JPS6194710A - Removal of flashes - Google Patents

Abstract

PURPOSE:To remove flashes in a very short time, at a high accuracy, with a simple device and operation by irradiating flashes using a stroboscope etc. on the flashes of a thermoplastic resin molded piece. CONSTITUTION:The mask plate 5 is mounted and fixed on the thermoplastic resin molded piece 2 leaving the squeezed-out part 2a and the flash 1 is removed by irradiating flashes using the stroboscope, etc.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a secondary processing method for resin molded bodies.

More specifically, the present invention relates to a method for deburring a thermoplastic resin molded body.

[Technology from Fengrai]

When thermoplastic resin is molded by injection molding, injection compression molding, or the like, molten resin flows out into the joints of the molds used for molding, and when it cools and solidifies, burrs often occur.

Conventionally, methods for removing this type of burr include (1) directly using thermal energy such as hot air blowing or infrared irradiation to melt and remove the burr, and (2) using chemicals such as acids to dissolve the burr. Method for removing burrs (3) Methods for removing burrs by mechanical processing such as honing, press cutting, and polishing are known.

[Problem that the invention seeks to solve]

However, in method (1), since the heat is applied to the burr slowly, some of the burr melted by the heat during processing wraps around the body of the molded product, reducing the accuracy of the attached part. There were drawbacks.

Furthermore, in method (2), the machining time generally took several tens of minutes, resulting in poor machining efficiency. Furthermore, there were disadvantages in that parts other than the edges were also melted, impairing the appearance of the molded product itself, and reducing processing accuracy.

Method (3) has the disadvantage that many thermoplastic resin molded bodies are too soft to undergo mechanical processing, so sharp edges cannot be obtained in the processed parts, resulting in poor processing accuracy. Ta. This defect tends to become more pronounced as the molded product becomes thinner in the form of a film, and as the thickness of the burr itself becomes thinner, ranging from tens of microseconds to several tens of microseconds.

The present invention has been made to solve the above problems, and aims to provide a deburring method that requires extremely short machining time, has high machining accuracy, and can be carried out using simple equipment and operations. purpose.

[Means for solving problems]

The deburring method of the present invention is a method for deburring a molded body of thermoplastic resin, and is characterized in that the burrs of the molded body are irradiated with flash light to concentrate energy in a very short period of time.

[Preferred mode for carrying out the invention]

Hereinafter, the invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the deburring method of the present invention, and shows an example of deburring a thermoplastic resin molded body shown in the plan view and side view of FIG. . The present invention will be explained based on this example.

In the molded body shown in FIG. 2, l represents a burr, 2 represents a body of the molded body, 3 represents a gate portion, and 4 represents a part of a runner. Place. This plate 6 is a table on which the molded body is placed, and is also used to attach removed burrs.

Next, the mask plate 5 is moved by appropriate positioning means (not shown) so that the flash light does not hit the molded body l.
Place and fix on the molded body. FIG. 3 shows a view from above of the molded body on which the mask plate 5 is placed and fixed. In FIG. 3, 2a is the protruding part of the molded body that is not covered by the mask plate 5. be. Part 2
It is originally preferable that a does not exist. However, if the molded body 1 is covered with a mask plate 5 having the same size as the molded body 1 so that the portion 2a does not exist, if the position of the mask plate 5 shifts even slightly, part of the burr 1 will emit light. In order to prevent the tube 7 from being irradiated with inter-strip light and the burr from this portion not being removed, the protruding portion 2a is provided in consideration of the positioning error of the mask plate 5.

Since the width of the protruding portion 2a is extremely narrow and it is usually considerably thicker than the burr, even if the portion 2a is irradiated with flash light, the influence of the flash light on the external shape of the molded product will not be a problem. However, in order to improve machining accuracy, the protruding portion 2a should be removed as much as possible within the range that takes into account positioning errors.
It is preferable to narrow the width of the molded body 1 and to provide it so as to have a uniform width over the entire outer periphery of the molded body 1.

Here, in order to explain the extremely short processing time using flash light of the present invention, a comparison will be made with conventional infrared irradiation.

The strobe used in the examples described below irradiates the molded body with concentrated energy of 300 WS within a time of less than 0.01 seconds to deburr the molded body. In contrast, with conventional infrared heaters, for example, in the case of a commercially available heater capacity of 2KW, the time required to provide the same energy as above is as long as 0.15 seconds, resulting in a short concentrated irradiation. It is not possible.

The strobe is composed of conventionally known strobes,
Any material may be used as long as it can emit a predetermined radiation intensity, and the radiation intensity is appropriately determined depending on the thickness of the mold. Note that the flash referred to in the present invention is not limited to that obtained by the strobe described above, but may also be obtained by a flash.

Next, as shown in FIG. 1, a flash light is emitted at a predetermined radiation intensity from a strobe 9 installed above the molded body and having a built-in arc tube 7 and a reflecting mirror 8 (reflecting mirror 8 can be omitted). When this flash of light is irradiated onto the burr 1 of the molded body, the emitted light energy is rapidly converted into thermal energy, and the burr 1 is instantaneously melted. The melted resin becomes fine droplets and forms plate 6.
The deburring process is complete.

Normally, sufficient machining accuracy can be obtained in the presence of the protruding portion 2a that takes into account the positioning error of the mask plate, but if a higher degree of machining accuracy is required,
What is necessary is to improve the positioning accuracy of the mask plate 5 and narrow the width of the protruding portion 2a to the utmost limit. Furthermore, if the distance #l between the lower end of the strobe body 9 and the burr l is kept at a constant value in advance, the luminous energy irradiated to the flasher l will depend on the radiation intensity at each wavelength of the light emitted from the arc tube 7. It is convenient to define and manage the deburring method of the present invention.

Furthermore, by irradiating flashlight with appropriate masking, it is also possible to provide a fine pattern on the surface of a thermoplastic resin molding or to make minute holes in a thin resin film.

〔Effect of the invention〕

The deburring method of the present invention removes burrs only by irradiating flash light, so processing can be completed in an extremely short time and work efficiency is high.Furthermore, only burrs can be removed without substantially damaging the body of the molded product. It can be removed with high precision. It is especially effective for highly accurate deburring of resin molded objects and when the burrs are minute.

Furthermore, since burrs can be removed by non-contact processing, all you need to do is determine the distance between the strobe, which is the means for removing burrs, and the molded object.
Since no other positioning is required, deburring can be performed with simple operation and compact and inexpensive processing equipment.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Molded body sample (POM: polyacetal resin) Molded body: Rectangular shape of 13 mm x 25 am, with a waveform on the negative side, thickness 0.2 ma + Burr: Width 2 mm thick around the entire outer periphery of the molded body 0.
003ma+ The above molded body sample was deburred under the following processing conditions.

Processing conditions Luminous time: Less than 0.01 seconds Output of arc tube 300WS Number of firings = 1 Distance between strobe and burr 11liI:1OIII As a result, the width of burrs was 0.03 mm or less at all locations.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the deburring method of the present invention, and FIG. 2 is a plan view and a side view of the resin molded body to be deburred in FIG. 1. FIG. 3 is a view from above of the molded body on which the mask plate is placed and fixed. 1...Flash 2...Molded body main body 2a...
・Protruding part 3...Gate part 4...Part of runner 5...Mask plate 6...Plate
7... Arc tube 8... Reflector 9... Strobe Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1) A method for removing burrs from a thermoplastic resin molded article, which comprises the step of irradiating the burrs on the molded article with a flash of light from a strobe or the like, thereby applying energy in a very short period of time.