relates to the baling of pulp and is particularly concerned with the provision of novel pulp bale strap means for retaining pulp securely in baled form during shipment and storage.

Wood pulp is commonly baled by pulp producing mills for the purposes of both storage and shipment. The pulp, when baled, normally contains a quantity of water, at least about 5 to by weight. This water content may change during storage or shipment depending upon atmospheric conditions. Change of moisture content exerts a varying degree of stress by the bale upon the usual metallic baling strapping.

The metallic baling strapping generally used commercially in pulp baling is in the form of quite narrow widths of flexible steel or the like and may be identified as the type of strapping used as the strapping on large cardboard cartons. Such metallic strapping is costly in pulp baling procedures, both from the point of View of the strapping itself and from the point of view of handling. The metallic strap is particularly disadvantageous in that it must be removed before the pulp bale is fed to the equipment containing the aqueous medium in which the pulp is redispersed. Upon removal, the metallic strapping may have some slight value as scrap metal but the handling and storage costs do not make this procedure economically attractive. Also, in handling such metallic strapping the possibility of injury is present because of the springiness and resiliency of the strapping.

By my present invention the necessity for metallic strapping, and its consequent disadvantages, is eliminated. I have found that dry sheet pulp in the form of relatively narrow bands may be made endless and employed as the sole retention means for bales of cellulosic pulp. By relatively narrow bands I mean bands which are narrow in relation to the dimensions of the pulp bales. For the purposes of attaining adequate strength in the relatively narrow bands, the pulp material forming the bands should preferably be of long fibered pressed pulp material.

Importantly, the pulp material which forms the strength member is itself water dispersible. Also the pulp material need not itself be specially made for the purpose; narrow widths may be skived from regular pulp sheet production in substantially continuous lengths for use as the strapping material. While kraft pulp is preferred, any strong pressed pulp sheet having strength characteristics similar to kraft may be employed. Water dispersibility provides that the bale itself, including the bale strap, may, upon usage, be fed directly to the tanks in which pulp dispersion is to take place. In a preferred embodiment of the invention the bale strapping material is made endless with a water dispersible adhesive; the adhesive may be selected to be compatible with conditions of the process for which the pulp, when dispersed, is intended. Alternatively, the bale strapping material may be made endless with staples, synthetic glues, mechanical devices or the like-and before use the joint may simply be snipped from the main body of the bale strapping means and discarded or directed to other purposes. It is to be particularly noted that the bale strapping material is made endless at the time of application of the strap material to the bale in the same manner as conventional metallic strapping is applied.

It is, accordingly, an object of my present invention to provide a pulp bale strapping which is readily handled, is economical, is of the same general nature as the material which it bales, may be subjected to the same pulp dispersion processes and utilized as a component of the same end product for which the baled pulp is intended-and which requires essentially no separate handling by a user of the baled pulp.

These and other allied objects of the invention will be apparent from the following detailed deescription and accompanying drawings wherein:

FIG. 1 is a perspective view of a pulp bale retained by a pair of bale straps formed in accordance with the invention;

FIG. 2 is a view of a strap in completed form but in which form it would normally be made endless and complete in a circumferential sense about the bale;

FIG. 3 is an enlarged and fragmentary view illustrating the corrugated nature of the surface of a preferred embodiment of strapping material;

FIG. 4 is an enlarged and fragmentary edge view illustrating a strap joint;

FIG. 5 is a fragmentary view in plan of another embodiment of the strap of invention;

FIG. 6 is a view taken on line 6-6 of FIG. 5;

FIG. 7 is a view of yet another embodiment of a joint useful in conjunction with the bale strap of the invention and which includes staples;

FIG. 8 is a fragmentary View of a further embodiment in which the strap on the bale is provided with an additional protection against contamination with liquid; and

FIG. 9 is a view of a further embodiment of the strap joint in which the joint includes punched openings.

Referring to the drawings, the numeral 1 designates the ordinary pulp bale which may have the following dimensions: 28 inches by 32 inches by 16 inches. The bale is formed, pressed under high pressure, and then allowed to relax somewhat before strapping.

The bale is retained by the bale straps designated at 2; the strap material is made endless about the bale by joints as at 3. As shown more clearly in FIGS. 2 and 4, the joints of the structure of FIG. 1 may simply include an adhesive 4. The adhesive 4 is preferably water dispersible; one such glue is animal glue which penetrates pulp stock well.

The surfaces of the strap material, as shown at 5 in FIG. 3, is preferably corrugated. These corrugations assist in retention of the glue or adhesive 4 and materially assist the formation of a strong joint. These corrugations normally occur in the production of the sheet pulp material in procedures employing the well known Kamyr press; they are not essential to the practice of the invention but provide for some interlocking at the joint. When the corrugations or the like are not normally present in the pulp material as formed, the surfaces may be roughened if necessary to aid the strong joint formation.

As shown in FIG. 5, the joint may be formed by sections of strap material of diiferent widths. For this purpose one end of a single length may be skived down; or pieces of differing widths may be employed, in which case the complete bale strap has two or more joints. Such arrangements afford, by virtue of the provision of a Wide slot 7 through the thickness of the wide material 6, a better gripping capacity for the end of strap 8 which, as is shown, is serrated at 9. The serrated end passes through slot 7 and overlies material 6. As indicated in FIG. 6, when such arrangement is employed, glue is utilized to retain the serrated portion in intimate contact with the lower strap portion; the serrations inhibit withdrawal through the slot.

As shown in FIG. 9 the glued joint may be further strengthened at the joint by simply punching the superposed straps 2 completely through, as indicated at 1 1,

such that the pulp material is peened over as at 12. An-

use. As shown in FIG. 8, a bale may be suitably provided at its lower end with an overlying protective water resistant film strip of polyethylene, for example, glued to the strap and bale body with the same material as the glue of the strap joint. This protective material serves the purpose of preventing intimate contact of the strap with water or the like on the floor of a freight car, for example. Commonly, such strip is unnecessary, however.

In practice I have found that the strap material may be formed insubstantially endless lengths by skiving an appropriate width of material from pressed pulp sheets as they are formed. The sheet material, preferably for the baling purpose, is conveniently solely of softwood (coniferous) kraft long fibered pulp; southern pine, spruce and the like serve the purpose well. The kraft (sulfate) pulp is commonlyof greater strength than sulfite pulp, particularly hardwood sulfite pulps and, accordingly, a greater width and thickness is usually necessary to attain the same strength property with the latter material. Some sulfite pulps tear readily and are, accordingly, not recommended for the purpose. The strap ing material may be and usually is bleached in the normal course of production, and no special precaution need be taken in this respect with respect to strength factors. The strap width for the typical bale dimensions mentioned hereinbefore may be less than four inches. The optimum width for particular conditions to which the bale strapping may be subjected varies somewhatwater pickup by the strap material tends to weaken the strapywhen the conditions for water pickup are not present to any material extent, strap widths as low as about one inch have been found suitable with the bale dimensions mentioned and utilizing kraft (sulfate) hard pressed dry pulp. The strap material, while normally relatively inextensible and demonstrating more than suflicient strength in thin thicknesses of about to A inches, will extend somewhat with moisture pickup; the bale of pulp, of course, also tends to extend in dimension under the same moisture conditions. Accordingly, stress caused by bale expansion tends to be relieved by strap extension due to the moisture pickup. More specifically, the strap tends to expand and contract with the bale. However, complete wetting of the strap is to be avoided and, if water dispersible adhesives are employed, the joint should, of course, be well up on the bale and away from contact with sources of liquid water. The extent of the overlap at the joint is usually between about 2" to 3" with the adhesives and joint form- 'ing means I have employed the pulp redispersion process. The water soluble or water ing production. A 50% solids content of animal .glue in water serves the purpose well. If heated to about 140, such adhesive penetrates quickly and dries to a hard set condition in less than four minutes. The strap material, however, is characterized by a high degree of flexibility and may be bent quite sharply without serious fracture through its thickness and, accordingly, conforms well to the shape of the baled pulp. Other adhesives which I have found useful include synthetic rubber (neoprene) polyvinyl acetate solutions in toluene having a solids content of about 21.523% and a viscosity of about 800 to 1300 centipoises. Adhesives produced by the Borden Chemical Company Arabol Division under the trademark SN-905 are of the latter type and serve the purpose. The V adhesive, however, as long as it is capable ofproviding sufiicient bond strength, is not critical as the joint may be snipped from the strapping and the remainder of the pulp of the strap employed in conventional pulp'processes, for the remainder of the strapping requires no treatment whatsoever to make it acceptable for the purpose.

In application to the pressed bale of pulp the strapping is simply drawn about the bale under tension and secured mechanically or by adhesive. With some adhesives a holding time of about 10 minutes may be required to permit the adhesive to set-such holding time characterizes the synthetic rubber base adhesives which I have employed. Pressure may be employed in conventional manner to assist adhesive setting.

In practice the pressed pulp has proved useful for its intended purpose and to withstand handling in shipment in a thoroughly satisfactory manner.

' It will be understood that this invention is susceptible to modification in order to adapt to different usages and conditions and, accordingly, it is desired to comprehend such modifications within the invention as may fall within the scope of the appended claims.

What is claimed is:

1. In combination, a pulp bale and bale strap means made endless in a circumferential sense about the bale retaining the pulp bale, said bale strap means being in the form of relatively narrow band means of long fibered softwood pulp, the pulp of said bale and of said band means being of the same general characteristics such that the band means has essentially the same utility for pulp processing as does the pulp of the bale.

2. The combination as claimed in claim 1 and in which the bale strap means includes at least one joint whereby the bale strap means is made endless and said joint com- References Cited UNITED STATES PATENTS 981,890 1/1911 Smith. 1,779,335 10/1930 Remrey 206. X 2,004,098 6/ 1935 Andrews 20665 2,271,632 2/ 1942 Diehl. 3,089,634 5/1963 'Heise et al. 209-49 3,235,071 2/1966 Simich et al 20683.5

LOUIS G. MANCENE, Primary Examiner,

Claims (1)

1. IN COMBINATION, A PULP BALE AND BALE STRAP MEANS MADE ENDLESS IN A CIRCUMFERENTIAL SENSE ABOUT THE BALE RETAINING THE PULP BALE, SAID BALE STRAP MEANS BEING IN THE FORM OF RELATIVELY NARROW BAND MEANS OF LONG FIBERED SOFTWOOD PULP, THE PULP OF SAID BALE AND OF SAID BAND MEANS BEING OF THE SAME GENERAL CHARACTERISTICS SUCH THAT THE BAND MEANS HAS ESSENTIALLY THE SAME UTILITY FOR PULP PROCESSING AS DOES THE PULP OF THE BALE.

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