Resealable Leak-Resistant Containers Having A Pressed Pulp Tray With A Thermoformed Plastic Lid

Abstract

A leak-resistant pulp container with a plastic lid is disclosed, including a tray formed of molded pulp and having a boom and a sidewall forming an interior volume. The tray has an edge extending peripherally outward from an upper edge of the sidewall, and the tray edge has an outer portion. The container further includes a plastic lid having an edge extending peripherally outward therefrom, and the lid edge having an outer portion.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This is a U.S. national stage of application No. PCT / US2014 / 028541, filed on 14 Mar. 2014, which claims the benefit of U.S. Provisional Patent Application No. 61 / 799,008, filed on 15 Mar. 2013, both of which are hereby incorporated by reference in their entireties.FIELD OF THE INVENTION[0002]The disclosed embodiments relate to resealable containers with leak-resistant features for storing food, liquids, and various other items. In particular, the disclosed embodiments relate to resealable leak-resistant containers having a molded pulp tray with a plastic lid.BACKGROUND OF THE INVENTION[0003]The use of plastic disposable containers and trays for packaging, distributing, food are widespread in the marketplace. There is a need for containers that are easy open and close, but at the same time, resist leaks. This is especially true for containers designed for liquids, e.g., soup containers. The leak-resistance must be maintained even when the c...

AI Technical Summary

Benefits of technology

[0008]The disclosed embodiments provide leak-resistant, resealable containers, e.g., for food products. The disclosed embodiments include containers designed for liquids, e.g., soup containers, and the like. The leak-resistance is maintained even when the container is tilted so that the liquid contained therein reaches the seam where the bottom (i.e., tray) and lid of the container are joined.

Problems solved by technology

However, the physical properties of pulp material and its production processes can make it difficult to produce a pulp container with leak-resistant properties.

For example, it can be difficult to manufacture a pulp container with a small “draft angle,” which is the angle of the upper edge of the container wall relative to vertical.

Due to the nature of the manufacturing processes of pulp containers, small draft angles can create an array of production and quality problems, such as uneven distribution of fibers in the produced part, inconsistent part geometry, damage to manufacturing equipment, etc.

A container having a small draft angle is difficult to achieve in a molded pulp process, because a larger, i.e., wider, draft angle typically must be used with pulp materials due to the nature of the pulp molding process.

Therefore, a conventional pulp container can be harder to seal in a leak-resistant manner.

Another physical property of pulp material which can make a leak-resistant container difficult to manufacture is the relative lack of flexibility of molded pulp.

The lack of flexibility arises from the characteristics of the natural fibers, which tend not to stretch very much on their own or when molded together.

This lack of flexibility means that certain geometries, known as “undercuts,” cannot easily be used in pulp containers.

However, a pulp container part having undercuts will likely tear as it is removed from the mold due to its lack of flexibility and also due to inherent texture characteristics of the pulp arising from its manufacturing process.

This characteristic effectively limits the geometries which can be used in a pulp container and makes it more difficult to achieve a leak-resistant design.

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