Injection molding tool and injection molding process for producing a plastic molded part with insert, and such a plastic molded part.

Abstract

An injection mold for producing a plastic molded part comprises a first mold half and a second mold half, which, when closed, form an injection molding cavity. The first mold half has a contoured surface with a linear vacuum slot running through it. This linear vacuum slot is provided with transverse slots in the contoured surface and / or has an oscillating line pattern to create a band-shaped vacuum zone on the contoured surface, through which the insert can be fixed to the contoured surface by applying a vacuum.

Description

[0001] The invention relates to an injection mold and an injection molding process for producing a plastic molded part with an insert. The invention further relates to such a plastic molded part with an insert.

[0002] It is already known to insert components, such as films, into an injection molding cavity and overmold them. In this way, plastic molded parts with a surface formed by the insert can be produced. Such in-mold processes make it possible, for example, to integrate inserts with functional elements (e.g., electrical, electronic, or optical functional layers) into the plastic molded part or to produce decorative parts whose appearance can be determined by the film design.

[0003] A known problem is that the insert is subjected to shear forces during the injection process, which can lead to wrinkling or slippage of the insert within the injection mold cavity. Especially with plastic molded parts with curved surfaces, it is often difficult to secure the insert's position during injection.

[0004] It is already known to use a line-slot vacuum to hold the insert in the mold, whereby the insert is drawn along the slot line to the cavity surface. The problem is that the effect of the line-slot vacuum is comparatively weak and in some cases, especially with a curved surface of the molded part, it cannot reliably prevent the insert from slipping during the injection molding process.

[0005] To increase the effect of a line vacuum, the slot width must be increased, which in turn increases the surface defects (imprint of the vacuum slot on the surface of the insert) caused by the injection pressure (and to a small extent also by the application of negative pressure).

[0006] In many cases, it is necessary to use a pre-formed insert to ensure precise alignment of the insert with the line slot, which is required to generate the vacuum. This necessitates an additional process step (pre-forming the insert), increasing the overall process costs.

[0007] DE 10 2008 027 522 A1 describes a method and a device for manufacturing a transparent outsole using injection molding or casting. One of the tool components has suction openings in a contoured surface that can be connected to a vacuum source. A flat material can be fixed to the contoured surface by means of the vacuum.

[0008] One of the problems underlying the invention is to create an injection mold for producing a plastic molded part with an insert, which improves the retention of the insert in the mold in a simple manner. In particular, a method is to be specified by which the retention of an insert in the mold is reliably ensured. Furthermore, the invention aims to create a plastic molded part that has a plastic component and an insert overmolded by the plastic component, wherein the insert is implemented with as few defects as possible in the area where it is fixed in the injection molding cavity by means of a vacuum.

[0009] The problem addressed by the invention is solved by the features of the independent claims. Advantageous embodiments and further developments are the subject of the dependent claims.

[0010] First aspect of the invention: Accordingly, an injection mold for producing a plastic molded part with an insert comprises a first mold half and a second mold half. The two mold halves are designed to form an injection molding cavity when closed. The first mold half has a contoured surface with a linear vacuum slot running through it. This linear vacuum slot is provided with transverse slots in the contoured surface to create a band-shaped vacuum zone on the contoured surface, through which the insert can be fixed to the contoured surface by applying a vacuum.

[0011] The transverse slots significantly increase the holding force with which the insert is held in the mold cavity. This ensures secure adhesion of the insert to the contour surface, considerably improving process reliability in the production of the plastic molded part. Furthermore, by reducing the slot width compared to a linear slot vacuum, it is possible to minimize surface defects caused by the vacuum application. Additionally, the band-shaped vacuum zone ensures more reliable suction and thus a more consistent vacuum between the contour surface and the insert. Even if the insert is not in contact with the entire band-shaped vacuum zone, the remaining vacuum is usually sufficient to hold the insert securely. Overall, this significantly increases process reliability.For example, it is possible to forgo pre-deformation of the insert, especially even with curved molded part surfaces, thereby saving costs.

[0012] In a first embodiment, the transverse slots can extend from only one side of the linear vacuum slot. In this case, the band-shaped vacuum area is defined on one side by the linear vacuum slot and on the other side by the end of the transverse slots. The width of the band-shaped vacuum area can thus be adjusted by means of the slot length.

[0013] In a second embodiment, the transverse slots can extend from both sides of the linear vacuum slot. Compared to the first embodiment, this allows the width of the band-shaped vacuum area to be increased (e.g., doubled). The width of the band-shaped vacuum area is calculated as the sum of the lengths of the transverse slots on both sides of the linear vacuum slot, plus the slot width of the vacuum slot itself.

[0014] A process for manufacturing a plastic molded part with an insert by injection molding involves inserting the insert into the first mold half of an injection mold. Closing the first mold half with a second mold half creates an injection molding cavity. The insert is fixed to a contoured surface of the first mold half by applying a vacuum using a band-shaped vacuum zone on the contour surface. This band-shaped vacuum zone is formed by a linear vacuum slot running along the contour surface, which is provided with transverse slots present in the contour surface. After the insert is fixed, plastic material is injected into the injection molding cavity. After the plastic material has cooled, the plastic molded part with the insert is demolded.

[0015] Preferably, the insert is not pre-deformed according to the shape of the contour surface before insertion. This step can be omitted because the effect of the band-shaped vacuum zone according to the invention ensures reliable suction and adhesion of the insert even without pre-deformation.

[0016] Furthermore, the invention relates to a plastic molded part comprising a plastic component and an insert, in particular a film, which is overmolded by the plastic component. An outer surface of the insert has a linear imprint with ridge-like transverse imprints. The imprints are created by the band-shaped vacuum area on the contour surface of the first mold half. Due to the improved vacuum effect, the imprints can be more delicate and thus less visually noticeable than would be the case with the use of a linear vacuum slot. This reduces the optical defects on the plastic molded part that inevitably result from the vacuum application.

[0017] Second aspect of the invention: Accordingly, an injection mold for producing a plastic molded part with an insert comprises a first mold half and a second mold half. The two mold halves are designed to form an injection molding cavity when closed. The first mold half has a contoured surface with a linear vacuum slot running through it. This linear vacuum slot has an oscillating profile to create a band-shaped vacuum zone on the contoured surface, through which the insert can be fixed to the contoured surface by applying a vacuum.

[0018] The oscillating line pattern significantly increases the holding force with which the insert is held in the mold cavity. This ensures secure adhesion of the insert to the contour surface, considerably improving process reliability in the production of the plastic molded part. Furthermore, by reducing the slot width compared to a straight line-slot vacuum, surface defects caused by the vacuum application can be minimized. Additionally, the band-shaped vacuum zone ensures more reliable suction and thus a more consistent vacuum between the contour surface and the insert. Even if the insert is not in contact with the entire band-shaped vacuum zone, the remaining vacuum is usually sufficient to hold it securely. Overall, this significantly increases process reliability.For example, it is possible to forgo pre-deformation of the insert, especially even with curved molded part surfaces, thereby saving costs.

[0019] The oscillating line pattern can be free of kinks, at least in certain areas or entirely, particularly at the turning points (maxima, minima), and / or without transverse slots. In this case, the line pattern contains no sharp corners or intersections that could be problematic with regard to the formation of optical defects (e.g., color imprints).

[0020] The oscillating line pattern can be realized, at least in some areas, as a serpentine, wavy, meandering or polygonal line pattern, the latter especially with rounded corners.

[0021] The first mold half can be designed with a receptacle and an insert arranged within the receptacle, and the linear vacuum slot can be bounded by a side wall of the insert and a side wall of the receptacle. The shaping of the opposing side walls can be achieved with high precision by milling. In particular, this makes the aforementioned small slot widths possible.

[0022] A process for manufacturing a plastic molded part with an insert by injection molding involves inserting the insert into the first mold half of an injection mold. Closing the first mold half with a second mold half creates an injection molding cavity. The insert is fixed to a contoured surface of the first mold half by applying a vacuum using a band-shaped vacuum zone on the contour surface. This band-shaped vacuum zone is formed by a vacuum slot with an oscillating line pattern running along the contour surface. After the insert is fixed, plastic material is injected into the injection molding cavity. After the plastic material has cooled, the plastic molded part with the insert is demolded.

[0023] Furthermore, the invention relates to a molded plastic part comprising a plastic component and an insert, in particular a film, which is overmolded by the plastic component. An outer surface of the insert has a linear imprint with an oscillating line pattern. The imprint is created by the band-shaped vacuum area on the contour surface of the first mold half. Due to the improved vacuum effect, the imprints can be more delicate and thus less visually noticeable than would be the case with a straight vacuum slot. This reduces the optical defects on the molded plastic part that inevitably result from the vacuum application. In particular, the risk of defects potentially caused by corners or intersections of the vacuum slot can be avoided.

[0024] The following are exemplary embodiments explained with reference to the drawings. Identical or corresponding parts are identified by the same reference numerals. Features of the illustrated embodiments can be selectively combined, provided they are not alternative or mutually exclusive features. Furthermore, features of the embodiments can be selectively omitted, provided they are not described as mandatory features in the description. Fig. Figure 1 shows a schematic view of an exemplary pointed casting tool. Fig. Figure 2 shows a top view of the first mold half with a linear vacuum slot. Fig. Figure 3 shows two examples A and B of band-shaped vacuum areas according to the first aspect of the invention, which are formed by transverse slots extending away from the linear vacuum slot on one side. Fig. Figure 4 shows two examples C and D of band-shaped vacuum areas according to the first aspect of the invention, which are formed by transverse slots extending away from the linear vacuum slot on one side (Example C) or by transverse slots extending away from the linear vacuum slot on both sides (Example D). Fig. Figure 5 shows an example of an insert according to the first aspect of the invention in a side view looking towards the side wall of the insert, which limits the linear vacuum slot and has vacuum channels for the transverse slots. Fig. Figure 6 shows an example of a plastic molded part with an insert according to the first aspect of the invention in a top view. Fig. Figure 7 shows an example of a band-shaped vacuum area according to the second aspect of the invention, which is formed by a vacuum slot with an oscillating line profile. Fig. Figures 8A to 8D show examples of oscillating line patterns.

[0025] Fig. Figure 1 shows a schematic sectional view of an injection mold 100. The injection mold 100 has a first mold half 110 and a second mold half 120. In the closed state, which is shown in Fig. As shown in Figure 1, an injection molding cavity 130 is formed between the mold halves 110, 120.

[0026] The injection molding cavity 130 is sealed, for example, at edge areas 112, 122 of the first mold half 110 and the second mold half 120, respectively. Not shown is in Fig. 1 a plastic feeder that makes it possible to introduce plastic plastic mass into the injection molding cavity 130.

[0027] Fig. Figure 2 shows the first mold half 110 in a top view. The first mold half 110 has a contour surface 210, which can be encompassed by the edge region 112 of the first mold half 110.

[0028] A linear vacuum slot 250 is formed in the contour surface 210. The linear vacuum slot 250 is bounded by two opposing slot walls 250A and 250B.

[0029] For example, the diaphragm wall 250A can be formed by a side wall of an insert 260. The insert 260 can be arranged in a receptacle 270 of the first mold half 110. In this case, the diaphragm wall 250B can be formed by a side wall of the receptacle 270.

[0030] The receptacle 270 can, for example, be implemented as a recess in the contour surface 210. The insert 260 can, for example, be received in the receptacle 270 without a gap by its side wall 260B opposite the slot wall 250A. A surface 260C of the insert 260 can serve as a contour surface, which continues the contour surface 210 of the first mold half 110 flush and, if necessary, seamlessly and / or without kinks at the transition from the receptacle 270 to the insert 260 (i.e., at the line defined by the side wall 260A).

[0031] In Fig. Figure 1 also schematically shows a vacuum supply 280, via which a vacuum can be applied to the vacuum slot 250.

[0032] Before the injection process, an insert part ET (see Fig. 1) inserted into the first mold half 110. The insert ET can be, for example, a film or another flat insert ET.

[0033] Inserts ET differ from a plastic component of the plastic molded part to be manufactured in that they are prefabricated. That is, an insert ET is not formed in the injection molding process described here, but is placed into the injection molding cavity 130 (for example, into the first mold half 110) and then overmolded (back-injected) with a plastic compound.

[0034] The insert ET can be, for example, a decorative element that determines the appearance of the plastic molded part being manufactured. It is also possible that the insert ET is a functional element, such as an electrical, electronic, or optical component, like a heating film with integrated heating wires, an electronic circuit on a flexible printed circuit board, or a display.

[0035] The insert ET can contain or be a film, e.g., PC film. The thickness of the film can be, for example, between 0.1 mm and 1 mm, particularly between 0.3 mm and 0.6 mm.

[0036] Since films of this thickness exhibit a certain degree of internal stress, prior art often requires the insert ET to be placed into the first mold half 110 as a pre-formed film. This ensures that the insert ET fits snugly against the linear vacuum slot 250 and seals properly. However, in the applications described here, it is possible to insert the insert ET into the injection molding cavity 130 without pre-deformation, i.e., with internal stress. As explained in more detail below, this is made possible by the fact that, according to the invention, the vacuum area is designed in a band-like manner, so that even without a precisely (complementary) fit of the insert ET to the contour surface 210 in the area of ​​the vacuum slot 250, a secure suction and retention of the insert ET can be guaranteed.

[0037] Fig. 3 and Fig. Figure 4 shows four different embodiments A, B, C and D for realizing a band-shaped vacuum area on the contour surface 210 of the first mold half 110. Referring to Fig. 3, Example A, is the one in Fig. 2. The linear vacuum slot 250 described above is provided with transverse slots 350. In the example shown here, the transverse slots 350 extend only from one side (slot wall 250A) of the linear vacuum slot 250. The transverse slots 350 open into the linear vacuum slot 250 and, in the example shown here, are manufactured in the insert 260.

[0038] The area formed by the linear vacuum slot 250 and the transverse slots 350 is hereinafter also referred to as the band-shaped vacuum area BU. In the lower part of the Fig. In example A shown in Figure 3, the band-shaped vacuum area BU is straight. The width of the band-shaped vacuum area BU is determined by the slot width of the vacuum slot 250 plus the length of the transverse slots 350.

[0039] In all embodiments, the band-shaped vacuum zone BU can be realized, for example, near a plastic feed (not shown). Such a plastic feed can, for example, be located in Fig. 3, Example A, is arranged at the lower cavity boundary (edge ​​area 112) so that an insert part ET (not shown) is held near the injection point by the band-shaped vacuum area BU.

[0040] Fig. Example 3, B, shows another possible implementation of a band-shaped negative pressure area BU. Here, the band-shaped negative pressure area BU is implemented as a circumferential band. This circumferential band can be closed, for example, ring-shaped or circular.

[0041] Such a structure can be formed, for example, by an insert 260, the side wall 260A of which (forming a diaphragm wall 250A) is provided with transverse slots 350 around its perimeter. For example, the insert 260 can be circular or have another shape (e.g., polygonal, possibly with rounded corners).

[0042] In this embodiment, the plastic feed (not shown) can be arranged, for example, in the second mold half 120 above, in particular centrally above, the insert 260.

[0043] Further embodiments C and D with curved, band-shaped vacuum zones BU are described in Fig. 4 shown. In example C, the band-shaped negative pressure area BU is, for example, shaped as a circular segment. To avoid repetition, reference is made to the description of Fig. 3 referred.

[0044] In the upper area of ​​the Fig. Figure 4, Example D, shows a band-shaped vacuum region BU in which the transverse slots 350 extend from both sides of the linear vacuum slot 250. Such a band-shaped vacuum region BU can be realized, for example, by an additional insert 460 in which further transverse slots 350 extend, opening into the linear vacuum slot 250. In this case, the slot walls 250A, 250B of the linear vacuum slot 250 can be formed, for example, by a side wall 260A of the insert 260 and an opposing side wall 460A of the additional insert 460.

[0045] The transverse slots 350 in the two inserts 260, 460 can be aligned with each other (see Fig. 4) However, it is also possible that the transverse slots 350 are arranged with an offset to each other (for example, half the slot spacing) along the linear vacuum slot 250.

[0046] Since the insert ET (e.g., film) is back-molded under high pressure, the slot width of the transverse slots 350 and / or the linear vacuum slot 250 must be only a few hundredths of a millimeter. For example, the slot width of the linear vacuum slot 250 and / or the transverse slots 350 can be equal to or less than 0.1 mm, 0.08 mm, 0.06 mm, 0.05 mm, or 0.04 mm. In many cases, the slot width will be between 0.03 mm and 0.06 mm, for example, to minimize the visibility of the vacuum slots on the product (plastic molded part).

[0047] Another practical advantage of a small slot width (e.g., equal to or less than 0.06 mm, 0.05 mm, or 0.04 mm), achievable by providing a band-shaped vacuum zone BU, is that liquid plastic material cannot pass through such narrow vacuum slots and enter the vacuum system if the insert does not completely cover the band-shaped vacuum zone BU. Partial coverage of the band-shaped vacuum zone BU by the insert ET can either occur unintentionally due to the insert ET slipping during the injection molding process or—according to the invention, with small slot widths—can now also be intentional, since the vacuum system can be protected against the ingress of liquid plastic material through the small slot width.

[0048] In all embodiments, the length of the transverse slots 350 can be equal to or less than 10 mm, 5 mm, 3 mm, or 1 mm. Even if the length of the transverse slots 350 is only about 1 mm, the effect of the negative pressure is increased many times over compared to a line vacuum, while at the same time significantly less marking can be achieved on the visible side of the insert ET (e.g., film).

[0049] The shorter the transverse slots 350, the smaller the distance between adjacent transverse slots 350 can be. With longer transverse slots, a larger distance between them is required to ensure sufficient stability of the contour surface 210 in the band-shaped vacuum zone BU (because, as will be explained in more detail below, the depth of the transverse slots 350 should be as small as possible). For example, with a transverse slot length of, say, 1 mm, the distance between adjacent transverse slots 350 can be between 0.5 mm or 1 mm and approximately 2 mm. With a transverse slot length of, say, 5 mm, the distance between adjacent transverse slots 350 can be, for example, between 3 mm, 5 mm, or 10 mm.

[0050] In general, the distance between adjacent transverse slots 350 can be equal to, less than, or more than 20 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm. The slot width of the linear vacuum slot 250 and the transverse slots 350 can be the same or different and can each be equal to, less than, or more than 0.1 mm, 0.08 mm, 0.06 mm, 0.04 mm, 0.03 mm, or 0.02 mm.

[0051] In all examples, the length of the linear vacuum slot 250 can be significantly greater than the length of the transverse slots 350. For example, the length of the vacuum slot 250 can be equal to or greater than 0.1 m, 0.3 m, 0.5 m, or 0.7 m.

[0052] In the examples shown here, the transverse slots 350 run perpendicular to the linear vacuum slot 250. However, it is also possible for the transverse slots 350 to be oriented obliquely, i.e., at an angle other than 90° to the linear vacuum slot 250. The fine transverse slots 350 can be produced, for example, by laser cutting, micro-milling, or micro-cutting.

[0053] Fig. Figure 5 shows a side view of an insert 260 looking towards the side wall 260A, which defines the slotted wall 250A of the linear vacuum slot 250. The transverse slots 350 are connected to a vacuum system. In the example shown here, the vacuum system comprises vacuum channels 550 running under each of the transverse slots 350, which are connected to the transverse slots 350. The vacuum channels 550 open into a longitudinal channel 510 of the vacuum system, which extends along and below the linear vacuum slot 250.

[0054] A vacuum can be applied via the longitudinal channel 510 to both the longitudinal vacuum slot 250 and - via the transverse vacuum channels 550 - to the transverse slots 350.

[0055] To minimize vacuum losses in the transverse slots 350, even with small slot widths SW of the transverse slots 350, a minimal slot depth ST is advantageous. The slot depth ST is measured between the contour surface 210 and the upper end of the vacuum channel 550, where the transverse slot 350 widens into the vacuum channel 550. The vacuum channel 550 has a significantly larger channel width KW than the slot width SW, resulting in much lower vacuum losses in the vacuum channel 550 than in the transverse slots 350. For example, the channel width KW can be equal to or greater than a factor of 3, 5, or 10 larger than the slot width SW of the transverse slots 350.

[0056] On the other hand, due to the channel width KW of the vacuum channels 550 and the desired small slot depth ST, the distance SA between adjacent transverse slots 350 can only be reduced depending on the slot length, since the stability of the contour surface 210 in the band-shaped vacuum area BU decreases with larger slot lengths. The slot depth ST should therefore be equal to or less than or more than 5 mm, 2 mm, 1 mm, 0.5 mm, or 0.1 mm.

[0057] The presence of the transverse slots 350 also makes it possible to adjust the slot width of the linear vacuum slot 250 to a very small size. In principle, it is even possible to reduce the slot width of the linear vacuum slot 250 to 0, in which case the vacuum application in the band-shaped vacuum area BU is effected solely by the transverse slots 350. In most cases, however, the linear vacuum slot 250 is maintained, with the transverse slots 350 according to the invention resulting in a significant reduction of the slot width of the linear vacuum slot 250 compared to the example of the Fig. 2 (without cross slots 350) make this possible. This reduces optical defects on the product (plastic molded part) that arise due to the application of negative pressure.

[0058] Fig. Figure 6 shows a schematic representation of an example of a plastic molded part 600 with plastic component 640 and insert ET in a top view. The plastic molded part 600 can be a flat part whose thickness is, for example, only a few millimeters (e.g., less than one centimeter). The visible side of the plastic molded part 600 is shown, which is at least partially formed by the insert ET (e.g., film). The plastic molded part 600 can be obtained by demolding from the injection molding cavity 130 using the described injection molding process with vacuum application.

[0059] In the example shown, the plastic component 640 surrounds the insert ET and is therefore visible in the top view as the enclosure of the insert ET. The circumferential edge of the insert ET is marked with the reference numeral 630. In contrast, the circumferential edge of the plastic component 640 would be in the Fig. The cavity shown in 130 should be flush with the circumferential edge 630 of the insert ET.

[0060] In the example shown, the insert ET has a transparent central area 610 and an outer area 620 that is colored (e.g., black). However, it is also possible that the insert ET has a different design, for example, being completely transparent or completely colored (e.g., black).

[0061] On the surface of the insert ET, where the insert ET is held by the band-shaped vacuum area BU, an imprint 650 of the band-shaped vacuum area BU is formed. This means that the band-shaped vacuum area BU is more or less clearly visible on the product as a surface irregularity in the form of a raised embossing. The embossed imprints (of the imprint 650) each have two parallel edge lines, which are caused by and trace the slot edges (in conjunction with the vacuum and the injection molding pressure). The dimensions of the parallel edge lines of the linear imprint and the ridge-like transverse imprints correspond to the dimensions of the corresponding vacuum slots.

[0062] Paint may also flake off the imprint 650. Furthermore, the linear imprint with the ridge-like transverse imprints can also be visible in the plastic component, i.e., transferred to the plastic component as a surface defect. The imprint 650 is characteristic of the injection mold according to the invention or the inventive method with which the plastic molded part 600 is produced.

[0063] It has been shown that, due to the band-shaped vacuum area BU according to the invention, an imprint 650 can be produced which is barely visible and represents a significantly smaller optical defect on the plastic molded part 600 than is the case with an injection molding tool or manufacturing process according to Fig. 2 would be the case.

[0064] The imprint 650 is optically detectable on the finished plastic molded part 600; for example, it is visually perceptible to the naked eye under direct illumination and may also be perceptible by touch or at least detectable as a surface irregularity. As shown, it can, for example, be placed in a colored area 620 so that it is barely or not at all visible to the naked eye on the plastic molded part 600.

[0065] According to one example, the insert ET can form a visible surface (e.g., outer surface) of the plastic molded part 600. This can optionally be overmolded with another plastic component (not shown), e.g., with a transparent and / or colored polyurethane (so-called PUR flooding). Since the optical defect caused by the band-shaped vacuum area BU is already relatively small according to the invention, it is possible to achieve a further significant reduction in defects or a defect-free outer skin by flooding the insert ET with PUR. For example, the optical defect can be reduced by a PUR flood covering the imprint 650 to such an extent that it can be tolerated on a visible surface of the plastic molded part, or it can be eliminated (the latter is particularly feasible with colored PUR flooding). Alternatively, it is also possible for the insert ET to form a back side (e.g.,The inner (non-visible) surface of the plastic molded part 600 is formed. This can optionally also be overmolded with another plastic component (not shown).

[0066] In the process for manufacturing a plastic molded part 600 with an insert ET, the insert ET can be fixed to a contour surface 210 of the first mold half 110 by applying a vacuum using the band-shaped vacuum area BU, e.g., before closing the first mold half 110 and the second mold half 120. The impression 650 on the insert ET is caused to a small extent by the application of the vacuum, but mainly by the injection molding pressure when injecting plastic material into the injection molding cavity 130; that is, the impression 650 is essentially created during the injection molding phase.

[0067] The demolding of the 600 plastic molded part with insert takes place after the plastic material has solidified. It is possible to injection-mold additional plastic component(s) before demolding to create a multi-component 600 plastic molded part. For example, one or more additional plastic components can be injection-molded onto the existing plastic component. Furthermore, it is possible (possibly after removing the plastic molded part from the cavity 130) to process it further by injection-molding another plastic component over the insert ET (e.g., as already mentioned, in the form of a PUR flood).

[0068] The removal of the plastic molded part can be facilitated by means of the band-shaped vacuum area BU, by supplying it with a positive pressure that releases the plastic molded part from the contour surface of the first mold half 110.

[0069] According to the second aspect of the invention, the vacuum slot can have an oscillating profile, with the band vacuum being formed by the amplitude of the oscillations. Fig. Figure 7 shows an example of a band-shaped vacuum region BU according to the second aspect of the invention, which is formed by a vacuum slot 250 with an oscillating line pattern. Further examples of vacuum slots 250 with oscillating line patterns are shown in the Fig. 8A to 8D shown.

[0070] In the Fig. In the example shown, the band-shaped area of ​​negative pressure BU is straight. However, it can also be curved or bent (compare Fig. 3, above, and Fig. 4) The width of the band-shaped negative pressure area BU is determined by the amplitude of the oscillating line. It can be constant or vary along the line (see e.g. Fig. 8B).

[0071] Analogous to the Fig. 3 and Fig. 4. In all embodiments, the band-shaped vacuum zone BU can be realized, for example, near a plastic feed (not shown). For example, such a plastic feed can be in Fig. 7 at the lower cavity boundary (edge ​​area 112) so that an insert part ET (not shown) is held near the injection point by the band-shaped vacuum area BU.

[0072] The vacuum slot 250 can, for example, be formed by an insert 260, the side wall 260A of which forms one slot wall 250A. The other slot wall 250B can be realized by an opposing side wall 270B of the receptacle 270. The slot walls can be manufactured by milling with extremely high precision in the range of less than 0.01 mm surface tolerance. In this respect, smaller slot widths of the linear vacuum slot 250 are possible than the widths of the transverse slots 350 that can be produced by sawing in the first aspect of the invention.

[0073] The oscillations of the line (750) can be periodic, but they don't have to be. For example, the period P can vary along the line (see e.g. Fig. 8B), i.e., P1 can be different from P2 (where the mean period length is obtained by the sum of all period lengths divided by the number of periods along an imaginary zero line NU). In the periodic case (zero crossings through NU at constant intervals), for example, P1 = P2 = P.

[0074] The amplitude A of the oscillations can be constant along the line or it can vary along the line, see e.g. Fig. 8B.

[0075] Fig. Figure 7 shows a multi-curved (e.g. serpentine or wavy) line pattern.

[0076] Other possible oscillating line patterns are in the Fig. Figures 8A to 8D illustrate this in an exemplary manner. Oscillating line patterns can be serpentine, wavy, meandering, or polygonal, at least in some areas (see Figures 8A to 8D). Fig. 8C - triangular or zigzag-shaped, and Fig.8D - trapezoidal or rectangular or crenellated) can be realized, whereby the polygonal line profiles can be designed with rounded corners in particular.

[0077] The amplitude A of the oscillating line pattern can be, for example, equal to or greater than 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, 15 mm, or 20 mm. By selecting the amplitude A, a suitable width BU of the tape vacuum can be set.

[0078] The mean period of the oscillating line pattern can be, for example, equal to or less than 20 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm, or 0.5 mm. The holding force can be adjusted by selecting the mean period (the smaller the mean period, the greater the holding force of the belt vacuum can be).

[0079] The slot width of the linear vacuum slot 250 can be, for example, equal to or less than 0.1 mm, 0.08 mm, 0.06 mm, 0.05 mm or 0.04 mm.

[0080] In a particularly advantageous embodiment, the oscillating line of the vacuum slot 250 is designed without kinks and / or without transverse slots, so that there are no “dead” corners or intersection points on the vacuum slot 250 where the ink print is more strongly indented.

[0081] All features and examples relating to the first aspect of the invention, in particular those relating to the line vacuum, also apply to the invention according to the second aspect. This applies in particular to the structural features of the insert 260 and the receptacle 270, wherein, from a functional point of view, the distance between the transverse slots 350 corresponds to the period length and the length of the transverse slots 350 to the amplitude of the line vacuum with oscillating line profile. Furthermore, this applies in particular to design and process-related features for the application of the vacuum. To avoid repetition, reference is therefore made to the above description of the first aspect of the invention.

[0082] Furthermore, it has been shown that it can be advantageous to switch the vacuum to a positive pressure even before the cooled plastic part is removed from the injection molding cavity. For example, the positive pressure (higher than ambient pressure, e.g., higher than 1, 2, 5, 8, or 10 bar) can be applied before the injection molding cavity is completely filled, as soon as plastic material covers the insert ET above the band-shaped vacuum zone BU. The positive pressure protects the insert ET and any color applied to it by preventing the insert ET from being pressed too deeply into the vacuum slot, thus reducing the unwanted impression on the plastic part. It is also possible to switch from vacuum to positive pressure at a later point, e.g.,During the cooling phase of the still-plastic material in the injection molding cavity, or before the cooling phase during a holding pressure phase (occurring between the injection and cooling phases in an injection compression molding process). In these cases, the duration of the injection pressure on the insert is also reduced, thus increasing the process reliability of the manufacturing process.

[0083] As already mentioned, to remove the plastic molded part, the band-shaped vacuum area BU can continue to be supplied with overpressure in order to detach the plastic molded part from the contour surface of the first mold half 110.

[0084] According to a further aspect of the invention, the early switching from negative pressure to positive pressure described above, occurring before the removal process, can be implemented for any desired design of a negative pressure slot in a contour surface of a first mold half of an injection mold. That is to sayThe application discloses a method for producing a plastic molded part with an insert by injection molding, comprising: inserting an insert into a first mold half of an injection mold; forming an injection molding cavity by closing the first mold half with a second mold half; fixing the insert to a contour surface of the first mold half by applying a vacuum by means of one or more vacuum slots in the contour surface; injecting plastic material into the injection molding cavity; and demolding the plastic molded part with the insert, wherein, during or before the cooling phase of the still plastic material, in particular during a holding pressure phase or before the complete filling of the injection molding cavity, the vacuum is switched to a positive pressure during the injection of the plastic material.

[0085] The application further discloses an injection mold for producing a plastic molded part with an insert, comprising: a first mold half and a second mold half designed to form an injection molding cavity when closed; wherein the first mold half has a contoured surface in which one or more vacuum slots extend, by means of which the insert can be fixed to the contoured surface by applying a vacuum. The injection mold is designed to switch the vacuum to a positive pressure during or before the cooling phase of the still plastic material, in particular during a holding pressure phase or before the injection molding cavity is completely filled when the plastic material is injected.

Claims

[1] Injection mold (100) for producing a plastic molded part (600) with an insert (ET) comprising: a first mold half (110) and a second mold half (120) which are designed to form an injection molding cavity (130) when closed; wherein the first mold half (110) has a contour surface (210) in which a linear vacuum slot (250) runs, which is provided with transverse slots (350) in the contour surface (210) to form a band-shaped vacuum area (BU) on the contour surface (210), over which the insert (ET) can be fixed by applying a vacuum to the contour surface (210). [2] Injection mold (100) according to claim 1, wherein the transverse slots (350) extend away from only one side of the linear vacuum slot (250). [3] Injection molding tool (100) according to claim 1, wherein the transverse slots (350) extend away from both sides of the linear vacuum slot (250). [4] Injection mold (100) according to one of the preceding claims, wherein the first mold half (110) is designed with a receptacle (270) and an insert (260) arranged in the receptacle (270), the linear vacuum slot (250) is bounded by a side wall (260A) of the insert (260) and transverse slots (350) extending in the insert (260) open into the linear vacuum slot (250). [5] Injection mold (100) according to claim 4, wherein the first mold half (110) has a further insert (460) arranged in the receptacle (270), the linear vacuum slot (250) is bounded by a side wall (260A) of the insert (260) and a side wall (460A) of the further insert (460), and transverse slots (350) extending in the further insert (460) open into the linear vacuum slot (250). [6] Injection mold (100) according to any of the preceding claims, wherein the length of the transverse slots (350) is equal to or less than 10 mm, 5 mm, 3 mm or 1 mm. [7] Injection mold (100) according to one of the preceding claims, wherein the distance between adjacent transverse slots (350) is equal to or less than 20 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm or 0.5 mm. [8] Injection mold (100) according to one of the preceding claims, wherein a slot width of the linear vacuum slot (250) and / or the transverse slots (350) is equal to or less than 0.1 mm, 0.08 mm, 0.06 mm, 0.05 mm or 0.04 mm. [9] Injection mold (100) according to one of the preceding claims, wherein the transverse slots (350) are connected to a vacuum channel (550) running under the transverse slots (350). [10] Injection molding tool (100) according to claim 9, wherein the slot depth, measured from the contour surface (210) to the vacuum channel (550), is equal to or less than 5 mm, 2 mm, 1 mm, 0.5 mm or 0.1 mm. [11] Method for producing a plastic molded part (600) with an insert (ET) by injection molding, which has: Inserting an insert (ET) into a first mold half (110) of an injection mold (100); Forming an injection molding cavity (130) by closing the first mold half (110) with a second mold half (120); Fixing the insert (ET) to a contour surface (210) of the first mold half (110) by applying a vacuum by means of a band-shaped vacuum area (BU) on the contour surface (210), which is formed by a linear vacuum slot (250) running in the contour surface (210) and which is provided with transverse slots (350) in the contour surface (210); Injection of plastic compound into the injection molding cavity (130); and Demolding of the plastic molded part (600) with insert (ET). [12] Method according to claim 11, wherein during or before the cooling phase of the still plastic plastic mass, in particular during a holding pressure phase or before the complete filling of the injection molding cavity (130) when injecting the plastic mass the negative pressure is switched to a positive pressure. [13] Plastic molded part (600) comprising a plastic component (640) and an insert (ET), in particular a film, which is overmolded by the plastic component (640), wherein an outer surface of the insert (ET) has a linear imprint with ridge-like transverse imprints. [14] Plastic molded part (600) according to claim 13, wherein the linear imprint and / or the ridge-like transverse imprints are formed in the form of raised embossed impressions (650). [15] Plastic molded part (600) according to claim 13 or 14, wherein the linear imprint and / or the ridge-like transverse imprints each have two parallel edge lines. [16] Injection mold (100) for producing a plastic molded part (600) with an insert (ET) comprising: a first mold half (110) and a second mold half (120) which are designed to form an injection molding cavity (130) when closed; wherein the first mold half (110) has a contour surface (210) in which a vacuum slot (250) with an oscillating line pattern is present to form a band-shaped vacuum area (BU) on the contour surface (210), over which the insert (ET) can be fixed by applying a vacuum to the contour surface (210). [17] Injection molding tool (100) according to claim 16, wherein the oscillating line pattern is realized at least in some areas without kinks and / or without transverse slots (350). [18] Injection mold (100) according to claim 16 or 17, wherein the oscillating line pattern is realized at least in some areas as a multi-curved, serpentine, wavy, meandering or polygonal line pattern, the latter in particular with rounded corners. [19] Injection mold (100) according to one of claims 16 to 18, wherein the amplitude of the oscillating line pattern is equal to or greater than 1 mm, 3 mm, 5 mm, 8 mm, 10 mm, 15 mm or 20 mm. [20] Injection mold (100) according to one of claims 16 to 19, wherein a mean period of the oscillating line pattern is equal to or less than 20 mm, 10 mm, 8 mm, 5 mm, 3 mm, 2 mm, 1 mm or 0.5 mm. [21] Injection molding tool (100) according to any one of claims 16 to 20, wherein the slot width of the linear vacuum slot (250) is equal to or less than 0.1 mm, 0.08 mm, 0.06 mm, 0.05 mm or 0.04 mm. [22] Injection mold (100) according to one of claims 16 to 21, wherein the first mold half (110) is provided with a receptacle (270) and an insert (260) arranged in the receptacle (270) and the linear vacuum slot (250) is bounded by a side wall (260A) of the insert (260) and a side wall of the receptacle (270). [23] Method for producing a plastic molded part (600) with an insert (ET) by injection molding, which has: Inserting an insert (ET) into a first mold half (110) of an injection mold (100); Forming an injection molding cavity (130) by closing the first mold half (110) with a second mold half (120); Fixing the insert (ET) to a contour surface (210) of the first mold half (110) by applying a vacuum by means of a band-shaped vacuum area (BU) on the contour surface (210), which is formed by a vacuum slot (250) running in the contour surface (210) with an oscillating line profile; Injection of plastic compound into the injection molding cavity (130); and Demolding of the plastic molded part (600) with insert (ET). [24] Method according to claim 23, wherein during or before the cooling phase of the still plastic plastic mass, in particular during a holding pressure phase or before the complete filling of the injection molding cavity (130) the negative pressure is switched to a positive pressure. [25] Plastic molded part (600) comprising a plastic component (640) and an insert part (ET), in particular a film, which is back-injected by the plastic component (640), wherein an outer surface of the insert part (ET) has a linear imprint with an oscillating line pattern, which is in particular formed in the form of a raised embossed imprint (650).

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