Special receptacle or package – Plural paper bags
Reexamination Certificate
2000-04-27
2001-09-11
Bui, Luan K. (Department: 3728)
Special receptacle or package
Plural paper bags
C383S009000, C383S103000, C383S110000
Reexamination Certificate
active
06286681
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a ventilated plastic bag particularly adapted for carrying hot food from fast food restaurants, a pack of such bags, and a dispensing system utilizing such bags.
BACKGROUNG OF THE INVENTION
Since the 1970's, plastic bags have been replacing paper bags in the United States for the grocery and retail products industries because of the superior strength and inherent moisture resistant properties and strength of plastic, among other things.
These plastic bags have taken various shapes and forms including T-shirt type plastic bags which include front and rear wall sections integrally connected together by gussetted side walls and connected at the bottom to define a closed bottom on the bag. At least a part of the top of the front and rear wall sections are open at the tops to define an open mouth and laterally spaced handles which are integral with the wall sections extend upwardly from opposed sides of the mouth portions for carrying of the bags. This type of plastic bag is illustrated assignee's prior U.S. Pat. No. 4,676,373 (the disclosure of which is incorporated herein by reference).
Other types of plastic bags include what is known in the industry as a die-cut handle bag which has front and rear wall sections preferably connected by gussetted side wall sections integrally extending therefrom and positioned therebetween and wherein the bottom of the bag is closed and the top of the bag is open. These die-cut handle bags include a cut out hole, preferably of a kidney-shape, positioned generally centrally of a top area of the bag for receiving fingers of the user for carrying of the bag. Other bag constructions have been proposed with handle means provided in top areas of the bag formed by a cut out of front and rear wall sections.
All of these bags are usually utilized in a pack of a plurality of bags and in a dispensing system in which the bag pack is mounted in generally vertically suspended position for successive removal of the bags by a user.
Notwithstanding the success of plastic bags and replacement of plastic bags in the grocery and retail products industries, paper bags have for the most part continued to be used in the fast food restaurant industry for packaging and carrying hot foods. There are a number of problems associated with the use of such paper bags in the fast food restaurant industry, including the difficulty in handling of the paper bags, the inherent opaque nature of the paper bags resulting in the inability to see the hot food items packaged in the bag and resulting mistakes in filling customers' orders, the inherent weaknesses in the bags when they become moist or the like, etc. On the other hand, plastic bags have not been used for packaging and transporting hot foods in the fast food restaurant industry primarily because of the problem which occurs with moisture collecting on the insides of the plastic bag when filled with hot foods. This moisture will condensate and cause the food to get soggy and will wet the hand of the user when reaching into the bag.
In an attempt to overcome this problem with the use of plastic bags in the fast food restaurant industry, a T-shirt type plastic bag for carrying hot foods was developed, as illustrated and described in assignee's prior U.S. Pat. No. 5,362,152 (the disclosure of which is incorporated herein by reference). The T-shirt type plastic bag of this prior patent provided apertures extending through at least one of the wall sections of the bag for providing a path for venting air flow from the outside of the bag and through the inside of the bag when the bag is carrying hot food. The apertures comprise a generally semi-circular shaped cut out defining a flap portion which opens up to produce a generally half moon-shaped aperture. These C-shaped apertures were preferably spaced about 2½″ to 3″ apart and were of relatively large sizes to allow the above-described flow of air.
While this ventilated plastic bag construction of assignee's prior U.S. patent overcame some of the previous problems presented with paper bags and provided a plastic bag construction which could be utilized by the fast food restaurant industry, it did not sufficiently prevent condensation within the bag. Because of the size of the C-shaped vent apertures, a spacing of 2″ to 3″ apart was necessary to preserve the strength of the bag. However, this created dead zones within the bag with no airflow and thus did not sufficiently prevent condensation from forming on the inside of the bag.
OBJECT AND SUMMARY OF THE INVENTION
Accordingly, it is the object of this invention to provide a ventilated plastic bag which is particularly adapted for carrying hot foods from fast food restaurants and which will overcome the problems discussed above.
By this invention it has been found that the above object may be accomplished by providing a ventilated plastic bag comprising any desired construction including at least front and rear wall sections connected together to define a closed bottom area and an open top area and handle means in the top area which is at least partially formed by a cut out of the front and rear wall sections resulting in reduced strength regions with resulting high potential for tearing in the front and rear wall sections around at least a part of the cut out. Closely spaced micro-perforations extend through the wall sections in at least a major portion of the plastic bag to provide desired ventilation to an interior food carrying area of the plastic bag.
Micro-perforations have been utilized in plastic bags for purposes other than in the fast food industry, i.e. plastic bags with micro-perforations have been utilized for holding loafs of bread and have been utilized with zip-lock bags for containing vegetables or the like food products. In these bags, the pattern of micro-perforations consumed substantially the entire surface areas of the bags.
Micro-perforations in a plastic bag to be utilized in the fast food industry would have two primary, yet sometimes conflicting purposes. These are to prevent condensation within the bag and to keep the food in the bag warm. Closely spaced micro-perforations provide virtually 100% venting coverage in the food carrying portion of the bag while keeping the food warm in the bag. By placing small perforations close together, all surface areas of the bag having the perforations are subjected to a small airflow from the natural convection created to prevent condensation from forming on the inside surface of the bag. The micro-perforations, as opposed to large vent openings, keep the food warmer while providing desired ventilation. However, it has been determined by this invention that these closely spaced micro-perforations tend to weaken the resistance to tear in the bag and if placed along substantially the entire surface area (as had been done in prior micro-perforated plastic bread and vegetable bags) and in the reduced strength regions created by the cut out utilized to form the handle means in the bag, and create greater tear propagation providing problems in use of the bags. Therefore, in accordance with this invention the closely spaced micro-perforations are positioned in a major portion of the plastic bag other than the reduced strength regions to provide the desired ventilation to an interior food carrying area of the bag while not further weakening the reduced strength regions of the bag and increasing the potential for tearing.
The ventilated plastic bag of this invention may be of the T-shirt type having a generally U-shaped cut out in the top area of the bag to produce laterally spaced handles extending upwardly from the top area of the bag, or it may be of the type having a cut out defining a hole of sufficient size in generally a central area of the open top area of the bag for receiving fingers of the user and to function as a handle. This hole may preferably be kidney-shaped. Other types of plastic bags having handles including cut out portions of the front and rear wall secti
Fletcher Wade
Wilfong, Jr. Harry
Alston & Bird LLP
Bui Luan K.
Sonoco Development Inc.
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