DE2255018C3 - Method for shaping the end of the strip in the case of plastic strips that can be deformed without cutting, in particular plastic decorative strips - Google Patents

Description

The invention relates to a method for shaping the end of the strip of plastic strips which can be deformed without cutting and which have a strip middle part with both sides have integrally formed flange-like strip edge parts, the connecting lines of which with the strip middle part run in the longitudinal direction of the bar, with for Shaping at the end of the strip part of the strip material is separated out so that between the Leftover parts of the strip material create a recess, the edges of which are deformed the remaining strip parts are brought together relative to each other and by connecting the remaining strip parts, the position on one another can be fixed by welding or gluing, to plastic strips are used as decorative and protective strips in many ways. They are used on counters, Counters, packaging containers and packages are attached Motor vehicle construction used They are mostly designed in such a way that they not only have a decorative function, but also have a protective function at the same time. Such decorative strips have a plastic strip body, which is glued or with its underside is attached to the pad in another way, and the one on its top from a decorative element can be covered, which z. B. from a metallized polyethylene terephthalate film or one with a printed pattern, such as B. wood pattern, provided plastic film

Plastic strips of the type in question are generally made by extruding a plastic produced, with strips of the desired length transversely from the extruded plastic strip be separated. The application of the decorative elements can be carried out in one operation with the extrusion Made of bar.

If the plastic strips are cross-cut to individual lengths and attached to the connecting surfaces, such as B. the side and door surfaces of a car body rie, should be attached, the ends of the strips should be like this processed and designed so that they do not affect the decorative effect of the bar, if possible even him to enhance. So far, the moldings were generally perpendicular to their longitudinal direction or at an angle

ίο cut off to the longitudinal axis. In these cases, the strips end in blunt or sloping separating surfaces, which look unattractive and, depending on the cross-sectional shape of the strip, considerably impair the decorative effect. Blunt or cut off at an angle

Plastic strips are everywhere where, especially in Motor vehicle construction, stylistic design features

are important or even in the foreground, inconvenient and undesirable.

It is already known from a vinyl material

extruded plastic decorative strips, which have a bead-shaped strip middle part and are molded onto it on both sides have narrow flange-like strip edge parts, to be processed at their strip end in a special way, to taper to a point that is as shapely as possible of the end of the last (magazine »PRODUC TION «, October 1971). The processing takes place here in such a way that initially a symmetrical V-recess is cut, the apex of which is in the longitudinal center axis of the plastic bar lies with such a tailored art fabric strip, the V-legs remaining at the end of the strip are then heated, brought together by means of a pressure jaw and at the cut surfaces welded so that the tapered end of the strip is obtained. In this processing and shaping of the strip end accordingly extends the weld seam in the longitudinal center axis of the plastic strip of the tapered end to the bead-shaped

In the middle of the groin. As a result, a clearly visible, unattractive-looking seam line on the bead-shaped strip surface, since the V-legs are used for manufacturing the shape of the strip end the welded joint must be pressed against each other with relatively high pressure, it is inevitably that during this pressing process plastic material on the cut surfaces of the V-legs is squeezed up so that ugly bulges on the upper side of the bar at the end of the bar at the seam form, the subsequently severed vein sanded off must be in order to achieve an acceptable shape design of the last end. It goes without saying that a Such post-treatment is cumbersome in terms of production technology, even with careful post-processing a seam line which adversely affects the decorative effect remains on the bead-like projecting strip middle part.

The invention is based on the object of the known method for shaping the strip end to improve a plastic strip in such a way that a flawless, clean and shapely looking Inguinal closure with avoidance of the inguinal middle part on a more or less great length in the middle penetrating, outwardly visible seam line that requires special post-processing will. It should be possible to make the strip ends appealing in different ways, such as this is desirable when using the strips in automobile manufacture for different types of vehicles. For example, according to the method according to the invention, strips of different profiles with a pointed tapered end, a rounded, fishtail-like end or a similarly beautifully designed one End to be provided.

The inventive method for solving the problem is characterized in that the recess at the end of the strip is created so that at least on the one strip edge a strip lying in the connecting line between the strip middle part and the strip edge part and running in the longitudinal direction of the plastic strip Separating cut is made which intersects with a second separating cut transversely penetrating the middle part of the strip in the named connecting line, and that subsequently the strip edge part cut free as an end border of the exposed one The strip middle part is deformed against its cut surface and is set in contact with this cut surface.

In this procedure, one running outside of the central axis of the bar Separating cut at least the one narrow strip edge part cut free so that it is at the end Edging of the remaining strip middle part is deformed against its cut surface and in contact with it this cut surface can be determined by welding or gluing. With this shape of the The last end of the last no longer or less large length penetrating the middle of the last, Outwardly visible and ugly-looking seam line that requires post-processing. Since only the comparatively narrow cut-free strip edge part needs to be deformed in order to make it into contact Bringing the middle part of the last can be done with comparatively low foaming forces, so that severe crushing and warping of the plastic material in the Vui'ormungsbereich cannot occur. Another advantage is that the bar end fell in different ways, e.g. B.

pointed, rounded or fjschtail-shaped, and that in all these cases the narrow flanschajtigen strip edge parts a clean and create a shapely edging of the middle part of the last. If the groin edge parts with a thin Ornamental film or the like are occupied, it can be with the elastic Deformation does not result in tearing or upgrading of the decorative film, since, as mentioned, only slight Material deformations are required.

In detail, the inventive method z. B. perform so that both strip edge parts of the plastic strip are worked out by separating cuts, one of which is in the Connection line between the middle part and the edge part in the longitudinal direction of the bar and the the other extends transversely through the middle part of the strip as far as the said connecting line, whereupon the strip edge parts exposed on both sides of the middle part of the strip from both sides against the central surface of the Last center part shaped like this and on their end faces be brought to bear in such a way that they form an edging of the middle part of the strip at the end of the strip. Man In this way, it has a tapered, rounded or fishtail shaped last end, in which both cut-free strip edge parts form the border of the strip middle part. Will on the other hand, only one of the two strip edge parts cut free, so you can z. B. a spiiz tapered one Make the end of the last whose tip lies outside the central axis of the last in the seam line between the central part of the last and the remaining part of the edge of the last In all of the above cases, it is advisable to cut out the bar at its end so that at the Strip middle part is formed at least one curved connection surface. Against this curved connection surface, the cut-free narrow strip edge part can be formed with little deformation effort will.

The connection of the strip parts to the cutting surface (s) is carried out by gluing or welding, the weld joint is generally preferred. It is best to remove the bar before deforming it to heat the remaining strip parts in order to bring the strip parts together and / or the To facilitate welding of the same. Even if the connection of the remaining strip parts is not made by welding, heating can occur of the end of the last to make it easier to put together the remaining parts of the last.

Plastic strips, the ends of which are processed by the method according to the invention, can have different profiles and are made of different ones Be made of materials. Plastic strips, soft ones made of organic plastics, are particularly suitable are made that can be easily softened or shaped by mechanical or chemical action while possessing sufficient toughness and strength. To this. Above all, plastics count synthetic resins and cellulose derivatives and thermoplastic vinyl polymers, suitably polyvinyl chloride.

In the case of a plastic strip made of vinyl polymer, it is advisable to bring it to a temperature of to be heated around 205 to 235 ° C in order to achieve a reliable weld. The inventive The method can be used in particular with plastic strips which have a pronounced line lying between two flange-like strip edge parts.

have central part, which is opposite the inguinal edge files is clearly set off by withdrawals or graduations.

For a further explanation of the method according to the invention, reference is made below to FIG Drawing in which the strip ends designed according to the method according to the invention are exemplary embodiments are shown. In the drawing shows

Fig. 1 is a perspective view of a blunt cut at the end, unprocessed decorative strip, the The end is edited and designed,

F i g. 2 and 3, likewise in perspective representation, the processing of the decorative strip according to FIG. I to Production of a closed, tapering strip end, 1 '

4 and 5, in a perspective representation, the processing of the decorative strip according to FIG. 1 for production of a rounded strip end,

6 and 7 a further possible embodiment.

where the LciSic gciTiäu F ι g. ί cm asymmetrical, ■><) tapered last end,

FIGS. 8 and 9 show a further design option in perspective, in which the bar according to FIG. 1 is provided with a fishtail-like strip end, 2 = 1

Fig. 10 shows another in perspective Last profile, which can be processed at the end,

11 and 12 show the processing of the bar according to FIG FIG. 10 shows a perspective illustration of the manufacture of a tapering strip end, in FIG

13 shows a third strip profile which is being processed can be,

14 and 15 in perspective representation Processing in Fig. 13 shown strip profile for Production of a pointed end of the last. s>

A trim strip 10 according to FIG. B. is made of an extruded vinyl polymer, has a solid strip middle part 12 with flange-like strip edge parts 14 and 16 formed thereon on both sides, which extend along the strip middle part 12, 1 »the latter has a convexly curved top 18. The strip edge parts 14 and 16 are also provided with convexly curved surfaces 20 and 22 on their upper side. The surfaces 18, 20 and 22 can be provided with an embossed pattern, which gives the plastic strip a decorative effect. In the decorative strip according to FIG films 24 and 26 are applied from a metallized polyethylene terephthalate, while the top of w strips central portion is provided with an imprint or impression in the manner of a dotting 12 eighteenth the trim strip 10 therefore has the appearance of a plastic strip, which on its two longitudinal edges of shiny metallic edge portions The strip middle part 12 can be colored in such a way that it has a contrasting color to the metal of the power edge parts 14, 16. Decorative strips of this type are generally fixed to a connection surface by gluing, although another type of fastening is also possible, e.g. by dielectric means or by mechanical means Decorative strips have a thin metal base on their underside in order to increase the bending stability and the stability of the strip against longitudinal shrinkage &■> and / or to create a special support surface for adhesive.

From Figures 2 and 3, the processing and Shaping of the trim strip 10 according to FIG. According to FIG. 3 becomes the trim 10 at the end designed so that the strip edge parts 14, 16 together with that enclosed by them Strip middle part 12 taper in an arc shape and taper in a point. This tapering shape is according to FIG. 2 achieved in that a part of the strip material is cut away at the end of the strip in this way is that the remaining strip edge part 30 with the strip middle part 32 has a recess 34 and the latter forms a further recess 38 with the other strip edge part 36. The recess 34 is of two surfaces, namely the cut surface 30a of the remaining strip edge part 30 and the opposite one curved cutting surface 32a of the strip middle part 32 limited. The Lesser recess 38 on the one hand through the cut surface 36a on the inside of the remaining strip edge part 36 and on the other hand by the curved SciiniiifiäLMc 32ύ des Leisienmiiieiieiis 32 limited, the latter terminating in a tip lying symmetrically to the longitudinal center axis of the decorative strip 10. the Both recesses 34 and 38 are made by cutting out the strip material from the solid material the trim strip 10 is formed. Each recess 34, 38 is produced by making a cut along the seam between the middle part 12 and the respective edge part 14 or 16 in FIG Afford!; established direction and at the same time that Last middle part 12 is cut along a line obliquely to the last longitudinal axis, which is the former Cutting line intersects and curves from the point of intersection to the end of the strip towards the central axis the trim 10 extends towards. The remaining strip edge parts 30 and 36 are end on a cut such a length that it from the position of FIG. 2 in the position of FIG. 3 inward can be pressed, in which they comprise the cut middle part 32 in the manner shown and face each other with their mitered front end faces 30Z> and 36f>.

When the strip edge parts 30 and 36 are placed against the strip middle part 32, the cut surfaces 30a and 32a or 36a and 32b delimiting the two recesses 34, 38 come into mutual contact. The strip edge parts 30 and 36 are each connected to the strip middle part 32 in such a way that this surface abutment is fixed. This connection can take place in different ways, e.g. B. by mechanically attaching the strip edge parts 30,36 to the strip middle part 32 or by gluing said parts using an adhesive we.cJen. The connection is preferably made by welding. The heating of the strip end facilitates the deformation and pressing of the strip edge parts 30, 36 against the strip middle part 32. The heating of the strip end to be carried out for this shaping and / or the welding can be effected in different ways, the heating temperature differing depending on the type of plastic used is. In the case of a trim strip 10 made of vinyl polymers, it is advisable to heat it to a temperature of about 205 to 235 ° C. in order to achieve a reliable weld. The heating can e.g. B. by electrical means, by thermal radiation, by the action of a hot gas or by inductive means. Preferably the heating is on electric

Ways made, with z. B. a heating block 40, in FIG. 2 indicated by dashed lines, is used. This Heating block 40 has an outline shape corresponding to the shape of the recesses 34, 38; therefore he lets himself into the Introduce recesses 34, 38 so that its heating surfaces are at or near the recesses 34, 38 limiting cut surfaces 30a, 32s, 326, 36a lie. The ErKiUung of the heating block 40 can, for. B. with help electrical heating electrodes are carried out, which are located in recesses 42 of the heating block 40. But it would also be The heating of the heating block is easily conceivable 40 z. B. by means of steam or another medium which flows through the heating block 40, to undertake.

The deformation of the strip edge parts 30 and 36 and the lateral application of the same against the middle part of the groin 32 can be done by hand or by means of a tool. Preferably a couple will do this sideways actual groin profile over. Because of this shape of the trim 10, the seams are on Last end largely covered and invisible.

In FIGS. 4 and 5 there is a different strip termination for the in F i g. 2 decorative strip 10 shown. In this case, there are recesses at the end of the bar 50 and 52 incorporated so that two over the strip middle part 54 protruding strip edge parts 56 and 58 are formed. The recess 50 is formed by the inner cut surfaces 56a and 54a of the strip edge part 56 or of the central part 54 of the cistern. The cut surfaces 58a and 546 of FIG Bar edge parts 58 and 54 the other recess 52. The cut surfaces 54a and 546 are arcuate curved and at the front end of the l.eistenniitteltcils 54 connected to each other at 54c. The strip middle part 54 therefore has an approximately semicircular end face: according to FIG. 5 a rounded

tun- üi'iu Mci'ucwcgudrci * ι ui'iViuäCKcM ττί üiiu το used, which bring the strip edge parts 30, 36 into contact with the strip middle part 32 after they have been heated to the required temperature and the heating block 40 has been removed. F i g. ; i shows that the pressure surfaces of the mold jaws 46 and 48 are shaped like an arc in accordance with the contour shape of the strip end.

The deformation and pressing of the power edge parts 30, 36 against the strip middle part 32 could also be performed Help other pressure elements, z. B. with the help of a back and forth in the longitudinal direction of the bar, one or several pressure organs can be accomplished. Also making the shaped cuts at the end of the last or the cutting of the recesses 34, 38 can be done in different ways by several successive Cuts or a single cutting operation using an appropriately shaped one Cutting template or cooperating cutting tools are made. It is best to use the Decorative strip 10. z. B. in a jig to set while it is cut to the end, heated and is brought into the mold jaws 46,48. The one for cutting. Heating up and pressing the The tools used for molding edge parts 30, 36 in this case are opposite to the fixed decorative molding 10 moveable. Fs could also be worked in the opposite way, by attaching the decorative strip t0 to the in In this case, fixed mold jaws 46, 48 are brought up. Around the connection between the first edge of the groin To improve 30, 36 and the strip middle part 32, the strip edge parts 30, 36 are expedient held under pressure on the central portion 32 during the establishment of the connection. This Pressure can cause a small amount of the Plastic of the trim strip tO along the connecting seam between the strip middle part 32 and the Bar edge parts 30 36 is pushed out. This squeezed out plastic will be used after completion of the end of the last to achieve a neat finish.

As Figure 3 shows, the trim 10 in this Embodiment a tapered end. in which the strip edge parts 30, 36 form the strip middle part 32 Border on the side up to the tip. The strip edge parts 30, 36 are mitred at the top intersected surfaces 306 and 366 together. The curved ones go behind the shaped end of the last Seams between the middle part 32 and the edge parts 30. 36 continuously into the 56 and 58 are cut to such a length that their end faces 566 and 586 lie against one another. when the strip edge parts 56, 58 are in contact with the rounded end face of the strip middle part 54 are located. The cutting of the strip end, the lateral positioning of the cut-free strip edge parts 56 and 58 and their connection to the strip middle part 54 can be carried out in the manner described above. Here, too, a clean, largely seamless, and continuously merging into the actual trim strip 10 Last achieved.

In order to produce the first edge termination shown in FIGS. 6 and 7, the decorative strip 10 is provided according to FIG. 1 at the end of the last just a single recess 60 by making a cut along the seam line between the one the two l.cistcnrandteilc 14, 16 and the strip middle part 12 and a second cut is made obliquely to this, which the first cutting line on the cuts a, rear end and from here obliquely over the strip middle part 12 to the strip front edge extends towards. A strip edge part 62 is cut free on one side, while the other strip edge part 66 remains connected to the strip means 64. The recess 60 is defined by the inner cut surface 62a of the last edge part 62 and the front cut surface 64a of the last middle part 64 limited. The across to The cutting line running along the strip axis extends according to FIG. 7 arched across the entire width of the Middle part 64. They are at the seam between middle part 64 and the edge part 66 ends. The result is therefore the one shown in FIG. 7 shown, asymmetrical to the longitudinal axis of the bars Leis \; n conclusion. in which the decorative strip 10 on the strip edge part 66 is straight up to the strip tip continues while it is arcuate on its opposite ledge edge portion 62 up to the tip rejuvenates. The cut surface 64a could also have a shape deviating from the convex shape. z. Legs have a concave shape, a straight course or some other contour. The end faces 626 and 66a the strips edge pieces 62 and 66 are also cut here so that they are in accordance with in the production state Fig. 7 place against each other. Here, too, a clean, largely seamless strip finish is achieved.

As FIGS. 8 and 9 show, the decorative strip 10 according to Fig.! also be edited so that a approximately fishtail end results. In this case, two Aussoaruneen 70

and 72 incorporated so that the remaining strip parts 74 and 78 the recess 70 and the Cut strip parts 76 and 80 form the recess 72. The recess 70 is from the inner Cut surface 78a of the middle part 78 and the inner cutting surface 74a of the cut free edge part 74 formed. Correspondingly, the recess 72 of the cut surfaces 80a and 76a of the Last means part 80 or of the last edge part 76 is formed. The cut surfaces 78a and 80a extend of the strip edge parts 74, 76 obliquely backwards into the strip middle part 78, 80 so that they are in the Cut line 82 which lies in the longitudinal center axis of the decorative strip IO. However, this cutting line 82 could also lie asymmetrically on one side or the other of the power center axis.

To the in F i g. 8 in the finished shape shown in FIG. 9 will bring the Inguinal shape is different. The shaping and machining of the strip end of the decorative strip 110 shown in FIG. 10 can be carried out in the manner described above in FIG Connection with Fig. I described manner take place.

In the exemplary embodiment according to FIGS. 11 and 12 the trim 110 is processed so that a pointed tapered strip end, similar to that of FIG. 3, results. For the production of the last end are accordingly worked into the strip end recesses 110 and Π2 so that between the The middle part of the bar is cut free I34 and 138 a Lcistcnmittclteil 136 tapering towards the end of the strip is formed. the Recess 130 is from the cut surfaces 134a and 136a of the inguinal edges 134 and 136 formed while the recess I32 is delimited by the cut surfaces 138c and I36oder Leislenränder I38 and 136. That

/ -Ψ UtIVi / ti I

the V-shaped cut strip middle part 78,80 folded inwards. To do this folding movement make it easier, the strip edge parts 74 and 76 are provided with notches 84 and 86 at the folding points, whose side surfaces run obliquely to one another and to the cut surfaces 78a and 89a, so that the Place side surfaces of these notches 84, 86 against one another when the I eistenrandteile 74 and 76 in the Finished form according to Fig.9 are brought. Here, the strip edge parts 74, 76 with their cut surfaces 74a and 76a attached to the cut surfaces 78a and 80a of the strip middle part 78, 80. With welded connection of the cut surfaces 74a, 76a, / 8a, 80a can be a heating tool with a corresponding shape, for example one indicated by dashed lines in FIG. 9 Tool 88, are used, which can be inserted into the recesses 70, 72 of the strip end. Then, with a suitably shaped but unheated tool, pressure can be applied to the End of the groin to be exercised. If the end of the last is heated in some other way, this can happen Tool 88 can only be used to exert contact pressure during the welding process. It it can be seen that even with the arrangement according to FIGS. 8 and 9, a shapely looking, cleaner Bar end with a largely seamless transition from the decorative strip 10 to the bar end is achieved.

Fig. 10 shows another trim strip 110, whose Strip body 112 is provided with an approximately roof-shaped outer contour. which of two to the surfaces 114 and 116 sloping down towards both ledge edges and the steeper ones adjoining them sloping ledge surfaces 118 and 120 is formed. It it goes without saying that this decorative strip 110 on their The top is provided with decorative elements such as embossed patterns and prints or decorative film overlays can be. In the illustrated embodiment is on the trim 110 a thin metallized Polyethylene terephthalate film applied, which the Decorative strip 110 gives the appearance of a metal strip.

In contrast to the trim strip 10 according to FIG. 1, the trim strip 110 according to FIG. 10 does not have any pronounced strip edge parts that are offset from the strip middle part. The connecting line between the middle part and the edge parts is rather determined by imaginary lines 126 and 28, the distance between which from the side edges of the bar depends on the shape of the upper side of the bar, the width of the bar and the desired shape of the nilUf uCl \ CI! ULI Il Clgt ^ CllllltlCllt.'ll I.CfMCIM ClIIUCI I- Jt Il IIU I38 against the inguinal part 136 can be done in the manner described in connection with the above exemplary embodiments. The same applies to the connection of the strip edges 134, 138 at the arcuate seam between the strip middle part 136 and the respective strip edge 134 or 138

The decorative strip HO according to FIG. IO can otherwise also a ledge closure according to FIGS. 4 to 8 received.

The versatility of the possible design of the last can also be seen from FIGS. 13th to 15. In Fig. 13, a trim 140 is shown at which the strip middle part in contrast to the decorative strip IO according to FIG. I is narrower than the first edge of the groin. The trim 140 has a trim body 142 with a concave trim surface 144 that is formed with a in the middle of the first strip, the rib I46 running along the decorative strip 140 is provided as a bumper strip. These Rib 146 can be integrally formed on the strip body 142 or as a separate part with this be connected. The rib 146 and the plastic of the last body I42 lying thereunder form a middle part. while the ledge parts located laterally next to the rib 146 are viewed as ledge edge parts can be. The seam lines between the strip edge parts and the strip middle part run at the same time the root lines of the rib 146. In the embodiment shown, the tops are the ridges edge portions each coated with a metallized polyethylene terephthalate film 148. The trim 140 has thus the appearance of a metal bar. on the center a plastic protective strip running over the length of the bar sits.

The decorative strip 140 according to FIG. 13 can have a strip finish, as described above in Connection with the F i g. 1 to 12 is described. In the embodiment according to FIGS. 14 and 15 the end of the strip is designed in such a way that it is tapered to a point. For this purpose, the Last end two recesses 150 and 152 incorporated, such that two protruding ledge edge parts 154 and 158 and an intermediate strip middle part 156 is formed. The recess 150 is of the Cut surfaces 154a and 156a of the strip edge parts 154 u "d 156 bounded, while the cut surfaces 158a and j56ö of the strip edge parts 158 and 156 the recess 152 limit. The cut-out power edge parts 154 and 158 are printed laterally inwards.

whereby the cut surfaces 154a, 156a, 156fr. 158; / in Attachment to be brought. The strip edge parts 158, I5ß ind at the end faces 1546 and 158Λ at an angle cut so that when pressed against tfas Place the middle part 156 against one another. as FIG. 15 shows. Pressing the cut free Strip edge parts 156, 158 and the fixing of the same can be done in the manner described above, a welded connection is also preferably provided here.

In the exemplary embodiments described above, 3ie are cut-free strip edge parts predominantly of the same length, so that their butt joint lies in the central axis of the strip middle part. But it is It is easily possible to measure the length of one of the two Lcisttnrar.dteile so that it completely around the cut end face of the last middle part, i.e. from one side of the last extends to the other side of the last.

For this purpose 2 sheets of drawings

Claims (4)

Claims; 1, method of shaping the last end in the case of non-cutting, deformable plastic strips that have a middle section of the strip with flange-like strip edge parts molded onto it on both sides, whose connecting lines with the strip middle part run in the longitudinal direction of the strip, with for Shaping at the end of the strip part of the strip material is separated out so that between the remaining parts of the strip material creates a recess, the edges of which are relatively deformed while the remaining parts of the strip are deformed are brought together and fixed by joining the remaining strip parts in abutment by welding or gluing, characterized in that the recess is created at the bar end so that at least on one strip edge (14, 16) an in the connecting line between the middle part (12) and the edge part (14 or 16) lying, in The longitudinal direction of the plastic strip running separating cut is made, which is with one of the Last middle part (12) transversely penetrating second severing cut in said connecting line cuts, and that then the so cut-free strip edge part as the end border of the exposed strip middle part is fixed against the cut surface in contact with this cut surface. 2. The method according to claim r, characterized in that both strips edge parts (14, 16) of the Plastic strip can be carved out by cutting disc, one of which is in the Connection line between the middle part (12) and the edge part (14 or 16) in FIG The longitudinal direction of the bar and the other extending transversely through the bar middle part (12) up to the aforementioned Connecting line extends, whereupon the bar edge parts exposed on both sides of the bar middle part (14, 16) so shaped from both sides against the cut surface of the last middle part and on their End faces are brought to bear in such a way that they form an edging of the strip middle part at the strip end. 3. The method according to claim 1 or 2, characterized in that the bar is cut out is that at least one curved connection surface is formed on the strip middle part. 4. The method according to any one of claims 1 to 3, characterized in that the bar before Deformation of the remaining parts of the bar is heated. & Method according to one of Claims 1 to 4 for use in plastic strips made of a vinyl polymer, characterized in that the strip material is heated to a temperature of approximately 205 to 235 ° C is heated.