Patent ID: 12246908

In the figures, like reference numerals refer to like or corresponding elements.

DETAILED DESCRIPTION

FIG.1is a schematic depiction of a tubular and/or rod-shaped glass article1. The glass article has longest dimension l, likewise depicted inFIG.1. The longest dimension—or simply length l—of the tubular and/or rod-shaped article1extends along a first direction of a Cartesian coordinate, that is, here in this case, from the left to the right of the figure.

FIGS.2a-2bare schematic depictions of a close packing of equal circles in the sense of the present disclosure. InFIG.2a, the close packing may be understood in this case as a cross-sectional view of a bundle of rod-shaped glass articles11, whereas, inFIG.2b, the close packing may be understood as a cross-sectional view of a bundle of tubular glass articles12. For the sake of visibility, only one article11,12has been indicated. It is pointed out that the arrangement of circles (as inFIG.2a) or rings (as inFIG.2b) each consists, in this case, of four different layers of circles or rings, respectively. These layers may be understood as a layer of rod-shaped glass articles or tubular shaped glass articles, the number of layers, NL, being, in this case, 4. However, generally, without being bound be the depiction inFIGS.2a-b, different, particularly higher, numbers of layers are possible, of course. Further, the circles or rings are spaced apart slightly.

Now, inFIG.3ais a cross-sectional view of rod-shaped glass article (or glass rod)11with outer dimension do, the latter being equal to the diameter of the cross-section. InFIG.3b, a cross-sectional view of tubular glass article12is shown. This cross-section can be defined by outer dimension doand inner dimension di, wherein the wall thickness twof the tubular glass article (or glass tube)12corresponds to:
tw=½*(do−di).

It is to be noted that in the case of a rod-shaped glass article (or glass rod), the wall thickness corresponds to:
tw=½*do,
as indicated inFIG.3a. That is, the wall thickness twmay also be understood as the radius of the rod-shaped glass article (or glass rod).

Now, with regard toFIGS.4a-4b, two different embodiments of bundles10of tubular and/or rod-shaped glass articles1are shown.

FIG.4adepicts schematically bundle10, comprising tubular and/or rod-shaped glass articles as well as a thread-like element2. As can be seen, the cross sections of tubular and/or rod-shaped glass articles1form a close packing here. Further, here, thread-like element2is positioned to the rear of the bundle10as well as near the front region. It may be noted that at both position, that is, to the rear and at the front, thread-like element2may be the same, that is, just one thread-like element is first wrapped around the glass articles at least partially at the rear side portions and, after that, at the front side portion. However, if may be more suitable to use, at each spacer position, a separate thread-like element2. Further, it is to be noted that, according to the actual method used to wrap the thread-like element2around a glass article at least partially, more than one thread-like element may be present at a single spacer position, for example, an upper thread-like element and a lower thread-like element.

InFIG.4banother bundle10is depicted. In this case, the rod-shaped and/or tubular glass articles have been arranged so that their cross sections form a simple cubic packing. Here, the thread-like element2is position at three different spacer positions.

FIGS.5a-5cshows three schematic and not drawn to scale depictions of bundles10. Here, in each case, bundle10comprises thread-like element2that has been wrapped around the rod-shaped and/or tubular glass articles (not indicated) at least partially at three positions. Further, the bundles10each comprise at least one film3wrapped around bundle10radially. Now, inFIG.5a, film3is wrapped around the bundle10completely, however, for the sake of visibility, film3is only depicted in the rear part of bundle10.

FIG.5bshows bundle10. Here, the film3has been wrapped around bundle10only in a middle section thereof, so that both ends of bundle10remain free of film3.

FIG.5xshows yet another embodiment of bundle10. Here, bundle10comprises three films3wrapped around bundle10radially so as to cover thread-like elements2(not indicated) at each of the three spacer positions. Such an embodiment is particularly preferable, as only a minimum amount of waste is produced.

Now, inFIGS.6a-6d, a tubular and/or rod-shaped glass article1is depicted. It is once again pointed out that these depictions each are merely schematic depictions and not drawn to scale. The tubular and/or rod-shaped glass article1in each ofFIGS.6a-6dis bent. However, the amount of bending has been exaggerated for illustrational issues.

FIG.6ashows the case where at least one thread-like element2has been positioned at to spacer positions ntalong length l of the article2. These positions may be characterized by distance a, a being a first distance a between the half-length of the tubular and/or rod-shaped articles and at least one first spacer position of at the least one thread-like element.

Now, if there are, as depicted inFIG.6b, there are three spacer position nt, these three positions can be characterized by distances a and b, a being a first distance a between the half-length of the tubular and/or rod-shaped articles and at least one first spacer position of at the least one thread-like element and b being a second distance b between the half-length of the tubular and/or rod-shaped articles and at least one second spacer position of the at least one thread-like element; a being smaller than b.

Further, in the case shown inFIG.6c, four spacer positions are distributed along length l. These four positions can likewise be characterized by distances a and b, a being a first distance a between the half-length of the tubular and/or rod-shaped articles and at least one first spacer position of at the least one thread-like element and b being a second distance b between the half-length of the tubular and/or rod-shaped articles and at least one second spacer position of the at least one thread-like element; a being smaller than b.

Furthermore, as shown inFIG.6d, if five spacer positions are distributed, then these can be characterized by distances a, b, and c, a being a first distance a between the half-length of the tubular and/or rod-shaped articles and at least one first spacer position of at the least one thread-like element, b being a second distance b between the half-length of the tubular and/or rod-shaped articles and at least one second spacer position of the at least one thread-like element, and c a third distance c between the half-length of the tubular and/or rod-shaped articles and at least one third spacer position of at the least one thread-like element, with a being smaller than b and b being smaller than c. Distances a, b and c are chosen according to the following table:

ntabc20.25 ≤ a/L ≤ 0.293−0.015 ≤ a/L ≤ 0.0150.32 ≤ b/L ≤ 0.4040.10 ≤ a/L ≤ 0.160.36 ≤ b/L ≤ 0.435−0.025 ≤ a/L ≤ 0.0250.18 ≤ b/L ≤ 0.240.38 ≤ c/L ≤ 0.44

FIG.7shows schematically the determination of the circularity error, here denoted as ci. The circularity error ci, in this case, is a measure for the deviation of a given shape from the ideal circular shape, Here, a circumferential line of a cross section has to lie in a plane defined by two concentrical circles (that are depicted inFIG.7with dotted lines) with a specific, predefined distance from each other. The actual value of the circularity error ci is one half of the maximum difference the outer diameters in the respective plane. In actual practice, instead of the circularity error, the ovality may be given, the ovality being the difference of the maximum outer cross section and the minimum outer cross section in a direction perpendicular to the length l of a rod-shaped or tubular glass article. The ovality is two times the value of the circularity error.

InFIG.8, a schematic diagram for determination of the tensile elasticity is shown.

It is reminded that CC, the tensile elasticity, is given according to the following equation:

CS=L·Δ⁢FΔ⁢L,wherein L corresponds to the initial length of the thread-like-element (plotted along the y-axis), ΔL is the amount by which the length of the thread-like element changes, and ΔF is the change of the tensile force in the thread-like element, as determined in usual load-strain-curves as shown in the schematic diagram ofFIG.6, that is, by the ratio of the strain (or relative elongation of the respective thread-like element ΔL/L) and the change of the tensile strength, ΔF, in the respective thread-like element.

FIGS.9to13show diagrams of pulling forces obtained for thread-like elements2in bundles10according to embodiments of the present disclosure. In all bundles, thread-like elements arranged at a spacer position had been wrapped around the glass articles at least partially in order to space the glass articles apart. Further, the thread-like elements had been wrapped around the glass articles at least partially, forming several knots. These knots were, for each bundle, formed as releasable knots, that is, knots that could easily be untied by pulling one free end of one thread-like element forming the bundle. Furthermore, in all cases, bundles were arranged in a horizontal position. In each ofFIGS.9to13, the pulling force (or tension), given in N, has been plotted over the position of the puller used for withdrawal of the at least one thread-like element. Puller position is given in arbitrary units. In each of the diagrams, measurement was conducted for four different layers of glass articles. The number of knots, in each of the examples used for measurement, corresponded to the number of glass articles in a layer. Maximum values correspond to untying of the knot and, thus, to the maximum adhesive force of the knot. Therefore, the maximum measured value corresponds to the minimum value of tension needed for untying of a knot.

In between the maxima, measured tension values correspond to those stages of unpacking wherein simple withdrawal of the thread-like element takes place. In consequence, as no adhesive force of a knot needs to be overcome, much less tension is needed in these stages.

As can be seen in the five diagrams depicting measured tension values needed for withdrawal and untying of knots in bundles of glass articles with different cross sections, minimum pulling forces required depend upon the cross section of the bundled glass articles.

FIG.9is a diagram depicting pulling forces measured in bundles of tubular and/or rod-shaped glass articles with cross sections of 10.95 mm, indicated as data sets9-1,9-2,9-3and9-4. The statistical nature of minimum pulling force or maximum adhesive force of a knot can clearly be seen, as peak values obtained during measurement may range from a value of slightly more than 3 N (data set9-1, first peak value) to less than 1.5 N or even less (data set9-3), with an average value of about 2.2 N.

FIG.10depicts pulling force over puller position for bundles of tubular and/or rod-shaped glass articles with a cross section of about 16 mm, indicated as data sets10-1,10-2,10-3and10-4. Minimum pulling forces ranged from 1.1 N or even less (data set10-3) to a value of 2.13 N (data set10.1), with an average of about 1.6 N.

InFIG.11, for data sets11-1,11-2,11-3and11-4, obtained for a cross section of the bundled tubular and/or rod-shaped glass articles of 28 mm, the maximum measured pulling force value (corresponding to the minimum pulling force or, in the alternative, to the maximum adhesive force of the knot) was about 2.1 N (set11-2), whereas very low values were obtained in set11-3, corresponding to about 0.5 N. The average “minimum pulling force” amounted to about 1.2 N.

FIG.12, depicting data sets12-1,12-2,12-3and12-4, for cross sections of glass articles of about 8.65 mm, shows a peak value of the pulling force of about 2.4 N (data set12-2), whereas for some knots, a pulling force as low as 1.4 N (12-3) or even less proved sufficient for releasing tied knots. Average “minimum pulling force” amounted to about 2 N.

Finally,FIG.13depicts data sets13-1,13-2,13-3and13-4, for cross sections of bundled glass articles of about 42 mm. A peak value of 1.3 N was obtained for set13-2, whereas pulling forces for releasing knots could also be as low as 0.7 N (set13-1) or lesser still, for example 0.4 N (set13-2). Average was about 0.9 N.

As can be seen, the force required for untying a knot differs and in general is lower the larger the cross section of the bundled articles. However, for smaller cross sections, that is, for cross sections less than about 12 or 11 mm, there seems to be a plateau or “pedestal” section, with minimum pulling forces varying about an average value of about 1.9-2.3 N.

REFERENCE NUMERALS

1tubular and/or rod-shaped glass article

11rod-shaped glass article

12tubular glass article

10bundle

2thread-like element

9-1,9-2,9-3,9-4data sets for pulling forces for glass article cross sections of 10.95 mm

10-1,10-2,10-3,10-4data sets for pulling forces for glass article cross sections of 16 mm

11-1,11-2,11-3,11-4data sets for pulling forces for glass article cross sections of 28 mm

12-1,12-2,12-3,12-4data sets for pulling forces for glass article cross sections of 8.65 mm

13-1,13-2,13-3,13-4data sets for pulling forces for glass article cross sections of 42 mm

a, b, c distances

l length of the glass article

doouter dimension of cross section, diameter of a rod, outer diameter of a tube

diinner dimension of tubular cross section

twwall thickness

ci circularity error