JP2002292684A - Intervenient paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intervenient paper used in a mold assembly to contribute to produce a good molded product and easily subjected to disposal work after molding. SOLUTION: The intervenient paper has a basis weight of 50-80 g/m<2> and a thickness of 0.07-0.15 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interleaving paper used for a mold apparatus.

[0002]

2. Description of the Related Art For example, a mold apparatus K 'used for simultaneously molding a plurality of injection molded articles (hereinafter referred to as "molded articles S") such as rubber stoppers used as sealing members of waterproof connectors. In FIG. 7, there is an apparatus provided with a base part 10 'and a mold body part 30' shown in FIG.
The base 10 ′ is a base 1 having a primary sprue 17a ′.
1 'and the heat insulating plate 14' having a communication sprue 20d 'forming a plurality of secondary sprues 20'. I have. The mold body 30 ′ includes an upper mold 31 ′ having a supply sprue 20 e ′ that forms a plurality of secondary sprues 20 ′ and a plurality of cavities for molding a molded product. It is formed from a middle mold 32 'having a core 32a' and a lower mold 33 'having a core pin 36' corresponding to each cavity 32a '. In this mold apparatus K ', when molding a molded product, a sheet material 50' such as paper is interposed between the heat insulating plate 14 'and the upper mold 31' in advance, and the molding material is injected into the sheet material 5 by injection pressure.
It passes through 0 '.

[0003] A method for molding a molded product S 'using the mold apparatus K' having the above structure is as follows. First, an injection nozzle (not shown) is connected to the primary sprue 17a ', and the heat insulating plate 14' and the upper mold 31 'are brought into close contact with each other to be in a mold-clamped state. Then, a molding material is injected from the injection nozzle into the primary sprue 17a, and the molding material is cured by injecting the molding material into the inside of each cavity 32a 'via the secondary sprue 20'. At this time, since the sheet material 50 'is sandwiched between the heat insulating plate 14' and the upper mold 31 ',
The molding material hardens integrally with the sheet material 50 '.

Thereafter, the mold is opened, and the primary sprue 17 is opened.
a ', the molding material held in a fluidized state inside the secondary sprue 20', and a cured product (hereinafter referred to as "runner") cured inside the secondary sprue 20 'and a molded product S cured inside the cavity 32a' , And then the runner and the molded product S ′ are released, and only the molded product S ′ is released. At this time, since the sheet material 50 'and the runner interposed between the heat insulating plate 14' and the upper mold 31 'are integrally attached, the sheet material 50' is separated from the upper mold 31 'by And the sheet material 50 'can be removed.

[0005]

Conventionally, however, various materials are used as the sheet material 50 '.
Above all, when a paper material was used, the following inconvenience occurred. In other words, the weight of the paper material is light, and
If the thickness is too thin, the runner is apt to be torn, and the position of the piece 50a 'of the paper material sandwiched between the runners is not stable. Therefore, the cross-sectional area of the runner may be reduced depending on the position of the piece 50a'. . If there is a portion where the cross-sectional area of the runner is small as described above, when opening the mold, the runner may be torn off from a portion having a small cross-sectional area above the lower end of the runner, which is the original separation position, In this case, a part R1 'of the runner adheres to the molded product S', resulting in a defective product (see FIG. 8). Also, when the paper is removed after molding, it is easily broken due to its low strength. In addition, when heating at a high temperature during molding (when using a thermosetting resin material), the moisture of the paper is lost. Therefore, the strength was further reduced. On the other hand, if the weight of the paper material is heavy and the thickness thereof is too large, the injected molding material cannot penetrate the interposed paper.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is used for a mold apparatus which contributes to producing a good molded product and which can be easily removed after molding. The purpose is to provide an interleaving paper.

[0007]

In order to solve the above-mentioned problems, an interleaving paper according to the present invention comprises a base having a primary sprue connected to an injection nozzle and a plurality of secondary sprues communicating with the primary sprue. And a mold body having a plurality of cavities aligned with the plurality of secondary sprues, the mold body being detachable from the base. Interleaving paper interposed between the main body and the mold body, wherein the basis weight is 50 g / m ^{2 to} 80 g / m ² ;
The thickness is in the range of 0.07 mm to 0.15 mm.

[0008] Here, the weight and thickness of the interposed paper are such that the injected molding material easily penetrates, the strength necessary for performing the removing operation after molding, and the moisture content under heating conditions are obtained. The appropriate range is determined in consideration of the prevention of strength reduction due to evaporation of the paper, and it is more preferable to use a half paper (Japanese paper), particularly a calligraphy half paper or a straw half paper as a material, and to use it by shaping it into a predetermined shape. .

[0009] According to the interposition paper of the present invention, the injected molding material penetrates properly, and the positions of the fragments of the paper material sandwiched between the runners can be kept within a predetermined range. Therefore, it is possible to prevent a part of the runner from adhering to the molded product, and it is possible to prevent the molded product from becoming defective. Further, it is possible to prevent the occurrence of breakage and the like when performing the removing operation after molding.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description, the vertical direction corresponds to the vertical direction in FIG. 1 unless otherwise specified.

As shown in FIGS. 1 to 4, a mold apparatus K according to the present invention comprises an upper base 10 and a lower mold body 3 underneath.
0 as a main part. The base unit 10 is formed of a substrate 11, a pot plate 12, a cooling plate 13, a heat insulating plate 14, and a sprue plate 15 in order from the top. A sprue bush 17 is inserted into the center of the substrate 11, and a primary sprue 17 a is formed inside the sprue bush 17. A locating ring 18 is provided at an end of the upper surface of the sprue bush 17, and the locating ring 18 is connected to an injection nozzle (not shown). ) Can flow in.

The pot plate 12 has a concave portion 12a formed in a central region thereof, and a pool space 19 (molding material supply space) is formed between the concave portion 12 and the substrate 11 thereabove. The lower end of the primary sprue 17a is connected to the pool space 19. And the pot plate 12
A plurality of secondary sprues 20 communicating with the pool space 19 are provided to penetrate between the upper die 31 and the die main body 30. The secondary sprues 20 are provided at predetermined intervals in a circular area centered on the primary sprue 17a. From above, the introduction sprue 20a, the first communication sprue 20b, the second communication sprue 20c, and the third communication sprue 20d. , And a supply sprue 20e (see FIG. 3). Further, a plurality of introduction sprues 20 a connected to the pool space 19 are formed in the pot plate 12.

The cooling plate 13 is provided with a cooling water flow passage 13a for flowing cooling water of a predetermined temperature, so that the molding material inside the pool space 19 and the introduction sprue 20a does not harden. It is kept in a fluid state. The cooling plate 13 has a plurality of first communication sprues 20b penetrating the upper and lower surfaces thereof, and the plurality of first communication sprues 20b are arranged so as to be individually aligned with the introduction sprue 20a. Have been.

The heat insulating plate 14 is made of silicon glass as a main material, and has a plurality of second communication sprues 20c formed therethrough on both upper and lower surfaces thereof. The plurality of second communication sprues 20c are connected to the first communication sprue 20c. It is arranged so as to be individually aligned with the sprue 20b. The heat insulating plate 1
4, the lower part is maintained at about 180 degrees and the upper part is maintained at about 60 degrees.

The sprue plate 15 is formed with a plurality of third communicating sprues 20d penetrating the upper and lower surfaces thereof.
The plurality of third communication sprue 20d are of the plurality second
It is arranged so as to be individually aligned with the communication sprue 20c.

On the lower surface of the four corners of the pot plate 12 of the base 10, guide pins 22 having locking portions 22a for locking the upper die 31 are vertically provided. This guide pin 22
Is slidable in a guide hole 21 penetrating through each corner of the mold body 30. As a result, the upper die 31
Is capable of moving up and down (contactable and separable) between the sprue plate 15 and the locking portion 22a as the part below the middle mold 32 of the mold body 30 moves up and down. The substrate 11, the pot plate 12, the cooling plate 13, the heat insulating plate 14, and the sprue plate 15 that constitute the base unit 10 are integrally formed.

The mold body 30 is arranged in order from above.
An upper mold 31, a middle mold 32, a lower mold 33, a spacer 34, and a movable side mounting plate 35 are provided. The upper die 31 is formed with a plurality of supply sprues 20e penetrating the upper and lower surfaces thereof, and the plurality of supply sprues 20e are arranged so as to be individually aligned with the plurality of third communication sprues 20d. I have. As shown in FIG. 4, the middle mold 32 is formed with a plurality of cavities 32a which are individually aligned with the plurality of supply sprues 20e in order to form the outer peripheral side surface of the molded article S. The inner circumference of
An uneven portion is formed so as to have an outer peripheral shape of the molded product S.

On the upper surface of the lower mold 33, the outer periphery is a molded product S
A core pin 36 having concavities and convexities so as to have an inner shape and protruding concentrically in each cavity 32a is provided. When the core pin 36 projects into the cavity 32a, the dimensions are set so that a ring-shaped gap is opened between the upper peripheral edge 36a of the core pin 36 and the lower opening edge 20f of the supply sprue 20e. The gap forms a gate G from the supply sprue 20e into the cavity 32a. Further, a heater (not shown) for burying the molding material in the cavity 32a, the third communication sprue 20d and the supply sprue 20e at a predetermined temperature is embedded in the lower mold 33. Thereby, the molded product S cured in the cavity 32a becomes a cylindrical rubber stopper (see FIG. 6).

Further, at the time of mold clamping, the sprue plate 15
Is interposed between the lower surface of the upper mold 31 and the upper surface of the upper mold 31. When the molding material is injected in a flowing state, the interposition paper 50 is easily broken so that the molding material can penetrate while making a small hole, and has a strength capable of holding the cured molding material at the penetrated portion. Having a basis weight of 50 g / m ^{2 to} 80 g /
m ^2, and those are preferably used thickness 0.07mm to 0.15 mm, density calligraphy paper sheet which is in the range of 0.71 g / cm ³ to 0.53 g / cm ³ as a material.

Further, an interposed paper feeding / discharging device (not shown) is provided at a rear portion of the mold device K. This interleaving paper feeding / discharging device mounts the interleaving paper material 50 cut into a circle having the same diameter as the ring groove of the upper die 31 at a predetermined position on the sprue plate 15, and after molding. A mechanism is provided so that the protruding portion of the runner in the interposition paper 50 integrated with the runner can be gripped and removed.

As shown in FIG. 5, the lower end surface of the sprue plate 15 forming the lowermost part of the base 10 is provided with a ring groove 2.
8a, a vertical groove 28b, a horizontal groove 28c, and a connection groove 28d. The ring groove 28a is a groove formed in an annular shape so as to surround the third communication sprue 20d. Vertical groove 28b and horizontal groove 28
c is provided inside a region surrounded by the ring groove 28a, and is a plurality of grooves formed at predetermined intervals in a vertical direction and a horizontal direction which is a direction orthogonal to the vertical direction, respectively. is there.

The vertical grooves 28b and the horizontal grooves 28c connect the adjacent third communication sprues 20d so that all the third communication sprues 20d are continuously connected. In addition, the vertical groove 28b and the horizontal groove 28c
The ring groove 2 is formed at a predetermined location by the connection groove 28d.
8a.

On the upper end surface of the upper die 31 forming the uppermost part of the mold body 30, the same arrangement pattern (ring groove, vertical groove, horizontal groove, and connection groove) as the upper groove 28 in plan view is provided. The lower groove (not shown) is formed so that all the supply sprues 20e are continuously connected. When the mold is clamped, the upper groove 28 and the lower groove are formed. And match. Further, when the mold is clamped, the air in the cavity 32a is sucked by a vacuum pump (not shown), so that the lower groove portion and the upper groove portion 28 are sucked.
, The interior of the cavity 32a can be brought into a vacuum state.

Next, the operation of the mold apparatus K will be described. First, the interposed paper 50 is placed on the upper die 31 of the mold body 30 by an interposed paper supply / discharge device (not shown). Then, the mold main body 30 is raised to bring the sprue plate 15 and the upper mold 31 into contact with each other to be in a mold clamped state, and an injection nozzle (not shown) is connected to the primary sprue 17a. Subsequently, the vacuum pump is operated to suck the air inside the cavity 32a to make a vacuum state.

Next, the molding material in a fluid state is sequentially passed through the primary sprue 17a, the pool space 19, and the secondary sprue 20, injected into the cavity 32a, and vulcanized for a predetermined time. At this time, the molding material flows into the supply sprue 20e from the third communication sprue 20d and breaks into the cavity 32a through the gate G by breaking through the interposition paper 50 and penetrating while opening a small hole. become.

At this time, since the upper part of the second communication sprue 20c is held at about 60 degrees with respect to the heat insulating plate 14, the molding material maintains a fluid state. On the other hand, the molding material S in the third communication sprue 20d, the supply sprue 20e, and the cavity 32a is heated to about 180 degrees by the heater, and is cured. Also, the interposing paper 50
In the portion where the molding material penetrates, the splinters of the interposed paper 50 bite into the cured molding material, so that the third communication sprue 20d and the supply sprue 2
The runner cured at 0e is integrated with the interposed paper 50. At this time, the molding material flows into the vertical grooves 28b and the horizontal grooves 28c of the sprue plate 15, and adheres integrally on the upper surface of the interposed paper 50.

Thereafter, opening of the mold is started, and the sprue plate 15 is opened.
By separating the mold body 30 and the mold body 30, the molded product S is detached. Thereafter, the molded product S left in the mold body 30
, But the description is omitted. The interposed paper 50 left on the sprue plate 15 is removed by the interposed paper supply / discharge device by gripping the runner projecting from the upper surface of the interposed paper 50.

As described above, by using the interposing paper 50 of the present invention, when filling the cavity 32a with the molding material, the small holes are appropriately formed by the injection pressure of the molding material, and the gate G It is possible to keep the position of the fragments of the interposition paper 50 sandwiched between the runners within a predetermined range without being torn so that a part of the interposition paper 50 enters the inside. Therefore, it is possible to prevent a part of the runner from adhering to the molded product S, and it is possible to maintain good quality of the molded product S. Further, since the interposed paper 50 has a predetermined strength, it does not break when the interposed paper 50 is separated from the upper mold 31 after molding, and does not require any special work. It can be easily removed. In particular, since the interposed paper 50 has a predetermined thickness, even if it is heated to a high temperature during molding, the strength is not unnecessarily reduced.

As described above, an example of a preferred embodiment of the present invention has been described. However, the present invention is not limited to this embodiment, and a design change can be appropriately made without departing from the gist of the present invention. In particular, the interposed paper is not limited to cut paper, but may be continuous paper, and its shape and the like are not limited. Further, the type of the molding material is not limited, and can be applied to a case where the molding material is a thermosetting material other than silicone rubber or a case where the molding material is a thermoplastic material. It is not something to be done.

[0030]

EXAMPLES In order to verify the effect of the interposed paper 50 of the present invention, a molded article S was manufactured using various types of paper shown in Table 1, and the number of defective products at that time was examined. As the mold device, the mold device K described in the section of the embodiment of the invention was used. The molding material used was silicone rubber, the mold clamping pressure was 75 tons, and the vulcanization time was 60 seconds. In addition, the mold apparatus K is
344 molded articles S are produced by repeated use. However, the number of defective articles in the table indicates the number at the time of one molding. Testing has been done.

According to the results, it is understood that the use of the calligraphy paper of sample number 4 as a material can prevent the occurrence of defective products. Further, even if the copy paper of sample number 3 is used, it is possible to prevent the occurrence of defective products at a considerable rate. The upper limits of the weight and thickness are determined so that a test is performed separately and the molding material penetrates when injected.

[0032]

[Table 1]

[0033]

By using the interposer used in the mold apparatus of the present invention, it is possible to produce a good molded product, and the removal operation becomes easy even after molding.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a mold device (in a mold-clamped state) of the present invention.

FIG. 2 is a side sectional view showing a mold device (in a mold open state) of the present invention.

FIG. 3 is a schematic sectional side view showing a primary sprue and a secondary sprue in the mold apparatus of the present invention.

FIG. 4 is an enlarged side sectional view of a main part showing the vicinity of a cavity in the mold device of the present invention.

FIG. 5 is a view taken in the direction of arrow A in FIG. 1;

FIG. 6 is a side view showing a molded product manufactured by the mold apparatus of the present invention.

FIG. 7 is a side sectional view showing a conventional mold apparatus (mold closed state).

FIG. 8 is a side view showing a molded product manufactured by a conventional mold device.

[Explanation of symbols]

 K Mold device G Gate R Runner 10 Base 11 Substrate 12 Pot plate 13 Cooling plate 14 Insulating plate 15 Sprue plate 17a Primary sprue 19 Pool space 20 Secondary sprue 20a Introducing sprue 20b First communicating sprue 20c Second communicating sprue 20d First Three communicating sprue 20e Supply sprue 30 Mold main body 31 Upper die 32 Middle die 32a Cavity 33 Lower die 34 Spacer 35 Movable mounting plate 36 Core pin 50 Intermediate paper

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F206 AJ08 AM10 JA07 JM04 JN14 JQ55 JQ90

Claims (2)

[Claims] 1. A base having a primary sprue connected to an injection nozzle, a base having a plurality of secondary sprues communicating with the primary sprue, and a plurality of cavities aligned with the plurality of secondary sprues. A mold body comprising a mold body that can be moved toward and away from the mold part, and an interposed paper interposed between the base part and the mold body. 50 g / m ^{2 to} 80 g / m ² , thickness 0.07 mm
An interleaving paper characterized by being within a range of 0.15 mm to 0.15 mm. 2. The interleaving paper according to claim 1, wherein half paper is used as a material.