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(11) | EP 4 556 600 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 153(4) EPC |
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| (54) | STRUCTURE FOR EVENLY DISTRIBUTING THICKNESSES OF METALLIC LAYERS DEPOSITED WITH A GALVANISING PROCESS |
| (57) The present invention relates to a structure and method for chrome plating plastic
parts aimed at reducing the variation in metal thickness across all areas of the part
during chrome plating. This is achieved through the use of a specially designed support
means that allows for the reduction of excess metal in chrome-plated plastic parts. |
TECHICAL FIELD
[0001] The invention belongs to the technical field of electroplating processes and more particularly to the area of electroplating on non-metallic surfaces, particularly plastic surfaces.
BACKGROUND
[0002] Electrodeposited metal layer coatings with electrolytic baths are used as protective layers against corrosion and as a decorative finish; in general, these coatings are carried out in chemical baths formulated, for example, with hexavalent chromium, a process widely used on plastic parts for automobiles.
[0003] Considering that plastics do not conduct electricity, they require complex pretreatment processes to receive coatings that confer the appropriate properties, involving complex preparation using highly toxic and difficult-to-control products. Commonly plated plastics are ABS and PC-ABS, and to ensure proper chrome deposition and achieve the desired color and shine, successive layers of copper, semi-bright nickel, bright nickel, and chrome can be applied to the plastic article. It is known that the introduction of intermediate metal layers increases the possibilities of corrosion protection for the part.
[0004] Various chroming methods exist, such as the following example: The plastic part to be chromed is first cleaned to remove particles that may be adhered to the surface. Cleaning is done using organic solvents to remove oxides and surface particles with minimal attack.
[0005] The cleaned part is then immersed in a container with a chromic acid solution at a temperature between 60 and 75°C. This "dissolves" one of the components of these plastics, creating micropores on the surface of the part.
[0006] After being washed with water, the part is immersed in a palladium chloride solution at 32°C to activate the plastic, making it conductive to electricity.
[0007] In the next step, the part, held in a suitable tool called a support means or rack that has conductive contacts as in all steps of the process, is immersed in a chemical nickel bath at a temperature of 32°C to reinforce the palladium layer. After rinsing the part, it is immersed in a chemical copper bath containing copper sulfate and sulfuric acid at a temperature of 36°C. A traditional procedure of this type of treatment can be observed in Figure 10. Once the palladium layer is reinforced with the chemical nickel layer, the parts are immersed in a compound of copper sulfate and sulfuric acid without current called "immersion copper"; this compound is necessary to prepare for the deposition of metal copper in the next step, with the aid of direct current applied to an anode and a cathode supplied through rectifiers.
[0008] In this context, the invention is aimed to solve the technical problem of obtaining an average thickness close to the desired level in chromed parts, given that during electroplating baths, more chroming material and higher voltage must be applied to meet a minimum thickness required for each part. It is known that parts placed in the chrome support structures can exhibit different thicknesses after the entire process, representing a problem of lack of part standardization and increased production costs.
[0009] It is known that during the chroming process, when implementing any racks, bars, hooks, or support means for parts to be chromed that will eventually be immersed in a chroming container, there is a tendency for non-uniform chroming, with parts having thicker chrome layers at the sides of the support means or, in other words, thinner chrome layers on parts located closer to the support means. Correctly placing the support structures or support means in a production line and promoting a support structure that provides stability and promotes the positioning of parts to be chromed in an optimal position for metal deposition is particularly relevant when analyzing the necessary inputs for such purposes. In many cases, implementing a chroming process with traditional support means and their traditional configuration, consisting of a plurality of bars with aligned support means, has the disadvantage of presenting a non-homogeneous metal layer deposit for all the parts placed in the support structure. It is known that parts placed at the ends of the support means or rack receive more metal than parts in the middle/central part of the rack, resulting in disadvantages such as material wastage, standardization limitations, weight differences, and sometimes piece waste due to excess metal that prevents the part from being used for its intended purpose. Moreover, handling this type of structure becomes limited as it lacks an arrangement adaptable to various container dimensions and capacity requirements for electrolysis, often requiring direct replacement or substitution of the structure for a different process or for chroming different parts.
[0010] Furthermore, during the chroming process, parts to be chromed may be subject to incidents that affect their stability in the support structure, resulting in more exposed part surfaces during the chroming process. Particularly, parts on the edges or sides of a support structure are more likely to experience alterations in their deposited thickness due to the incidence of electric current during the galvanizing process.
[0011] Additionally, it is known that the loading racks or frames of the support structure have a series of hooks or hook frames frequently used to hold and maintain the parts to be chromed within an electrolyte solution. They are typically used when processing large batches of parts with the same format. There are design and construction differences, which must be adjusted to the format and size of the parts. Essentially, the hook frames are made of various metals, coated with insulating plastic and plastic resistant to the chemicals used in galvanic solutions. Generally, the frames are used in anodic or cathodic processes indiscriminately.
[0012] Therefore, there is a need for a support structure for chroming processes that can mitigate at least some of these inconveniences. In this sense, the object of the invention is aimed at standardizing the average thickness of chrome on plastic parts subjected to a chroming process. Although various proposals are known to solve the technical problem posed, they have opted to modify formulations, process times, chroming tanks, among others, and none of the proposals known to date have disclosed or suggested a solution like the one illustrated in this specification.
OBJECT OF THE INVENTION
[0013] An object of the invention is to provide a support structure for chrome plating that promotes the accommodation conditions of a plurality of support pieces with a certain variation in distance with respect to the support structure. Particularly, the present invention consists of providing a support structure characterized in that a series of connectors comprise a variable length along a vertical and horizontal distribution, where said connectors are specially configured to have a greater length to the extent that they are closest to the central part of the support structure. Improvements are also obtained in the reduction of production costs such as energy consumption and additives.
[0014] In one embodiment of the invention, there is the elimination of current collectors while, in another embodiment of the invention, there is the incorporation of current collectors. One of the advantages of the present invention is that dimensional problems due to issues related to high metal thicknesses in plastic parts are eliminated.
[0015] Another object of the invention is to provide a structure that promotes less use of electrical rectifiers and reduces their maintenance.
[0016] Another object of the invention is to provide a structure that promotes the generation of longer life cycles of load support structures.
[0017] Another object of the invention is to provide a structure that promotes better cleaning of the support structure in each chrome plating cycle.
[0018] Each of the embodiments of the invention has at least one of the objects and/or aspects mentioned above but does not necessarily have all of them. It should be understood that some aspects of the invention that have resulted from the attempt to achieve the aforementioned object may not satisfy this object and/or may satisfy other objects not specifically listed herein. Additional and/or alternative features, aspects, and advantages of embodiments of the present technology will become apparent from the following description, drawings, and claims.
BRIEF DESCRIPTION OF THE FIGURES
[0019]
Figure 1 shows an isometric view of the structure for uniform distribution of thickness of metallic layers.
Figure 2 shows a top view of the structure for the uniform distribution of thicknesses of metallic layers with detailed views of the middle area and various points along its length.
Figure 3 shows a top view of the structure for the uniform distribution of thicknesses of metallic layers with detailed views of the lateral area and an area close to the lateral area.
Figure 4 shows a front view of the structure for uniform distribution of thickness of metallic layers.
Figure 5 shows a side view of the structure for uniform distribution of thickness of metallic layers.
Figure 6 shows an isometric view of the structure for the uniform distribution of thicknesses of metallic layers with a detailed view at the top.
Figure 7 shows an isometric view of the structure for the uniform distribution of thicknesses of metallic layers with a detailed view at the bottom.
Figure 8 shows an exploded isometric view of the structure for uniform distribution of thickness of metallic layers.
Figure 9 shows a top view of the structure for uniform distribution of thickness of metallic layers.
Figure 10 shows a flow diagram of a normal chrome plating procedure of the state of the art.
Figure 11 shows a diagram of the factors involved during testing and examples 1. Contact length. 2. Position of the piece in the support structure ("x" and "y") and 3. amperage (Cu, Ni and Cr).
Figure 12 shows a diagram of the assignment and sample of positions in each of the supports where the support medium has been divided into nine quadrants taking the average thicknesses and total amperage calculation used during the tests and examples.
Figure 13 shows a diagram of position assignment and sampling on a support structure during a chrome plating test.
Figure 14 shows a graph of thickness values from a chrome plating test.
DESCRIPTION OF THE INVENTION
[0020] The invention is aimed at providing a support structure and a method for chroming plastic parts that allows reducing the difference in the average thickness of parts to be chromed and reducing the excess of metal in chromed plastic parts; in view of the plastic chrome plating process presents a difference in metal thickness according to the area where the piece is located in the frame, rack, load structure or support structure that is used in the chrome plating process, the main objective is to standardize (in all areas of the support structure) the thicknesses of the metals (copper, nickel and chromium) in the plastic parts.
[0021] Therefore, the invention refers to a support structure specially conceived so that the resulting thickness in chrome plastic parts is uniform in all the plastic parts that are placed or distributed in a series of support means or support racks coupled to the support structure, where there is an arrangement or arrangement of said support means that allows a better distribution of the chrome plating during an electrolysis process, by defining a curved arrangement with a distance from the anode in the area of the sides of the support structure of the pieces to be chromed, and a close-up of the anode in the middle/central areas of the support structure where the plastic pieces are placed. Said arrangement is achieved by arranging a plurality of connectors or support means in horizontal and vertical lines separated equidistantly, where said connectors or support means have a variable length, this being an initial length that begins at the lateral ends of the support structure and increases as it approaches the central area of the support structure, in such a way that when placing the support means in the support structure for chrome plating, an elongated circular shape can be seen from a top view.
[0022] It is a preferential aspect, the first or first connectors or support means located at the lateral ends of the support structure in a vertical line, have a first length, so the next connector in a horizontal line has a longer length by at least 1 mm to the one preceding it and so on until reaching the central part of the structure. The difference in length between each connector or support means that begins at the lateral ends of the support structure and increases as it approaches the central area, is preferably between 1 mm to 10 cm. In a more preferential aspect, the length difference between connectors located in the horizontal plane is 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 mm or any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 cm.
[0023] In a further aspect, the connectors or support means located below the midline of the support structure for chrome plating may also have a difference in length between each connector or support means that begins in addition to the lower ends of the support structure and that increases as it approaches the central area of the support structure, with a half ellipse shape. The difference in length between each connector is preferably between 1 mm to 10 cm. In a more preferential aspect, the difference in length between connectors located in the vertical plane is 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 mm or any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 cm.
[0024] In the present description, various terms related to spatial orientation will be used such as "front", "back", "up", "down", "left", "right", "up", "down", etc. provide a clear description of current technology. However, it is understood that these terms are used simply to improve clarity of description and are in no way intended to limit guidance.
[0025] In order to make the description of the present invention clearer, as well as for a better understanding thereof, it should be understood that the terminology used in this document is not intended to be limiting.
[0026] As used herein, the singular forms "a", "an" and "the" include both singular and plural references unless the context clearly indicates otherwise. By way of example, "a nanoparticle" means one nanoparticle or more than one nanoparticle. Throughout this application, the term "approximately" is used to indicate that a value includes the standard deviation of the error for the device or method that is used to determine the value. The terms "comprising", "comprises" as used herein are synonymous with "including", "includes" or "containing", "contains", and are included or open-ended and do not exclude additional, no recited members, elements, or stages of the procedure. It will be appreciated that the terms "comprising", "comprises" and "comprising" as used herein comprise the terms "consisting of", "consists of" and "consists of". Recitation of numerical intervals by endpoints includes all whole numbers and, where appropriate, subsumed fractions within that range (for example 1 to 5 may include 1, 2, 3, 4 when referring to, for example, a series of elements, and may also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). Recitation of endpoints also includes the endpoint rates themselves (e.g., 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range cited herein is intended to include all subranges subsumed therein.
[0027] Herein, the term "an embodiment" or "an embodiment" is used to mean a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Therefore, appearances of the phrases "in an embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment but may. Furthermore, particular features, structures or features may be combined in any suitable manner, as would be apparent to one skilled in the art from this description, in one or more embodiments. Furthermore, although some embodiments described herein include some, but not other features included in other embodiments, combinations of features of different embodiments are intended to be within the scope of the invention, and form different embodiments, such as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments may be used in any combination. Additional embodiments of the invention, as well as its characteristics and advantages, will be evident to those skilled in the art from the descriptions set forth in this specification.
[0028] In order to promote understanding of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. However, it will be understood that it is not intended to limit the scope of the description, such additional alterations and modifications to the illustrated device and its use, and such additional applications of the principles of the disclosure as illustrated therein are contemplated as would normally occur to an expert in the subject matter to which the disclosure relates.
[0029] The invention refers to a support structure for uniform distribution of thicknesses of metal layers in plastic parts deposited with a galvanizing process which are placed or distributed in a series of support means contained in the support structure. The arrangement or placement of these support means allows for better distribution of chrome onto the part during an electrolysis process by defining a curved arrangement that approaches the sides of the support structure, moving the parts to be chromed away from the corners of an electrolysis container.
[0030] Initially, the structure of support has a plurality of supporting bars (10) arranged vertically and joined at their top and bottom ends by a closing bar (11), which connects perpendicularly to the supporting bars (10) and promotes the formation of a frame-like arrangement in which an arrangement of connecting bars (12) is arranged, which form a support structure for a series of loading connectors (13) that hold partes or pieces to be chromed and where the connecting bars (12) have an insertion means for a chroming contact (14), which is positioned parallel to the connecting bar (12) and where for each of the front and rear sides of the structure of support, the set of connecting bars (12) and loading connectors (13) are distributed equidistantly in the space between the upper and lower closing bars (11), each in the same direction. Each of these connecting bars (12) has a plurality of through holes (15) that allow the loading connector (13) to be received, preferably with a rib that allows the loading connector (13) to be screwed in for adjustment within the through-hole (15).
[0031] Additionally, there is a non-linear distribution of the sets of connecting bars (12) and loading connectors (13) forming a semicircular arrangement on both the front and rear portions of the supporting bars (10); and in the central area of the structure of support there is a greater separation distance of the connecting bars (12) and the loading connectors (13) with respect to the supporting bars (10) while each side of the structure of support has a shorter separation distance of the connecting bars (12) and the loading connectors (13) relative to the sides of the support structure, which allows said sides or lateral ends of the structure of support to be further away from the vertices or corners of an electrolysis container when the structure of support is submerged in a chrome plating solution. In other words, the loading connectors (13) are specially configured to have a greater length relative to the structure of support to the extent that said loading connectors (13) are closer to the central part of the structure of support.
[0032] In one embodiment of the invention, the supporting bars (10) have a plurality of extensions that are joined with a plurality of delta connectors (16) at the top of the supporting bars (10), allowing contact with a transport bar (not shown) which is energized. This arrangement of delta connectors (16) maintains electrical conduction properties. In one embodiment, each of these connection terminals has a plurality of grooves that improve the connection with the transport bar.
[0033] In another embodiment of the invention, the supporting bars (10) have an arrangement of current collector (17) at their top, which are arranged perpendicularly to the upper closing bars (11). These current collectors (17) prevent the direct incidence of current on the piece to be chromed, which could damage it.
[0034] In an alternative embodiment of the invention, there is an arrangement of five sets of supporting bars (10) and closing bars (11) supporting the sets of connecting bars (12) and loading connectors (13), with a plurality of current collectors (17) protecting the pieces to be chromed from the direct incidence of current. Additionally, a set of protectors (18) is attached, maintaining a curved arrangement that provides a greater distance from the supporting bars (10) in the center of the support structure, while the distance is shorter on each side of the support structure. This configuration coincides with the distance of each connection arrangement formed by the sets of connecting bars (12) and loading connectors (13).
[0035] In another embodiment of the invention, the support structure has a plurality of lateral protection means (19) placed on each side of the support structure as a barrier that prevents or reduces direct erosion on the pieces to be chromed that are located on the sides of the support structure.
[0036] According to one aspect, the present invention provides a support structure that includes an arrangement of a plurality of vertical posts, each having a plurality of horizontal connecting means, which in turn have a plurality of grooves extending horizontally on their outer surface. These grooves are vertically separated from each other, where a support means for a piece to be chromed is inserted.
[0037] The loading connectors (13) coupled to the connecting bar (12) that support the pieces to be chromed can be a plurality of loading hooks, which are additionally supported by the chroming contact (14) and the horizontal connecting means, respectively. Each loading hook has a loading body that is only partially received around its corresponding post, and each of these posts includes a rib extending horizontally, received in one of the grooves of the connecting bar (12)
[0038] In another embodiment, the present invention provides the loading connectors (13) coupled to the connecting bar (12) as support means for a structure to be mounted on the support structure, which has a substantially horizontal configuration. The support means of the support structure may include a loading body that defines an inner channel for reception around a connecting bar of the support structure.
[0039] In another embodiment, the present invention provides a plurality of connecting means made of an electrically conductive material.
[0040] In another embodiment, the present invention provides a plurality of conducting means distributed non-linearly within the support arrangement.
[0041] In another embodiment, the invention provides a support apparatus that includes an arrangement of connection to a lifting mechanism that, through a driving means, modifies the position of the support structure.
[0042] According to one aspect of the present invention, a method is provided for positioning a support structure for parts to be chromed with respect to a chroming tank, where the support means comprises left and right vertical supporting units laterally separated from each other, the method comprising:
- a) connecting or racking at least one part to be chromed to at least one of the loading connectors (13) coupled to the connecting bar (12) of the support structure for chroming on a front and/or rear side thereof, such that: part of one of the at least one loading connector (13) extends to the left from a left end of the support structure for chroming; and part of one of the at least one loading connector (13) extends to the right from a right end of the support structure;
- b) positioning the part to be chromed so that its widest side is oriented towards the lower portion of the support structure;
- c) opening the arrangement of the loading connectors (13) coupled to the connecting bar (12) and inserting a tab of the part to be chromed,
- d) positioning the tab of the part to be chromed so that it contacts the bottom of the structure coinciding with the loading connectors (13) coupled to the connecting bar (12);
- e) checking that the part to be chromed is properly racked by applying slight movements to the rack in a lateral and front-rear direction;
- f) placing a plurality of current collectors (17) at the top of the support structure;
- g) lifting the support structure for chroming;
- h) inserting the support structure for chroming between left and right vertical supporting units until at least one front fixing member abuts the left and right vertical supporting units; and
- i) moving the support structure for chroming to the left or right until a hook portion of the at least one loading connector (13) engages with the left vertical supporting unit or the right vertical supporting unit to establish a lateral position of the frame of the data center between the left and right vertical supporting units.
[0043] In some embodiments, the method further comprises, after inserting the support structure for chroming between the left and right vertical supporting units, lowering the support structure on each side until its bottom is perpendicular to a horizontal plane.
[0044] In some embodiments, the method further comprises, after inserting the support structure between the left and right vertical supporting units, connecting at least one rear fixing member to the support structure on a rear side thereof, such that: part of one of the at least one rear fixing member extends to the left from the left end of the structure; and part of one of the at least one rear fixing member extends to the right from the right end of the support structure.
j) Connecting the support structure to a means of conducting electrical energy.
k) Transporting the support structure with the parts to be chromed to a specific area in an upper portion of a chroming container.
l) Submerging the support structure with the parts to be chromed coupled to the loading connectors (13) coupled to the connecting bar (12) in the chroming container.
m) Remaining for a period of 1-60 minutes or preferably 10-50 minutes, more preferably 20-40 minutes, or as determined by the chroming process or specified thickness in the chroming solution in the chroming container.
n) Raising the support structure;
o) Removing the current collectors;
p) Placing identification labels;
q) Removing the part by opening the rack contact;
r) Inspecting the chromed part;
s) Packaging the chromed part.
[0045] According to another aspect of the present invention, a shelving system is provided comprising: a shelving support frame comprising a left vertical supporting unit and a right vertical supporting unit laterally separated from each other; a central frame located between the left vertical supporting unit and the right vertical supporting unit, the central frame having a front side and a rear side opposite the front side; at least one front fixing member connected to the support structure on the front side thereof, part of one of the at least one front fixing member extending to the left from a left end of the central frame is connected to the left vertical supporting unit, part of one of the at least one front joining member extending to the right from a right end of the data center frame is connected to the right vertical supporting unit; and at least one rear fixing member connected to the data center frame on the rear side thereof, part of one of the at least one rear fixing member extending to the left from the left end of the central frame is connected to the left vertical supporting unit, part of one of the at least one rear fixing member extending to the right from the right end of the central frame is connected to the right vertical supporting unit, wherein the at least one front fixing member comprises a hook part that rests on a surface of one of the left and right vertical supporting units to establish a lateral position of the data center frame between the left and right vertical supporting units to house the chromed parts in an additional inspection stage.
[0046] In some embodiments, each of the loading connectors (13) coupled to the connecting bar (12) is a fixing element of the plurality of fixing elements that can be a bar formed by bending such that the part of the piece fixing, the part of the connecting bar (12) fixing, and the part of the chroming contact (14) connection are different sections of the bar.
[0047] In some embodiments, the loading connectors (13) coupled to the connecting bar (12) have a part of the body fixing of the connecting bar perpendicular to the part of the loading connectors (13) fixing.
[0048] In some embodiments, for the loading connectors (13) coupled to the connecting bar (12), each fixing element of the plurality of fixing elements has a part of the body fixing of the connecting bar generally parallel to the part of the loading connectors (13) fixing.
[0049] In some embodiments, for each of the loading connectors (13) coupled to the connecting bar (12) or joining members of the plurality of joining members, the coupling portion of the part to be chromed extends at least partially in the depth direction of the support structure.
[0050] In some embodiments, for each fixing element of the plurality of fixing elements, a spring part extends at a non-right angle with respect to the fixing part of the frame and the fixing part of the support structure maintaining a semicircular arrangement.
[0051] In some embodiments, the coupling portion of the loading connectors (13) coupled to the connecting bar (12) is generally flat.
Examples, Tests and Results obtained:
[0052] The present examples are illustrative and not limiting, as one skilled in the art will understand that there are variations that fall within the scope of protection of the present invention. To determine the factors that most influence the final thickness gain of a chromed part, various tests were conducted with different configurations of support means, which are:
- 1. Traditional support structure (STANDARD BAR 1) - comprised of a structure with flat faces where the mounted parts have the same separation distance from the walls of the chroming tank.
- 2. Support structure with rounded corners (STANDARD BAR 2) - comprised of a structure with flat faces and rounded corners only in areas near the corners of the structure, where the mounted parts have a shorter separation distance from the corners of the chroming tank because this is where the rounded areas that move the part away are located.
- 3. Support structure of the invention (INVENTION BAR) - comprised of a structure that includes the characteristics described above.
[0053] Considering the structures mentioned above, different tests were conducted on these configurations to find the factors that most influence the final thickness of a part to be chromed. The test results showed that the length of the contact was the factor that most influenced the final thickness, followed by the position of the part in the rack and the amperage. Additionally, tests were conducted to generate a model that helps predict the thickness of the chromed part. The results of these tests showed that the generated model was effective in predicting the final thickness of the chromed part and maintaining consistency in its thickness.
[0054] In conclusion, the test results demonstrated that the factors that most influence the final thickness gain are the length of the contact, the position of the part in the rack, and the amperage. Additionally, a model was generated to help predict the thickness of the chromed part.
[0055] Details of the tests conducted are now provided:
- 1. Initially, the following objective has been determined:
"Find the factors that most influence the final thickness gain of a chromed part, in addition to generating a model that helps predict the thickness of the chromed part."
[0056] This is also intended to ensure that the average thickness of the chromed parts is homogeneous in the different areas of the bar, within the minimum required thickness, and to gain in reducing the amperage used in the process.
[0057] Currently, the support means for parts is submerged in up to five tanks where three materials (Cu, Ni, and Cr) adhere to the surface layer of the plastic parts. Tests were conducted with different shapes of support means and contact lengths, as well as varying the amperage in each tank.
[0058] During the tests conducted, these were some factors that were significant in the final thickness:
- 1. Length of the contact.
- 2. Position of the part in the structure of support ("x" and "y")
- 3. Amperage (for Cu, Ni and Cr).
For a better understanding of the aforementioned factors, review Figure 11.
- 1. A part that could be held on each of the bars of these tests was selected to later be chromed.
- 2. Two types of "standard bar" were selected to have reference data of the metal thickness in the traditional chroming rack. These bars will be referred to as: "standard bar 1" and "Standard Bar 2", while the support structure of the invention will be referred to as "invention bar."
- 3. A sampling of positions on each of the racks or bars was determined, where the bar was divided into nine quadrants, taking the average thickness and total amperage used. The distribution of the positions on each of the racks, as well as the quadrants, can be seen in Figure 12.
- 4. Different experimental runs were proposed to meet a required minimum thickness determined for the test part, aiming for the different quadrants to have the same thickness, where the thickness contains a mix of Cu + Ni, Ni, and Cr in the following amounts:
| Cu + Ni | ≥30µm |
| Ni | ≥15µm |
| Cr | ≥0.25µm |
TEST I
[0060] Test execution: Each of the support structures was subjected to a chroming process in a chroming tank for the mounted parts to obtain the chroming. The support structures are placed in the chroming tank, which contains the chroming bath with the materials mentioned above. Once the chroming process starts, the support structures were kept inside the tank for a period of 45 minutes. After this period, the support structures were lifted and allowed to cool. Once cooled, the parts were washed with water to remove chemical residues and dried. Subsequently, the parts were inspected to verify that the chroming process was carried out correctly, and a measurement of the chroming thickness for each quadrant area was taken, yielding the following results:
| STANDARD BAR 1 | ||||
| 65.0 | 67.3 | 65.4 | ||
| 71.0 | 69.3 | 68.1 | ||
| 60.3 | 45.3 | 58.5 | ||
[0061] The values: 65.0, 67.3, 65.4, 71.0, 69.3, 68.1, 60.3, 45.3, and 58.5 correspond to the average chrome thickness (µm) of the parts located in each respective quadrant. The table above shows the representation of the location of each of the nine quadrants with its respective average thickness data. The overall average thickness for this Standard Bar 1 is 63.35 µm.
[0062] Other data collected during the tests are as follows:
Total amperage (A) used during the chroming refers to the number of amperes required to carry out the chroming of the parts contained in the rack or bar. The total amperage is determined according to the size of the part, the type of material, and the thickness of the chrome to be applied. Chrome manufacturers typically use a combination of direct current (DC) and alternating current (AC) to achieve the desired results. The total amperage used during chroming is usually estimated before starting the process to ensure that the chrome is applied correctly; however, in this case, the magnitude of the amperage was measured during the test until the part to be chromed met the residence time. In this case, the total amperes required was 18835 (eighteen thousand eight hundred thirty-five).
[0063] % RSQ, which stands for Reliability, Safety, and Quality, is a notion used to define product quality standards. It is related to quality control and ensuring that a product or service is safe, reliable, and free from defects. This is achieved through the use of quality standards, testing, and quality manufacturing processes. The implementation of RSQ standards in a production environment ensures that products are safe, reliable, and free from defects. In this case, the %RSQ is 47.86.
[0064] Variation, which is a parameter used to describe the difference or change in a measurement or characteristic between chromed parts, in this case in terms of thickness. This means that the lower the variation, the closer to homogenization the chromed parts will be. In this case, the variation was 6.
[0065] The other results are shown below:
| STANDARD BAR 2 | Average Thickness (µm): 58.8 | |||
| 58.9 | 63.5 | 56.4 | Total amperage (A): 18535 | |
| 68 | 66.8 | 68.1 | RSQ (%):77.86 | |
| 50.5 | 45.4 | 51.7 | Variation:8.3 | |
| INVENTION BAR TEST 1 | Total amperage (A): 52.3 | |||
| 54.7 | 47 | 53.5 | Total amperage (A): 16587 | |
| 57 | 55.7 | 56.9 | RSQ (%):27.24 | |
| 49.2 | 45.5 | 51.5 | Variation: 6.5 | |
| INVENTION BAR TEST 2 | Average Thickness (µm): 48.3 | |||
| 46.9 | 45.9 | 50.5 | Total amperage (A): 15412 | |
| 52 | 52 | 52 | RSQ (%):62 | |
| 45.3 | 45 | 45.3 | Variation: 5.9 | |
| INVENTION BAR TEST 3 | Average Thickness (µm): 53.7 | |||
| 51.7 | 56.5 | 57.4 | Total amperage (A): 14515 | |
| 58.2 | 57.6 | 58.3 | RSQ (%): 57.62 | |
| 50.8 | 45.5 | 47.8 | Variation: 10.17 | |
| INVENTION BAR TEST 4 | Average Thickness (µm): 46.4 | |||
| 51.3 | 45.3 | 55.4 | Total amperage (A): 14513 | |
| 44.2 | 41.9 | 44.2 | RSQ (%):45.13 | |
| 45.9 | 45.3 | 44.6 | Variation: 6.72 | |
| Summary Results | ||||
| Average Thickness (µm) | Amperage A | RSQ (%) | Variation | |
| STANDARD BAR 1 | 63.3 | 18835 | 47.86 | 6.00 |
| STANDARD BAR 2 | 58.8 | 18535 | 77.86 | 8.30 |
| INVENTION BAR TEST 1 | 52.3 | 16587 | 27.24 | 6.50 |
| INVENTION BAR TEST 2 | 48.32 | 15412 | 62.00 | 5.90 |
| INVENTION BAR TEST 3 | 53.75 | 14515 | 57.62 | 10.17 |
| INVENTION BAR TEST 4 | 46.45 | 14513 | 45.13 | 6.72 |
| Best result / Worst result |
[0066] Therefore, it is notable that, in each of the tests of the invention presented in this specification, advantageous results have been obtained in terms of material savings, where up to 20.16 µm per piece have been saved by implementing the structure with the characteristics disclosed in this descriptive report, as well as significant energy savings (4,322 amperes) to comply with the thicknesses required in the tests.
[0067] In other words, in the standard bars used, a greater energy supply was required to reach the minimum necessary requirements while, for example, in test 4 there was a saving of almost 23% of energy while meeting the thickness requirements. Even though the %RSQ is greater in Standard Bar 2, it is a fact that is understandable to the extent that the pieces in these tests have a greater thickness, so it is normal for it to be decreased since the thickness of the pieces is lower in the bars of the invention and results in greater fragility, which is the cause of the decrease in the %RSQ, despite the thicknesses requested or required by the test having been met.
[0068] TEST II - The second test consisted of subjecting two bars to the same amperage conditions to analyze the thickness results once the chrome plating process has concluded. The test requirements are the following:
Chrome (Cr) required thickness: >0.25 µm.
Nickel (Ni) required thickness: >15 µm.
Copper (Cu) required thickness: >15µm.
[0069] The dimensions of the connector for the bar of the invention are indicated in the distance column (mm), while the distribution in the bar is as shown in Figure 13. The amperage supplied for both tests was 14,513 amperes, and the limits of the component specification (piece thickness) are between 30 and 60 µm for the entire piece.
[0070] The results obtained are the following:
| STANDARD BAR | INVENTION BAR | |||||||||
| Connector | Thickness [µm] | Connector | Distance (mm) | Thickness [µm] | ||||||
| Cr | Ni | Cu | Total | Cr | Ni | Cu | Total | |||
| 1 | 0.3 | 21.8 | 24.1 | 46.2 | 1 | 82 | 0.27 | 20.7 | 17.6 | 38.57 |
| 2 | 0.24 | 22.6 | 26 | 48.84 | 2 | 84 | 0.25 | 22.2 | 22.7 | 45.15 |
| 3 | 0.23 | 22.3 | 20.2 | 42.73 | 3 | 88 | 0.33 | 27.3 | 28.4 | 56.03 |
| 4 | 0.21 | 21.03 | 27 | 48.24 | 4 | 92 | 0.24 | 23 | 26.7 | 49.94 |
| 5 | 0.2 | 19.9 | 24 | 44.1 | 5 | 106 | 0.23 | 21.8 | 27.4 | 49.43 |
| 6 | 0.19 | 19.3 | 24.6 | 44.09 | 6 | 100 | 0.22 | 21 | 22.9 | 44.12 |
| 7 | 0.23 | 18.5 | 22.3 | 41.03 | 7 | 106 | 0.24 | 19.6 | 22.7 | 42.54 |
| 8 | 0.28 | 39.6 | 25 | 64.88 | 8 | 105 | 0.28 | 17.2 | 21.9 | 39.38 |
| 9 | 0.27 | 20.5 | 21.5 | 42.27 | 9 | 92 | 0.29 | 21.4 | 16.1 | 37.79 |
| 10 | 0.21 | 21.4 | 23.8 | 45.41 | 10 | 92 | 0.25 | 23.8 | 21.9 | 45.95 |
| 11 | 0.18 | 19.8 | 21.3 | 41.28 | 11 | 92 | 0.19 | 20 | 20 | 40.19 |
| 12 | 0.19 | 19.8 | 23.8 | 43.79 | 12 | 115 | 0.26 | 24.1 | 26 | 50.36 |
| 13 | 0.2 | 17.8 | 21.6 | 39.6 | 13 | 120 | 0.25 | 19.4 | 20.7 | 40.35 |
| 14 | 0.23 | 13.6 | 20.1 | 33.93 | 14 | 125 | 0.3 | 15.1 | 16.8 | 32.2 |
| 15 | 0.27 | 21.6 | 23.2 | 45.07 | 15 | 82 | 0.29 | 18.5 | 21.1 | 39.89 |
| 16 | 0.27 | 23.4 | 30.1 | 53.77 | 16 | 87 | 0.32 | 26.7 | 26.6 | 53.62 |
| 17 | 0.22 | 22 | 23.9 | 46.12 | 17 | 92 | 0.23 | 22.9 | 25.2 | 48.33 |
| 18 | 0.19 | 18.7 | 24.1 | 42.99 | 18 | 105 | 0.25 | 22 | 28.3 | 50.55 |
| 19 | 0.34 | 28.9 | 34.9 | 64.14 | 19 | 95.5 | 0.29 | 24.1 | 33 | 57.39 |
| 20 | 0.2 | 17.4 | 20.3 | 37.9 | 20 | 104 | 0.24 | 18.7 | 23.2 | 42.14 |
| 21 | 0.25 | 16.4 | 20.9 | 37.55 | 21 | 106 | 0.26 | 16.9 | 18.9 | 36.06 |
| 22 | 0.25 | 14.5 | 20.7 | 35.45 | 22 | 117 | 0.31 | 15 | 17.8 | 33.11 |
| 23 | 0.22 | 12.7 | 14.1 | 27.02 | 23 | 120 | 0.32 | 15 | 20.5 | 35.82 |
| Average | 44.191304 | Average | 43.865652 | |||||||
| Does not comply / Complies. |
[0071] Where we can observe that in the standard bar, there are up to 19 dimensions from different tests that do not meet the minimum required thickness, with a higher occurrence in the Chrome (Cr required > 0.25 µm), while in the invention bar, only on 8 occasions did it fail to meet the minimum required thickness in chrome. Additionally, the average shortfall to reach the minimum required thickness is 0.02 µm for Chrome in the invention bar, whereas in the standard bar, the average shortfall is 0.04 µm for Chrome, 1.4 µm for Nickel, and 0.9 µm for copper.
1. A structure for chrome plating plastic parts comprising:
support means attachable or attached to a support structure, where said support means define a curved arrangement, the support means being configured to distribute plastic parts for chrome plating during an electrolysis process, wherein said arrangement comprises a plurality of equidistantly separated loading connectors in horizontal and vertical lines, wherein said loading connectors have different lengths that increase from a first length of loading connectors located at the lateral ends of the support structure to a second length of loading connectors located in a central area of the support structure.
support means attachable or attached to a support structure, where said support means define a curved arrangement, the support means being configured to distribute plastic parts for chrome plating during an electrolysis process, wherein said arrangement comprises a plurality of equidistantly separated loading connectors in horizontal and vertical lines, wherein said loading connectors have different lengths that increase from a first length of loading connectors located at the lateral ends of the support structure to a second length of loading connectors located in a central area of the support structure.
2. The structure for chrome plating plastic parts according to claim 1, wherein the loading
connectors located at the ends of the support structure in a vertical line have a
first length and a next connector towards the central part of the support structure
in a horizontal line has a length at least 1 mm greater than the preceding one, and
so on until reaching the central part of the support structure.
3. The structure for chrome plastic parts according to claim 1, wherein the difference
in length between each loading connector at the lateral ends of the support structure
increases as it approaches the central area between 1 mm and 10 cm.
4. The structure for chrome plating plastic parts according to claim 1, wherein the loading
connectors located below the middle line of the support structure have a difference
in length between each loading connector located at the bottom of the support structure
and increase as they approach the central area of the support structure.
5. The structure for chrome plating plastic parts according to claim 1, wherein the support
structure comprises a plurality of supporting bars (10) arranged vertically and joined
at their top and bottom ends by a closing bar (11) which connects perpendicularly
to the supporting bars (10) and forms a frame-like arrangement in which an arrangement
of connecting bars (12) is provided, forming a loading structure for the loading connectors
(13) that hold the parts to be chromed, wherein these connecting bars (12) also have
an insertion means for a chroming contact (14), which is positioned parallel to the
chroming contact (14), and wherein for both the front and rear sides of the support
structure, the connecting bars (12) and the loading connectors (13) are distributed
equidistantly in the space between the upper and lower closing bars (11), and each
of these connecting bars (12) has a plurality of through-holes (15) with a rib that
allows the loading connector (13) to be screwed in.
6. The structure for chrome plating plastic parts according to claim 5, wherein the supporting
bars (10) have a plurality of extensions joined with a plurality of delta connectors
(16) at the top that allow contact with a transport bar (not shown) which is energized,
wherein said arrangement of delta connectors (16) maintains electrical conduction
properties as well as a plurality of grooves.
7. The structure for chrome plating plastic parts according to claim 5, characterised by comprising an arrangement of five sets of supporting bars (10) and closing bars (11)
supporting the sets of connecting bars (12) and the loading connectors (13) with a
plurality of current collectors (17), wherein additionally a set of protectors (18)
is attached, maintaining a curved arrangement with a greater distance from the supporting
bars (10) in the center of the support structure, while on each side the distance
is shorter relative to the support structure, coinciding with the distance of each
connection arrangement formed by the sets of connecting bars (12) and the loading
connectors (13).
8. The structure for chrome plating plastic parts according to claim 1, wherein the support
structure comprises a plurality of lateral protection means (19) on each side of the
support structure.
9. The structure for chrome plating plastic parts according to claim 1, wherein includes
a structure with a plurality of vertical posts, each of which has a plurality of horizontal
connecting means, which in turn have a plurality of grooves extending horizontally
on their outer surface, wherein the grooves are vertically separated from each other,
and where a support means for a part to be chromed is inserted.
10. The structure for chrome plating plastic parts according to claim 5, wherein the loading
connectors (13) coupled to the connecting bar (12) are loading hooks supported by
the chroming contact (14) and by the horizontal connecting means, respectively, wherein
each of the loading hooks (13) has a loading body received only partially around a
corresponding post, and each of these posts includes a rib extending horizontally,
received in one of the grooves of the connecting bar (12).
11. The structure for chrome plating plastic parts according to claim 5, wherein the loading
connectors (13) are coupled to the connecting bar (12) as support means for a structure
to be mounted on a horizontal support structure.
12. A method for chrome plating a plastic part characterized by comprising the steps of:
a) connecting or racking at least one element to be chromed to at least one of the loading connectors (13) coupled to the connecting bar (12) of the front fixing to the support structure for chroming on a front and/or rear side thereof, such that: part of one of the at least one loading connector (13) extends to the left from a left end of the support structure; and part of one of the at least one loading connector (13) extends to the right from a right end of the support structure;
b) positioning the part to be chromed so that its widest side is oriented towards the lower portion of the support structure;
c) opening the arrangement of the loading connectors (13) coupled to the connecting bar (12) and inserting a tab of the part to be chromed,
d) positioning the tab of the part to be chromed so that it contacts the bottom of the support structure coinciding with the loading connectors (13) coupled to the connecting bar (12);
e) checking that the part to be chromed is properly racked by applying slight movements to the loading bars (10) in a lateral and front-rear direction;
f) placing a plurality of current collectors (17) at the top of the support structure;
g) lifting the support structure for chroming;
h) inserting the support structure for chroming between left and right vertical supporting units until at least one front fixing member abuts the left and right vertical supporting units; and
i) moving the support structure for chroming to the left or right until a hook portion of the at least one front joining member engages with the left vertical supporting unit or the right vertical supporting unit.
13. The method for chrome plating a plastic part according to claim 12, wherein after
inserting the support structure for chroming between the left and right vertical supporting
units, lowering the support structure on each side until its bottom is perpendicular
to a horizontal plane.
14. The method for chrome plating a plastic part according to claim 12, wherein.
after inserting the support structure between the left and right vertical supporting units, connecting at least one loading connector (13) to the support structure on a rear and front side thereof, such that part of one of the at least one loading connector (13) extends to the left from the left end of the structure; and part of one of the at least one rear fixing member extends to the right from the right end of the support structure, and subsequently connecting the support structure to an electrical energy conductor means, and then includes the steps of:
after inserting the support structure between the left and right vertical supporting units, connecting at least one loading connector (13) to the support structure on a rear and front side thereof, such that part of one of the at least one loading connector (13) extends to the left from the left end of the structure; and part of one of the at least one rear fixing member extends to the right from the right end of the support structure, and subsequently connecting the support structure to an electrical energy conductor means, and then includes the steps of:
j) transporting the support structure with the parts to be chromed to a specific area in an upper portion of a chroming container.
k) submerging the support structure with the parts to be chromed coupled to the loading connectors (13) coupled to the connecting bar (12) in the chroming container.
l) remaining for a period of between 1 minute and 60 minutes inside the chroming solution in the chroming container.
m) raising the support structure;
n) removing the current collectors;
o) placing identification labels;
p) removing the part by opening the rack contact;
q) inspecting the chromed part;
r) packaging the chromed part.