The present invention relates to sealable and/or resealable containers used primarily for bulk packaging more particularly the present invention relates to bulk packaging of pharmaceuticals and the like and more particularly materials that are in the form of powders.
Pharmaceuticals, cosmeceuticals and nutraceuticals are frequently packaged in bulk for shipment from the place of manufacture to another location. The other location may be where the composition undergoes further formulation or where the composition is packaged in smaller quantities for users, etc.
Currently many bulk shipments of pharmaceuticals is done in drums whether plastic or metal or in bags, usually flexible bags made of plastic, or paper or a multi layer composite where at least one layer is a plastic and at least one layer is paper. During filling, these bags, no matter what the composition or structure of the bags, are usually filled individually. By individually is meant each individual bag is filled in turn by a process at the filling station. The bag then can be sealed in place or moved to a sealing station for sealing. The bag can be sealed by a variety of means including a heat seal, a sewn seal or other suitable sealing methods.
One of the problems with the prior packaging system is that a great deal of product dust can be generated by the process. As product flows into one end of the bag, product dust is generated and becomes airborne. Following the filling step, if the bag is manipulated while open including for sealing, dust is frequently a by-product of the manipulation. If the bag is transported to the sealing station where the top of the bag is sealed, the transportation step can jostle the bag and cause product dust generation. Whether the top is sealed by a heat seal or by sewing or by other means, the manipulation of the bag can generate product dust during the manufacturing process.
Product dust generated by the packing process and other steps in the manufacturing process have been the subject of several recent studies. Besides damage the dust can cause to the lungs when the dust is inhaled there is also the problem of workers receiving undesired doses of the pharmaceuticals, neutraceuticals or cosmaceuticals. The ingestion of some of the pharmaceutical dust can be very damaging to the workers. For example in one recent instance it was found that the workers in a pharmaceutical plant manufacturing birth control pills had inordinately high levels of estrogen. These high estrogen levels were due to physical contact with the ingredients used in manufacturing the birth control pills, either through breathing the dust or from physical contact with the workers skin.
As a result, there is a need for an improved packaging system and a package that reduces the risk of product contact with workers during the filling and sealing process.
It is an object of the present invention to provide an improved system for bulk packaging pharmaceuticals, nutraceuticals, cosmaceuticals and the like.
It is also an object of the invention to provide an improved bulk package for containing pharmaceuticals, nutraceuticals, cosmaceuticals and the like.
It is another object of the invention to provide a tubular bag for use in bulk packaging of pharmaceuticals, nutraceuticals, cosmaceuticals and the like.
It is a still further object of the invention to provide a system that reduces dust generation in the bulk packaging of pharmaceuticals, nutraceuticals, cosmaceuticals and the like.
It is still another object of the invention to provide a bagging system for bulk powdery material that reduces dust generation.
It is a further object of the invention to provide a bagging system that reduces worker contact with powdery product that is being packaged.
The present invention is directed to a system of forming one or more bags from a tubular sleeve of film. The invention is also directed to a system that takes a tubular film and fills and forms individual bags without generating dust from the filling process as much as current systems. The film used in the present invention may be a cast film that has been, for example, folded and sealed along the edge opposite the fold to form a tubular film. However the film is preferably a blown film of one or more layers that have been coextruded. The film could also be laminate of two or more sheets of film. The sheets may be sealed at the opposite outer edges to form a tube or the film could be folded over and the two sides sealed together to form a tube. The film could be any suitable thickness. However, in a preferred embodiment the film could have a thickness that ranges from about 0.1 mils to about 5 mils. In a more preferred embodiment the film could have a thickness that ranges from about 0.5 mils to about 3 mils.
The tube of film has at least one sidewall. One end of the tube is sealed to form a bag bottom. Sealing consists of creating a seal in order to prevent the packaged product from being released from the package unless the seal or the sidewall is broken. The product is deposited into the bag through the end opposite the sealed end. In one embodiment, the tubular film may, for example, be extruded through a ring or circular die where there is an open area in the center of the die. Through the open area of the die there may be an outlet pipe from the manufacturing equipment or other means for providing the product to be packaged into the tubular film having one or more sidewalls and a sealed bottom. This arrangement prevents product dust from easily escaping into the air from the bag. When the bag is filled the appropriate amount, the bag is sealed. When the suitable amount of product has been deposited in the bag the outlet will cease depositing product in the bag. At that point a seal is formed between the product containing portion of the tubular film and the remainder of the tubular film. In the same step or in a different step the sealed bag is then separated from the remainder of the tubular film. The bag may be sealed by a heat seal from one side to the other side, including but not limited to an axis along the transverse to the sidewalls of the tubular film. Other types of seals may be formed instead. The seal so formed becomes the seal for the top of the first bag. The first heat seal may form the top seal of the first bag and the bottom seal of the second bag. Alternatively, the first seal may be the top of the first bag and a separate seal may be formed that constitutes the bottom seal of the second bag. In this instance the two bags may be separated or they may be bound together at the seals or by an area of tubular film between the two seals. This arrangement of seals can proceed over the length of the tubular film thereby forming a series of bags that are either connected together or as individual bags.
Besides a heat seal in another embodiment the bag may be sealed by an adhesive along the length of the tubular film. A strip of adhesive is applied to the inside surface of the bag by a second outlet member and sealing is effected by contacting the surface having the adhesive strip with a second inside surface on the opposite side of the tubular film. The opposite side of the inside surface may also be provided with an adhesive if desired. The adhesive seal so formed can be the initial bottom seal, it can be the seal for the top of the first bag and/or can form the bottom seal of the second bag.
The bag can be made resealable by having an embodiment that uses a releasable adhesive that can be resealed or by means of a mating seal. The mating seal can be a pair of generally parallel beads formed along the inner surface of the one side of the bag. There are also one or more beads formed on the inside surface of the opposite wall of the bag. One bead is pushed between the two opposite beads on the inner opposite wall to form a reclosable bag. A mating seal can also be accomplished by interlocking rib and groove elements. In this case the mating seal would include at least one rib on the inside surface of one side of the tubular film and at least one mating groove on the opposite inside surface of the tubular film. When the two inside surfaces are pressed together, the rib is positioned inside the groove forming a seal that retains the bag in a closed position.
The system and resulting bag of the present invention preferably entails a tubular film such as a blown film process or tubular film extrusion. The film, however, can include a flat sheet of film that has been formed into a tubular sleeve. The process may, for example, involve extrusion of a plastic through a circular die, followed by “bubble-like” expansion. The principal advantages of manufacturing film by this process include the ability to produce tubing (both flat and gusseted) in a single operation. Another benefit is the regulation of film width and thickness by control of the volume of air in the bubble, the output of the extruder and the speed of the haul-off. Blown films also eliminate end effects such as edge bead trim and non-uniform temperature that can result from flat die film extrusion. Finally, blown films have the capability of biaxial orientation (allowing uniformity of mechanical properties). Blown Film Extrusion can be used for the manufacture of co-extruded, multi-layer films for high barrier applications such as food packaging.
In the manufacture of a blown film a plastic melt is extruded through an annular slit die, usually vertically, to form a thin walled tube. Air is introduced via a hole in the center of the die to blow up the tube like a balloon. Mounted on top of the die, a high-speed air ring blows onto the hot film to cool it. The tube of film then continues upwards, continually cooling, until it passes through nip rolls where the tube is flattened to create what is known as a ‘lay-flat’ tube of film. This lay-flat or collapsed tube is then taken back down the extrusion ‘tower’ via more rollers. On higher output lines, the air inside the bubble is also exchanged. This is known as IBS (Internal Bubble Cooling). The lay-flat film is then either kept as such or the edges of the lay-flat are slit off to produce two flat film sheets and wound up onto reels. If kept as lay-flat, the tube of film is made into bags by sealing across the width of film and cutting or perforating to make each bag. This is done either in line with the blown film process or at a later stage. Typically, the expansion ratio between die and blown tube of film would be 1.5 to 4 times the die diameter. The drawdown between the melt wall thickness and the cooled film thickness occurs in both radial and longitudinal directions and is easily controlled by changing the volume of air inside the bubble and by altering the haul off speed. This gives blown film a better balance of properties than traditional cast or extruded film which is drawn down along the extrusion direction only. The film could be any suitable thickness. In a preferred embodiment the film could have a thickness that ranges from about 0.1 mils to about 5 mils and in a more preferred embodiment the film could have a thickness that ranges from about 0.5 mils to about 3 mils.
Polyethylenes (HDPE, LDPE, and LLDPE) are the most common resins in use, but a wide variety of other materials can be used as blends with these resins or as single layers in a multi-layer film structure. These include polypropylene, polyamides, ethylene vinyl alcohol. In some cases, these materials do not gel together, so a multi-layer film would delaminate. To overcome this, small layers of special adhesive resins are used in between. These adhesive layers are sometimes called “tie layers.”
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There are various types of seals that can be used to bond the bottom end 13 of the tubular film and then subsequently seal the top of that bag as well as the bottom of the next bag and so on depending on the length of the tubular film used. One type of seal that can be utilized is a heat seal in which heat is applied along the length of the tubular film under pressure that melts the bag and welds the two sides of the bag together. If a heat seal is used to seal the top of a bag after the appropriate amount of product has entered the open end 14 of the tubular film, it can constitute the top seal of that bag as well as the seal at the bottom of the next bag in the length of tubular film. This can be seen in
Another embodiment can employ an adhesive seal in order to bond the top and bottom of the bags. A machine will apply adhesive to the inside surface of one side of the bag and when pressure is applied allowing the surface having the adhesive strip to come into contact with the surface on the opposite side of the tubular film, the seal will result. There are various adhesives that can be used in this application. One such adhesive is a hot melt adhesive which is solid at room temperature but when heated becomes a liquid capable of quickly bonding the plastic. Another adhesive is a heat-activated adhesive that can be applied to the plastic bags in a thin non-tacky film which when heat activated becomes tacky and can remain tacky even after cooling. Yet another adhesive that can be used is a pressure sensitive adhesive which forms a bond when pressure is applied to marry the adhesive with the adherent; no water, solvent or heat is needed to activate this adhesive. As an alternative to an adhesive a cohesive also known as a cold-seal adhesive, can be applied to opposite sides of the inside of the bag. When pressure is applied the intermolecular attraction between like-molecules will act to unite the two inside surfaces of the bag. If an adhesive seal is used to seal the top of a bag after the appropriate amount of product has entered the open end 14 of the tubular film, it can constitute the top seal of that bag as well as the seal at the bottom of the next bag in the length of tubular film. This can be seen in
In an alternative embodiment, instead of sealing the ends with a heat seal or an adhesive seal, a mating seal can be employed. In a preferred embodiment, there are two generally parallel beads 20 and 21 formed on the inside surface of the tubular film and at least one bead 22 on the opposite inside surface of the tubular film. When the bag is formed of two separate sheets one sheet will have the two beads and the second sheet will have at least one bead. The two surfaces of the sheets that have the beads become the inner surfaces of the bag when the sheets are formed into a bag by sealing two opposite parallel edges. As the two inside surfaces are pressed together, the single bead is positioned so that it becomes positioned between the double bead members forming a resealable seal that retains the bag in a closed position where the bag has been filled. In another embodiment, the beads can be formed at the ends of the tubular film when the heat seal is formed. The tubular film can have these beads or ribs at various locations along the length of the tubular film. This permits a first bag to be filled with product. The bag is then sealed by positioning the single bead between the dual beads. The portion of the tubular film above the sealed beads can be cut off. In a preferred embodiment, the bottom of the next bag is formed by another set of beads and a cutting means separates the filled bag from the next bag as seen in
Another mating seal can be accomplished by interlocking rib and groove elements. A strip will comprise a web which has longitudinally extending interlockable profiles 6 and 7, as seen in
If desired, the mating seals can be any other suitable locking members known in the art. In addition, if desired, the mating seals can make the bag resealable so that some product can be removed and the bag can be reclosed keeping the product protected from the environment. In this embodiment, the sealed portion 24 between the two mating seals can be cut away leaving the reclosable mating seals.
Another embodiment can have the open end 13 of the tubular film sealed by a heat or adhesive seal before the product enters the tubular film via the opposite open end 14. The product can then be discharged from the manufacturing equipment into the open end 14 of the tubular film and when a suitable amount of product has been sent into the bag, the bag is sealed by a mating seal. The seal for the bottom of the consecutive bag may be a heat or adhesive seal and when that bag is filled with a suitable amount of product, the bag may be sealed by a mating seal. This chain of bags can continue for the length L of the tubular film which can vary depending on the amount of product to be packaged or based on other considerations. This embodiment can be seen in
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This application claims priority on U.S. Provisional Patent Application Ser. No. 61/131,565 filed Jun. 10, 2008 the disclosures of which are incorporated herein by reference.
Number | Date | Country | |
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61131565 | Jun 2008 | US |