JPS6260889A - Method for plating injection-molded article - Google Patents

Abstract

PURPOSE:To improve the quality of a product without increasing man-hours by applying various processes to an injection-molded article of synthetic resins, etc., integrated with a runner while using the runner as a hanging hook for plating, hence facilitating the washing in the pretreatment and securing the electric conductivity. CONSTITUTION:When the surface of a cylindrical core molded body 1 of plastics is electroplated, for example, the molded body 1 is arranged in the form of a comber at the end of a runner consisting of a main runner rod 3 and a branch runner rod 4 through a gate part 5. The main rod 3 is extended in parallel with the center axis C of a rotating branch shaft 6 which is continuously molded at one end and one detaining protrusion 7 is provided on the main rod in correspondence with each branch rod 4. When the midway part 4a is bent to detain the cylindrical hole of the molded body 1 by the end part of the protrusion 7, the center axis of the molded body 1 is aligned with the axis C. The whole body is rotated with the shaft 6 as the center while the molded body 1 is thus detained by the protrusion 7 and plating is carried out.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the improvement of plating technology for injection molded synthetic resin products, and is a novel method for electroplating the surface of injection molded products such as plastic resin cores. This invention relates to a method of plating injection molded products.

[Conventional technology]

Conventionally, as shown in Fig. 3, a core (with plating applied to the surface of a molded product made by injection molding of plastic resin) has been used.
2), first a large number of core molded bodies (51
) is molded using an injection mold having a piece arrangement as shown in Fig. 4, and each molded body (51) is placed in the gate part (52) of the runner (52).
53), a screw (54) is applied to the bottom of the molded body (51), and the plating hanging jig (55) shown in FIG. 5 is made using the screw (54). each attendance (5
6) At the same time as being supported on the end, the molded body (51) is supported in parallel on the axis extension of the pivot shaft (57) of the plating hanging jig (55), and the chemical plating process, electroplating process and A core (2) whose surface was electroplated was obtained by carrying out a number of steps such as washing with water and carrying out continuous processing.

[Problem that the invention seeks to solve]

However, as mentioned above, when the molded body (51) is made of a synthetic resin material such as plastic and is non-conductive, chemical plating is performed as a pretreatment when electroplating is performed.

This pre-treatment and electroplating.

Generally, the process is carried out through many processes and liquid types, and the previous process must be thoroughly cleaned after each process. The preliquid remains on the molded body (51), which causes plating defects, and also causes poor contact between the screws (54).
However, problems such as electroplating may not be applied because the current does not flow have occurred. In addition, in the conventional method, the molded body (51
) to the plating hanging jig JA (55).
54) There were problems such as requiring processing and labor for attachment and detachment.

The present invention was made for the purpose of eliminating the above-mentioned problems, and aims to provide a method of plating injection molded products without increasing the number of steps, and to improve the quality of the plated product. .

[Means for solving problems]

In the method for plating injection molded products of the present invention, a runner for arranging a large number of molded products in blocks by injection molding is used as a hanging jig for a key, and electroplating is performed. In other words, for the upper part of the runner where a large number of injection molded products are arranged, there is a runner branch extending to each molded product, and in this runner branch, the molded product is folded onto the axis of a rotating support shaft formed continuously with the upper part of the runner. A locking protrusion that locks the molded body in a bent state is integrally molded, and a rotating support shaft above the runner is supported on a rotary drive body while each of the molded bodies is engaged with the locking protrusion. A large number of molded bodies are moved through the electroplating process and its pretreatment process while rotating around the pivot shaft as a central axis, and the surfaces of the molded bodies are plated. Therefore, after the plating process, a plated molded body can be obtained by separating the product from the gate part of the runner branch.

[For production]

The plating process for the molded product described above is characterized by the arrangement of a large number of injection molded bodies with respect to the runner and the change in the posture of the molded bodies after molding. The present invention was achieved by positioning each molded body coaxially with the pivot shaft by hooking the molded body onto a locking protrusion formed at the same time as the upper part of the runner. In other words, when applying electroplating, it is very important to always position the body to be plated at the same distance from the anode and rotate it in the liquid to remove uneven plating, and to ensure that the molded body stabilizes the cathode. However, in the method described in J:, each molded body is an integral part until it is cut and separated from the runner after plating, so there is no problem such as poor current conduction, and there is no problem with locking. By engaging each molded body with the protrusion, each molded body is arranged in a wave array at the rotation center position, so that uniform plating can be achieved. Therefore, by cutting at the end and appropriately selecting the gate position where the non-plated part appears, it is possible to perform the plating finishing process of the injection molded product within the cylinder.

〔Example〕

The method for plating injection molded products of the present invention will be explained below with reference to the drawings. Figures 1 and 2 show a core (2) in which the surface of a cylindrical core molded body (1) of plastic resin is electroplated. ).

A core molded body (1) molded by an injection molding device is formed by a runner first step (3) and a runner first step (3) for feeding melted resin into each core molded body (1). A piece is placed at one end of the runner consisting of a runner branch (4) branched from 3) via a gate part (5). The runner upper section (3) extends in a direction parallel to the central axis (C) of the rotating support shaft (6) formed with continuous bA at one end, and has one runner section corresponding to each runner branch section (4). A locking projection (7) is provided in a protruding manner, and the cylindrical hole (1a) of the core molded body (1) is locked to the hooked end (7a) of the locking projection (7). When the middle part (4a) of the runner branch (4) is bent and supported, the central axis of the core molded body (1) coincides with the central axis (G) of the rotation support shaft (8) (second (see figure).

When plating the surface of the core molded body (1), each core molded body (1) is placed in the molded state using the runner 1 rod (3) as a hanging jig for plating as shown in FIG. Locking protrusion (7
), attach the rotation support shaft (fi) to the movable beam (not shown) of the plating processing equipment.

After undergoing numerous conductive pretreatment processes such as chemical plating treatment tanks and cleaning treatment tanks, plating treatment is performed in an electroplating tank.
In this electroplating tank, the plating process is performed while rotating the entire body around the pivot shaft (8), and each core molded body (1)
rotates around the central axis (C) so that the peripheral surface maintains a uniform distance from the anode.

- Since the core molded body (1) is integrated with the runner first step (3) and the runner branch rod (4) during the electroplating process described in -, each core molded body (1) is It is electrically connected reliably to the runner 1 rod (3) and is polarized as a cathode via the pivot shaft (B).

After completing the plating treatment through the above steps, the rotary shaft (6) is removed from the movable beam after washing and drying, and the gate portion (5) is cut to obtain the product core (2). Gate part (5
) The cut surface of the core (2) is not plated, so the mold should be designed in consideration of the position of the gate part (5) so that it does not appear on the surface side of the molded product. is desirable.

〔Effect of the invention〕

As described above, in the method for plating injection molded products of the present invention, each plating process is performed while the injection molded product remains integrated with the runner, and the runner is used as a plating hanging jig, so there is no joint and the front Not only is the process easy to clean, but
Since the conductive state is reliable, chemical plating and electroplating can be applied satisfactorily, improving the quality of the product.

In addition, the plating method of the present invention has the feature that it is possible to omit pre-processing for attaching and detaching the molded product to and from the plating hanging jig, and it is possible to improve productivity. , the effects of the present invention are extremely significant.

[Brief explanation of the drawing]

: Figure 51 is a front view showing an example of the frame arrangement of a synthetic resin molded body for carrying out the present invention, Figure 2 is a front view showing a plating treatment mode of the same synthetic resin molded body, and Figure 3 is an example of the product. FIG. 4 is a front view of a synthetic resin molded product showing a conventional frame arrangement, and FIG. 5 is a front view of the same molded product attached to a plating hanging jig. (1) Core molded body (2) Core (3) Runner 1 (4) Runner branch (5) Gate part (6) Rotating support shaft (7) Locking protrusion (C) Center axis C -- -φ1 length axis

Claims (1)

[Claims] In electroplating of injection molded products such as plastic,
After injection molding, each molded body to be integrated with the runner is engaged with a locking protrusion formed to protrude from the runner at the same time as the molded body,
The runners are aligned and supported on the runners, and the runners are used as plating hanging jigs to be transported to each plating process, and the runners are used as rotational shafts for agitation plating. After that, each molded body is cut and separated from the runners to obtain products. A method for plating injection molded products.