Patent Application
20200079565
This invention relates to blister packs, especially the push-through type of blister packs for containment and dispensing of deformable or fragile articles.
Blister packs have been used for containing various products such as medicine, food, cosmetics, personal cleansing products or laundry care products, while protecting such products from damage or exposure. Unit doses of such products are stored in readily accessible, individually sealed compartments (i.e., blisters) of such blister packs. Typically, a back sheet is used to seal the individual compartments in the blister packs. Each compartment can then be opened independent of any other compartments in such blister packs.
In some blister packs, the back sheet can be peeled back to expose the contents of individual compartments. However, it is not uncommon for an area of such peelable sheet to tear away in such a manner as to expose more than one compartment, leaving the contents in the other compartments (other than the one intended to be opened) at risk for contamination. Therefore, such peelable type of blister packs may be undesirable.
In other blister packs, the back sheet is frangible and can be broken when the contents of individual compartments are pushed against it by application of external force thereon. Blister packs with such frangible back sheets are referred to as the “push-through type”, and they can be readily used for containing solid and rigid products that are structurally sound, such as pills or lozenges. However, when the products to be contained and dispensed are elastically deformable or fragile, it is difficult to push through such products to break the back sheet without damaging or severely deforming the product. Therefore, the push-through type blister packs may be unsuitable for housing and dispensing deformable or fragile products or contents.
In certain push-through type of blister packs, internal or external openers or cutters are provided for piecing or cutting the back sheet to release the contents of individual compartments. For example, U.S. Pat. No. 5,816,404 discloses a blister pack with an opener that is supported by a frame over the blister opening, and such opener can be displaced downwardly to first piece a back sheet that covers the blister opening and then to remove such back sheet by rotation. For another example, U.S. Pat. No. 6,443,307 discloses a blister pack with dome-shaped blisters sealed by a lower membrane, while each dome-shaped blister contains an annular-shaped internal cutter that can be used to cut through the lower member by simply depressing the dome-shaped blister. However, such known internal or external cutters or openers tend to have complex structures, and to make them requires significant additional materials and complicated processing steps, which can be cost-prohibitive for certain consumer goods such as cosmetics, personal cleansing products or laundry care products.
Therefore, there is a need for new blister pack designs that are particularly suitable for housing and dispensing deformable or fragile articles, which are both easy to open and easy/inexpensive to make.
The present invention provides push-through type of blister packs with built-in ledges formed by at least one reinforcing sheet, which are both easy/inexpensive to make and effective for cutting the back or lid sheet that seals the blisters. Such built-in ledges enable easy release of products/contents from the blister packs with minimal damage or deformation, so are particularly suitable for use with deformable or fragile products/contents, more preferably a product/content that is elastically deformable.
The present invention in one aspect provides a package for containing and dispensing at least one article, which comprises:
The present invention in another aspect provides a blister pack for containing and dispensing multiple unit doses of a product, which comprises:
Such package or blister pack with the reinforcing sheet is easy/inexpensive to make, while the cutting ledges formed by the cut-out sections in the reinforcing sheet are simple yet structurally sound/robust. More importantly, they are effective for cutting the lid sheet with minimal impact/force on the article or product contained therein during release.
Further objects and advantages of the present invention will become apparent in the following description.
The present invention provides a new push-through type of blister pack or package.
In a conventional blister pack of the push-through type, as shown in
However, when such conventional blister pack as described hereinabove is used to house and dispense an elastically deformable product 4′, the external force F applied onto the blister cavity 2 will mostly be absorbed by the product 4′ to effectuate its deformation into the compressed form 4″, instead of being applied to the metal foil lid sheet 5 to effectuate its rupture, as shown in
In order to solve the above technical problem, the present invention provides a package or blister pack with a reinforcing sheet attached to the lid sheet at a side opposite to the blisters. Such a reinforcing sheet helps to improve the overall structural integrity of the blister pack against bending under excessive external force. More importantly, such reinforcing sheet forms cutting ledges near the openings of the blisters, and such ledges are particularly effective in converting external force applied generally to the lid sheet into a highly localized cutting force for rupturing the lid sheet along such ledges, thus minimizing the de-blistering force.
For example,
Further, the use of such a substantially planar reinforcing sheet 40 to structurally reinforce the package 10 and to provide built-in cutting ledges 44A and 44B for rupturing the lid sheet 30 adds little or no additional cost and complexity to the manufacturing process, and it requires minimal additional capital investment. More importantly, such built-in cutting ledges 44A and 44B are structurally integral with other components of the package 10, and they are unlikely to be damaged or cause damages to the articles or products 23A and 23B contained in the package 10 or to other components during shipment or transportation.
The depressions or blisters according to the present invention may be of any suitable shape, e.g., cubical, rectangular, cylindrical, semi-spherical or dome-shaped. It is preferred that the depressions or blisters have round edges, and more preferably the depressions or blisters have a semi-spherical or dome shape (as shown in 22A and 22B of
The article or product to be housed by the package or blister pack of the present invention can be of any form, e.g., solid, semi-solid, powder, paste, liquid, gel, foam, and the like. Preferably, such article or product is deformable or fragile. More preferably, such article or product is elastically deformable, i.e., it can be deformed under stress but can eventually return to the original shape with little or no change in shape when the stress is removed. Most preferably, such article or product is characterized by a Young's Modulus of no more than about 5, preferable from about 0.01 to about 1, more preferably from about 0.01 to about 0.5, most preferably from about 0.01 to about 0.1. In a particularly preferred embodiment of the present invention, such article or product is flexible, porous and dissolvable, which may contain one or more water-soluble polymer in combination with one or more functional ingredients.
The article or product of the present invention may have any shape or size suitable for its intended use, as long as it is configured for passing through the blister opening and the cut-out section in the reinforcing sheet after the lid sheet has been broken or ruptured by the ledge, while itself will not be cut or damaged by the ledge. To maximize the force transfer during dispensing preferably the article should have a footprint area smaller than 600 mm2, more preferably below 400 mm2 and even more preferably below 200 mm2 and a thickness preferably above 6 mm, more preferably above 10 mm and even more preferably above 15 mm. The base sheet of the present invention is preferably a flexible yet structurally sound sheet with a substantially planar base portion and one or more depressions or blisters formed therein.
The base sheet may be formed of any suitable materials, including but not limited to: plastic materials, plastic laminates, and the like. The base sheet materials should be compatible with the product stored inside and have a low water-vapor transmission rate (depending on the specific application). Suitable plastic materials for making the base sheet of the present invention may be selected from the group consisting of polypropylene (PP), copolymers and terpolymers of propylene, polyethylene (PE), polyvinyl chloride (PVC), polyvinyl dichloride (PVdC), copolymers and terpolymers of vinyl chloride and/or vinyl dichloride, poly-chloro-tri-fluoro-ethylene (PCTFE), cyclic olefin copolymers (COC) and combinations thereof. In a particularly preferred embodiment of the present invention, the base sheet is formed by a transparent PP material.
The base sheet may be characterized by a thickness at its base portion (i.e., base thickness) ranging from about 100 microns to about 1000 microns, preferably from about 200 microns to about 800 microns, more preferably from about 300 microns to about 600 microns, most preferably about 500 microns. The thickness of such base sheet at the depression or blister portion (i.e., depression thickness or blister thickness) is preferably significantly smaller than that of its base thickness, so as to enable easy deformation or compression of the depressions or blisters without compromising the overall structural integrity of the blister pack. For example, the depression/blister thickness of the base sheet may be no more than ¾, preferably no more than about ⅗, more preferably no more than about ½ of its base thickness. Depressions or blisters with such reduced depression thickness are easily deformable and can be deformed/compressed downwardly toward the blister openings when an external force is applied, while offering sufficient strength to prevent denting or damage during distribution or package handling.
The lid sheet as used in the present invention may be substantially planar and is preferably coterminous with the base sheet. Such a lid sheet can be attached to the base sheet by any attachment mechanisms, e.g., heat-sealing, adhesives, stamping, pressure-sealing, and the like. Preferably, the lid sheet has a heat-sealable coating and is heat-sealed to the base sheet. More preferably, the heat-sealable coating is applied by lacquer and should have low density to minimize the film stretching and enhance its pierce-ability. Such a lid sheet may be formed of any suitable materials, such as aluminum foil, aluminum laminates, polymer laminate such as polyester laminates, polymer/aluminum laminates (especially polyester/aluminum laminates), paper, paper/aluminum laminates, and combinations thereof. Preferably, such lid sheet is soft or hard tempered aluminum foil or aluminum laminate. More preferably, the aluminum foil should be hard tempered with a thickness ranging from 12 to 30 microns, and most preferably between 15 to 25 microns. In a particularly preferred embodiment, the lid sheet is a hard aluminum of 20 micron.
The reinforcing sheets as used in the present invention may be formed of any suitable materials, including but not limited to paper laminates and paper/polymer laminates. Such reinforcing sheets preferably are thick enough to provide sufficient structural support for the blister pack of the present invention, i.e., to avoid significant bending of such blister pack during opening of the blisters and dispensing of the contents therein. Further, thicker reinforcing sheets provide stronger cutting ledges that can localize the cutting force more effectively.
Preferably, the reinforcing sheets of the present invention have a thickness (i.e., measured at a location away from the cut-out sections) ranging from about 0.5 mm to about 2 mm, preferably from about 0.7 mm to about 1.5 mm, more preferably from about 0.8 mm to about 1.2 mm More preferably, the blister pack of the present invention comprises both the top and bottom reinforcing sheets, which are formed by folding a single paper laminate (preferably with a polymer coating thereon) into two halves and then stamped or punched to form the corresponding cut-out sections thereon.
The cutting ledges formed by the offset portions of the bottom reinforcing sheet preferably have a semi-circular or arched shape, similar to those shown in
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | |
|---|---|---|---|
| 62730010 | Sep 2018 | US |
