US 20060110078 A1
A plastic bag for vacuum sealing that has a folding line formed during fabrication of a plastic bag to form an air channel communicating with a housing chamber so that when the plastic bag is coupled on a vacuum sealing machine remaining air in the housing chamber may be fully extracted before the plastic bag is sealed.
1. A plastic bag to be coupled with a vacuum sealing machine, comprising:
a first air impermeable layer and a second air impermeable layer bonded to form a housing chamber to hold goods having at least one bag opening communicating with the housing chamber; and
at least one air channel selectively formed on the first air impermeable layer or the second air impermeable layer by forming at least one folding line on the first air impermeable layer or the second air impermeable layer that communicates the bag opening with the housing chamber;
wherein the plastic bag is coupled with the vacuum sealing machine so that remaining air in the housing chamber is extracted by the sealing machine through the air channel, and the bag opening is sealed thereafter.
2. The plastic bag of
3. The plastic bag of
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5. The plastic bag of
The present invention relates to a plastic bag for vacuum sealing and particularly to a plastic bag for holding goods that has a suction pocket for extracting remaining air then be sealed to prevent external air from entering to protect the quality of the goods.
In the general household preserving goods that easily rust or perish is a commonly encountered problem, especially for food. While fresh vegetables and fruits may be held in containers and stored in a refrigerator to maintain the freshness, the general foodstuffs such as biscuits, potato chips, candies cannot be stored in the refrigerator once unpacked and not consumed immediately. They tend to lose the original tasty flavor after having exposed to the air. To remedy this problem, many vendors have developed household sealing machines so that users can store goods to be preserved in an air impermeable thermoplastic bag and extract the remaining air from the thermoplastic bag, and seal the opening of the plastic bag. Thereby the goods can maintain their original taste next time they are removed from the plastic bag.
Owing to the housing chamber of the plastic bag has a selected length, when the sealing machine starts suction and extracts the air, the air around the bag opening is extracted immediately. As the plastic bag is made from thermoplastic material which has viscosity, extracting the air around the bag opening tends to make the sealing machine mistakenly judge that the remaining air in the housing chamber has been completely extracted and proceed sealing operation. As a result, there is still air trapped inside the housing chamber coexisting with the goods held inside. The sealing effect is compromised. In order to remedy this problem, U.S. Pat. No. 4,756,422 (RE34,929) discloses a plastic bag for vacuum sealing. It has air channels formed in a spaced pattern by heat embossing on at least one air impermeable layer to communicate the housing chamber with the bag opening. Through the air channels, the plastic bag opening does not partially seal and all the air in the plastic bag may be extracted before the sealing machine starts sealing operation.
Nevertheless, the cited reference mentioned above has to form the air channels by heat embossing, and the air impermeable layer of the plastic bag has to be thickened. Hence, not only the fabrication process is more complicated the costs of fabrication and material increase greatly and the products become more expensive as well. With increased thickness, more sealing time is required. As most sealing machines are designed to stop air extraction during the sealing process, while the plastic bag is sealed, the air tends to reenter the plastic bag through the air channels, and the actual air extracting and sealing effect is not desirable.
Other references also can be found in U.S. Pat. Nos. 3,809,217 and 4,093,068.
The primary object of the present invention is to solve the aforesaid disadvantages. The invention provides a plastic bag that has an air channel communicating the bag opening with the housing chamber of the bag at a lower fabrication and material cost without the need of altering the bag thickness. The air channel is formed on a first air impermeable layer or a second air impermeable layer through injection by directly forming a folding line on the first air impermeable layer or the second air impermeable layer. When the plastic bag is coupled with a sealing machine, the remained air inside the housing chamber can be fully extracted through the air channel before sealing process is started.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please referring to
The main feature of the invention is to form at least one air channel 15 a on the first impermeable layer 11 or the second air impermeable layer 12. The air channel 15 a is formed by fabricating at least one folding line a on the first impermeable layer 11 or the second air impermeable layer 12 during the integrated injection molding process of the plastic bag 10. The folding line a may be one line or double lines b and c. Refer to
By means of the construction set forth above, the plastic bag 10 of the invention may be made without adding material. The cost is lower and fabrication process also is simpler. Thus total production cost may be reduced. In addition, the sealing time does not increase, and air return flow may also be reduced.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.