Patent Application
20060144854
The present invention relates to cartridge packs for the dispensing of various components and, more particularly, to cartridge packs employing a pair of film bags containing flowable compositions which are to be admixed when ejected from the dispenser.
Various compositions are packaged in tubular cartridges for use in caulking guns and other types of dispensing mechanisms. In some instances, the dispensing mechanisms will take two or more cartridges side-by-side so that the contents of the cartridges are dispensed simultaneously and admixed in a mixer as they flow towards the point of deposition. Typically, such cartridges have employed tubes of plastic, or coated or laminated paperboard, and the like. Moreover, the tubes generally have been filled through one end of the tube after which a closure is placed thereover. Using such side-by-side cartridges to dispense two components involves a substantial amount of waste and expense.
In recent years there has been considerable activity in cartridges comprising a pair of film bags within a cylindrical shell. Exemplary of such cartridges are those disclosed in Keller U.S. Pat. No. 5,647,510.
Although such cartridges have represented an improvement from the standpoint of ease of use, generally the structures have been relatively complicated to fabricate and relatively costly. Obtaining good seals between the bags and the face piece of the cartridge has been a problem. Filling of the film bags and their handling has often presented a problem in automated equipment.
It is an object of the present invention to provide a novel film pack cartridge for dispensing dual components which is relatively simple to fabricate easy to fill and relatively trouble free during the dispensing operation.
It is also an object to provide such a dispenser cartridge which is relatively economical to fabricate and which permits dispensing of the contents at several different times.
Another object is to provide such a dispenser cartridge which is readily adapted to different ratios of the components.
A further object is to provide a dispenser cartridge which can be filled after assembly of the bags to the face plate.
It has now been found that the foregoing and related objects may be readily attained in a film pack cartridge including an integrally molded synthetic resin face plate having a discharge opening and a nosepiece on one face extending about the opening. A pair of flexible synthetic resin bags each have one end sealingly adhered to the other face of the face plate about the discharge opening, and the other ends of the bags are sealed.
Preferably, the face plate has a flange on the other face which extends about the opening, and one end of each of the bags is sealingly adhered to the flange. The bags and the face plate are fabricated from substantially the same synthetic resin to obtain a good bond.
In one embodiment, the pair of tubular bags each have one end adhered to the face plate in side-by-side registry with a portion of the discharge opening, and the discharge opening has a divider extending therein so that the contents of the bags remain separated as they pass through the opening. The nosepiece has a partition therein aligned with the divider in the opening to maintain separation of contents passing thereinto.
In another embodiment, the opening has a generally circular periphery and the face plate includes a generally circular divider supported within the opening to provide a generally annular peripheral portion of the opening and a generally circular portion spaced centrally thereof. One of the bags is of annular configuration and has the one end sealingly adhered to the face plate about the peripheral portion of the discharge opening, and the other of the bags has a circular cross section and is disposed in the center of the annular bag and in sealing engagement with the circular divider. The face plate has a nosepiece thereon extending from the discharge opening and a circular partition corresponding to the divider to maintain separation of the contents passing thereinto.
The cartridges are filled with flowable compositions and will normally have a sealing cap on the end of the nosepiece which is replaced by a static mixer when discharging the contents.
In use, the filled film bag cartridge is mounted in a dispenser including a housing with a dispensing end, a tubular sleeve, and a piston is movable in the sleeve towards the dispenser end. The film pack which is disposed in the tubular sleeve can be removed so that the sleeve can be reused.
In the preferred method for producing dispenser packs of flowable compositions, a generally tubular flexible synthetic resin bag is supported on a mandrel, and the mandrel and bag are inserted into a mold providing a cavity about the end of the mandrel and bag; the cavity is configured to provide the face plate and nosepiece. Molten synthetic resin of substantially the same composition as that of the bag is injected into the cavity to form a face plate with the end of the bag sealingly adhered thereto. The face plate has a discharge opening therein and a nosepiece about the opening aligned with the end of the bag. The face plate, bag and mandrel are received from the cavity, the bag and face plate are removed from the mandrel, and the end of the bag spaced from the face plate is sealed. A flowable composition is injected through the nosepiece and opening in the face plate and into the bag, and a sealing cap is mounted on the nosepiece.
In one embodiment, a pair of synthetic resin bags are mounted on a pair of mandrels which are cooperatively configured and cooperate to define a generally circular cross section when placed in a cylindrical sleeve. The mold cavity and mandrels are configured to provide a partition in the opening in the face place and a nosepiece separating the contents of the two bags as the compositions in the bags flow therethrough. Flowable compositions are injected into each of the bags through the nosepiece.
In another embodiment, a pair of synthetic resin bags are mounted on a pair of mandrels, one of which is annular cross section and the other is of circular cross section and disposed within the annular mandrel. The mold cavity is configured to provide a face plate with a partition in the opening and nosepiece separating the contents of the two bags as the composition in the bags flow therethrough.
a is a rear view of the face plate of the cartridge shown in
a and 12b are respectively side and rear elevational views of a cap;
a and 13b are respectively side and front views of a coupler; and
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The passage through the nosepiece 36 has a partition 48 which maintains the separation of the two streams until they enter the static mixer generally designated by the numeral 50 and which is secured onto the nosepiece 36.
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Molten synthetic resin is injected into the cavity portion 86 through runners (not shown) to produce the desired face plate 30 including the flanges 32, discharge opening 34 and nosepiece 36. The molten resin heats the exposed end portions of the bags 26,28 to effect a strong bond between the bags 26,28 and face plate 30. After cooling, the mold 76 is opened and the mandrel fixture is withdrawn. The film bags 26,28 are slid off the mandrels 78,80 and the opposite ends of the bags are sealed to provide an empty cartridge.
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The coupler 104 also serves to mount the static mixer generally designated by the numeral 110 since the coupler 104 bears against the flange 112 of the mixer 110.
As used herein, the term “discharge” opening includes single partitioned openings and spaced, separate openings. The configuration and size will vary with the volume to flow therethrough and the bag configuration.
As used herein, the term “synthetic resin” includes homopolymers and interpolymers, and various additives including fillers, reinforcing elements, etc. In the instance of the film bags, it includes not only homogenous films but also laminates of different resins with and without additives. A preferred resin is polypropylene but polyethylene and nylon may also be used. For some applications, it is desirable to use a composite film with a center layer of nylon and inner and outer layers of polypropylene.
As used herein, the term “substantially identical” composition refers to resins of similar chemistry which will bond strongly. In the instance of laminates, the resin providing the surface of the bag to be bonded to the face plate should be substantially identical to that the resin of the face plate so that the bag will firmly bond thereto.
The film bags are generally formed from tubular film cut to the desired length. Although blown film is preferable, flat film may be formed into a tube with bonded overlapping edges.
Bonding of the ends of the bags remote to the face plate can be effected by adhesives, heat, sonic welding, and other readily available techniques.
Various flowable compositions may be used in the film packs including sealants, adhesives, protectants, paints and other coating materials, foams, etc. The film exposed thereto and the face plate should have a composition which will not be adversely affected thereby.
The mixed components exiting the static mixer can be applied directly or sprayed by use of a pressurized air source and a suitable nosepiece assembly.
The dimensioning (cross sectional area) of the bags in a film pack will allow proportionating the two components to be mixed. For a 1:1 ratio, the bags have the same cross sectional area. For a 3:1 ratio, one of the bags will have a cross sectional area which is three times that of the other. When the relative viscosity of the compositions or the ratios warrants, the discharge openings may also be customized to facilitate or retard flow therethrough.
The discharge opening may assume several different configurations but should provide partitioning of the flowable compositions until after they have passed into the nosepiece. Moreover, the configuration and dimensioning of the separate portions may provide a restriction for one of the flowable compositions to accommodate variation in viscosity, different ratios, etc.
The bags are filled by injecting the flowable compositions through the discharge opening(s). After sealing the opposite end of the bags, the face plate can be mounted on a fixture which allows the bags to extend vertically downwardly. A vacuum may be drawn on the bags through the nosepiece to facilitate the filling of the bags without having to vent air from the bags as they are being filled, or a nitrogen purge may be used. Alternatively, the bags may have a porous vent to permit air to pass therethrough but not the composition being introduced into the bag.
The dispensers conveniently use as sleeves cylindrical tubes of synthetic resin, spiral wound paperboard, metal and laminates which can be reused. By use of shuttles acted on by the pusher of the piston, the shuttles are moved in the sleeve against the bags to compress them. When the film packs are only partially discharged, the static mixer can be removed and discarded, and the cap is placed on the nosepiece. If the contents are fully discharged, the static mixer is removed and the film pack can be removed from the sleeve; both are discarded. A new film pack can be placed in the sleeve which is rotated end for end before placement in the dispenser. Thus, the shuttle is at the opposite end of the dispenser to be acted upon by the pusher of the piston when the sleeve and cartridge are placed in the dispenser.
Thus, the discharged film pack cartridges and static mixers are discarded, but the dispensers, sleeves and shuttles are all reusable.
Thus, it can be seen from the foregoing detailed description and attached drawings that the film bag cartridges of the present invention are relatively simple to fabricate and the components are bonded to provide good sealing. The bags can be filled easily after assembly of the components.
