JPS58188632A - Method and apparatus for transfer type molding - Google Patents

Abstract

PURPOSE:To effectively mold plural pieces of moldings having different shapes in a high yield at the same time at small cost, by relatively approvaching the cutting edge protruded to the direction of opening and closing of a cooling force and pushingly pressuring a semi-fabricated product at clamping molds. CONSTITUTION:Prefoamed thermoplastic resin particles are caused to be foamed with heat by filling them into the cavity of heating mold, and mutually molded in fusion to be a monobloc semi-fabricated product. Said semi-fabricated product is transferred to the cooling forces 16 and 18 of which the inner surface of one force is extruded with a cutting edge 27, and the forces are clamped under cooling. At clamping molds, the cutting edge 27 extruded on the bottom force 16 relatively approaches to the semi-fabricated product in the top force 18 pushingly pressured manner and penetrates the inside of semi-fabricated product, the tip thereof leading to its back. The semi-fabricated product is cut within the cavity 19 of cooling force, and plural pieces of products are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention further foams and molds the foamed thermoplastic resin particles in a heating mold to form a semi-finished product, and then transfers the semi-finished product to a cooling mold to form a semi-finished product. The present invention relates to a so-called transfer molding method for molding products, and particularly to a transfer molding method and its apparatus for simultaneously manufacturing a plurality of products in a fist process.

In general, foamed wood '41 molded products have excellent heat retention, slow gun action, toughness, chemical stability, light weight, and low cost.
It has a wide range of uses as packaging material for various products.

Such a molded body is packaged, and the shape of the packaged article, ・r
Depending on the law, packaging, and shape of the package, a wide variety of shapes and sizes are required for these barriers or fixing materials.

To obtain such multi-moth molded bodies, pair 1+i'
Preparing a mold with ,, is a significant economic disadvantage.
However, in order to increase the product price, some deformation is done by cutting after molding or by cutting before cutting, but this requires a very separate processing process and causes a decrease in yield due to the generation of scraps, etc. , the productivity decline is significant.

In addition, among cushioning materials and fixing materials with a wide variety of shapes, there are many whose shapes complement each other and can be created by dividing a single molded object with a simple form. In such a case, the cavity of the molding die is partitioned by a partition wall G, and a plurality of molded bodies can be molded in one process. In the method of using such a divided mold cavity, it is possible to efficiently produce molded bodies of 11j at the same time without lowering the yield. It is necessary to attach a co-painting machine for supplying the raw material resin particles, which complicates the structure of the molding apparatus vi, and inevitably increases the equipment cost by -L.

In addition, originally, in the foam molding of M-shaped plastic resin, the entire cycle of heating, foam molding, and cooling is performed in the same mold. There is an inherent problem in that it takes a long time, which is a factor that has led to a historic decline in productivity.

In order to solve the problems inherent in foam molding of thermoplastic and fat-resistant materials, the invention disclosed in Japanese Patent Application Laid-Open No. 52-90578 provides an excellent method.

This invention is a so-called transfer molding method, in which a molded article to be produced is filled with foamed thermoplastic resin particles into a heating mold having a corresponding mold cavity shape and dimensions,
130
is combined into a mold to form a semi-finished product, and after the semi-finished product is removed from the heating mold to complete foaming, the above-mentioned is placed in a cooling mold having a cavity shape and dimensions that more accurately correspond to the product to be manufactured. By inserting the semi-finished product, a final product with stable curing is obtained.

However, applying the transfer molding method to the above-mentioned mold cavity partitioned into multiple areas not only complicates the structure of both the heating mold and the cooling mold, but also increases the probability of generating transformer 7 amise, which is not necessarily advantageous. .

The present inventors have improved and developed the invention of JP-A No. 52-90578 in view of the current state of the technology and the problems described above, and have improved the invention to efficiently produce multiple molded bodies of different shapes. The present invention was completed with the aim of obtaining a high yield at low cost.

That is, the method of the present invention for achieving the above-mentioned object uses a heating mold and a cooling mold each having a pair of male mold and female mold to form a mold cavity, and a pre-foamed thermoplastic resin. The particles are filled into the cavity of the heating mold, heated and foamed, and fused together to form an integral semi-finished product.Then, the product is transferred to the cooling mold, and the mold is closed while cooling. In the transfer molding method, when closing the +tif mold, a cutting blade extending inwardly of the cooling mold and protruding in the direction of its opening/closing axis is placed relatively close to the '1'-cracked crystal. Press 1 (
This method is characterized by cutting a semi-finished product in a cooling JINO mold cavity and molding a plurality of products at the same time.

Further, the feature of the apparatus of the present invention for carrying out such a method is that it consists of two sets of molding molds each capable of forming a mold cavity with a pair of male and female molds that can be freely opened and closed. The first mold is equipped with a supply port for the foamable heat i+J plastic fat-resistant particles into the mold cavity and a means for heating the inside of the mold cavity, and the second mold a is equipped with a means for releasing the molded article in the mold cavity. In a transfer type molding apparatus, the male mold of one mold can be connected to and disengaged from the female mold of the other mold, and one of the second molds has a cooling means. , extending along its inner surface,
fl, provided with a cutting blade protruding in the direction of the opening/closing axis of the mold, so that the cutting blade can cut the molded object in the mold cavity and divide it into a plurality of products when the mold is closed. It is in.

Embodiments of the invention will now be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 are longitudinal cross-sectional views of molding molds applied to the method of the present invention, with FIG. 1 showing a heating mold and FIG. 2 showing a cooling mold.

In No. 11A, the male mold (2) attached to the formwork (1)
) and the female mold (4) attached to the mold frame (3) are clamped together to form a mold cavity (5). The female type (4) is usually
The mold is fixed on a frame (not shown), and the mold is opened and closed by the forward and backward movement of the male mold (2), but the reverse is of course also possible.

One of the molds, for example, in the example shown in FIG. 1, the female mold (4) has a feeder (6) for pre-foamed thermoplastic resin particles, which is a molding raw material.
is mounted with its supply D (7) facing into the mold cavity (5). Male! ! On the backs of a (2) and the female mold (4), there are formed mantle parts (8) and (9) which are partitioned by the mold frame (]) and the mold frame (3), and the heating medium supply port (10 ),
A heating medium such as heated steam is supplied from (11) to the mantle parts (8) and (9), respectively, and is passed through the mold into the mold cavity (
5) The inside is heated and discharged from υ[output II (+2), (+3). -Also, if a through hole (14) is made in the mold,
The heating medium flows into the mold cavity (5) through the through holes (1→).

Furthermore, these heat medium supply ports (10), (11) and discharge port (+2).

(13) to 11: The molded product can be released from the mold by supplying compressed air, or the release of the molded product can be prevented by vacuum suction.

Although an example in which a heating fluid is used as a heat medium as the mold heating means is shown here, it is possible to easily replace it with other commonly used means by a simple design change.

The molding die shown in FIG. 2 is combined with the mold shown in FIG. 1 to constitute the apparatus of the present invention. In Fig. 2, the male mold (16) attached to the mold frame α→ and the female mold (+8) attached to the mold frame (17) are closed to each other and the mold cavity θ
9). Again, the female mold (18) is usually fixed on a frame (not shown) and the opening and closing of the mold is controlled by the male J%4J.
(46), but the reverse is also possible.

In addition, the female type (18) is the male type in Figure 1 (= so that it can be detached, the male type (2) can be separated from the male type (2) by appropriate lS control).
It is designed so that you can go back and forth between the two.

It goes without saying that if the male type is a fixed type, Ig will be a mobile type. Furthermore, one mold of the a-th mold, for example, the female mold 0
8) is an ejector for releasing the molded body into town.
I' is installed through a gasket.

Also, each of the male mold (16) and the female mold (18); one part includes a cooling mantle part 1. Jl)a is formed. Refrigerant such as air, cold water, etc. is supplied from the refrigerant supply port (231, C!4) to the outer part Q.
Refrigerant discharge r,] (251C) 6). Of course, in addition to forced cooling using a ν medium, 11 cooling simply by placing it in the air may be preferable.

Note that an empty device (not shown) is connected to the refrigerant supply port or the closing discharge port for sucking and holding the product into the mold.

The two molding molds shown in FIGS. 1 and 2, each consisting of a pair of male and female molds, are combined to constitute the transfer device of the present invention, which is most distinctive. The point is at the point where a cutting blade (2° C.) is protruded from the inner surface of at least one OIψ↓ of “Cold” 1.

This cutting blade (27) is extended to the inner surface of the 4J by a total of 1% with a V-surface shape (matching the division boundary line for dividing the molded product into 1 product). It protrudes into the mold cavity along the opening/closing axis of the mold. In the example shown in FIG. 2, the cutting blade I2 is provided protrudingly from the movable male mold (1a).

Next, the mode of carrying out the method of the present invention using such an apparatus will be described in detail along with its operation.

In the apparatus described in L, first, with the heating mold closed, the supply device (6) is operated, and pre-foamed thermoplastic resin particles, such as polystyrene beads, are introduced into the mold cavity (5) from the supply port (7). , polyethylene beads, etc. are supplied and filled. However, polystyrene beads are particularly preferably used in the present invention.

The foaming ratio of these raw resins is up to about 100 times, but it is usually preferable to have a foaming ratio of about 30 to 60 times. Heat medium supply port Qo after charging raw materials.

According to (11), a heating medium, most preferably made of heated steam, is supplied to the mantle parts (8) and (9), and the inside of the mold cavity (5) is heated to about 110 to 120°C. In less than a second, the pine resin particles become fiJ plasticized2 and foam further.
Inner j1: is fused to phase II) to become a semi-finished product.

When the time was right for the two to become integrated, the supply of the heat medium was stopped, and the male mold (2) was overtaken.When the problem occurred, the semi-finished product separated from the female mold (4) and was carried by the male mold. state. To release the mold from the female mold, apply a release layer such as silicone to the inner surface of the mold, or apply back pressure from air to the outer part (9) of the female mold, or vice versa. Methods such as generating a negative IE with a vacuum device behind the mold are preferred.

The male mold (2) carrying the semi-finished product then moves to a position where it faces the cooling female mold α8) shown in FIG. 2, and then moves forward and engages with the female mold (18). During this transfer, the semifinished product is moved into a free atmosphere. The female mold (18) has a back mantle (υ) formed with a flow path through which cold water (preferably cold water) is supplied from the refrigerant supply port and is discharged from the refrigerant discharge port (e). , the semi-finished product inserted into the female mold (3) by the advancement of the male mold (2) passes through the cooled female mold (
18) Cooling cannot proceed from the part that is in contact with the inner wall surface.

Note that the purpose of cooling is often achieved only with air blown for mold release, and in this case, it is not necessary to discharge from the discharge [].

Next, the male type (2) heat medium supply r, 1 (10) and discharge 0 ((2) to 11 (supplying condensed air to act on the back IE, and refrigerant supply 111.'4) or refrigerant outlet f
2 (If you apply vacuum suction from 9 and make it back i1J, the semi-finished product will remain in the female mold (E), and the male mold (2) will move into the female mold ((8)
At the same time as the cooling male mold (16), which has been waiting at a distance, moves forward and engages with the cooling female mold (18).

Male type Qa) tri, is cooled by a refrigerant such as cold water flowing from the refrigerant supply port toward the refrigerant discharge port (c).

In this way, when the cooling mold is closed by the 1111 movement of the cooling male mold (16), the cutting blade @ protruding above the male mold (16) is relative to the product in the female mold ((6)). The semi-finished product enters the inside of the semi-decoy crystal, and the tip finally reaches its back surface.The semi-finished product is thus cut in the cooling type pharynx (19), and multiple products are separated. It is molded.

It is also possible to provide the cutting blade C force on a fixed mold.

In this case, when the semi-finished product supported on the heating movable mold is fitted with the cooling fixed mold to transfer the semi-finished product, the semi-finished product is cut and divided by the cutting blade, and after the heating movable mold retreats, the semi-finished product is cooled. The movable mold moves forward, closes the mold, and performs cooling molding. Of course, it is possible to have the cutting blades facing each other in the cooling type, but care must be taken in designing and manufacturing to prevent the cutting blades from coming into contact with each other excessively and causing damage when the mold is closed. is essential.

In addition, in order to easily and reliably cut the cutting blade, the back side of the 'f'-product into which the cutting blade enters has a shape that corresponds to the planar shape of the cutting blade, so that the tip of the cutting blade can be seen when the mold is closed. It is highly preferable to form concave grooves having a certain depth in advance on the semi-finished product during heat foam molding.

In other words, a cut is made on the inner surface of the heat-fixing mold (4) in the example shown in FIGS. When a protruding strip (c) corresponding to a mirror image of the planar shape of the blade (two paths) is extended and the heating mold is closed, the distance formed between the top of the protruding strip and the mold surface facing it The above-mentioned operation is carried out using a device with a specified method so that the separation does not exceed the length of the cutting blade (2).

FIGS. 3 and 4 are partial vertical cross-sectional views showing the relationship between the protruding shin and the cutting blade (2η).

In FIG. 3, a protruding strip (two combs) is extended on the inner surface of the heat-fixing mold (4), and when the heating mold is closed, the top surface of the protruding strip and the opposing mold ( 2) and the surface is (a), and as shown in Fig.
6) Adjust the height of the cutting blade (27) protruding from J- to (b
), then the dimensions of both are determined so that the relational expression a≦b holds true.

1-As mentioned above, molding the part to be cut of the T# product to be particularly thin is effective for complete cutting and separation, but when the semi-finished product is opened with a heated mold, In order to expand the width, 1) the depth of the four-striped groove @ formed by the ridges (28) mentioned in 11 becomes smaller than the depth of the ridges;
When closing a cooling mold, the tip of the cutting blade may not be visible inside the four-strip groove, resulting in poor cutting.Also, if the product is not sufficiently cooled and hardened, its viscoelasticity may deteriorate. makes complete cutting and splitting difficult.

An advantageous method to overcome this difficulty is to use a cooling type without a cutting blade (i.e., a fixed type in the example shown in Fig. 2 08).
A convex strip that fits into the four-strip groove is extended on the inner surface of the mold, and when the mold is closed,
The tip of the cutting blade (21) and the top surface of the protruding stripes should be in uniform contact with each other to cut through the semi-finished product.In other words, the heating mold with the protruding stripes and the corresponding cooling mold also have a shape on their inner surfaces. 9. Apparatus a provided with protrusions having substantially the same dimensions and arrangement is preferably used for the above purpose.However, in this case, when closing the cooling mold, the tip of the cutting blade and the top of the protrusions It is important to design and manufacture the parts with precision so that they make uniform and light contact without causing contact failure or excessive pressure.

In order to avoid the complicated design and manufacturing considerations as mentioned above, the convex strip of the cooling mold is biased inward into the mold cavity, and the push 11 at the tip of the cutting blade. Most preferably, it is retracted by force.

In FIG. 5, which shows a longitudinal cross-sectional outline of the example, a protruding strip member 13+1 is loosely fitted into a through hole (1) made in the mold wall of a cooling fixed mold (18), and Member 01) is
Spring G housed in casing C32; urged toward mold cavity (19) and stopper 04)
The protrusion is suppressed and regulated by tJ].

The crown part (35) of the convex strip member (2) is thus formed in the mold (18).
) uniformly protrudes into the mold cavity (19) from the inner wall surface of the mold cavity (19), but due to mold closing of the cooling mold, the tip force of the cutting blade 07) on the movable mold (]6) When the semi-finished product is cut and divided by contacting the top of the head, and the top of the head is pressed once, it is pushed back against the elastic force of the spring (33) by the convex strip member C31), so it is cut) Jc! Excessive force is not applied to the tip of the cutting blade, and the life of the cutting blade can be extended.

Approximately 10 to 20
After the male mold (16) is retracted and the mold is opened, the vacuum device that sucks from the refrigerant supply port or refrigerant discharge port is stopped, and at the same time, the ejector tip is made to protrude. Release the body.

1- As already clear from the above explanation, the present invention skillfully utilizes and improves the transfer molding method, so like conventional foam molding, heating, foam molding, and cooling can be performed in the same mold. It is possible to perform molding operations one after another in a short cycle by organically combining a heating mold that is constantly heated and a cooling mold that is constantly cooling, without having to perform the process cycle over a long period of time. Thermal energy losses can also be reduced, molded bodies of different shapes can be produced simultaneously in a single mold with remarkable ease, and expensive It is an extremely useful invention in the field of 56 foam molding technology, as it can be efficiently obtained at a low cost with a yield of 1 ton.

Examples of the method of the present invention will be described below.

(Example 1) Using the transfusing device shown in FIG. 1 and FIG.
Foam molding of 0x poly and styrene beads was performed. The shape of the cavity of the mold is 300 mm in outer diameter at the top, 180 mm in inner diameter, 1 mm in the center, and 60 mm in thickness at the edge.

The toe edge had a fornix shape with an outer diameter of 31° and an inner diameter of 190°. The inner surface of the cold Uj moving type, that is, the male type, is provided with a cutting blade that extends concentrically in an α circle with an Iμ diameter of 108 mm and protrudes to a height of 1,32 fi, and the JJlT hot type, that is, the female type The inner surface was also provided with a protrusion whose top center line formed a perfect circle with a diameter of 108a and extended concentrically, and which protruded to a height of 20a and had a trapezoidal cross section.

The heating mold is closed, the raw material feeder is activated, the polystyrene beads prepared by A in the preheating mold are loaded into the mold cavity, and steam at a gauge pressure of 1.0 jaws is applied to the mantle (8) (9) around the heating mold. Foam molding was performed at a temperature of 120° C. for 8 seconds.

After stopping the steam supply, the female steam supply port (11)
15 condensed air is sent from the exhaust D Oa) to extrude the molded body, and the male steam supply port θ0) and extraction [7 (
12) The male mold (2) was retreated while applying vacuum suction. The resin molded body is suction-supported onto the male mold (2), and each particle is t (: ini fused 4f L, integrated into a semi-finished product V,
Ru,.

The male mold (2) then moved to a position where it faced the cooling female mold (e), moved forward, and inserted the molded object into the female mold (e).

In this state, compressed air is supplied to the mantle (8) behind the male 11, 4J (2), and the molded body is pushed forward by the back Y1- while the refrigerant is supplied I-1+! 4) The male mold (2) was retracted with the molded body joined by vacuum suction. Female type (
The molded body left in g) was then closed by the cooling male mold 06 that was engaged forward. By cooling for about 10-20 seconds, the compact was hardened and the shape was stable.

Open the mold and close the refrigerant supply port (2).
At the same time, the ejector (a) was projected to release the molded product.

The obtained molded body has an outer diameter of 300 m! I + inner diameter 1081
11 donut-shaped molded products and diameter 1081111. thickness 5
It was separated into a 0° disc-shaped molded product. The doughnut-shaped molded product was used as a packing fixing material for an electric mixer, and the disc-shaped molded product was also used as a guard material for the end of the electric mixer.

1 (Example 2) It was
It has a length of 42.5+a, a height of 18 fulfil, a cross section, and a cooling fixed +5qJ with four trapezoidal arc-shaped protrusions arranged rotationally symmetrically. A through hole with a width of 10 mm was bored, and a convex member was fitted into the through hole rL with the +It sound shown in FIG. The height of the crown of the convex member protruding into the mold cavity was 22ffi.

) A semi-finished product of the same thickness as in Example 1, in which the convex portions are not connected, is filled and molded using such a heating mold by ordinary means, and is molded into a cooling fixed mold using a cooling moving mold. When the container was closed, the face was not cut by the convex member and the cutting blade having a height of 32 mm, and a separated molded product with a stable shape was obtained.

1 After that, when this process was repeated, it was possible to carry out molding 200 times in a row without causing any cutting rate of 1.

[Brief explanation of drawings]

Fig. 1 and Fig. 2a, respectively jJI heat of the present invention device a)
It is a longitudinal cross-sectional view which shows the aspect of a whole and a cooling type. 3 to 5 are longitudinal cross-sectional views showing essential parts of the apparatus of the present invention. (2) (16)・・・Male type, (4)C8)
......Female type (5)Oo)...
...Mold cavity, (7)...Resin particle supply port. (10) C11)・・・Heat medium supply port, @4
・・・・・・・・・Ejector. (23+ (24)...Refrigerant supply port, @
・・・・・・・・・・・・Cutting blade. (28)・・・・・・・・・・・・Convex streaks, haze...
.....through hole. C)1)・・・・・・・・・・・・・・・Convex strip member, profit...
・・・・・・・・・It starts. Rod/In nihana 2 troubles

Claims (1)

[Claims] 1. Using a heating mold and a cooling mold that can form a mold cavity for coloring with a pair of male and female molds,
The thermoplastic resin particles thus obtained are filled into the mold cavity of the heating mold described in I, heated and foamed, and fused to the phase rT to form an integral product.Then, the semi-finished product is transferred to a cooling mold. In a transfer molding method in which a product is formed by closing the mold while cooling, when closing the mold, a cutting blade extending along the inner surface of the cooling mold and protruding in the opening/closing axis direction of the cooling mold and a 4' JiJ product are used. Cooling (41
A transfer molding method characterized by cutting semi-finished products in the mold cavity and molding multiple products at the same time. 2. Transfer according to claim 1, in which the cold JAJ mold of the piece Jj carrying the semi-finished product transferred from the heating mold is joined with the other cooling mold provided with a cutting blade to close the mold. Expression molding method. 3. Transformer 77 type molding according to claim 1, in which a cutting blade is provided on the cooling mold on the side that receives and supports the semi-finished product transferred from the IJII thermal mold, and the mold is closed by engaging with the other cooling mold. Law. 4゜ On the back side of the semi-finished product where the cutting blade enters, four grooves with a shape corresponding to the NP surface cedar shape of the cutting blade and a depth such that the tip of the cutting H can be seen when the mold is closed are made in advance during heat foam molding. A transformer 77 type molding method according to any one of the claims above, which is formed on a semi-finished product. 5. A protruding strip that fits into the four-striped groove is extended on the inner surface of the cooling mold where no cutting blade is provided, and when the mold is closed, the tip of the cutting blade and the top surface of the protruding strip uniformly contact each other to form a semi-finished product. 5. The transfer molding method according to claim 4, which presses out. 6. The transfer molding method according to claim 5, wherein the protruding strip is provided so as to be biased inside the mold cavity, and is retracted by the pressing force of the tip of the cutting blade. 7. Consisting of two sets of molding molds each having a pair of male and female molds that can be opened and closed to each other to form a mold cavity, the first mold injecting expandable thermoplastic resin particles into the mold cavity. The second mold is equipped with a means for releasing the molded article in the mold cavity and a means for cooling it, and the second mold is equipped with a means for releasing the molded article in the mold cavity and a means for cooling the molded product in the mold cavity. In a transfer type molding device configured such that the mold can be connected to and removed from the female mold of the other mold, one of the second molds has a cutter extending along the inner surface of the second mold and protruding in the direction of its opening/closing axis. A transfer type molding device comprising a blade, and characterized in that (1) the cutting blade is capable of cutting the molded product in the mold cavity and dividing it into ff11 products when the mold is closed; 8. The transfer molding apparatus according to claim 7, wherein a cutting blade is provided on the side of the second mold that is not engaged with or disengaged from the first mold. 9. The transfer molding apparatus according to claim 7, wherein a cutting blade is provided on the side of the second mold that engages and disengages from the first mold. 10. Among the first molds, a protrusion corresponding to the mirror image of the planar shape of the cutting blade is extended on the inner surface of the mold corresponding to the second mold having no cutting blade, and the mold l' with closed mold
The distance between the top surface of the convex strip and the opposing mold surface does not exceed the crystallinity of the cutting blade described in Section 11. The L.Lance 77 type molding device according to any one of items 9 to 9. 11. According to claim 10, wherein a protruding strip having substantially the same shape, dimensions, and arrangement is also provided on the inner surface of the first mold that corresponds to the first mold having the protruding strip. Transfer type molding equipment. 12. The protruding strip provided on the second mold is loosely fitted into the through hole drilled in the mold wall by being biased toward the mold cavity, so that the top of the head is more uniform than the mold wall surface. 12. The transfer molding apparatus according to claim 11, comprising a member protruding into the mold cavity.