Fluent material handling – with receiver or receiver coacting mea – With soil removing – coating – lubricating – sterilizing and/or...
Reexamination Certificate
2000-07-27
2001-09-04
Douglas, Steven O. (Department: 3751)
Fluent material handling, with receiver or receiver coacting mea
With soil removing, coating, lubricating, sterilizing and/or...
C141S114000, C141S313000, C141S31100A, C383S105000
Reexamination Certificate
active
06283174
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus, system, and method for dispensing fluids into containers and, more particularly, to an improved mechanism for cleaning fluid dispensers associated with such apparatus, system, and method. The invention also relates to a film from which the containers can be made and which also facilitates the cleaning of the dispensers.
The invention finds particularly utility in the field of foam-in-place packaging, which is a highly useful technique for on-demand protection of packaged objects. In its most basic form, foam-in-place packaging comprises injecting foamable compositions from a dispenser into a container that holds an object to be cushioned. Typically, the object is wrapped in plastic to keep it from direct contact with the rising (expanding) foam. As the foam rises, it expands into the remaining space between the object and its container (e.g. a corrugated board box) thus forming a custom cushion for the object.
A common foamable composition is formed by mixing an isocyanate compound with a hydroxyl-containing material, such as a polyol (i.e., a compound that contains multiple hydroxyl groups), typically in the presence of water and a catalyst. The isocyanate and polyol precursors react to form polyurethane. At the same time, the water reacts with the isocyanate compound to produce carbon dioxide. The carbon dioxide causes the polyurethane to expand into a foamed cellular structure, i.e., a polyurethane foam, which serves to protect the packaged object.
In other types of foam-in-place packaging, an automated device produces flexible bags from flexible, plastic film and dispenses a foamable composition into the bags as the bags are being formed. As the composition expands into a foam within the bag, the bag is sealed shut and typically dropped into a container holding the object to be cushioned. The rising foam again tends to expand into the available space, but does so inside the bag. Because the bags are formed of flexible plastic, they form individual custom foam cushions around the packaged objects. Exemplary devices are assigned to the assignee of the present invention, and are illustrated, for example, in U.S. Pat. Nos. 4,800,708, 4,854,109, 5,376,219, and 6,003,288, the contents of each of which are incorporated entirely herein by reference.
One problem with the foamable compositions used to make polyurethane foam for foam-in-place packaging is that the foam precursors and resultant foam tend to have somewhat adhesive properties. As a result, the foamable composition tends to stick to objects that it strikes and then hardens into foam. One location where this causes a particular problem is the discharge nozzle of the dispenser from which the foam precursors are ejected. As is known, the polyol and isocyanate foam precursors must be withheld from mixing with one another until just prior to injection. In the most common type of dispenser, the two foam precursors enter the dispenser, mix with one another, and then exit the dispenser via the discharge nozzle as the foamable composition. As the dispenser operates over and over again, particularly in automated or successive fashion, foamable composition tends to build up around the discharge port of the dispenser, harden into foam, and block the proper exiting of further foamable composition. As a result, the discharge nozzle and discharge port must be frequently cleaned to ensure continued operation of the dispenser.
A number of cleaning solutions have been proposed. One such solution employs a solvent that is capable of dissolving the foamable composition. Such solvent is continually pumped into the dispenser and through the discharge port to carry away any residual foamable composition remaining on or around the discharge port. While this solution has proven to be somewhat effective, the discharge port nevertheless eventually becomes occluded with foam, requiring the dispenser to be disassembled and cleaned. Furthermore, the solvent adds to the expense and complexity of the foam-in-place packaging machinery.
Another solution is to employ a solvent-soaked pad on which to wipe the face of the discharge nozzle in order to remove residual foamable composition therefrom, e.g., as disclosed in U.S. Pat. No. 4,674,268. While this solution has also been shown to be somewhat effective, it entails a rather complex mechanized system for moving the dispenser into contact with the wiping pad, thereby adding expense, complication, and potential for mechanical problems to the foam-in-place system in which it is incorporated. Additionally, the wiping pad frequently becomes fouled with the precursors and foam, necessitating continuous monitoring and replacement of the pad. As can be appreciated, such limitations are not conducive to an automated foam-in-place packaging process.
A further solution to the problem of dispenser cleaning is the use of two discharge nozzles to dispense separately the polyol and isocyanate foam precursors into a bag, wherein the two precursors are mixed. Although this arrangement avoids the mixing of the two precursors in a single dispenser, and therefore also avoids the formation of foam on and around the discharge port of the dispensers, the need to periodically clean the discharge nozzles remains. This is particularly true for the nozzle used to dispense the isocyanate precursor because the isocyanate reacts with moisture in the air to crystallize at the discharge port of the nozzle. Thus, some method for cleaning such a dual nozzle dispenser must still be employed.
Accordingly, a need exists in the art for an improved means for automatically cleaning dispensers used in foam-in-place packaging.
SUMMARY OF THE INVENTION
That need is met by the present invention, which, in one aspect, provides an apparatus for dispensing fluid into containers, comprising:
a. a mechanism that conveys a web of film along a predetermined path of travel and converts the film into one or more containers;
b. a dispenser through which fluid may flow in predetermined amounts, the dispenser positioned adjacent the travel path of the film web such that the dispenser is capable of dispensing fluid into the containers, the dispenser having a discharge nozzle comprising an end- face and a discharge port disposed in the end-face, wherein fluid exits the dispenser through the discharge port; and
c. a cleaning mechanism that brings the discharge nozzle of the dispenser into the travel path of the film web so that the end-face can make contact with the film web to remove from the end-face at least a portion of any fluid or reaction-products of the fluid that may be in adherence with the end-face.
Another aspect of the present invention is a system for dispensing fluid into containers, comprising:
a. a web of film;
b. a mechanism that conveys the film web along a predetermined path of travel and converts the film web into one or more containers;
c. a fluid source containing therein a fluid;
d. a dispenser in fluid communication with the fluid source and being positioned adjacent the travel path of the film web to dispense a predetermined amount of the fluid into the containers, the dispenser having a discharge nozzle through which the fluid flows into the containers, the discharge nozzle comprising an end-face and a discharge port disposed in the end-face, the fluid exiting the dispenser through the discharge port; and
e. a cleaning mechanism that brings the discharge nozzle of the dispenser into the travel path of the film web so that the end-face makes contact with the film web to remove from the end-face at least a portion of any fluid or reaction-products of the fluid that may be in adherence with the end-face.
A further aspect of the present invention is a method for dispensing fluid into containers, comprising:
a. providing a web of film;
b. conveying the film web along a predetermined path of travel and converting the film web into one or more containers;
c. providing a fluid source containing therein a fluid;
d. dispensing a predetermined amount of the fluid into the
Drake Jesse
Hickey Steven
Kane Eric
Sperry Laurence
Douglas Steven O.
Lagaly Thomas C.
Sealed Air Corporation
LandOfFree
Cleaning mechanism for fluid dispenser does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cleaning mechanism for fluid dispenser, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cleaning mechanism for fluid dispenser will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2465928