JPS59120432A - Simultaneous double sides drawing method of synthetic resin molding - Google Patents

Abstract

PURPOSE:To obtain the titled molding at a high molding efficiency without a changeover valve by arranging a plurality of molding dies with respect to one injection equipment to perform a molding alternately removing solidified sprues sequentially. CONSTITUTION:Nozzles 5 and 6 of an injection equipment 1 are communicated with a molding die 17 through sprues 14 and 14' and injects a melted resin to an extent of filling the sprues to be solidified. Then, one molding die is released to remove the solidified sprue therefrom, a set of surface and back print sheets 18 and 18' premolded are mounted and after the clamping of the die, a melted resin is forced inside the sheets to mold. While the resin is cooled and solidified, another molding die is opened to remove the solidified sprue therefrom, a set of surface and back print sheets premolded mounted and after the clamping thereof, the process of an injection molding is repeated.

Description

Detailed Description of the Invention Technical Field The method of the present invention relates to a method of injection molding a synthetic resin molded article by applying a printing sheet on both sides. Two or more means are placed side by side to stretch printing sheets on both sides of a synthetic resin molded product in one step by injecting molten plastic into the inside of the molded plastic, and the molten plastic is supplied from one molten plastic supply source through a switching valve. Inject to each molding means +1 fi without
A leap forward is made to a method for simultaneously painting both sides of a synthetic resin molded product, which is characterized by sequentially molding one by one.

Prior Art Conventionally, as a means of paying for injection molded products, a pre-printed notebook was placed in a mold.
-Fused glass on the back side after all pre-forming
6, (and
: For example, 1975 Special dT Application Publication No. 19132
(Refer to Publication No. 1, Other Methods for Manufacturing Painted Synthetic Resin Molded Products)
Molded products formed using the above method have a printed sheet on the surface.
□ is called recessed (it is very beautiful, but the back side is made of raw material, so for example, the panel of To-1 between the points,
For items such as plaques that are double-sided, please send one-sided
After forming the V shape, each back side was glued (~) to obtain a beautiful molded product on both the front and back1.For this purpose, duplication of molding and bonding process are required, so it is inevitable that had the disadvantage of being expensive,
3. Purpose Is the method of the present invention conventional? ``J-1'' Improved the drawbacks associated with the above-mentioned molding method L, improved the simultaneous painting method on both sides, and the decrease in molding efficiency due to the prolongation of the molding cycle due to the thickening of the molded product. The alternating molding method V is used to replenish the molten plastic, and by simplifying the molten plastic supply switching means and rationalizing the mold clamping mechanism, a new type of plastic deck molded product with printed sheets pasted on both sides can be created. The overall objective is to create a mass production method and thereby provide quality products at low prices.

Structure The method of the present invention is characterized in that the front and back surfaces of the mold are formed in advance in the mold of a mold.
A set of printing sheets is attached, and molten plastic is pressed on the inside of the sheet, and a relatively thick synthetic resin molded product with both sides (C printing sheet 1-'%-stretched) is made by one injection molding. A method in which a plurality of molded films are formed using one injection device, the number of films is I~, and a nozzle of the same device is passed through each spool L7.
7, first, inject and solidify enough molten plastic to fill the spool, then open one of the molds and remove the solidified spool from the mold. Attach the preformed front and back printed sheets, close the mold, operate the injection device, and press-fit and mold the molten plastic into the inside of the sheet, while the plastic in the mold cools and solidifies. , another mold is opened and the solidified spool is removed from the same mold, and the front and back sets of printed sheets that have been preformed)' (i-T culm to be injection molded after installation and mold clamping)'5f: Repeat This makes effective use of the time while the plastic in the original mold hardens, thus repeating the injection molding cycle in which the original mold is opened and the spool and part are removed from the mold.
This method is characterized by the fact that molten plastic can be sequentially supplied to each mold from a single plastic injection device with or without switching. An apparatus for carrying out the ten-described method will now be described with reference to the drawings.

The details of the method of the present invention will become clear as the apparatus described in F is explained.
□It will become clear.

Embodiment FIG. 1 is a partially cutaway side view of an embodiment of a molding apparatus for carrying out the method of the present invention. This is an injection device installed vertically for injecting melted plastic.
is bored at the end of the injection device 1, and the base nozzle 2
The nozzle part is equipped with a runner 4 that communicates with the runner 4, and the circumferential surface of the nozzle part is surrounded by a band heater to heat the inside of the nozzle member to an appropriate level of humidity so that the fluidity of the plastic in the runner 4 does not deteriorate. 17. The ends of the same tubes 4 are each traced to a nozzle 5.6. The nozzle member 3 is capable of supplying and press-fitting molten PlusDeck into molds provided at a plurality of locations using nozzles 5 and 6. That is, the portion where the tip nip of the mold 3 and the fixed die 8 of the mold are in contact is connected to the nozzles 5, 6 and the fixed die 8 by a spool (7).

7 is perpendicular to the machine base 33, and the pair 1-1 is in the center.
2 is a symmetrically installed fixed frame, vertical injection device 1 and water 3
In addition to supporting the nozzle member 3 provided at F and connecting the two at the base nozzle 2, there are also four supports 22 pushed in the horizontal direction υ and the nozzles 5 and 6 of the nozzle part. and its spools respectively support fixed molds 8 which communicate with each other.The fixed molds 8 are connected to the open surface of the female mold 0x)9 through an open surface 11 (joint) with the open surface of the female mold 9). 9 corresponds to the open surface of the female mold (B) 10 via the open surface (joint) 12, and the female mold B is supported by the horizontal support 22 and is slidable in the longitudinal direction of the support 22. It is fixed to the suspended left and right pressure plates 20 and 21.The HF plate 20,
21 four corner ends.

A cylinder 24 that is concentric with the axis of the IT support 22 is formed around the support 22 in each portion that supports the support support 22.
Inside the cylinder 24 is a piston 72 fixed to the column 22.
3 is fitted, and the force space of the cylinder 24 defined by -) is an advance chamber 25, and its end has a hydraulic hole 27,
The other space is a reversing chamber 26, and an oil FF hole 28 is also bored at the end thereof (2).

Now, when pressure oil is introduced into the forward chamber 25 from each hydraulic hole 27, the advance chamber increases by l''llllll, and the volume of the other reverse chamber 26 decreases by L2, and the oil in the same chamber increases from the hydraulic hole 28. 4-
1 [To be released, the pressure plate 20. 21 is mounted on the support 22 and placed in front toward the center of the device, # (-5 fixed type 87 curved type) 9 and female type (B) 10 (these Move the molds (generally referred to as molds) so as to reduce the distance between them, so that the open surfaces 1], , 12 face each other, and compress the molds evenly.
Ru. (Please refer to the structure on the left side of the center of the device shown in the first diagram.) In addition, a valve device N is provided in the hydraulic circuit of pressurization &20.21 so that its movement can be controlled separately. In a state where the molds 8, 9 and IO are pressed uniformly and integrally by the pressure plate 20, the injection device 1 also injects molten plastic, and the base nozzle 2. runner 4
．． Plastic is press-fitted into the mold through the entire injection nozzle 5.

11c, when pressure oil is supplied to the hydraulic hole 28 and the volume of the backward movement chamber 26 in the cylinder 24 is expanded, the oil in the forward movement chamber 25 is removed from the abutment 27, and as a result, the pressure plate 21 moves backward along the support B22. The molds 8, 9 and 10 are spaced apart from each other to form an open surface 1. i, , 12 move to the world. At this final stage, the double-sided printed synthetic resin molded product, mold runner, and spool that have been molded in the mold are removed from the mold using a knocking mechanism. Subsequently, after the printed sheets of the front and back sets, which have been previously formed by a method such as vacuum forming, are mounted in the mold, the pressure plate 21 is moved forward by operating the hydraulic device, and the molds 8, 9 and 10 Tighten evenly and then enter the injection Jl type process.

Figure 2(a) is a longitudinal cross-sectional view of the mold used for producing fruit according to the method of the present invention, and Figure 2(a) is a plan view thereof. A mold 8 of the same type is fixed to a fixed frame 7 of the device, and a nip receiver is provided at the center of the back side, and a nozzle 5 of the nozzle member 3 provided on the fixed frame 7 is mounted.
The injection device 1 communicates with the mold ranker 13 which receives the mold 6 and cuts the open surface 11 on the opposite side through the spool gear 2. A) Drill and mold the L-11 runner 13 along the longitudinal direction between the molds 9 and 7. A mold 17 is formed between the gate surface) 12 and a plurality of gate runners 15.
15' are provided parallel to the foot runner 917, and the foot runners 15.15'id rise from the center to the spools 14.14', and grooves 11' are provided on opposite sides thereof.
The mold 1 is connected to the end of the mold runner 13 which has been iljed, and is connected to the mold 1 through a thin and wide nozzle by the FL flat gate 16.
It is connected to 7. (See Figure 2 (1)) Female type (
B) 1-0 has a female type (Δ) 9 drilled and a sprue 41
4. Corresponding to the 14' position, the opening/closing bin 19
The end faces of the bottle 19 are aligned and driven by a hydraulic device provided on the opposite side to the bottle 12, and a spool l with a VP port in the center is driven. 4, L 4. ' passage opens and closes 1, 1
8.18' is a molded sheet of silk with the front and back sides formed by forming a printing sheet (film 18 is paper) in advance by means such as vacuum forming. 17
It was installed on the inner surface υ without any gaps.

2nd (1)) See all figures 7, 31 is female type (A)
, (+3'), the molten plastic is injected into the mold 17, press-fitted, cooled, and solidified.
^11 Inject compressed air into the core of the plastic in the mold 17 using a syringe nail, and by kneading, the meat becomes comparatively white! A cavity 32 is artificially formed in the center of a molded product to prevent cracks, holes, or distortion from occurring on the surface of the molded product.

Figure 3 shows an IJy-shaped product case in which molten plastic was injected into a mold, cooled and solidified, and then removed from the mold.
13 is a mold runner, 14.14' is a spool connected to both ends of the mold runner, and 1,5,15' is a gate in (b). In the cross section of the runner, I6 is a flat gate, 18.18' is a set of front and back printed sheets formed by vacuum forming or other means and is pasted on the surface of a synthetic resin molded product, and 19 is a knock bottle and passageway. Kate runner 15.15 in the direction of the arrow with an open/close bottle
Push up 9 to release the molded product from the mold, and close the passages of spools 1..1 and 4.'
・Part 3.32, which serves as the structure treatment A'1 for the actual Mji of the method of the present invention, is a cavity provided in the core of the molded product, and when the thick-walled molten Zolastite solidifies, This is a nest that has been artificially formed to prevent cracks, large dimensions, or distortions from occurring on the surface of the molded product due to changes in appearance. A molded article can be obtained by operating the method as described below.

(]) First, in Figure 1, pressurized oil is inserted into the oil hole 27.
Oil is supplied to fully expand the volume of the advance chamber 25 in the cylinder 24 provided on the pressure plate 20.21. 'i
Move it toward the center of the device and press the left and right molds equally. At this time, the knock bottle 19 is press-fitted into the mold, and the passage of the spool 14° 14' is completely closed.
, (2) Second scale, the injection device 1 through the nozzles 5 and 6, and the runner and spool quickly inject and supply molten plastic gold to the extent that the original is drawn 61. At this time, the plastic is prevented from being press-fitted into the mold 17 by the end face of the knock bottle.

(3) Third step, supply pressure oil to the hydraulic hole 28 and
Move only the I pressure plate 20 in the return direction and open the left mold 7.
) (a) Solidified mold runner 13. Spool 14°14'
(3rd (a) Same diameter $) Remove from the X-type 3, (b) Preformed front and back = - set of printing sheets 1-1.8.

18' Installed in the i-type 17 1, Q→ Next, send pressure oil to the hydraulic hole 27, move the pressure plate 20 toward the center of the device, and move the mold between the fixed frame 7 and the pressure plate 2.
Tighten with 0 and press close.

(Refer to the state on the left side of the center of the device in FIG. 1) At this time, the knock bottle 19 returns to the normal position and opens the passage for the spools 1Δ, 14'. .

(4) Fourth block, inject molten plastic through nozzle 5, press fit into the left mold and fill it 3, the fly
The molten plastic is injected and press-fitted into the mold J, blocked by the solidified mold runner and spool.
b) 7' Injection of compressed air into the core of the molded product by 132, (5) Fifth-r: Pj, Meanwhile, pressurized oil is supplied to the oil L hole 28, and the force 11 Return the pressure plate 21 and fully open the right mold 7.The subsequent steps are exactly the same as the third step performed for the left mold.1-10 (6) Sixth step, left molding Apply the same method to the right mold as in the fourth step +11Fi performed on the mold1.
, At this time, the left mold is filled with injection molding plastic, so the molten plastic is not press-fitted into the left mold.

(7) Seventh step: Pressure oil is supplied to the hydraulic hole 28, and the plate 20 is moved in the return direction, and the left mold is opened.
2. (a) Activate the cutter 719 and remove the molded product, such as the runner 15.15', from the mold 17.

([-1) Mold runner 13 and spool 14.11'
Excludes. , (c) Pre-(i!N-molded front and back-set printing/'to' fs
: That's 11 type 17 inner wall and 1 to be installed on both sides→
Send FF oil f to the 1 hydraulic hole 27 and apply force [1 3° to operate the pressure plate 20 in the mold clamping direction. Perform the same procedure as the seventh step for the left mold on the right mold. As can be immediately understood from the explanation in section 7 above J and I,
According to the method of the present invention, a synthetic resin molded product with a double-sided printed sheet can be obtained by one injection molding, and a highly efficient mass production method can be adopted. i fc, although the base nozzle 2 is connected to a mold two stages above, no distribution valve is required for supplying molten plastic. , That is, with full reference to Figure 4, the same figure shows the actual Mij
This is a cross-sectional view of the nozzle member. 29 is a switching valve with a recessed single-shaped flow path, and 3o is a valve body and has runners 4 on the left and right sides, the ends of which communicate with the nozzle (
-2. The flow path of the valve is communicated or cut off between the left and right runners 4 bored in the valve body (10 devices) and the drain 2 [7, the flow path is located on the left side or right side (especially 1. Conventional equipment like this, which supplies molten plastic, requires a power source or mechanism to operate the JJ switching valve at the correct timing, making the entire structure complicated. .

(b) There is a risk of plastic leaking from non-sliding surfaces during injection of molten plastic.

(c) There is a risk of deterioration of the plastic due to friction on the rotating surface of the switching valve.

However, by following the method of the present invention, it is possible to achieve substantially the same effect and effectiveness as a distributing valve by installing a distributing valve, and to avoid the drawbacks of the conventional device. It can be improved.

Furthermore, as mentioned above, synthetic resin molded products with double-sided printed sheets are required to be large in size and thick, which requires time for assimilation of the glass and molding, and volume changes occur during cooling. Since there is a risk of scratches or scratches occurring on the mold, multiple molds are connected using one injection device, and the entire cooling and assimilation time of the plastic in the mold is used to perform separate molding. Time spent on preparation work for injection into the mold and work on cutting out the molded product ``1-'' At that time, melting; changing the flow path of the plastic, no need for a switching valve, etc.
By injecting a compressed blank into the core of the plastic before it cools down, artificial nests are created to reduce the number of defective products. Furthermore, the molding efficiency of good products is extremely high.

Effects As shown in Table 1, the method of the present invention can obtain a synthetic resin fJy-shaped product with simultaneous painting on both sides through - times of molding operations.3. By connecting all the molds and operating them separately, the molding time for large and thick molded products can be easily matched, making it possible to mold other molds.
In addition to allocating the time to the I work and cutting out the molded products and spools, it can also be used as a means for cutting the flow path of molten plastic, eliminating the need for the conventional switching valve structure. We were able to increase molding efficiency.

In addition, the molten plastic is assimilated in the mold by injecting compressed air into the core of the molded product.
The internal stress generated within the molded product due to cooling has been reduced by 40%, and the incidence of defective products has been drastically reduced.The cooling and solidification time of the molded product can also be completely shortened. , which has a remarkable effect.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view of an actual example of an injection molding apparatus for carrying out the method of the present invention, and FIG.
The mold attached to the device is shown, the (n,) figure is a sectional view, and the (n) figure is a plan view. Figure 3 (a)
, side view of heli runner and spool, 3rd (1
)) Figure 1 shows a vertical cross-sectional view of the molded product (including the knock bottle), and Figure 4 shows a vertical cross-sectional view of the switching valve nozzle section installed in a conventional device. ) The figure shows the state in which the valves are switched.'1-6.1... Injection device,
3...Nosuru kidnapping, 4...Runner, 5.6...Nosuru, 8...fixed type, 9...ridge, type (IV), 10 female type (■U, 13...type runner, 14.14'... Spool, 15, ] 5' Gate runner, 1616
'Flat, F-type, 18.18'... Preformed printed sheet, 19. Knock and passage opening/closing bottle, 20° 21.
Force (1 pressure plate, 22... support, 24... shilling, 27.
28...Hydraulic hole, 31...Shogisen, 32. Cavity (nest). Agent Patent Attorney Makoto Kon Figure 4-139-

Claims (4)

[Claims] (1) A front and back set of printing sheets preformed by vacuum forming or other means with the printed side facing inside) ・A set of printed sheets are attached closely to both sides of the inner wall of the mold, and then the mold is clamped and the corresponding printed sheets are attached. 7. A method for simultaneously painting both sides of a synthetic resin molded product, which is characterized by injecting and press-fitting molten Plasdec into a gap formed inside the sheet, cooling and molding. (2) A patent characterized in that compressed air is injected into the core of the molten plastic injected and press-fitted into the mold before it cools and solidifies, thereby artificially collecting and generating sound inside the molded product. A method for simultaneously painting both sides of a synthetic resin molded article according to claim 1. (3) A plurality of molds were installed in one injection molding device, and a small amount of molten plastic was injected from the injection device to the extent that the runners and spools in all 1 inch molds were filled and solidified. After that, one of the molds was opened and the solidified runner and spool were removed from the mold, and the preformed front and back silk printing sheets were tightly attached to the inner wall of the mold and then the mold was closed [-7 , operate the device to inject and press the molten plastic into the mold, and while the plastic in the same mold is cooling and solidifying, open another mold and remove the assimilation runner spool. At the same time, the above-mentioned preformed printed sheet is installed in the mold, a mold clamping process is performed, molten plastic is injected and press-fitted, and the first mold is fully opened to obtain a molded product. 1. A method for simultaneously applying both sides of a synthetic resin molded product as claimed in claims 1 and 2. (4) First, fill and solidify the molten plastic into the runners and spools of all the molds, and then remove the solidified runner and spool from one of the molds to transfer it to only that mold. Next time, by removing the molded product, solidification runner, and spool from the mold, the injection flow path for the same mold will be opened.
・The synthetic resin molded product according to claim 3, characterized in that plastic is supplied to only one mold (7) and a switching valve (17) is provided so as to distribute the molten plastic without using a thick structure. A method of painting both sides at the same time.