RESEALABLE FLEXIBLE PACKAGING AND SEALING TAPE THEREFORE

Abstract: A sealing tape for resealable flexible packaging comprising a plastic tape, one section of which is provided with a permanent high-tack adhesive, the second section being provided with a low-tack adhesive and being folded onto itself with the interposition of a layer of silicone, the face end of said second section being adhesive free and resealable flexible packaging comprising a conventional bag and a sealing tape, wherein the section with high-tack adhesive is attached to the bag at a suitable distance from the end to be opened, said end of said second section facing said end of the bag to be opened and serving as a finger lift.

Description: The present invention concerns flexible packaging, made from one layer film or from laminate, in particular the kind of packaging used for marketing food stuffs in bulky or granular form, and a sealing tape thereof. Most flexible packaging is usually made up of a laminated plastic film constituted by two or more laminations, the plastics for the outside laminate being chosen with a view to preserve the contents of the bag, and to carry the printed text. The inside film is chosen with a view to give a good sealibility. The film for the bag is chosen to be more or less flexible depending on the product to be packaged. The bag is sealed at least along one longitudinal sean and at two-cross seans. In order to open the sealed package, one of the seans generally is torn or cut (see for instance US.A. 4584201). If the products packaged in these bags are bulky, e.g. cheese, olives or like, the bags will bulge considerably. If the products are granular, i.e. ground coffee or must and the like, they will be distributed in the bag wich will then be more or less flat. In either case, the package must be reclosable, since all the contents are generally not removed at one time, i.e. when the bag is first opened. The reclosing of the bag and sealing it, in this condition to prevent damage to the contents, presents a great problem and many attepmts have been made to find a suitable solution. In one type of reclosable flexible packaging an adhesive tape is attached across the width of the entire bag, and when the later has been partly emptied, the open end is folded over once or twice onto itself, the tape is removed and is reapplied partly across the end of the fold and partly across the bag. The main drawback of this solution is the fact that the packaged bag is bulky and is thus distorted by its contents, the tape, which is less flexible than the film of the bag loosens automatically, its ends lifting away from the surface of the bag. This presents a problem in the handling of an unopened bag, since these ends will become attached to adjacent packaged bags. If the bag has been opened and resealed, the seal will become loose. In either case, the tape may become detached altogether. Another disadvantage of this solution is the fact that the tape will not seal properly when applied to a full bag and this will effect the shelf life of the product, and also dust can adhere to such tape, preventing it from performing its function. In another type of reclosable flexible packaging, an adhesive tape is provided across an opening in the bag. This opening may be an unsealed sean, a slit, or perforations which are to be torn to provide said opening. When the bag is to be opened, the tape is partially lifted and some of the contents are removed through said opening. Thereafter, the bag is held at the two ends of the opening and said ends are pulled away form each other to close the opening. The removed part of the tape is then pressed back to its former position. The main drawback of this type of resealing is as in the above mentioned type the fact that the tape when applied to a full bag will not seal properly and therefore will adversely affect the shelf life of the product. Furthermore, if the contents of the bag are granular, they will adhere to the tape so that it can no longer perform its function. A further consideration in making resealable flexible packaging is the attachment of the sealing means during or after the production of the bag itself which is effected with a minimum increase of costs. It is the object of the present invention to provide resealable flexible packaging which overcomes the above mentioned disadvantages and problems in the manufacture, handling, as well as use of the bags known up to now. This object is attained by a sealing tape and a packaging according to to claims 1 and 2 respectively. The invention consists of resealable flexible packaging comprising the conventional bag and a relatively short plastic tape, one section of which is provided with a permanent high tack adhesive on one surface and is attached to the bag at a suitable distance from the end destined to be opened the another section being provided with a low tack adhesive folded onto itself with the interposition of a layer of silicone, the free end of said second section facing said end of the bag to be opened and being adhesive free to serve as a finger lift. The terms high-tack and low-tack adhesives are well known in the industry and do not require detailed explanation, the high-tack adhesive adhering permanently to a surface, while the low-tack adhesive adheres well, but can be removed and reattached a great number of times. In a preferred embodiment of the invention, said suitable distance is equal to at least the space required for folding over twice the end of the bag. The tape is made of a thin film of plastic material, e.g. polypropylene, polyvinyl chloride or the like. It is preferably of a width of between 10% - 30% of the width of the package, the actual width depending on the flexibility of the bag after it has been filled, i.e. granular contents require a narrower tape to hold the folded-over end of the bag, while bulky contents require a wider tape. In use, the bag is opened and as much of the contents as necessary is removed. Thereafter, the open end of the bag, which now lies flat, is folded over at least twice, a process which seals the bag substantially hermatically. The tape is then grasped by the fingerlift and is pulled, which causes the said low-tack adhesive section to unfold and to become one straight piece, so that it can be applied to the folded-over part of the bag to which it will adhere tightly. When the bag is to be reopened, the finger lift is grasped and the low-tack section of the tape is peeled off from the folded part of the bag and is again folded onto itself. Thus, while the contents of the bag are removed, the tape will not become dirty and thus loose its ability to stick. The reasealing process can be repeated as many times as required, without impairing the tape, the bag or its contents. The tape can easily be attached, by conventional means, well known in the industry, to a prefabricated bag or in coordination with the actual manufacturing and/or filling machinery of the bag itself. Although the tape will, according to the invention, project beyond the surface of the bag, it will not interfere with the handling of either an empty or a full bag, since it is very thin and flexible, and applies itself against the flat or the bulging surface or a filled bag, since, when not in use, the tape is folded onto itself, it will not adhere to any other surface such as an adjacent bag. At no time, either during filling or emptying the bag, will the tape be in contact with the packaged product.

Claims: A sealing tape for resealable flexible packaging comprising a plastic tape, one section of which is provided on one surface with a permanent high-tack adhesive, the second section being provided on the same one surface with a low-tack adhesive and being folded onto itself with the interposition of a layer of silicone, the free end of said second section being adhesive free. Resealable flexible packaging comprising a conventional bag and a tape as claimed in claim 1, wherein the section with high-tack adhesive is attached to the bag at a suitable distance from the end to be opened, said free end of said second section facing said end of the bag to be opened and serving as a finger lift. Resealable flexible packaging as claimed in claim 2, wherein said suitable distance is equal to at least the space required for folding over twice the end of the bag. Resealable flexible packaging as claimed in claim 2 or 3 wherein the width of the tape is preferably 10% - 30% of the width of the bag.

Inventors: LINNEWIEL, RON
Applicants: LINNEWIEL, RON
Application year: 1987
Main classification: B65D33
IPC codes: B65D33, C09J7, B65D65