GB2036683A

GB2036683A - Twist-wrapping

Info

Publication number: GB2036683A
Application number: GB7934325A
Authority: GB
Original assignee: ICI Americas Inc
Current assignee: Zeneca Inc
Priority date: 1978-10-16
Filing date: 1979-10-03
Publication date: 1980-07-02
Also published as: NZ191861A; AU5163879A; GB2036683B

Abstract

An article is encircled by a sheet of an embossed polymeric film, e.g. a biaxially oriented polyester film, which is twisted to form at least one end closure. The embossments are preferably hexagonal and improve twist retention.

Description

SPECIFICATION A wrapped article and a method for wrapping an article The present invention relates to a wrapped article and to a method for wrapping an article.

In the packaging of small articles, such as confec tionaries, a method commonly employed is twist wrapping in which the article is surrounded by a sheet of the desired wrapping material and the free - ends of the sheet are twisted to hold the sheet about the article. The wrapping material is generally brought together and twisted to form either a single closure or two closures, one at each end of the article.

Paper and cellophane (Registered Trade Mark) (a cellulosic film) have generally been used as the wrapping materials for twist-wrapping. Although both of these materials have some deadfold charac teristics, they do not adequately protect the contents of the package from adverse changes on storage.

Polymeric film materials exhibit certain well known advantages over paper and cellophane pack aging materials. However, one ofthe disadvantages of the polymerisfilm materials that have previously been used for packaging was the lack of "deadfold" characteristics of the films making them unsuitable for use in twist-wrapping applications. As a result of their lack of deadfold properties, after twisting the open ends of the wrapper, the twisted ends had a tendency to unwind and open up shortly after the twisting operation. It would, therefore, be desirable to have a polymeric film material having sufficient deadfold characteristics as to be useful in a twist wrapping operation.

In accordance with the present invention, a wrap ped article is prepared by wrapping an article with an embossed polymeric film and twisting the ends of the film to form at least one closure.

According to one aspect of the invention a wrap ped article comprises an article encircled with a sheet of an embossed polymeric film gathered together beyond the article and twisted to form at least one closure.

According to another aspect of the invention a method for wrapping an article comprises placing the article on a sheet of an embossed polymeric film, encircling the article with the sheet, gathering the sheet together beyond the article, and twisting the gathered sheet to form at least one closure.

The polymeric film wrapper should be of sufficient size to encircle the article with the ends beyond the article so as to form at least one twisted closure when gathered and twisted together.

The embossed polymeric film is preferably a single thickness of said film. The film may be printed, dyed or metallized, if desired. The films are deformed to provide thereon permanent, pre-set embossments which are of like configuration and in closely-packed relationship with each other. The embossments project from one surface of the film and on the opposite surface there is a series of individual depressions being aligned with the embossments. Preferably, the embossments are aligned in substantially parallel rows. However, this is not critical to the present invention and films in which the embossments are arranged in random order may be utilized The embossments in aligned parallel rows are-preferably arranged in staggered relationship with the embossments in the rows directly adjacent thereto.Preferably, the emboss menus are arranged in almost abutting relationship.

The perimeters of the embossments may be circular or may be defined by straight or arcuate lines.

Preferably, the perimeters of the embossments are of polygonal contour, as, for example, of hexagonal configuration to facilitate a close-packed staggered arrangement thereof and are separated from each other only by linear portions of the polymericfilm.

Any polymeric film that can be embossed may be used according to the present invention. However, preferred results are achievedwith a non-cellulosic film. Representative non-cellulosic films include, for example, oriented polyester, oriented polypropylene, oriented polyethylene and oriented nylon films.

Preferred results have been achieved with an embossed, biaxially-oriented, polyester film. The polyester films are preferably prepared frompolyethylene terephthalate. The thickness of the polyester film employed is not critical but it is preferred to employ films having a thickness of at least 0.35 x 103inch (9 yam). Films thinner than this are not preferred since they are difficult to handle and feed through twist-wrapping machines. Also, although films having thicknesses greater than 0.90 x 10-3 inch (23 lim) may be employed, it is not economically desirable to use such films and they result in an excessive bulk in the wrapped product.

Especially preferred results have been achieved with an embossed polyester film having a thickness of about 0.50 x 102 inch (12.7 Calm).

The embossed polymeric film can be prepared from a flat film by passing the film at an elevated temperature through a pair of rolls at least one of which has a pattern thereon corresponding to the pattern it is desired to transfer to the film surface.

The pattern may be applied to the film either during formation of the film or by reheating an already formed film. In-the case of biaxially-oriented polyestes film it is preferred to impose the pattern on an already formed and cooled film. This can either be done in a separate (off-line) operation or on-line in conjunction with the twist-wrapping machine.

Embossed polyester films and methods of preparing them have been described in the literature.

Representative films are described in US Defensive Publication T927 010, US patent 3842 152 and US patent 3 701 840, all of which relate to embossed films, i.e. films which have a series of bumps or protuberances on at least one surface thereof. Such films are suitable for use as the wrapping film in accordance with the invention.

Twist-wrapped articles are prepared, in accordance with the present invention, by placing the article to be wrapped on a sheet of embossed polymeric film, encircling or wrapping the article with the film, and twisting the end or ends of the film to form a closure. This operation may be carried out manually or on conventional wrapping machines known in the trade as twist-wrapping machines.

Such machines comprise the combination of a mechanism for enclosing individual articles, such as candy, tablets, or chewing gum, in sheet material and conveying the articles with the wrapped sheets folded about them in tubular form to a twisting station in which is mounted a twisting mechanism, such as two pairs of rotary grippers provided with gripping jaws. The grippers are each provided with separate actuating and reciprocating mechanisms and are adapted to operate simultaneously on the ends of the wrapping sheet clamped by the gripping jaws. The article may be wrapped by forming one end of the film into a twisted closure or by forming two ends into two closures.

In twisting the free ends of the wrapping material, both ends may be twisted in the same direction or in opposite directions. The wrapped articles prepared in accordance with the present invention have a more stable closure and a reduced tendency to open up, unwind and become unwrapped on storage when compared with articles prepared in the same manner but utilizing an unembossed wrapper of the same polymeric film.

Certain preferred embodiments of the invention are described below with reference to the accompanying drawings in which: Figure 1 is a plan view of a preferred embossed film, the figure being drawn on an enlarged scale to show the embossed pattern on the film; Figure 2 is a perspective view of the embossed polymeric film with the article to be wrapped placed thereon; Figure 3 is a perspective view of the article shown in Figure 2 at an intermediate stage in the wrapping operation; Figure 4 illustrates the article shown in Figures 2 and 3 with a twisted closure at each end thereof; and Figure 5illustrates an alternative wrapped article with all of the film twisted into a single closure.

Figure 1 illustrates a preferred embossed polymer icfilm comprising a biaxially-oriented and heat-set film of polyethylene terephthalate 10. The pattern of the embossments 12 formed in the film 10 are of like size and configuration and arranged in a closelypacked array so that only linear portions 14 of the original film separate adjacent embossments. The perimeters of the individual embossments are of hexagonal configuration to facilitate a close packaging thereof. The hexagonal embossments are arranged in substantially parallel rows with the embossments in the directly adjacent rows being in staggered relationship with each other. With this arrangement, only linear portions 14 of the original film remain between adjacent embossments 12.The lengths of these individual linear portions 14 will, of course, depend upon the particular configuration and size of the embossmentsthemselves.

Figures 2, 3 and 4 illustrate the preparation of a wrapped article in accordance with the present invention. As shown in Figure 2, an article 16to be wrapped is placed on the sheet of embossed biaxially-oriented polyethylene terephthalate film 10 as shown in Figure 1. The article 16 is then encircled with the sheet 10 thus forming an open-ended tube around the long axis of the article, as shown in Figure 3. Each of the two projecting free ends 17 and 18 of the sheet is clamped by a pair of gripping means and twisted to form a closure. After the finished package having two twisted end closures 19 and 20 is formed, and the clamped ends of the sheet are released from the gripping means resulting in a wrapped article as shown in Figure 4.

In an alternative embodiment, all of the film, as shown in Figure 1, may be wrapped about the article and twisted so as to form a single closure 21 as shown in the wrapped article depicted in Figure 5.

The invention is further described in the following example.

Example A preformed, biaxially-oriented and heat-set polyethylene terephthalate film having a thickness of 0.48x 10-3 inch (12.2 Fm) was embossed with a raised hexagonal pattern by heating the film to a temperature above its softening point and feeding the heated film between a pair of adjacent, counterrotating embossing rollers having thereon the hexagonal pattern which was to be imparted to the film.

A round piece of candy having a diameter of approximately 0.75 inch (1.9 cm) was placed on a sheet of the resulting embossed polyethylene terephthalate film having a size approximately 3 inches (7.6 cm) square. The film was wrapped around the candy to form a tube with the candy in the center and the two free ends of the film extending beyond the candy were manually twisted to form a closure. When released, the closure held the candy in place inside the wrapper without unwrapping.

Claims

1. Awrapped article which comprises an article encircled with a sheet of an embossed polymeric film gathered together beyond the article and twisted to form at least one closure.

2. Awrapped article according to claim 1, in which the sheet has at least one end extending beyond the article and formed into a twisted closure.

3. Awrapped article according to claim 1, in which the sheet has two ends extending beyond the article and each formed into a twisted closure.

4. A wrapped article according to claim 1, 2 or 3, in which the embossed polymeric film is a biaxiallyoriented polyethylene terephthalate film.

5. A wrapped article according to claim 4, in which the polyethylene terephthalate film has a thickness in the range 9 to 23 lim.

6. A wrapped article according to any preceding claim, in which the film is embossed with a polygonal pattern.

7. Awrapped article according to claim 6, in which the film is embossed with a hexagonal pattern.

8. Awrapped article according to any preceding claim, in which the polymeric film is a metallized film.

9. A method for wrapping an article, which comprises placing the article on a sheet of an embossed polymeric film, encircling the article with the sheet, gathering the sheet together beyond the article, and twisting the gathered sheet to form at least one closure.

10. A method according to claim 9, in which the article is positioned in the sheet with one end of the sheet extending beyond the article and the end is gathered and formed into a twisted closure.

11. A method according to claim 9, in which the sheet is encircled about the article to form a tube with the article in the center and the two opposite ends of the sheet are twisted to form closures.

12. A wrapped article substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

13. Awrapped article substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 5 of the accompanying drawings.

14. A method for wrapping an article substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

15. A method for wrapping an article substantially as herein before described with reference to and as illustrated in Figures 1 and 5 of the accompanying drawings.