Check Valves for Vacuum Packaging
Publication Date: 2005-Jun-22
The IP.com Prior Art Database
MICHAEL K. CARRIER: ATTORNEY [+8]
Check Valves for Vacuum Packaging Abstract of the Disclosure: The present disclosure relates to check valves that are suitable for use in the vacuum packaging of bulk material, such as acetate tow and the like, and that generally comprise a base, a plunger, and optionally, a cap. The base portion of the check valves may be sealed to a flexible packaging material that forms the exterior of the packaging, and the plunger may be movably attached to the base so that air may be withdrawn, and the plunger afterward drawn by the partial vacuum thereby created so as to seal the packaging from the air that would otherwise reenter the packaging. The optional cap may afterward be snapped or screwed on to a raised neck portion of the base to further seal and protect the packaging from contamination by the environment.
Check Valves for Vacuum Packaging
Field of the Invention:
The present disclosure relates to check valves suitable for vacuum-sealed packages and packaging systems. The check valves are particularly well suited for use with packages for bulk fiber materials, including polymeric fibers such as cellulose acetate fibers.
Staple items of commerce, including agricultural products, fibers, granular products, and the like, are often packaged, transported and stored in bulk form, such as in the form of bales. Typically these bales include a mass of material encircled by restraining straps, cords, wires, or the like.
During a typical baling operation, materials to be baled are compressed under pressure. When released from the applied pressure, the resilient material acts in a manner similar to a spring and expands or springs back causing pressure on all surfaces of the bale. Securing devices and fasteners, including straps, buckles, cords, wires, Velcro-type fasteners, and the like, are typically used to restrict the bale expansion. Generally a plurality of securing devices are used to encircle the bale.
A disadvantage of securing devices such as straps for resilient material bales is that the securing devices provide only localized restraint at its point of contact with the bale. Materials on either side of the securing device are only partially restrained and tend to exhibit spring back causing the bale to bulge in portions between adjacent securing devices. The overall bale acquires a non uniform rounded shape. Further, the dimensions of the overall package may vary over time. Thus, for these reasons, the bales can be difficult to stack or lay flat and therefore may be disadvantageous for storage, transport, or use.
A further disadvantage of securing devices for resilient material bales is that the securing devices themselves may be under tension. Thus, upon cutting the securing devices may exhibit springback and be potentially hazardous to users. In addition,
portions of the bale may explode upon the release of tension. In order to minimize some of these problems, the amount the materials are compressed may be reduced, thereby disadvantageously reducing the amount of material per unit volume in the bale.
In addition to the disadvantages just described, such traditional bulk packaging allows the materials to be exposed to the environment. As a result, the packaged materials may become damaged due to environmental forces, including exposure to moisture, odors, sunlight, dust, and the like.
In view of the foregoing disadvantages, new packages and methods for packaging have been developed, such as those disclosed in PCT Publn. No. WO 2004/074134 A1, published 2 September 2004, claiming priority to U.S. Pat. Appln. No. 10/672,825, the disclosures of which are incorporated herein by reference, that provide solutions to many or all of the foregoing problems, especially in reducing exposure of the contents to the environ...