Injection molding a device such as a cable holder with an integrated wireless tagging foil

Abstract

The disclosure relates to a method for injection-molding a device, in particular a cable tie, with an integrated wireless tag, comprising the method steps of a) putting a tagging foil with two main surfaces which are separated by an edge, into a mold cavity of an open mold, where the tagging foil is held in place by a supporting device; b) closing the mold; c) injecting an injection material into the mold cavity parts adjoining the two main surfaces of the tagging foil simultaneously and symmetrically with respect to a main extension plane of the tagging foil which is parallel to the two main surfaces of the tagging foil so as to simplify and speed up the manufacturing process of a device with an integrated wireless tag or label. The disclosure furthermore relates to a corresponding molding device as well as a corresponding device with an integrated wireless tag.

Claims

1. A method for injection-molding a device with an integrated wireless tag, the method comprising: a) putting a tagging foil with two main surfaces that are separated by an edge into a mold cavity of an open mold that includes mold cavity parts that adjoin the two main surfaces of the tagging foil, wherein the tagging foil is held in place by a supporting device; b) closing the mold; and c) injecting, in a single injection step, an injection material into the mold cavity parts simultaneously and symmetrically with respect to a main extension plane of the tagging foil parallel to the two main surfaces of the tagging foil to form the device with the integrated wireless tag.

2. The method according to claim 1, wherein the injecting step c) includes using an entrance to said mold cavity parts that is located such that the injection material that is injected through said entrance contacts the edge of the tagging foil and subsequently flows alongside the two main surfaces of the tagging foil.

3. The method according to claim 2, wherein the injecting step c) includes dividing, by the edge of the tagging foil, the injection material into two sub-streams flowing alongside the two main surfaces of the tagging foil.

4. The method according to claim 1, wherein the tagging foil is held in place by the supporting device by contacting the supporting device only in one or more areas of the tagging foil that have a minimal distance from a tagging-relevant area of the tagging foil, wherein the distance is measured in the main extension plane of the tagging foil.

5. The method according to claim 4, wherein the minimal distance is greater than zero and less than about 6 mm.

6. The method according to claim 1, wherein the putting step a) includes at least one of: holding the tagging foil in place by a vacuum; or holding the tagging foil in place by a positioning pin.

7. The method according to claim 1, wherein the closing step b) includes pinching the tagging foil in between a set of at least one pair of opposing surfaces of the supporting device.

8. The method according to claim 7, wherein the at least one pair of opposing surfaces comprise an even number of pairs.

9. The method according to claim 8, wherein the even number of pairs comprises at least 6, at least 8, at least 10, or at least 12 pairs of matching surfaces.

10. The method according to claim 7, wherein the pairs of opposing surfaces are arranged symmetrical in respect to at least one of a main flow direction of the injection material or a line perpendicular to the main flow direction.

11. The method according to claim 1, wherein the tagging foil comprises a chip-antenna-foil for wireless radio-frequency tagging.

12. The method according to claim 11, wherein the chip-antenna-foil for wireless radio-frequency tagging comprises a radio-frequency-identification (RFID) foil for passive-tag-radio-frequency identification.

13. The method according to claim 1, wherein the tagging foil comprises an optical foil for optical tagging.

14. The method according to claim 13, wherein the optical foil comprises at least one of an optical-barcode foil, an optical-matrix foil, an optical-logo, or an optical-picture foil.

15. The method according to claim 1, wherein the device with the integrated wireless tag further comprises at least one of a cable tie, a cable holder, or a token.

16. The method according to claim 1, wherein the device with the integrated wireless tag further comprises at least one of a gaming coin, a card, or an intermediate component for another device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments are further described by the following means of schematic drawings. Therein,

(2) FIG. 1 shows a perspective view of an exemplary embodiment of a device with an integrated wireless tag, here a cable tie;

(3) FIG. 2 shows a perspective view of an exemplary embodiment of a tagging foil;

(4) FIG. 3 shows a perspective view of an exemplary embodiment of an open mold with the tagging foil of FIG. 2;

(5) FIG. 4 shows a top view of the open mold of FIG. 3; and

(6) FIG. 5 shows a perspective view of a 3D-illustration of an exemplary injection of material into an exemplary embodiment of a closed mold.

(7) In the figures, identical or functionally identical elements have the same reference signs.

DETAILED DESCRIPTION

(8) FIG. 1 shows a perspective view of an exemplary embodiment of a device 1 with an integrated wireless tag 2. In the present example, the device 1 is a cable tie where the wireless tag 2 is arranged between the head 3 and the tail 4 of the cable tie 1. The wireless tag 2 is or comprises a tagging foil 5 which is, in the present example, a chip-antenna foil for RFID, in a short a RFID foil.

(9) The tagging foil 5 is shown in more detail in FIG. 2. Tagging foil 5 has a tagging-relevant area 6 in the center of the tagging foil 5 which is surrounded by a protective margin or frame 7 here. In the present example, the tagging foil 5 also has two holes 8a, 8b at opposite ends in the z-direction for precisely adjusting the tagging foil 5 in its place. In the present example of the tagging foil as RFID foil, the tagging-relevant area is an antenna-chip-area where the antenna and chip required for the RFID function of the tagging foil 5 is located. The tagging-relevant area 6 is thus more susceptible to damage than the frame 7.

(10) In FIG. 2, the view of one of two main surfaces 9a, 9b of the tagging foil 5 is provided. Here, for illustrative purposes, the shown main surface may be referred to upper main surface 9a without delimiting character, as its orientation in space is arbitrary. Upper main surface 9a and lower main surface 9b (now invisible) are separated from each other by an outer edge 10.

(11) FIG. 3 shows a perspective view of an exemplary embodiment of a mold 11 for injection-molding a device 1, in the present example a cable tie, with an integrated wireless tag 2. Here, for exemplary illustration purposes, the tagging foil 5 of FIG. 2 is put into a mold cavity where it is held is place by a supporting device 13 described in more detail later referring to FIG. 4.

(12) The tagging foil 5 is held in place by the supporting device 13 such that a mold cavity part 14 comprising the tagging foil 5 is separated into two mold cavity parts 14a, 14b adjoining the two main surfaces 9a, 9b. Advantageously, two mold cavity parts 14a, 14b are of equal volumes. Note that for illustrative purposes, only one half of the mold 11, which may be referred to as the lower half of the mold 11, is shown.

(13) Consequently, the edge 10 of the tagging foil 5 is fixed in a position such that a stream of injection material injected into the mold cavity 12 at an upper left of the figure, that is, flowing from the injection site 15 (here, corresponding to the head 3 of the cable tie) through mold cavity 12 in x-direction into the mold cavity part 14 via an entrance 16 is divided by the edge 10 into two sub-streams flowing alongside the two main surfaces 9a, 9b of the tagging foil 5 have equal size (see FIG. 5). Consequently, in the present example, the entrance 16 is located such that the injection material contacts the edge 10 of the tagging foil 5 before subsequently flowing alongside the two main surfaces 9a, 9b of the tagging foil 5 when the injection material is injected into the closed mold 11 (see FIG. 5). The edge 10 may be regarded as being located in a vertical centre of the entrance 16 leading to a horizontal division of the stream of injection material 21 (FIG. 5), as, corresponding to the two equal-sized sub-streams, the orthogonal projection onto the diameter area of the entrance 16 divides the diameter area into two areas of equal size. Here, as also apparent from FIG. 4, the orientation of the entrance 16 and, consequently, the direction of a flow of injection material into the injection step is running parallel to the main surfaces 9a, 9b, that is, parallel to the main extension plane of the tagging foil 5, the x-z-plane.

(14) FIG. 4 shows a top view of the mold 11 of FIG. 3. The support device 13 comprises a number of pairs of opposing surfaces 17a, 17b, 18a, 18b, 19a, 19b, where only one of the opposing surfaces of the respective pairs is shown as the second half of mold 11 comprising the (preferably symmetric) second half of mold cavity part 14, mold cavity part 14a (FIG. 3), is not depicted here.

(15) When the tagging foil 5 is put into the mold 11, it is laid onto said surfaces 17a-19b with the frame 7 in order to avoid mechanical interference of the support device 13 with the tagging-relevant area 6, in particular the chip-and-antenna of the RFID foil. Consequently, the tagging-relevant area of the tagging foil 5 is floating freely in the mold cavity 12. As shown in FIG. 4, the surfaces 17a, 17b, 18a, 18b, 19a, 19b preferably contact the tagging foil 5 at its edge 10, such that, when the mold 11 is closed, the tagging foil 5 is pinched between some opposing surfaces 17a, 17b, 18a, 18b, preferably but not necessarily all of the opposing surfaces 17a-19b. If pinched at the edge, this results in a stiffening of the edge 10 that fosters the simultaneous and symmetric flow of the injection material 21 (FIG. 5) into the mold cavity parts 14a, 14b adjoining the two main surfaces 9a, 9b of the tagging foil 5 and the balancing of the forces on the tagging foil 5 on its upper and lower side.

(16) In the present example, the pairs of opposing surfaces 17a-19b are arranged symmetrical to the main extension of the tagging foil 5 both in respect to the main flow direction, here x-direction, of the injection material 21 as well as in a line perpendicular to the flow direction (i.e. a line in the z-direction). Namely, in the example at hand, for each pair of opposing surfaces 17a, 18a located upstream in the flow direction (left side of the figure), there is a corresponding symmetric counterpart 17b, 18b located downstream the flow direction (right side of the figure). In the present example, two central pairs of opposing surfaces 17a, 17b closest to the entrance 16 have a smaller area than the outer pairs of opposing surfaces 18a, 18b, 19a, 19b further away from the entrance 16. This combines enhanced reliability in the holding of the tagging foil 5 with minimal obtrusion of the flow of injection material through the mold cavity 12 by the supporting device 13. In the present example, the upstream central pair of opposing surfaces 17a vertically divides the stream of injection material flowing through the entrance 16 into two sub-streams of equal size. This corresponds to the horizontal division by edge 10 explained above.

(17) In the present example, the outermost pairs of opposing surfaces 19a, 19b that are located at the opposing ends of the tagging foil 5 with a maximal distance feature a vacuum device. So, in the present example, at least one of the respective surfaces has holes 20 which allow, when connected to a vacuum, to hold the tagging foil 5 in place by the vacuum. Correspondingly, said outermost opposing surfaces 19a, 19b are not in contact with the edge 10 here. Said outermost pairs of opposing surfaces 19a, 19b also have the largest area in the present example as they are furthest away from each other and thus the emerging tension between the pairs of opposing surfaces 19a, 19b are larger than thus the emerging tension between the pairs of opposing surfaces closer to each other, e.g. the pairs of opposing surfaces 17a, 17b.

(18) FIG. 5 illustrates the flow of an injection material 21 at different times t1, t2, t3 for an exemplary mold 11 as shown in FIGS. 3 and 4. Following the injection direction D, which runs parallel to the x-direction here, the injection material 21 enters, at time t1, the mold cavity 12 at injection site 15 (FIGS. 3, 4). As it fills up the mold cavity 12, at time t2, it starts entering the mold cavity area 14 with the tagging foil 5 through entrance 16. At a third, subsequent time t3, it has, as apparent by the edges 21a and 21b of the injection material 21, moved into the mold cavity parts 14a, 14b adjoining the two main surfaces 9a, 9b of the tagging foil 5 simultaneously and symmetrically with respect to the main extension plane of the tagging foil 5. So, the lateral injection of the injection material 21 advantageously leads to balanced vertical forces on the tagging foil 5 (vertical relates to the y-direction in FIG. 5).

(19) This has the effect that the tagging foil 5 remains intact and well protected by the injection material 21, allowing the production of an injection-moulded device with integrated wireless tag with a single injecting step.