IE41463B1 - Warp knitted sack - Google Patents

Abstract

1474228 Woven bags J F ADOLFF AG [26 Sept 1963] 40391/74 Heading B8K [Also in Division D1] A sack is warp knitted complete as a two-ply fabric joined at three sides and the fabric consists of knitted warps 22 with laid in wefts 24 at least two tapes 26 being laid in between pairs of knitted warps and being no wider than the space therebetween, the tapes each being held by at least one weft and a label being attached to the tapes by adhesive or welding. The knitted warps and laid in wefts may be foil strips. The tapes and label may be thermoplastic foil.

Description

The invention relates to a sack made in the form of two-ply Raschel fabric, whose two plies formed from knitted warp and weft threads are joined together along the side edges and bottom of the sack during knitting.

It is possible to make a finished sack of the kind mentioned above on a Raschel warp knitting machine, wherein the weft threads are laid-in by the machine simultaneously with the knitting of the warp threads and wherein the two sack wails do not have to be stitched together after knitting either along the side edges or along the base. The warp threads form series of chain stitches and a weft yarn which runs to and fro in zigzag fashion between two chains may be called a weft inlay.

Sacks for products such as fruit, vegetables and the like are normally woven or knitted comparatively loosely so that the sack walls have considerable openings between the threads. If a label is then to be attached to a sack wall, substantial problems arise due to the presence of these openings. If the walls of a woven sack are formed from separate webs, 2. 41483 attaching the label before stitching the walls together can prevent the two walls from adhering together at the adhesive or welded points, but it is unavoidable that owing to these openings the goods with which the sack is later filled may come into contact with adhesive used for fastening the Tabel or that the fabric is weakened so much at welded points that the sack wall may tear during subsequent use. These disadvantages obviously also occur in finished sacks with an open structure made on a Raschel warp knitting machine, wherein it should be noted that a plate or the like must be pushed in between the sack walls before a label is stuck or welded onto a sack wall in order to prevent the sack walls from sticking or welding together. Finally, both in woven and Raschel-made sacks there is the possibility that the sack walls stick together whilst they are being stored through adhesive used for fixing the labels. Moreover the labels are not all that secure due to the open structure of the sack walls.

The object of the invention is to facilitate the fixing of for example, advertising aids, details of contents on finished sacks made on a Raschel warp knitting machine.

According to the invention there is provided a sack made in the form of a two ply Raschel fabric, the two plies being formed from knitted warp and laid-in weft threads, and joined together during knitting along the side edges and bottom of the sack, and wherein at least two tape members are provided each having a width no greater than the spacing between the knitted warp threads and positioned in at least one of the sack walls, each tape member being arranged between selected adjacent ones of the knitted warp threads and held by at least one weft thread which runs substantially transversely between the selected knitted warp threads, a label being attached to the tape members by adhesive or welding. 3. 4i4S3 If a label is to be welded onto the sack wall, then the inlaid tape member has the advantage that no inadmissible weakening of the sack wall at the welded points can occur.

The invention is particularly suited to sacks in which the knitted warp and laid in weft threads are strips of foil.

Consequently, it is preferable that the tape member is made from a thermoplastics foil, particularly if the label is to be welded on. Paper, a fabric tape or metal foil can also be used for the tape members which are to be inserted.

If a tape member is only held by a single weft thread running to and fro between two warp threads, then the tape member must run alternately in front of and behind the weft thread. Production is simpler tf several wefttnreads are provided in the region of the tape member, i.e. if .several weft threads extend between the warp threads on either side of the tape member so that the latter is held between the weft threads.

A weft thread at the front and one weft thread at the back of the taoe member is thereby sufficient so that the tape member is held between the two weft threads which run to and fro between the warp threads. This accumulation of material in the region of the inlaid tape member increases still further the reliability when welding on the labels.

Several tape members may be laid in a sack wall so that they are adjacent or spaced from each other. When attaching labels, it is advisable to arrange several tape members in a sack wall at intervals from each other and to fasten a label to these members, more particularly by gluing or welding.

In order to avoid a later additional application of adhesive, it is possible to use tape members which are coated on one side with an adhesive which may be a contact adhesive, but more particularly is an adhesive which can be heat-sealed. 4.

Since a label fastened to tape members which run transversely to the longitudinal direction of the sack forms a pocket open at the sides, the label may be damaged during transport of the sack. It is possible to incorporate tape members in the sack wall between the upper and lower edges of the label and fasten the label to these additional tape members. However, welded seams traversing the centre zone of the label could impair the written or illustrated part of the label. In order to avoid these problems, it is now proposed to use a label which extends into the regions of the side edges of the sack walls and to join the label to these regions by welded or adhesive seams running parallel to the edges. Since these edge regions are formed by twice as many warp and weft threads as the simple sack wall, the danger of inadmissible weakening does not occur even during welding. Furthermore, since the contents of the sack cannot reach the edge regions there are no objections to gluing the label in these regions.

The invention will now be described by way of examples with reference to the drawings wherein: Figure 1 is a view of a Raschel-made sack with a label attached to two tape members incorporated in a sack wall; Figure 2 is an enlarged view of Section A of Figure 1 with the label partly removed from the sack wall; Figure 3 is an enlarged view of Section B of Figure 2 with part of the tape member removed; Figure 4 is a cross-section along the line 4-4 of Figure 3; Figure 5 illustrates the binding between the warp and weft threads in the wall of a Raschel-made sack; and Figure 6 illustrates the binding of the sack wall in a zone In which a tape member (not shown) can be incorporated.

The sack illustrated in Figure 1 and marked generally at 18 has two side edges 12 and a base 14. It is known to make a sack of this . kind of, for example, foil strips on a Raschel warp knitting machine so that the two sack walls are joined together along the side edges 12 and base during knitting so that a subsequent stitching process is no longer i required.

In the sack illustrated in.Figures 1 and 2, two tape members 26 and 28 are incorporated in the front sack wall at a distance from each other so as to lie under the upper and lower edges 20a, 20b of a label 20. The tape members and label 20 consist of a thermoplastic foil so that they can be joined together and with the foil strips of the sack by welding.

Figure 3 shows a part of the tape member 26; for a simpler illustration Only the front sack wall has been illustrated adjacent the left side edge 12; i.e. the web or wall lying behind it and formed at the same time by the Raschel machine has been omitted. From Figure 3 it can be seen that each sack wall is formed by warp threads 22 running at a distance from each other and by weft threads 24 wherein a weft thread runs to and fro in zig-zag fashion between two adjoining warp threads. Only in the zone of the tape member 26 do two weft threads 24a and 24b run oetween the warp threads 22a and 22b, with the weft thread 24a running in front of and the weft thread 24b behind the tape member so that the latter is held between the two threads. This is clearly shown in Figure 4..

Tape member 28 is held in the same way between two weft tnreads. Both tape members 26 and 28 serve as closed full-length Backings for attaching the label 20 which can be joined to the tape members and to the warp and weft threads by means of adhesive or welding in the zones of the tape members. Welded seams are indicated at 26a and 28a and in order that the label 20 does not form a pocket open on both s'5 les whereby the label could be easily damaged, a coating of adhesive 30 is provided by means of which the side edges of the label can be joined to the edges 12 of the sack. 6. 414 G «J Figure 5 illustrates a section of a sack wall of a Raschelmade sack, namely in an area where there is no .tape member. In accordance with Figure 3, the warp threads are marked 22 and the weft threads 24. As opposed to this, Figure 6 illustrates the two weft threads 24a and 24b and the two warp threads 22a and 22b with the two weft threads running to and fro therebetween. The tape member held between the weft tureads 24a and 24b have however been omitted from Figure 6.

The tape members are not laid in between the weft threads afterwards, but the Raschel machine allows the tape members to be laid and bound in during manufacture of the sack.

Claims (8)

1. A sack made in the form of a two ply Raschel fabric, the two plies being formed from knitted warp and laid-in weft threads, and joined together during knitting along the side edges and bottom of the sack, and 15 wherein at least two tape members are provided each having a width no greater than the spacing between the knitted warp threads and positioned in at least one of the sack walls, each tape member being arranged between selected adjacent ones of the knitted warp threads and held by at least one weft thread which runs substantially transversely between the selected 20 knitted warp threads, a label being attached to the tape members by adhesive or welding.

2. A sack as claimed in Claim 1 wherein the tape members carrying the label are spaced from each other.

3. A sack as claimed in Claim 1 wherein the warp and weft threads 25 are foil strips.

4. A sack as claimed in Claim 1 wherein the tape members consist of thermoplastics foil. 7.

5. A sack as claimed in Claim 1 wherein a plurality of weft threads extend between said selected warp threads and are disposed on either side of that tape member arranged between the two warp threads to hold the tape member in position. 56. A sack as claimed in any preceding claim wherein the tape members are coated with an adhesive which may be a contact adhesive, or an adhesive which can be heat-sealed.

6. 7. A sack as claimed in any preceding claim wherein the label extends into the side edge regions of the sack walls and is connected to the lo side edge regions by welded or adhesive seams running parallel to the side edges.

7.

8. A sack substantially as hereinbefore described with reference to the drawings-.