JPH0419923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding simultaneous painting device that performs painting simultaneously with injection molding.

Simultaneous painting with injection molding is generally done before injection molding by pressing a decorative sheet into the female mold using air pressure to preform the mold, then combining the female mold and male mold and injecting molten resin from the male mold side. The purpose of this method is to attach the above-mentioned illustrated sheet to the surface of.

Conventionally, this type of molding involves preparing an injection molding machine with a male mold and a female mold, feeding a heated transfer sheet between the two molds, preforming it inside the female mold, and then combining the male mold and female mold and performing injection molding. The printed pattern on the transfer sheet was transferred to the surface of the molded product. However, with this method, the base material of the transfer sheet remains attached during injection molding, so the surface of the resulting molded product reproduces the gloss of the peeled surface of the base material of the transfer sheet, and the female mold The gloss on the inside of the mold cannot be reproduced.

This invention has been developed in view of the problems of the conventional method, in which a roll-shaped continuous sheet with a pattern printed thereon is continuously supplied to an injection molding machine, and when the continuous sheet is supplied, the pattern is printed in advance for each pattern pitch. The sheet is fed at regular pitches while detecting the mark, the printed pattern is transferred to the inner surface of the female mold, and then the mold is set in a predetermined position by rotating the mold table half a turn to perform injection molding. It is.

According to the present invention, only the printed pattern is transferred to the molded product, and the gloss of the base material of the transfer sheet is not transferred, so that the gloss of the mold is reproduced.

First, a product molded according to the present invention will be described. FIG. 1 is an example of this, in which numeral 10 is a flower pattern formed in a convex shape, and numeral 12 is a letter. Parts 10 and 12 have the gloss of the ink composition that constitutes them, and the other parts reproduce the gloss of the mold during molding.

FIG. 2 is a partially cutaway plan view of the device according to the invention.

In the figure, 16 is a male type and 18 is a female type.
The male die is fixed to a stationary platen 20 of the injection molding machine, and the female die 18 is connected to a pressure ram 22 via a moving plate 24, so that the female die is movable relative to the male die.

An ejector 26 includes a protruding pin (not shown) for ejecting the molded product from the mold after injection molding.

28 is an injection device, and 30 is an injection hole for molten resin.

A transfer sheet 32 is configured to run horizontally between male and female molds of the injection molding machine as described above, and 34 is an unwinding roll of the sheet, 36 is a winding roll, and 38 is a guide roller.

A desired pattern is printed on the sheet 32 so that it can be peeled off by heating, and the sheet 32 is set so that the printed surface faces the male mold 18 side. Note that marks 40 (for example, register marks) are printed at regular pitches on the sheet along with the printed pattern. The marks 40 may be provided in the machine direction and the width direction of the sheet, if necessary.

At the female mold 18 return position, hold the mold from above and below,
In addition, the two rails 42 are fixed at positions that do not hinder the movement of the mold. The sheet 32 runs between these two rails and covers the opening of the male mold.

Furthermore, a hot plate 44 and a frame member 46 are installed at the other end of the rail 42. This position is the return position of the lid member, etc. In other words, the heating plate and the frame member can be moved from the upstream side of the sheet to the female mold 18 by one pitch of the pattern, and the sheet can be moved toward the female mold 18 with the sheet sandwiched between them even in the above-mentioned return position. ing.

The frame member 46 is approximately U-shaped and is adapted to move along the two rails,
The lid member 44 is a rod (not shown) implanted in the frame member.
It is inserted into the rod and can move up and down relative to the frame member while being regulated by this rod. The hot plate is moved up and down by an air cylinder (not shown). A rod member 48 is installed along one side of the female mold 18 for closing the open portion of the frame member 46 to form a loop-shaped frame. This is connected to the moving plate 24 via a suitable member.

The hot plate 44 has a ventilation hole 50 in a portion facing the inside of the female mold, and vacuum or compressed air can be introduced by switching. Further, the hot plate 44 has a mold blade 53 for cutting the transfer sheet by the necessary amount after molding, and it is preferable that this mold blade 53 protrudes from the hot plate during use, but it is not necessary to leave it protruding. It may be.

Reference numeral 52 denotes an air cylinder or an oil cylinder, the cylinder body of which is rotatably held by the frame of the apparatus, and the rod end of which is rotatably connected to the top of the hot plate 44.

54 is a detector such as a phototube for detecting the mark 40 on the sheet, and is fixed to a heating plate or a frame member. Numeral 56 is another rod member that holds the sheet together with the rod member 48, and is moved up and down with respect to the above member by an air cylinder (not shown) supported by the moving plate 24.

Next, the operation of the above device will be described.

First, the stepping motor is activated to perform positioning until the detector 54 detects the mark 40 on the sheet, so that the frame member 46 and the hot plate 44 surround one picture. A cylinder may be used instead of the stepping motor, or two conveying means that move along both the X and Y axes may be used to position not only in one direction but also in the vertical and horizontal directions. It's okay.

Next, the hot plate 44 is moved toward the frame member by the operation of an air cylinder (not shown), and the sheet 32 is moved together with the frame member.
is absorbed into the hot plate 44 by introducing a vacuum into the ventilation hole 50 of the hot plate 44.

Thereafter, as shown in FIG. 3, the air cylinder 52 is actuated to move both members 44, 46 along the rail 42 toward the female mold 18. At the same time, one pitch of the sheet is transferred from the unwinding roll 34 side to the winding roll 3.
It will run to the 6th side.

The hot plate 44 is now ready to seal the female mold and preform the sheet. Note that if three-dimensional molding is required using a hot plate, the sheet is heated and softened while moving one pitch.

In this state, exhaust air is first exhausted from both the ventilation holes 58 and 50, and then compressed air is supplied from the ventilation hole 50. As a result, as shown in FIG. 4, the sheet 32 comes into contact with the inner surface of the female mold, and the ink is transferred to the inner surface of the female mold. The hot plate 44 is attracted to the mold by an ejector, and at the same time the transfer sheet is cut into a desired size by a mold blade attached to the hot plate, and then transferred by suction by the hot plate 44 or by other peeling means. Only the base material of the sheet is removed, and only the printed pattern formed on the transfer sheet is transferred to the inner surface of the female mold.

Thereafter, the hot plate 44 is lifted from the frame member 46 by the operation of an air cylinder (not shown), and both members 44, 46 are returned to their original positions (FIG. 2) by the operation of the air cylinder 52.

Then, as shown in FIG. 5, the female mold 18 is moved by the ram 22 and unites with the male mold 16, and the molten resin is injected from the injection machine 28. Furthermore, the mold is released and the rod member 56 is separated from the sheet. In this way, a decorated molded product with only the printed pattern adhered to the surface of the injection molded part 60 is obtained.

Note that since the movement of the air cylinder 52 and the like is controlled using a known control circuit, a detailed explanation of the control device will be omitted.

Since the present invention is configured as described above,
Decorative molding can be performed while continuously feeding the sheet as a continuous body. Therefore, the production efficiency of molded products can be significantly improved.
In addition, since injection molding is performed with only the printed pattern attached to the inner surface of the female mold, the surface of the molded product reproduces the gloss of the inner surface of the mold, and especially in areas without printed patterns (plain areas), the surface of the molded product is reproduced. The gloss is accurately reproduced.

Furthermore, since the sheets can be fed accurately one pitch at a time, the injection molded product and the pattern can be accurately synchronized.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an example of a decorated molded product molded by the apparatus according to the present invention. 2 is a partially cutaway plan view of the apparatus according to the invention, FIG. 3 is a similar plan view in a state ready to preform a sheet, and FIG. 4 shows the female mold part in the state after preforming. 5 is a horizontal sectional view of male and female mold parts during injection molding. 16...Male type, 18...Female type, 32...Pictured sheet, 40...Mark, 42...Rail, 44...
...Hot plate, 46...Frame member, 50...Vent hole, 53
...Mold blade, 52...Cylinder, 54...Phototube.

Claims (1)

[Claims] 1 Before injection molding, the transfer sheet is pressed into the female mold using vacuum and/or compressed air to transfer the printed pattern of the transfer sheet to the inner surface of the female mold, and then the female mold and male mold are combined to transfer the molten resin to the male mold side. In an injection molding simultaneous painting device that integrates the printed pattern and the injected resin by injection from the sheet, an unwinding and winding roll for the sheet is installed so that the transfer sheet runs while covering the opening of the female mold. and a mold that is movable from the upstream side of the sheet to the female mold by one pitch of the pattern on the transfer sheet, has a ventilation hole in a portion facing the female mold, and cuts one pitch of the transfer sheet. a frame member that holds the transfer sheet together with the heat plate and moves together with the heat plate; and a conveyance means that reciprocates the heat plate and the frame member by one pitch of the printed pattern; A detector is fixed to the heating plate or frame member and reads marks formed in advance on the transfer sheet for each pitch, and a signal from the detector reading the mark is used to transfer the heating plate and the frame member to the transfer sheet. An injection molding simultaneous painting device characterized by comprising a control means for stopping the transfer sheet on the upstream side of the mold and then sandwiching the transfer sheet between a heating plate and a frame member, and a means for removing the transfer sheet from within the female mold. .