Plastic and nonmetallic article shaping or treating: processes – Forming continuous or indefinite length work – Shaping by extrusion
Reexamination Certificate
2000-07-10
2003-12-16
Loney, Donald J. (Department: 1772)
Plastic and nonmetallic article shaping or treating: processes
Forming continuous or indefinite length work
Shaping by extrusion
C264S177130, C264S17800F, C264S210100
Reexamination Certificate
active
06663809
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION(S):
NONE
BACKGROUND OF THE INVENTION
The present invention generally relates to a method of manufacturing a wireless twist tie and to the wireless twist tie produced by this method. More particularly, the present invention relates to a wireless twist tie that incorporates a thermoplastic copolyester and to a method of producing this wireless twist tie.
Twist ties are commonly used for a variety of different fastening and securing purposes. Twist ties typically look like thin ribbons of material. Twist ties are typically produced initially as long strands of ribbon; these strands may then be cut to form twist ties of a select length. Individual twist ties typically have lengths ranging from about two inches up to about ten inches, though twist ties designed for any particular purpose may have a length outside of this general range.
One common use of twist ties concerns closure of packages having an open end. To close the package, packaging material located adjacent to the open end is gathered. The twist tie is extended around the gathered packaging material and opposing ends of the twist tie are then placed adjacent to each other. These opposing ends of the twist tie are then twisted about each other relative to the remainder of the twist tie to secure the opposing ends together and prevent the gathered packaging material from reopening. Thus, the act of twisting the opposing ends of the twist tie about each other permits the twist tie to act as a locking device. One example of this entails use of the twist tie to close the opening of a bread wrapper to prevent the bread within the bread wrapper from being exposed to atmosphere.
Many twist ties include a length of metal wire that may be enclosed in a covering material, such as plastic or paper. Twist ties that include metal wire are subsequently referred to as wire twist ties. Wire twist ties have many advantageous properties that have led to widespread use of wire twist ties. For example, wire twist ties may generally be readily applied to packages to seal or close the packages using either manual application techniques or high-speed automated mechanical application techniques. In addition, the fastening ability of wire twist ties is typically not significantly affected by multiple twist tie fastening and unfastening cycles. Also, wire twist ties typically are usable over a wide range of temperatures without experiencing any significant reduction in fastening capability.
Wire twist ties are used in many food packaging applications. However, such use of wire twist ties in food packaging applications sometimes creates difficulties. For example, the wire portion of wire twist ties typically makes the wire twist ties unsuitable for use in microwave ovens.
This problem arises because the wire portion of the wire twist ties generally causes undesirable arcing when the wire twist tie is subjected to microwave radiation at intensities typically found in microwave ovens. Thus, food packages that include wire twist ties must be opened by removing the wire twist tie prior to placement of the food package in the microwave oven. This is an undesirable step, since many food packaging applications call for the food, when heated in a microwave oven, to be heated in the microwave oven while maintaining the food packaging in a generally closed configuration. While small holes are sometimes added to the packaging to prevent the package from overexpanding and blowing out, large holes and openings are typically not desirable. The large holes and openings, such as those that would exist in the absence of the wireless twist tie, are undesirable, since such large openings may permit the food to excessively dry out during heating in the microwave oven.
Use of wire twist ties in food packaging applications is also undesirable for an additional reason. Specifically, when food is commercially packaged for distribution to the public, it is desirable for the packaging to allow inspection of packaged food for contamination by foreign objects. One common method of inspecting food products entails use of metal detectors to confirm that no metal scrap or shards have inadvertently been incorporated in the food product during production or packaging of the food product. Wire twist ties preclude such use of a metal detector, since each package that is closed with a wire twist tie would typically generate a response by the metal detector indicating the presence of metal in the food package. Thus, rather than simply detecting the presence of any undesired metal in the packaged food, the metal detector would also indicate, for each package, the presence of the wire twist tie.
A number of different, non-metallic closures, such as wireless twist ties excluding metal wire, have been developed. While these various wireless twist ties do typically solve the problems described above relating to microwave heating and metal detection, these wireless twist ties have not proven entirely satisfactory. One problem is that some of these wireless twist ties exhibit excessive memory and consequently do not support secure closure of packaging after just a few wireless twist tie opening and closing cycles. Another problem derives from consumer perceptions that wireless twist ties are difficult to use, due to a high degree of twist tie rigidness that may make it perceptibly more difficult for a person with less dexterity to manually open and close the twist tie. Finally, many wireless twist ties do not exhibit sufficient degrees of strength while also exhibiting significant degrees of elasticity and flexibility. This lack of strength in combination with any lack of flexibility and/or elasticity may cause such wireless twist ties to break, or otherwise exhibit application difficulties, when attempts are made to attach such wireless twist ties using high-speed mechanical application machines in commercial food packaging operations.
The wireless twist tie of the present invention solves these difficulties that are exhibited by many existing wireless twist ties. For example, the wireless twist ties of the present invention exhibit a significantly minimized, or even eliminated, tendency to break during application by commercially available twist tie application machines, as compared to prior wireless twist ties. Also, the wireless twist ties of the present invention exhibit a soft feel due to a combination of enhanced flexibility and enhanced elasticity, as compared to prior wireless twist ties.
Furthermore, this soft feel that is produced by the enhanced elasticity. and enhanced flexibility provides the wireless twist tie of the present invention with application characteristics that are more user friendly to those with reduced dexterity in their hands, as compared to prior wireless twist ties. Thus, for those with reduced hand dexterity, the wireless twist ties of the present invention are easier to use than many prior wireless twist ties. Finally, due to the non-metallic nature of the wireless twist ties of the present invention, the wireless twist ties of the present invention continue to provide an adequate solution in those applications where the wireless twist ties will be exposed to microwave radiation and in those applications where the wireless twist tie will be subjected to metal detection techniques. Furthermore, these advantages of the wireless twist tie of the present invention are achieved while using relatively inexpensive components that help to make the wireless twist tie of the present invention less expensive to manufacture,. as compared to many prior wireless twist ties.
BRIEF SUMMARY OF THE INVENTION
The present invention includes a twist tie. The twist tie incorporates a thermoplastic copolyester. The present invention further includes a method of forming the twist tie, a wireless twist tie, and a method of forming the wireless twist tie.
REFERENCES:
patent: 819869 (1906-05-01), Dunlap
patent: 1606053 (1926-09-01), Bonette
patent: 2465319 (1949-03-01), Whinfield
patent: 2608720 (1952-09-01), Meissner
patent: 2654124 (1953-10
Burmeister Fern P.
Haddock Thomas E.
Langland Terry L.
Maltas Jeffrey S.
Bedford Industries, Inc.
Kinney & Lange , P.A.
Loney Donald J.
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