Document E8dkZwoKGDmx4b50jN8x0eN4

FILE NAME DuPont Remington DRM DATE 1966 Sept 6 DOC DRM027 DOCUMENT DESCRIPTION Patent Resubmit - Cartridge Wad and Process for the Manufacture Thereof with BC Notes BC Notes Remington patent refers to dusting which occurs when basewads made according to the original process are used Col. 3 Asbestos and wood fiber are used to make the shotgun shell wads Col. 4 BC Notes Remington patent refers to dusting which occurs when basewads made according to the original process are used Col. 3 Asbestos and wood fiber are used to make the shotgun shell wads Col. 4 United States Patent Office Office 3,440,072 Patented Apr. 22 1969 1 2 Various combinations of bindable fibrous materials 3,440,072 were tried in order to find a combination of materials CARTRIDGE WAD AND PROCESS FOR THE MANUFACTURE THEREOF which would have the necessary physical characteristics Benjamin K. Daubenspeck and Edward A. Rickey Strat- which would permit the mixed material to be molded ford Conn assignors to Remington Arms Company 5 directly into the completed wad in one step In addition Inc. Bridgeport Conn a corporation of Delaware to the characteristics which would permit molding the No Drawing Original application Apr. 29 1965 Ser No. mixture also had to have sufficient strength and other 452,007 now Patent No. 3,270,671 dated Sept. 6 1966 physical characteristics to be used as a shot shell basewad Divided and this application Feb. 23 1966 Ser No. It was found that asbestos not previously used in base- 529,218 Int Cl C09j 3/26 C08b 27/60 27/18 U.S. Cl 106 200 10 wad construction had the necessary characteristics which Claims permitted its use in this process First of all asbestos flows readily so that it can be controlled to plus or minus 5 grains important consideration in basewads where the weight must be carefully regulated Secondly asbestos ABSTRACT OF THE DISCLOSURE 15 is readily compressible so that in a short molding time air is removed and the wad will hold its dimensions A dry process of making ammunition wads by heating Furthermore asbestos has good strength qualities is a and blending asbestos with suitable filler material either natural binder is cheap and available and is stable in a ligneous cellulose material or some synthetic material heat moisture or corrosive atmospheres Finally asbes- adding a suitable wax binder blending and cooling the 20 tos is a known combustible and chemically re- dry mixture and then molding the mixture into the com- sistant mineral Asbestos dust when added to wood dust pleted wad in one step retards explosion and burning Varying compositions of asbestos were mixed with varying quantities of wood flour Silvacon bark fiber 25 and wood fiber with varying quantities of binder to suc- This application is a division of copending application cessfully make basewads by using the dry molding proc- Ser No. 452,007 filed Apr. 29 1965 now U.S. Patent ess An important consideration in limiting the amount No. 3,270,671 granted Sept. 6 1966 which in turn is a of asbestos is the weight factor since various functional continuation of application Ser No. 211,108 filed problems including shell ejection are encountered when July 19 1962 now abandoned 30 too great a quantity of relatively heavy asbestos is used This invention relates in general to shot shell wads In general it was found that all ligneous cellulose and particularly to an improved combination of materials materials are suitable for use as filler materials with for wads and the process of making the wads asbestos fibers Such synthetic materials as plastic flour An object of the invention is to provide an improved phenolics cellulose acetate polyvinyl alcohol and poly- cartridge wad which is practical and economical to 35 vinyl acetate also can be prepared in fibrous form and produce used as filler material with asbestos and still be compati- Another object of the invention is to provide a unique ble with the wax binders cold mold process of producing cartridge wads Another object of the invention is to provide an im- proved molded cartridge wad having fire and explosion 40 resisting characteristics Other objects will be apparent from reading the specification and the appended claims The following discussion will refer mostly to the manufacture of molded basewads However it must be appre- 45 ciated that the discussion is not intended to be limited to basewads only Although there are various processes of making base- wads most basewads which are made today are made by either a convolute wound process whereby a strip of 50 paper is wound continuously to form the wad or a wet process whereby the wads are molded from a fibrous slurry One of the main disadvantages of the wet process however is that the wads made by this process are variable and difficult to control The wound basewad on the It was found that microcrystalline wax or paraffin or blends of both with an additive to add strength and resiliency thereto e.g. butyl rubber could satisfactorily be used as a binder the exact composition depending on the product desired and the manufacturing circumstances involved Thus microcrystalline wax is very plastic at about 100 F. and is a source of some manufacturing problems at this temperature Paraffin wax is hard and brittle and may exhibit some objectionable fracturing characteristics on firing The ultimate of course is to find a formula which has the best compressibility characteristics and which is not sensitive to manufacturing con- ditions In general a wax binder would be suitable if the melting point was not substantially lower than about 120 F. and not substantially greater than about 200 F. ASTM Test D127-49 and if its hardness or needle penetration was between about 5 to about 100 tenths of a millimeter other hand is more expensive and has a serious defi- at 77 F. and under a 100 gram load ASTM Test ciency in that its sealing properties are poor Some D1321-57T manufacturers of wound basewads find it necessary to A preferred composition which can be utilized in mak- place an overlay over the wound basewad to seal the gas ing basewads by the cold molding process comprises This dual construction however is more expensive and 60 about has functional problems in that the overlay is not adequately fastened and sometimes comes loose in firing the shell A leaking basewad is objectionable because of its hard extraction especially with steel or aluminum heads and poor reloading characteristics 40 asbestos 60 wood fiber % of microcrystalline wax by weight of the above mix- ture of asbestos and wood fiber The sealing ability of the present mix coldmolded basewads is in itself an important improvement However it must be appreciated that the preferred percentages are not limiting in the exercise of the present in the art invention For example basewads can be produced of In the present new process low cost fibrous materials 100 asbestos plus binder or 100 wood fiber plus bind- are blended dry an adhesive material is added and the 70 er Obviously at these extremes it will be necessary to completed dry flowing mix is molded directly into sacrifice various physical characteristics which may make wads with no further treatment required the wads unacceptable for various types of shotshell use 3,440,072 4 It has been found that acceptable basewads for most general uses can be produced by varying the asbestos not substantially less than 30 and not substantially more than 60 Conversely the wood fiber or whatever other filler material is used can be varied from not substantially less than 40 and not substantially more than 70 Finally the binder e.g. microcrystalline wax can be present in an amount equal to 5-15 of the weight of the bindable fibrous materials Process 10 Assuming that the fibrous bindable material is to be the preferred mixture i.e. asbestos and wood fiber this mixture is blended in a ribbon mixer and the mixture is heated to a temperature of about 120 200 F. although the preferred range is about 180 200 F. Molten microcrystalline wax or a blend thereof is then sprayed on the hot fibrous mixture and the mixture and binder blended It is possible to add the binder with the original fibers but spraying the molten adhesive on the 20 blended fibers appears to give a more uniform mixture As mentioned above the preferred range to which the fibrous mixture is heated is about 180 200 F. However the mixture can be heated above 200 F. with 25 a corresponding result that more moisture is driven out of the mixture which moisture must be replaced before the final molding of the wad The temperature is kept low to keep as much inherent water in the fibers as possible 30 After blending the heated fibrous mixture and the molten wax binder the mixture is cooled and moisture added to bring the moisture content to the original content of the fibers 4 to % wet basis If the moisture is not brought up to the original content the final wad will take on moisture from the air and swell If there is too much moisture in the mixture the final wad will give off the excess moisture and shrinking will result The mixture can be cooled at room temperature or by feeding the mixture to a cooler Also the moisture con- 40 tent can be raised or lowered as circumstances require From the cooler the mixture goes to a storage hopper and then to feeders which feed the cooled mix to the tabletting or compressing machine where the mix is in- dividually apportioned and molded at pressures ranging from 10,000 to 40,000 pounds per square inch 45 It is possible to mold the basewads without cooling the blended mixture of fibrous material and wax binder However the hotter the material the more difficult it is to produce a physically strong basewad which can stand the material handling of the wads after they come from 50 the tabletting machine The strength obtained in cooling the mixture prior to tabletting aids materially in the handling of the wads after they are ejected from the tabletting machine A slightly modified process utilizes the addition of calcium resinate to the wax or wax blend in order to permit the use of higher percentages of wax and wax blends binders without altering the obturating charactersitics of the basewad and without sacrificing rigidity and strength The modified process is useful to cut down on 60 the amount of dusting which occurs when basewads made according to the original process are used With the higher wax content greatly improved moisture re- sistance is obtained as well as increased resistance to erosion and splitting tendencies of a dry mold basewad 65 It is believed that the calcium resinate improves the binding properties of the wax adhesion and tensile strength without inducing brittleness Assuming that the fibers to be used in the modified process are asbestos and wood fibers the mixture is 70 blended in a ribbon mixer and heated to a temperature of about 120 200 F. although the preferred range is about 180 200 F. After several minutes mixing added and the mixing continued to produce a homogeneous blend The percentage of precipitated calcium resinate added is determined by the properties desired in the molded basewad In the present example where the asbestos fiber ratio is about 40-60 the calcium resinate addition is equal to about 4-5 of the total weight of the asbestos fiber blend To the above mixture a molten binder preferably a blend of microcrystalline wax and paraffin wax is sprayed on to the mixture of fibers and calcium resinate The percentage of wax blend used depends on the properties desired in the molded basewad and in the present example is equal to about 15-20 of the total weight of the asbestos fiber mixture After all the ingredients have been mixed at a temperature of about 180 F.200 F. and thoroughly blended the batch is transferred to another ribbon mixer where it is cooled and sufficient water added to bring the moisture content to about 4-6 percent As in the first process in general all ligneous cellulose materials are suitable as filler materials with asbestos fibers Such synthetic materials as plastic flour phenolics cellulose acetate polyvinyl alcohol and polyvinyl acetate also can be prepared in fibrous form and used as filler material What is claimed is 1. A process of making a cartridge wad comprising blending a mixture of approximately 40 asbestos and 60 wood fiber heating said mixture to a temperature between 120 200 F. spraying molten wax binder on the hot mixture and blending cooling the wax and fiber mixture adding moisture thereto to bring the moisture content of the blended mixture to the original moisture content of the fibers and compressing said cooled and dry mixture at pressures ranging from 10,000 to 40,000 per square inch to its final wad form said wax binder having a hardness or needle penetration of be- tween about 5 to about 100 tenths of a millimeter at 77 F. and under a 100 gram load 2. A process of making a cartridge wad comprising blending a mixture of 30-60 of asbestos fibers and 70-40 of wood fibers with precipitated calcium resinatc heating the mixture to a temperature between 120 F.200 F. spraying molten wax binder on the hot mixture and blending cooling the wax and fiber mixture adding sufficient moisture thereto to bring the moisture content of the blended mixture up to between %% and compressing said cooled and dry mixture at pressures ranging from 10,000 to 40,000 pounds per square inch to its final wad form said wax binder having a hardness or needle penetration of between about 5 to about 100 tenths of a millimeter at 77 F. and under a 100 gram load 3. A method of making a cartridge wad comprising mixing quantities of bindable flowing fibrous materials blending and heating the fibers to a temperature of 120 200 F. adding a molten binder to the fibrous mixture and blending the resultant final mixture bringing the moisture content of the mixture to about the original moisture content of the fibers compressing the dry final mixture into final wad form said bindable fibrous materials comprising not substantially less than 30 and not substantially more than 60 of asbestos and not substantially less than 40 and not substantially more than 70 of other filler material selected from the group of low density fibrous materials consisting of ligneous cellulose fibers cellulose acctate fibers polyvinyl alcohol fibers and polyvinyl acetate fibers said binder comprising a wax having a melting point not substantailly lower than about 120 F. and not substantially greater than about 200 F. and a hardness or needle penetration of between about 5 to about 100 tenths of a millimeter at 77 F. and under a 100 gram load or at such time that the asbestos and wood fibers have been thoroughly mixed precipitated calcium resinate is 4. A process of making a cartridge wad consisting of mixing and blending a molten binder with a hot dry 3,440,072 6 flowing mixture of about -60 of asbestos penetration of between about 5 to about 100 tenths of a fibers and about -70 of at least one other filler millimeter at 77 F. and under a 100 gram load material selected from the group of density fibrous 5. A process as recited in claim 4 wherein said molten materials consisting of ligneous cellulose fibers cellulose binder includes wax and calcium resinate acetate fibers polyvinyl alcohol fibers and polyvinyl 6. A process of making a cartridge wad as recited in acetate fibers cooling the combined mixture bringing 5 claim 4 wherein said other filler material is wood fiber the moisture of the blended mixture up to about its original level and compressing the cooled mixture References Cited into final wad form said dry flowing mixture having UNITED STATES PATENTS been heated to about 120 F. to 200 F. said molten binder comprising a wax having a melting point not substantially lower than about 120 F. and not substantially 1,771,898 3,022,734 7/1930 2/1962 O'Neil et al eo ----e 102-44 Kidder 102-42 greater than about 200 F. and a hardness or needle ALLAN LIEBERMAN Primary Examiner