Method and apparatus for optically checking moulded parts

Abstract

Method and system for optically checking moulded parts (10) in a transmitted light method, more particularly closures or the like produced by thermoforming or compression moulding methods, comprising the steps of transporting the moulded parts (10) from a transport device (50) through an optical checking region, and recording at least one image of the moulded part (10) using a recording device (20), wherein the moulded part (10) is located between the recording device (20) and an illumination device (30) and is illuminated by same, wherein the image is evaluated using processing means (40) in such a manner that defects of the moulded part (10) and / or statistical deviations from a normal distribution can be determined, from which conclusions can be drawn about a manufacturing process of the moulded parts (10) in a moulding tool having a cavity, wherein the conclusions can be used to control the manufacturing process.

Description

[0001] Method and device for optical inspection of molded parts

[0002] Technical field of the invention

[0003] The present invention relates to a method and a device for the optical inspection of molded parts. In particular, molded parts that can be produced using a thermoforming or compression molding process, such as a closure or the like, are inspected for defects using a transmitted light inspection.

[0004] State of the art

[0005] Plastic parts can be produced in large quantities and at high speed using well-known primary forming and forming processes. Molded parts can be manufactured using thermoforming, compression molding, injection blow molding, or injection molding. Most finished plastic parts produced worldwide are made using injection molding, although extrusion with blow molding and film blow molding also play an important role. Flawless, high-quality molded parts require well-maintained molds and machines, as well as flawless control of the manufacturing process, which must be continually monitored.

[0006] In the injection molding process, plasticized plastic is injected into a mold with at least one cavity using an injection unit. The molded injection-molded parts are demolded and transported away using a conveyor system. In order to not only detect defects in a timely manner, but also to be able to assign them to the corresponding cavity of the mold, the relative sequential order of the injection-molded parts must be maintained up to an inspection system. If defects are detected in the inspection system, the cavity from which the defective injection-molded part originated can be identified, and corrections can then be made using selective control. However, this inspection proves problematic in connection with mass-produced molded parts. EP 2 976 204 B1 discloses an inspection system by means of which an optical inspection of so-called preforms is carried out.The preforms are, for example, preforms of PET bottles or plastic caps, which are inspected for color quality, defects, and dimensions. The preforms are conveyed by a conveyor to an inspection device, and an image of the preforms is captured using an image capture device in free fall or sliding across a plate to detect color quality and / or defective preforms. However, this method cannot clearly detect all defects in the manufactured preforms.

[0007] In principle, optical testing using a transmitted-light method is also known, in which the test piece to be inspected is arranged between a light source and a recording device. For example, a transmitted-light method is known in which the test pieces to be inspected glide over an at least partially transparent plate or a diffuser in the inspection area.

[0008] Furthermore, EP 2 969 269 A discloses an inspection method and device, wherein fast-moving items to be treated are transferred from an inspection unit to a conveyor path, and at least one inspection camera records image data for each item. The inspection unit transfers the items to a reject unit, wherein the items are ejected approximately in a free throw such that items identified as defective are separated from those identified as faultless. The items are transported individually by means of a transport device past at least one inspection camera, wherein the inspection camera is a daylight camera, an IR camera, and / or one or more sensors for detecting color and / or dimensions.

[0009] However, testing specimens made of opaque materials using the transmitted-light method is often not practical, as the light does not sufficiently penetrate the specimen. Another disadvantage is that transmitted-light testing requires finely tuned coordination with a transport system for the specimens into the inspection area, which is often difficult to implement. Summary of the Invention

[0010] It is an object of the invention to propose a method for the optical inspection of molded parts, in particular closures or the like produced by thermoforming or compression molding processes, for their quality and / or functionality, in which the aforementioned disadvantages of the known methods are avoided or at least greatly reduced. Furthermore, a system suitable for carrying out this method is described.

[0011] In particular, the object of the invention is to propose a method and the corresponding system for the optical inspection of molded parts, by means of which a reliable, fast, and very simple inspection is possible, based on a virtually mirror-free image. Based on the virtually mirror-free image of the molded part, a variety of errors, defects, and / or flaws can be identified early on, even in difficult-to-detect areas and even as a trend, which cannot be detected or can only be detected inadequately with other methods. The molding device, the molding tool used, and / or the material can be responsible for the errors, defects, and / or flaws, as well as changes.The complex interaction between the design of the molded part and the molding tool as well as between the properties of the material and various process parameters leads to a variety of defects that can render the manufactured molded part unusable.

[0012] By reliably inspecting molded parts for multiple defects and / or analyzing statistical data from the entirety of the molded parts, i.e., a large amount of data, conclusions can be drawn about process errors during production, so that the production process can thus also be verified and regulated or controlled. The production process can be optimized with a closed-loop control and / or regulation system based on an evaluation of the detected defects or statistical data. According to the invention, these objectives are achieved in particular by the subject matter of the independent claims. Further advantageous embodiments are also apparent from the dependent claims and the description.

[0013] The objectives of the present invention are achieved in that the method enables optical inspection of molded parts by means of optimal illumination in the form of transmitted light or backlight. In particular, the objectives are achieved by a method for the optical inspection of molded parts using the transmitted light method, in particular of closures or the like produced in a manufacturing process by thermoforming or compression molding. The method comprises transporting the molded parts from a transport device through an optical inspection area and recording at least one image of the molded part by means of a recording device, wherein the molded part is located between the recording device and an illumination device and is illuminated by the latter.The image is evaluated using processing tools to identify defects in the molded part and / or statistical data, which can be used to draw conclusions about the manufacturing process of the molded parts in a mold with a cavity and to control the manufacturing process. For example, process parameters can be adjusted accordingly.

[0014] An image of the molded part taken by a recording device in backlight suppresses or minimizes reflections on the molded part surface, allowing the resulting image to be easily evaluated by a processing device. Depending on the color of the molded part, the entire wall can be inspected, allowing defects in the wall, in an inner zone, and / or on the opposite side to be detected.

[0015] The image is evaluated by the processing device to inspect the molded part for defects. Furthermore, the acquired data volume can be statistically evaluated using algorithms, for example, to detect deviations from a normal distribution and / or patterns, from which further conclusions and predictions can be drawn. The evaluation can utilize adaptable algorithms. Detectable defects allow conclusions to be drawn about the manufacturing process itself, so that process parameters can be adjusted accordingly. However, not only detectable defects can be used to monitor and / or control the manufacturing process; the analysis and evaluation of the entire molded part can also be utilized according to the invention.Data from the inspected molded parts, including those identified as defective and those identified as defect-free, can be analyzed using algorithms and / or artificial intelligence to identify deviations from the normal distribution of the entire inspected molded parts and / or samples from statistical data. The analysis thus allows for early detection of trends. This allows for early correction of process parameters in the manufacturing process to counteract these trends.

[0016] In particular, the evaluation and / or control of the manufacturing process can be based on artificial intelligence or suitable algorithms. This allows for rapid adaptation to changing conditions, which is only possible to a limited extent in a conventional, parameterizable system. This allows for effective detection of errors and / or trends that cannot be predicted.

[0017] The lighting device can be configured to direct direct and / or indirect light through the molded part so that the recording device can record at least one image of the molded part on the side of the molded part opposite the light source. A light panel and the use of polarized light, a diffuser, or coaxial light are particularly suitable. However, dome lighting, i.e., dome-shaped lighting, in particular multicolor dome lighting, can also be used to achieve homogeneous illumination of the molded part while avoiding reflections from the molded part located between the light source and a recording device. Furthermore, multiple light sources with different light properties, for example, IR, UV, and / or X-rays, etc., can be used.According to the invention, test specimens that can be produced as molded parts in a preceding thermoforming or molding process are subjected to an optical inspection using the transmitted light method. The molded parts are, in particular, closures and / or lids or preforms, as well as plastic containers in general. In particular, the inner zone of a molded part designed as a closure can be inspected in backlight for a wide variety of defects that can be inferred from process errors.

[0018] Defects can be inclusions, which can occur in the form of air pockets, foreign bodies such as dust, dirt and / or metal particles, as well as prematurely solidified material. Included cooled material, also referred to as cold plug, occurs particularly in the area of ​​an injection or sprue point and is recognizable in thin-walled or transparent molded parts as a comet-tail-shaped marking or by locally concentrated streaks. Air inclusions, which can be traced back to air trapped by the molten material, show a varying defect pattern. This can lead to defects due to areas not filled with material, bubbles, pinholes, shrinkage cavities and / or dark spots on the molded part surface or, in the case of transparent materials, due to thermal damage inside.Air inclusions can occur when the air present in the mold does not escape quickly enough, for example, when ventilation ducts are blocked. Detectable inclusions can provide insight into the manufacturing process.

[0019] In one embodiment of the invention, the entire surface of the molded part is subjected to an optical inspection using the transmitted light method for defects and / or deviations. Of particular interest here is the area of ​​the sprue or injection point, which is difficult to inspect using the reflected light method.

[0020] In a further embodiment of the invention, the optical inspection of the molded part is carried out using a transmitted light method along flow lines in order to detect defects, including color deviations, streaks, holes and / or cracks, which allow conclusions to be drawn about the manufacturing process of the molded part.

[0021] A color deviation can occur particularly after a color change of the material used, the so-called masterbatch. In injection molding processes, the old color can still be detectable in or on the molded part many cycles after a color change, often visible along flow lines. However, color streaks can also arise from an uneven distribution of pigments in the material. One of the causes of such color streaks can be the wear of a mold insert known as a "gate insert." Especially in the case of translucent colors, which are becoming increasingly popular, such color streaks are easily visible and result in scrap. Early replacement of the mold insert reduces scrap.

[0022] Streaks can appear in several forms and for a variety of reasons. Water in various states of aggregation as a component of the material leads to clouding, water marks, and / or moisture streaks. The causes can be that the material used has a tendency to absorb water, the air humidity is too high, the mold wall is too cold, or the temperature at the material inlet is not right. Water from a leaky water cooling system can also be identified by defects. In addition, burn streaks can occur due to severe thermal damage to the material. The cause can be thermal damage to the molten material due to oxidation and / or material decomposition due to strong friction. This can possibly be inferred from faulty venting. Air streaks can also occur.

[0023] Other detectable defects can be in the form of shear marks caused by a pulsating material flow, the so-called diesel effect, differences in gloss, etc.

[0024] Detectable holes as defects, especially micro-holes, so-called pinholes, suggest the possibility of deposits in the area of ​​the injection point. These micro-holes influence the tightness of an injection-molded closure and are an important quality criterion. In contrast to known methods of detecting these micro-holes using a high-voltage test, the method according to the invention represents a significant simplification. However, it is also possible to detect not only actual holes, but also depressions.

[0025] Cracks, such as microcracks and / or stress cracks, can also be detected using the transmitted-light method. Stress cracks occur as internal and / or external cracks caused by local stress.

[0026] Depressions on the surface of the molded part can also be detected by means of transmitted light testing, as can calottes, which can be created, for example, by unmelted material or as deposits in an upstream hot runner.

[0027] If a protrusion, ie a burr, is found during the visual inspection of the molded part, it can be concluded that the molten material has penetrated into gaps or joints that are located in the parting planes of the tool and therefore do not close them sufficiently tightly.

[0028] In a further embodiment of the invention, the molded part is subjected to an optical inspection using a transmitted-light method to detect engravings, markings, etc., particularly on the top plate of a closure cap. The transmitted-light method allows for a virtually mirror-free optical inspection with optimal illumination, so that the function and quality of the molded part can be determined using image processing. In particular, a cavity number of the manufacturing tool, the so-called nest number, can be clearly identified with this setup. Furthermore, depending on the color of the molded part material, defects inside the closure and on the opposite side can be detected.

[0029] Furthermore, according to one embodiment, the molded part is inspected for geometry during the optical inspection using the transmitted light method. Particular attention is paid to functionally relevant areas, such as sealing elements and / or threaded areas. Defects in the sealing elements, such as notches or missing material, can render a closure unusable.

[0030] A detectable deviation in the geometry of the actual molded part from the ideal shape can include distortion, warping, warpage, and / or angular deviation. Wall thickness differences, which are crucial for the sealing function, can preferably be detected using the transmitted light method and thus with virtually no reflections.

[0031] In particular, defects can occur in the area of ​​the injection point, which is easily inspected using the transmitted light method. Optical inspection of the molded part using the transmitted light method preferably determines the geometry and, in particular, the diameter of the injection point, which allows conclusions to be drawn about the manufacturing process. If possible, the injection point is positioned on the molded part in such a way that the molten material flows strategically and as evenly as possible into the mold. For a rotationally symmetrical closure, the outside and inside of the closure must be coaxial in order to achieve a uniform wall thickness. Unequal wall thicknesses have a negative impact on the tightness of the closure. The position and / or shape of the injection point can therefore be used as a quality criterion.

[0032] A further exemplary embodiment of the present invention relates to the optical inspection of a test specimen produced in a multi-part mold using the transmitted light method. Even when the tool halves of a mold are exactly centered to one another, a so-called core shift can occur. If the mold filling is unbalanced, the core can shift, which leads to different wall thicknesses in the molded part. In particular, if the molded part is a closure lid, the core shift leads to a relative shift from the outside to the inside of the closure lid. An uneven wall thickness has a negative effect on the tightness and / or represents a weak point that influences functionality. For various reasons, deviations can occur in molded parts, for example with regard to the diameter and / or ovality.Roundness, as examples of geometric defects, can deviate from the desired geometry. In an advantageous embodiment, the outer diameter of a molded part is measured during optical inspection using the transmitted light method and compared to the diameter of an inner sealing diameter. From the determined ratio, for example, it can be concluded that the sealing diameter of a rotationally symmetrical molded part, such as a closure cap, is oval, which influences the tightness of the molded part designed as a screw cap. If this ratio lies outside a definable tolerance, process parameters are corrected or the molding tool is checked.

[0033] In an advantageous embodiment of the invention, the method is configured to perform an optical inspection of the molded parts produced in a manufacturing process using a transmitted-light method in line with the manufacturing process. The inspection time required for the optical inspection in the method according to the invention can be aligned with the manufacturing process cycle. Accordingly, the method can be carried out at high speed or at a speed independent of the manufacturing process.

[0034] The present invention also relates to a system for carrying out the method according to the invention. The system comprises a transport device for moving the molded parts along a transport path into an inspection area for optical inspection using the transmitted light method. The transport device is designed to guide the molded parts smoothly past the receiving device and in doing so avoid pendulum movements or slanting positions. In this case, the transport device can have two driven and pre-tensioned belts, each rotating around a drive wheel and a further wheel, which define a conveying path between them. The width of the conveying path can be slightly smaller than the free outer diameter of the molded part. This allows smooth, damage-free guidance of the molded parts with sufficient clamping force and at high transport speeds, whereby the molded parts are guided in a rotationally fixed manner, and unambiguous optical inspection is enabled.Both the rotational speeds of the two belts and the type of belt can be different. Furthermore, the number and type of drive wheels can be varied, and these can also be pre-tensioned using appropriately designed means. Alternatively, the transport device can comprise one or more star wheels. The inspection area has the recording device and an illumination device, which are arranged such that the molded part is located between the recording device and the illumination device during recording. This allows the recording quality to be increased, ultimately enabling improved image evaluation.

[0035] Advantageously, at least one light fixture is positioned behind a projection surface or plate so that molded parts are illuminated from behind relative to the recording device. This allows the molded parts to be optimally illuminated during optical inspection, allowing various defects and / or faults to be easily and accurately detected. Additionally, the transmitted light method can be combined with a reflected light method, which offers further advantages.

[0036] It should be mentioned again that the present invention relates not only to the above-described method according to the invention for testing test specimens using the transmitted light method, but also to a corresponding system.

[0037] Further details of the invention will become apparent from the following description of the preferred embodiments, which are illustrated by way of example in the accompanying drawings. The description reveals further advantages of the present invention, as well as suggestions and proposals for how the subject matter of the invention can be modified or further developed within the scope of the claims.

[0038] Short description of the drawings

[0039] They show:

[0040] Figure 1 is a schematic representation of a test area for an optical inspection of a molded part using the transmitted light method, Figure 2 is a schematic flow chart of a processing of the images for the verification of defects;

[0041] Figure 3 shows a schematic representation of detectable defects using the example of a closure;

[0042] Figure 4 is a schematic representation of a core offset using the example of a closure;

[0043] Figure 5 is a schematic representation of a transport device for passing a molded part through a test that can be carried out using the transmitted light method;

[0044] Figure 6 is a schematic representation of another transport device.

[0045] Preferred embodiments of the invention

[0046] Figure 1 schematically shows an optical inspection area for optically inspecting a molded part 10 using a transmitted light method. The system 1 for optically inspecting a molded part 10 comprises a transport device (not shown) for transporting the molded parts 10 in a transport direction indicated by arrow 2. In particular, the molded parts 10, which are shown as closure lids in Figure 1 by way of example, can pass through the optical inspection area in a defined orientation and in a row. In particular, the molded parts 10 can be introduced into the optical inspection area individually, which can be done via a suitable transport device. The closures designed as molded parts 10 can be in the form of a cylindrical hollow body closed on one side, comprising a lower part with an internal thread, and possibly a guarantee strip, which is injection-molded onto the lower part via webs.Furthermore, the molded part 10 can have one or more printed markings, which can be checked, for example, according to the invention. At least one recording device 20 is provided in the optical inspection area, which is configured to create at least one image of the molded part 10. As shown, the recording device 20 can comprise a camera arranged above the molded part 10 and optionally filter elements (not shown), so that their optical axis is oriented parallel to the molded part axis 10a of the inspected molded part 10. The optical axis of the camera runs approximately through the center of the rotationally symmetrical molded part 10. An illumination device 30 is arranged opposite the recording device 20 to generate transmitted light. The transmitted light preferably extends parallel to the optical axis in the direction of the recording device 20.Accordingly, in the optical inspection area, the molded part 10 to be inspected is located at least temporarily between the recording device 20 and the illumination device 30. The optical inspection can therefore be carried out using the so-called transmitted-light method, which is advantageous over other methods. In particular, the transmitted-light method is suitable for taking an image without disruptive reflections of the molded part 10 passing through the optical inspection area. For example, inclusions inside the molded part 10 can be detected, which allow conclusions to be drawn about the manufacturing process of the molded part 10, for example, an injection molding process. These detectable inclusions allow a change in process parameters after processing, evaluation, and analysis in a processing unit, for example, a processor and other components.In the following, reference numeral 40 designates a processing unit by means of which the recorded image of the molded part is processed and evaluated for inspection, and data is analyzed. Based on this, definable process parameters of the manufacturing process can be adapted. The image recorded by the recording device 20 can be subjected to appropriate processing or analysis by means of an image processing device in order to detect or determine various defects in the molded part 10 and statistical data. An algorithm can be used to evaluate the images or for statistical data evaluation, which algorithm can be adapted or selected accordingly for the molded parts 10 to be inspected. For the transmitted light method, the at least one illumination device 30 can be set up to optimally illuminate the molded part 10 directly or indirectly while the image is being recorded.Accordingly, a lighting fixture can be positioned behind a projection surface or plate of the lighting device 30 to enable optimal illumination without disruptive reflections on a molded part surface. Suitable options include a light plate, polarized light, a diffuser, and / or coaxial light. In principle, it is conceivable that, in addition to the positioned lighting device 30 shown in Figure 1, further lighting devices can be arranged, which additionally or alternatively also allow optical inspection of the molded parts 10 using the incident light method.

[0047] Figure 2 shows, in purely abstract terms, that the images recorded by the recording device 20 are processed and analyzed so that the resulting knowledge can be used to adjust the manufacturing process. Figure 2 schematically shows processing means 40 for processing and evaluating images of the molded parts 10. The processing means 40 comprise a processor 42 which evaluates the image recorded by the recording device 20 or the plurality of recorded images in order to detect defects and / or to collect and analyze statistical data from the entirety of the images. For this purpose, the processor 42 can comprise an image processing device which subjects the recorded images to appropriate processing necessary to detect the defects in the molded part 10 and / or to detect any statistical deviations even from defect-free molded parts.These defects can be, for example, inclusions in the form of air pockets, foreign bodies and / or solidified material, which can be detected inside and / or in the walls of the molded parts 10. In addition or alternatively, defects in the form of color deviations, streaks, holes, depressions, burns, foreign material and / or cracks can be identified. Any engravings and / or markings can also be checked. As will be explained below, the area of ​​the injection point, which experience has shown to be particularly susceptible to defects, can be checked in particular. A significant defect or error relates to the so-called core offset and different wall thicknesses, which impair the tightness of the molded part 10 designed as a closure. The core shift can occur if the tool halves are not precisely aligned with one another during the injection molding process.In closures, the outer surface is not centered on the inner surface. This creates different wall thicknesses, which negatively impact the seal.

[0048] To process and evaluate the recorded images, an analog-to-digital conversion may be necessary, for example. The processing means 40 therefore use algorithms that can vary depending on the type of molded part 10. After so-called preprocessing in a processing unit 44, which includes known image processing and statistical analysis, also using artificial intelligence or algorithms, the information thus obtained can be converted into control parameters for the manufacturing process or into corrected process parameters. These ascertainable control parameters are then transmitted to a controller 46 of the manufacturing process, which uses them to create process parameters in a transformation unit 48. In other words, process parameters of the manufacturing process or of the injection molding machine are adjusted based on the data ascertainable by the processing unit 44.For this purpose, statistical data and / or real-time data are exchanged between the processing unit 44 and the controller 46 in order to be able to detect trends, patterns and / or clusters of defects at an early stage. This can be counteracted by timely adjustment of process parameters or manipulated variables of the manufacturing process in order to avoid larger amounts of rejects. Figure 3 shows the various defects to be detected using the example of a molded part 10 designed as a closure. The molded part 10 largely has the shape of a cylindrical hollow body closed on one side and can be intended as a screw cap for bottles. Such closures are mass-produced in an injection molding machine from plastic, e.g., polyethylene, polypropylene or PET (polyethylene terephthalate). As already shown in Figure 1, the molded parts 10 are separated and sorted, i.e.conveyed into the optical inspection area lying on its end face 14. In the sectional side view of the molded part 10, a wall 12 is visible, with a defect 9 indicated in the closed end face 14. These may be microcracks, which are only indicated in Fig. 3. Furthermore, conclusions about the manufacturing process can be drawn from the appearance of an injection point 16. An off-center injection point 16 in a rotationally symmetrical molded part 10 can be inferred from a core offset and thus from an incorrect assignment of the injection mold halves. The injection point 16 is an area in which defects such as microcracks, microholes, etc. are more likely to occur.From the top view shown in Figure 3, both the injection point 16 and streaks 17, in particular color streaks and / or moisture and / or air streaks, as well as depressions or, for example, markings in the form of the so-called cavity or nest number 15 are shown as examples of defects or information that can be easily detected using the transmitted light method.

[0049] Figure 4 shows the core offset on a molded part 10 designed as a closure. The outer side 11 and the inner side 13 are not centered. This can occur due to a shift in the core under the injection pressure and / or asymmetrical injection of the injection molding compound and / or pressure differences and / or temperature differences on opposing mold walls. A shift can also be attributed to poor setup and / or precise mechanical adjustment of the mold halves. Uneven wall thicknesses arise. This is indicated in Figure 4 by an offset between an axis 11a assigned to the outer side 11 and an axis 13a assigned to the inner side 13.

[0050] Figure 5 schematically shows how a molded part 10 passes through the optical inspection area spanned between the receiving device 20 and the illumination device 30 in the transport direction 2 and is inspected using the transmitted light method. For this purpose, a transport device 50 is provided, which allows the transport of the molded part 10 to be tested or inspected. In the illustrated embodiment, the transport device 50 can comprise two parallel conveyor belts 52, which engage laterally on the molded part 10. Figure 6 shows a schematic detailed view of a star wheel

[0051] 54, which is conceivable in connection with an optical inspection that can be carried out using the transmitted light method. The star wheel 54 comprises several fingers 55, which form pockets 56 between them. The molded parts 10 can be continuously fed by means of a conveyor belt (not shown) and brought into engagement with the pockets 56 of the star wheel.

[0052] 55. Accordingly, the pockets 56 at least partially enclose the molded parts 10. The molded parts can optionally be held in the pockets 56 by means of a vacuum and inspected in this held position by transmitted light. The molded parts 10 can then be removed from the pockets

[0053] 56 and can be fed to further stations. In the example shown, the star wheel 54 rotates counterclockwise at an adjustable speed.

[0054] Alternatively, the molded parts 10 can slide over an at least partially transparent plate in order to be able to inspect the bottom area of ​​the molded parts 10.

Claims

AMENDED CLAIMS received by the International Bureau on 6 November 2023 (06.11.2023) 1. Method for optical inspection of molded parts (10) using transmitted light methods, in particular closures or similar items produced in a manufacturing process by thermoforming or compression molding processes, comprising - Transporting the molded parts (10) from a transport device (50) through an optical inspection area, and - Taking at least one image of the molded part (10) by means of a recording device (20), wherein the molded part (10) is located between the recording device (20) and a lighting device (30), and is illuminated by the latter, wherein the image is evaluated by means of processing means (40) in such a way that defects of the molded part (10) and / or statistical data can be determined, from which conclusions can be drawn about the manufacturing process of the molded parts (10) in a molding tool with a cavity, which can be used to control the manufacturing process.

2. Method for optical inspection of molded parts (10) according to claim 1 , characterized in that adaptable algorithms can be used for the evaluation.

3. Method for optical inspection of molded parts (10) according to claim 1 or 2, characterized in that inclusions in the form of air inclusions, foreign bodies and / or solidified material are detectable.

4. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection of the molded part (10) is carried out using a light-through method for the entire surface of the molded part (10). DECLARATION MENTIONED IN ARTICLE 19 (1) 5. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection of the molded part (10) is carried out in the transmitted light method along flow lines in order to detect defects in the form of color deviations, streaks (17), holes, depressions (15), burns, foreign material and / or cracks (9).

6. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection can be used in the transmitted light method to detect streaks (17) after a color change in the material.

7. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that detectable streaks (17) are traceable to material properties, process temperature and / or a leaking temperature control system of a molding tool.

8. Method for optical inspection of molded parts (10) according to claim 5, characterized in that the detectable depressions (15) and / or holes are in the form of micro-holes which are attributable to deposits in the molding tool in the area of ​​a injection point (16).

9. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection can be used in the transmitted light method to detect and check engravings and / or markings (15) on the molded part (10).

10. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection can be used in the transmitted light method to determine the arrangement and shape of a injection point (16).

11. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical DECLARATION MENTIONED IN ARTICLE 19 (1) Transmitted light inspection can be used to check the uniformity of wall thicknesses of the molded part (10) and / or to check for core misalignment.

12. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection can be used in the transmitted light method to detect ovality and / or other geometric defects of the molded part (10).

13. Method for optical inspection of molded parts (10) according to one of the preceding claims, characterized in that the optical inspection can be carried out using a transmitted light method in combination with a reflected light method and / or in line with the manufacturing process of the molded parts (10).

14. System for optical inspection of molded parts (10) according to a method according to one of the preceding claims, comprising a transport device (50) for transporting the molded parts (10) into an optical inspection area, a receiving device (20) for creating an image of the molded part (10) and processing means (40) to which the image can be transmitted for verification and an illumination device (30) for inspecting the molded part (10) in the transmitted light method during optical inspection, characterized in that defects of the molded part (10) and / or statistical data can be determined.

15. System for optical inspection of molded parts (10) according to claim 14, characterized in that the lighting device (30) is provided to illuminate the molded part (10) directly or indirectly during the recording of the image.

16. System for optical inspection of molded parts (10) according to claim 14 or 15, characterized in that the molded parts (10) are guided into the optical inspection area by means of side belts (52) or by means of a star wheel (54). DECLARATION MENTIONED IN ARTICLE 19 (1)

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