JP2590188B2 - Molding equipment for mold material containing release agent - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for molding a release material-containing mold material devised to stably maintain the releasability of a molded product.

[Conventional technology]

For example, a resin or rubber molding material for transfer molding contains a release agent such as wax for the purpose of facilitating release after molding.

When the molding is repeated, the amount of the adhesive remaining on the molding surface of the mold gradually increases. Since the mold is heated to a high temperature (approximately 175 ° C. in the case of epoxy resin molding), it is seized on the surface of the mold together with fine dust and the like, and the releasability is gradually deteriorated.

Therefore, the mold is periodically cleaned while monitoring the progress of the contamination. This cleaning is performed by, for example, performing dummy molding with a melamine resin to transfer the surface deposits to the dummy molded product. The cleaning time is determined by any of the following (1) to (3). As a result, the following problem has occurred.

(1) Clean at regular intervals. For example, once a week.

(2) The cleaning time is determined by the number of shots. For example, once every 500 shots.

(3) Visually check the contamination status and decide the cleaning time based on empirical intuition.

[Problems to be solved by the invention]

It is very difficult to estimate the degree of mold contamination based on the number of shots and the period. Because, even if the number of molding shots is small or the use period is short, if the mold is exposed to high temperature for a long time, seizure of surface deposits will progress,
In some cases, the contamination proceeds more than expected and the releasability deteriorates.

On the other hand, in the visual confirmation, individual differences, oversight, omission of confirmation, and the like occur.

Therefore, in any of the methods (1) to (3), the molding is performed in a state where the releasability is deteriorated. Therefore, the following inconvenience, that is, a part of the molded article is broken at the time of demolding. Therefore, it is impossible to avoid that the product remains defective in the mold and becomes defective, and that it takes a long time to remove the adhered mold material from the mold.

An object of the present invention is to provide a molding device effective for solving these problems.

[Means for solving the problem]

The present invention relates to an apparatus for injecting and molding a mold material such as a resin or rubber containing a release agent into a cavity formed between a pair of molds. The present invention is characterized in that a measuring device is added, and the cleaning time of the mold is determined based on the value measured by the measuring device.

[Action]

Since the release agent such as wax contained in the mold material has an electrical insulation property, the value measured by the measuring instrument (for example, the current value) gradually decreases in proportion to the progress of the mold fouling (resistance measurement). If so, the resistance will gradually increase). Therefore, for example, when measuring an energizing current value, a current value that can maintain the minimum releasability is obtained in advance, and a cleaning command is issued when the reference level is exceeded based on the current value. For example, the cleaning time can be accurately grasped.

〔Example〕

 1 and 2 show an example of the apparatus of the present invention.

In FIG. 1, reference numeral 1 denotes a mold composed of an upper mold 2 and a lower mold 3, and 4 is a molding surface of an upper and lower mold. When two and three are abutted, a cavity is created between both molding surfaces.

Reference numeral 5 denotes an electrical continuity measuring instrument attached to the lower mold. The measuring device 5 comprises a spring prog 7 attached to a holder 6, a power source 8 and an ammeter 9 inserted into an electric circuit connected to the lower die from the prog.

Note that the ammeter 9 may be replaced with a voltmeter or a resistance measuring device.

Further, since the degree of contamination of the upper mold 2 and the lower mold 3 proceeds almost in parallel, it is sufficient to measure the electrical conductivity of any one of the molding surfaces 2, 3, but if necessary, the upper mold, The same measuring instrument may be provided on both the lower mold and the surfaces of both the upper mold and the lower mold may be measured by the same measuring instrument.

Further, as a contact of the measuring instrument to be brought into contact with the molding surface of the mold, the illustrated springing prog for keeping the pressing force constant by the force of the spring is suitable, but not particularly limited thereto. However, no matter what kind of contact is used, it is desirable that its tip be rounded as shown in FIG. 2 in order to prevent the mold from being damaged.

The exemplary molding apparatus configured as described above retracts the spring prog 7 to a position where there is no obstacle to molding, and performs molding of the molding material. Then, for example, before the start of daily work, the prog is moved onto the molding surface to which the fouling substance A is attached, and the electrical continuity measurement is performed. The measurement may be performed for each shot or for every several shots by adding an automatic measurement mechanism.

〔effect〕

As described above, the molding apparatus according to the present invention includes the electric conductivity measuring device for the molding surface of the mold, and determines the cleaning time of the mold based on the measurement result by the measuring device. Thus, the cleaning time can be accurately determined by accurately grasping the degree of contamination, and the effect of eliminating defective products and loss of working time due to the contamination of the mold surface can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a molding apparatus according to the present invention, and FIG. 2 is a view showing a preferred tip shape of a contact. 1 ... mold, 2 ... upper mold, 3 ... lower mold, 4 ... molding surface, 5 ... measuring instrument, 6 ... holder, 7 ... spring prog, 8 ... power supply, 9 ... current Total.

Claims (1)

(57) [Claims] 1. An apparatus for injecting and molding a mold material such as a resin or rubber containing a release agent into a cavity formed between a pair of molds, wherein an electric power is applied to a mold molding surface including a current-carrying contact. An apparatus for molding a release agent-containing mold material, to which a continuity measuring device is added and a cleaning time of a mold is determined based on a value measured by the measuring device.