Field of the invention

The present invention relates to the field of embroidered products, and in particular to embroideries performed in optical fiber.

Background art

Optical fibers have been used for years in the textile industry to obtain particular light and decorative effects.

Optical fibers are normally woven together with natural or artificial fibers, thus being distributed in the fabric of which they therefore form a component; the ends of the optical fibers are then connected to light sources, generally battery-operated LEDs, and therefore once the light source is lit, they light up thus highlighting spots or light threads in the fabric depending on the density of the fibers present in a unit of surface of the fabric.

Considering now the decorative effect of an embroidery, it would be highly interesting to be able to generate said optical fiber embroideries so as to obtain multi-shape designs which light up on request.

However, the performance of optical fiber embroideries has not found a solution to date due to various problems, the main one being the fragility of the optical fiber which does not allow the outline of a complex design to be followed because it would break, and furthermore, while an optical fiber woven together with others to form a fabric results in a pleasing appearance, a simple fiber stitched on a fabric (or other material) would be too faint and practically invisible.

Summary of the invention

Optical fiber embroideries performed on various types of substrates, are described. Brief description of the drawings

Figure 1 diagrammatically shows an optical fiber thread used for the embroidery and the related securing with knotted stitch.

Figures 2a and 2b diagrammatically show in detail the device of the embroidery machine used for performing the same.

Figure 3 diagrammatically shows an embroidery according to the invention, comprising optical fibers and traditional fibers.

Detailed description of the invention

The present invention allows the aforesaid problems to be overcome and optical fiber embroideries to be performed on fabrics or other substrates (such as e.g. hides, leathers, non-woven fabrics, paper, etc.) using bundles of optical fibers which are secured to the fabric by means of knotted stitches.

According to the invention, the optical fibers are the ones normally obtainable on the market such as e.g. fibers made of specific side emitting polymethacrylate PMMA normally having a diameter between 0.15 and 0.50 mm, but preferably 0.25 mm.

Moreover, natural or synthetic traditional fibers may also be used in embroidery, such as rayon, silk or viscose, in order to make the semi-finished product pleasant to the touch.

As shown in figure 1 , the bundles 10 of optical fibers 1 1 according to the invention normally comprise from 4 to 8 optical fibers.

The knotted stitches 12 (see figure 1 ) serving to secure (stitch) the optical fiber thread at the base thereof are performed using a polyester or viscose thread with a runnage between 20 Ne and 80 Ne, preferably 40 Ne.

Normally, the optical fiber has a diameter of 0.25 mm and the stitching thread (that is the one used for the knotted stitches) has a runnage of 40 Ne.

The preselected optical fiber is then unwound to form the thread comprising from 4 to 8 optical fibers which is manually wound onto a bobbin.

The bobbin is mounted on an embroidery machine which takes the various optical fiber threads from the bobbin and embroiders them in groups of 4, 6, 8 (or 5, 7, if desired).

The embroidery machine comprises a guide which conveys the thread onto the base to be embroidered according to the profile of the embroidery design by moving it to the right and to the left (course which allows the fiber to be secured to the support), while the needle in which the thread is threaded for the stitching secures the optical fiber thread on the substrate; see figure 2 depicting in detail the mechanism which allows the thread to be laid out according to the embroidery design to be performed and it to be secured to the base and which comprises: bobbin 13 loaded with the optical fiber thread, guide A, needle 14 which performs the knotted stitch which secures the thread to the base.

There is a need to maintain constant control over the tension of the fiber on the bobbin caused by the action of the embroidery machine, for example by keeping the embroidery surface secure, in order to avoid knocks which are too violent which could damage the fiber; indeed it is to be considered that unlike weaving, embroidery needs one break alone and then is to be completely redone from the start.

Sewing machines suitable for the purpose are known in the art, for example Barudan model machines may be used.

Preferably, the profile of the embroidery 15 will be performed along continuous lines and according to curves which avoid creating straight corners which could penalize the final optical effect.

As shown in figure 3, the optical fiber will always have a start point E and a finish point U, that is the embroidery is performed continuously and the fiber is embroidered without interruptions.

If desired, the embroidery may be completed by filling profile 15, which is designed by the optical fiber, by using fibers of another type (that is non-optical), natural or synthetic fibers such as for example, silk, rayon, viscose, sequins, etc.; the use of traditional fibers for filling the optical fiber profile allows many variations of the appearance; filling 16 with the aforesaid fibers is performed with the techniques commonly used for this purpose; it practically is the embroidery machine as described above which also performs filling 16 by working with a different stitch.

Once the embroidery is complete, the ends of the optical fiber threads are connected to the light sources through usual wiring means (not shown in the drawings).