Abstract:
An apparatus and method for forming cavities in pouches. The packages are used for packaging sterile medical products. The apparatus has a frame and a tongue plate member. A pouch is placed onto the tongue plate member to form a cavity into at least one side of the pouch.

Description:
FIELD OF THE INVENTION 
     The field to which this invention relates is packaging machinery and processes, in particular, packaging and machinery for forming medical device packages. 
     BACKGROUND OF THE INVENTION 
     Pouch-type packaging is very flexible and adaptable to a variety of medical products, including medical devices. An example of a pouch-type package without formed cavities is two flat similarly sized rectangular sheets of material aligned and placed directly over one another and sealed together along three of their four edges. The fourth edge is left open to form the pouch and provide an entrance opening into the interior of the pouch. The fourth side may be sealed after a product such as a medical device is placed inside the pouch (often referred to the filling process). This operation is not typically conducted in a sterile environment, although it may be. Therefore, it is then desirable to sterilize the product that is now contained within the pouch, along with the interior of the pouch, in order to provide a sterile product. Various types of sterilization processes are known in the art to sterilize medical products, including gas sterilization, autoclaving, gas plasma sterilization, radiation and other conventional processes. When utilizing a gas sterilant process such as ethylene oxide, one of the flat rectangular sheets may include a gas permeable barrier such as a TYVEK® sheet. Sterilization gases can penetrate the gas permeable barrier to sterilize the product inside the sealed pouch. Once the sterilization process is completed, a fifth seal may be made to isolate the product from the gas permeable section of the sealed pouch. Following this operation, the portion of the pouch that contains the gas permeable barrier is removed. When using two sheets which are not gas permeable, the package is sealed along the fourth edge after ethylene oxide sterilization in a clean room. 
     Forming is defined as the process of creating a cavity in one or both sheets of material used to form the pouch to accommodate a product to be packaged. Formed cavities are especially useful in pouch-type packages because they allow larger products to be housed or filled within a given size pouch without the formation of wrinkles. Wrinkle formation in one or both sheets is typical of a non-formed pouch package. These wrinkles can be eliminated if one or both sheets have pockets formed in them to accommodate the intended product. There may be disadvantages associated with such wrinkles, including channels and unsealed sections or areas which result is a loss of sterility and barrier to moisture and oxygen. 
     Flat pouches are typically made form roll stock on seal and cut equipment. Pouches may be formed from two rolls of laminate foil material such rolls of heat sealable packaging materials. These materials can be foil laminates, films, heat sealable papers or spun bonded plastics. Thermo forming is performed on films while cold pressure forming is typical for foil laminates Forming process typically are performed on conventional form/fill/seal equipment. These types of systems can easily fabricate numerous flat pouches or envelopes that may be later transported to subsequent operations for filling and final sealing as described above. As previously mentioned, it is often desirable to have a formed cavity in one or both sides of the pouch. This is accomplished by forming a cavity in one (or both) sheet(s), placing the product into a cavity, and then placing and sealing the two sheets together. Where cavities are formed in both sheets, care must be taken to assure accurate registration and alignment of the sheets before they are sealed. This type of process may be automated as a continuous process wherein package formation, filling with product, and sealing are all conducted in a continuous manner. This type of system works well for most products that are not sterile, however, it does not work well for sterile product that needs to be aseptically filled and sealed into the pouch. 
     Aseptic packaging processes and equipment are known in the art. Aseptically filling and sealing a product into a package is typically conducted in an aseptic environment. Such environments are difficult and costly to fabricate on a scale large enough to accommodate form, fill, and seal systems as described above. One approach used for aseptic packaging is to manufacture pouches in a non-sterile environment, stack them, sterilize them, and then transfer them into an aseptic environment for the filling and sealing operation. This process works well with pouches that are not formed. However, formed pouches present some additional challenges. Formed pouches, when stacked take up much more space and therefore fewer pouches can be accommodated in each stack. Even if gently stacked, the pouches are typically easily damaged during the sterilization process and subsequent transport into an aseptic environment. Damage may include wrinkle formation and hole formation. Wrinkled or unsupported surfaces present yet additional challenges when the application of labels on the outer package surface is desired. 
     Therefore, there is a need for novel packaging processes and machines for making pouches having formed cavities adapted for use in an aseptic environment. 
     SUMMARY OF THE INVENTION 
     Accordingly, a novel apparatus for manufacturing pouches having cavities is disclosed. The apparatus has a frame. A bottom or lower clamp plate member is slidably mounted to the frame. The bottom plate member has a top side and a bottom side. A top die plate member is slidably mounted to the frame. The top plate member has a top side and a bottom side. First and second actuators are mounted to the frame for moving the bottom plate member and the top plate member toward each other. There is a die member extending from the bottom of the top plate member. Optionally, a die member extends from the top side of the bottom plate member. The die member has a cavity. The apparatus also has a tongue plate member plate having a first end and a second end. The second end of the tongue member is fixedly mounted to the frame between the top plate member and the bottom plate member such that the tongue member extends between the top plate and the bottom plate. The tongue member has a fluid passage having a first opening, and a second opening through the top side. The first and second openings are in communication with the fluid passage. Optionally, the tongue member has an opening on the bottom side. 
     Another aspect of the present invention is a method of manufacturing a pouch having a cavity using the above described apparatus. In this method, a pouch is provided. The pouch has two sheets aligned and sealed along three sides such that the pouch has an unsealed side and an opening into an interior. An apparatus of the present invention is provided. The apparatus has a frame. A bottom or clamp plate member is slidably mounted to the frame. The bottom plate member has a top side and a bottom side. A top die plate member is slidably mounted to the frame. The top plate member has a top side and a bottom side. First and second actuators are mounted to the frame for moving the bottom plate member and the top plate member toward each other. There is a die member extending from the bottom of the top plate member. The die member has a cavity. The apparatus also has a tongue plate member having a first end and a second end. The second end of the tongue member is fixedly mounted to the frame between the top plate and the bottom plate such that the tongue member extends between the top plate member and the bottom plate member. The tongue member has a fluid passage having a first opening, and a second opening through the top side. The first and second openings are in communication with the fluid passage. The pouch is placed over the tongue member, such that a section of the tongue member is contained within the interior of the pouch. The top and bottom plate members are moved toward each other such that the die contacts the top of the pouch and the bottom plate member contacts the bottom of the pouch against the bottom and top surfaces of the tongue member, respectively. A pressurized fluid is caused to move into the fluid passage of the tongue and out through the second opening, thereby causing a section of the top sheet of the pouch to be forced into the cavity of the die, and thereby forming a cavity in the top sheet. The top and bottom plate members are away from the tongue member, and, the pouch having a formed cavity is removed from the tongue member. 
     These and other aspects and advantages of the present invention will become more apparent from the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a pouch of the present invention prior to processing to form a cavity. 
         FIG. 2   a  is a perspective view of a machine of the present invention useful to manufacture pre-formed pouches illustrating the front of the machine. 
         FIG. 2   b  is a perspective view of a machine of  FIG. 2   a  illustrating the back of the machine. 
         FIGS. 3   a  and  3   b  are perspective views of the machine of  FIG. 1  illustrating an unformed pouch being inserted over the tongue member prior to forming a cavity in the pouch 
         FIGS. 4   a  and  4   b  are perspective views of the machine of  FIG. 1  illustrating the plate members closed about the tongue member and pouch for the cavity forming step. 
         FIGS. 5   a  and  5   b  are perspective views of the machine of  FIG. 1  illustrating the plate members opened after the cavity forming step and illustrating a cavity formed in the pouch prior to removal from the tongue member and the machine. 
         FIG. 6  is a perspective view of a tongue member used in the machine and process of the present invention 
         FIG. 7  is a perspective view of a lower clamp plate member of the machine of the present invention. 
         FIG. 8  is a perspective view of a cavity plate member of the machine of the present invention. 
         FIG. 9  is a perspective view of the pouch of  FIG. 1  after it has been processed using the machine and process of the present invention to form a cavity therein. 
         FIG. 10  is a perspective view of the pouch of  FIG. 9  after it has been filled with a medical device and sterilized. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The pouches useful in the practice of the present invention are made from sheets of flat materials know in this art useful for forming pouch packages for sterile medical products, particularly medical devices. Typically, each sheet is made from a conventional foil or a foil laminate made from materials such as aluminum foil, polymer sheets, coatings and the like, e.g., polyester/foil/polyethylene heat seal coating. Optionally, a first sheet is made from the previously described foil laminate, and the second sheet is made from a conventional gas-permeable polymeric material such as TYVEK spun polytetraflouroethane, heat seal coated medical grade paper, and the like. Optionally the second sheet can be made from a metal foil laminate and can have a vent opening with a section of a gas permeable polymeric sheet affixed over the vent opening. In addition, the second sheet is optionally a conventional polymeric gas impermeable sheet such as polethylene, polyester, halogenated films such as Aclar and PVC, and the like. The sheets of materials are bonded together via a peripheral seal in a conventional manners including heat sealing, ultrasonic welding, radiofrequency, microwave, gluing and the like. Packages using pouches and methods of packaging sterile medical devices are disclosed in the following U.S. Patents, which are incorporated by reference: U.S. Pat. No. 5,868,244; U.S. Pat. No. 5,732,529; U.S. Pat. No. 5,623,810; and, U.S. Pat. No. 4,482,053. 
     A flat pouch  10  useful in the practice of the process of present invention is illustrated in  FIG. 1 . The pouch  10  is seen to have top foil sheet  30  and bottom foil sheet  40 . The pouch  10  is seen to be sealed about the periphery of three sides using a conventional sealing process such as heat sealing or equivalent processes to form seal  50 . The seal  50  has lateral sides  52  and bottom side  54 . The pouch  10  has open top side  15  with entrance opening  20  to interior cavity  22 . The pouch  10  is seen to have optional gas vent  12 . Referring to  FIG. 9 , the pouch  10  is seen after processing using the equipment and process of the present invention to have a cavity  60  formed into bottom sheet  30 . A sterile package  10  of the present invention after filling with a medical device  70  and subsequent sealing (and conventional gas sterilization) is seen in  FIG. 10 . The package  10  is seen to have top side  15  sealed by top seal  56 , with the section of the package containing optional vent  12  removed in a conventional manner such as by cutting. If the pouch  10  does not have a gas vent, it may be filled with a medical device, sterilized with a conventional gas process, and then aseptically sealed. Optionally, other types of sterilization processes may be used including conventional plasma, radiation and autoclaving sterilization processes, and in the case of radiation and autoclaving, the pouch of the present invention having a cavity may be hermetically sealed prior to the sterilization process. 
     A novel package forming machine  100  of the present invention is illustrated in  FIGS. 2-8 . Machine  100  is seen to have bottom base member  1   10 . Extending upwardly from the top  112  of the base member  100  are the guideposts  120 , having bottoms  122  and tops  124 . Mounted to the tops  124  of the posts  120  is the top plate member  140 . The plate members  110  and  140  may be mounted to the bottoms  122  and  124  of posts  120  in a conventional manner such as screw head cap screws, nuts, welding, fittings, and the like. The lower cylinder actuator  160  is seen to be mounted to the top  112  of base member  110 . Cylinder actuator  160  is seen to have cylinder  162  and actuator rod  164  having end  166 . The lower clamp plate or bottom plate member  170  is slidably mounted to the guideposts  120  through guidepost openings  175 . Plate member  170  has bottom  177  and top  178 . Extending from one side of the plate member  170  is the extension member  180 . The end  164  of actuator rod  164  is connected to the bottom side  177  of plate member  170 . Upper cavity plate member  190  is seen to be slidably mounted to the guideposts  120  through the guidepost openings  195 . Plate member  190  has top side  198  and bottom side  197 . Mounted to the bottom  144  of top plate member  140  is the actuator cylinder  220 . Actuator cylinder  220  has cylinder  222  and actuator rod  224  having end  226 . End  226  of actuator cylinder  220  is mounted to the top  198  of cavity plate member  190 . Extending downwardly from the bottom side  197  of cavity plate member  190  is the die member  200 . Die member  200  is seen to have raised opposed sides  202  and  204 . The sides  202  and  204  extend above bottom  205  and surround cavity  207  formed by the sides  202  and  204  and the bottom  205 . Extending up from the top  112  of bottom plate  110  is the mounting tower  230 . Tower  230  has top  232  and bottom  234 . The forming tongue member  240  is seen to have top  242  and bottom  244 , and ends  246  and  248 . Extending from end  246  of forming tongue member  240  is the gas manifold member  249 . The manifold member  249  has connection  250  in communication with gas passage  252  contained in member  240 . Discharge opening  255  extends through the top  242  and is in fluid communication with passage  252 . Discharge opening  242  is in alignment with cavity  207  of die member  200 . The end  246  of tongue member  240  is fixedly mounted to the top  232  of tower member  230  such that the member  240  extends in a cantilevered fashion between the top  178  of plate member  170  and the bottom  197  of top plate member  190 , and over extension member  180 . 
     The machine  100  of the present invention operates in the following manner to form cavities in pouches utilizing the process of the present invention. As seen in the  FIGS. 2-8 , an operator faces the side of the machine  100  opposite the side where the mounting tower  230  is located, and facing free end  248  of forming tongue member  240 . In the starting position, the actuating cylinders  160  and  220  move the plates  170  and  190  downwardly and upwardly, respectively, to form an opening about the forming tongue member  240 . The operator then takes a pouch  10  and moves the top side  15  and entrance opening  20  over the free standing end  248  of the tongue member  240  and slides the pouch  10  onto section  242  until the end  15  of the pouch  10  engages or is proximal to the free end  248  of tongue member  240 , and tongue member  240  is contained in part in interior cavity  22  of pouch  10 . The operator then actuates the cylinders  160  and  220  to move the plates  170  and  190  upwardly and downwardly, respectively, so that the top side  178  of plate  170  is in contact with the bottom sheet  40  of pouch  10  pressing it against the bottom of tongue member  240  and die member  200  is in contact with a section of the top sheet  30  of pouch  10  pressing it against the top of and tongue member  240 . The operator then actuates a pressurized fluid supply such as air connected to manifold  248  causing the air to flow through the passage  252  in member  248  and exit through second opening  255  thereby pushing and forming the section of the top sheet  30  engaged between the side walls  202  and  204  of die member  200  into the cavity  207  of die member  200  thereby forming cavity  60  in sheet  30  of pouch  10 , having substantially the shape of cavity  207 . The operator then actuates the cylinders  160  and  220  to reverse their movement to pull plates  170  and  190  away from each other such that there is an opening about the tongue member  240 . The operator then removes the pouch  10  having cavity  60  from tongue member  240 , and proceeds to repeat the operation to form cavities in unformed pouches  10 . 
     Although this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the claimed invention.