JP2013176887A - Foamed resin molding mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamed resin molding mold which can lengthen a cleaning interval and thereby improving production efficiency.SOLUTION: In a foamed resin molding mold in which a plurality of steam holes 7 and 8 are formed in first and second molding surfaces 3 and 4, a raw material feeder 10 is provided on the first molding surface 3, and a foamed resin molding is molded by packing foamable resin particles into a molding cavity 6 from the raw material feeder 10, and making the foamable resin particles packed through a plurality of the steam holes 7 and 8 contact steam, while the molding cavity 6 is formed, at least in the region of the second molding surface 4 opposed to a raw material exhaust outlet 12 of the raw material feeder 10, the steam hole 8 is not formed. Since the steam hole 8 is not formed in a region to which resin residue most tend to attach, a steam hole cleaning interval can be lengthened.

Description

  The present invention relates to foaming for producing a foamed resin molded product by filling foamable resin particles in a molding cavity formed by a molding surface provided in a mold and bringing the filled foamable resin particles into contact with steam. The present invention relates to a resin mold and a foamed resin molded product obtained using the foamed resin mold.

  A first molding die having a first molding surface and a second molding die having a second molding surface are provided, and a molding cavity is formed by the first molding surface and the second molding surface. The first molding surface is provided with at least one raw material feeder, the first and second molding surfaces are formed with a plurality of steam holes, and foamed from the raw material outlet of the raw material feeder. Foam for forming a foamed resin molded product by ejecting the expandable resin particles, filling the foamable resin particles into the molding cavity, and contacting the foamable resin particles filled through the plurality of vapor holes Resin molding dies are known, and specific examples thereof are described in Patent Document 1 or Patent Document 2.

  Further, as a foamed resin mold particularly suitable for molding a plate-like low-magnification foamed product, Patent Document 3 discloses a first mold having a first molding surface and a second molding surface having a second molding surface. A molding device comprising a second molding die and a third molding die having a third molding surface, wherein the first molding surface and the second molding surface have both side surfaces divided by the third molding surface and the peripheral side surface thereof. The first molding surface is provided with at least one raw material feeder, the first and second molding surfaces have a plurality of vapor holes, and the raw material Foamed resin particles are ejected from a raw material outlet of a feeder, the foaming resin particles are filled into the molding cavity, and the foamed resin particles are brought into contact with the foamed resin particles filled through the plurality of vapor holes. A foamed resin mold for molding a molded article is described.

  When a foamed resin molded product is molded using the foamed resin mold as described above, the foamable resin particles filled in the molding cavity from the raw material outlet of the raw material feeder are in contact with the vapor in the molding cavity. In this way, they foam and fuse with each other. In order to obtain a uniform molded product with no difference in strength inside, it is necessary to supply steam to the filled foamable resin particles as uniformly as possible, usually on the molding surface of the mold. Has a plurality of vapor holes provided at regular pitches in the vertical and horizontal directions. In such a foamed resin mold, if foam molding is repeatedly performed, it is inevitable that resin soot and the like are gradually deposited and deposited in the vapor holes formed on the molding surface. If the amount of deposits increases, the steam holes may become clogged, or the steam supply at each steam hole may vary, and a good molded product cannot be obtained. For this purpose, the first mold and the second mold are periodically cleaned to remove deposits from the steam holes.

JP 2002-307469 A Japanese Patent Laid-Open No. 2003-251651 JP-A-8-25393

  In the in-mold foam molding method for a foamed resin molded product using a foamed resin mold, in order to obtain a good foamed resin molded product, a uniform vapor is supplied into the molding cavity and a corner in the molding cavity is obtained. It is necessary to fill the expandable resin particles. Therefore, the supply of the raw material from the raw material feeder into the molding cavity is usually performed by applying a high pressure. Then, at the beginning of the supply of the raw material, the expandable resin particles ejected from the raw material outlet of the raw material feeder collide with a molding surface on the side opposite to the raw material feeder side in the molding cavity with a high momentum.

  A core vent provided with a large number of steam blowing holes is usually attached to the steam holes of the foamed resin mold, and when foamable resin particles having a large momentum collide with the steam blowing holes formed in the core vent, A part of the material enters the hole and does not easily leave. At the time of foam molding, the expandable resin particles in that state are also supplied with steam and expanded in the same manner as the surrounding expandable resin particles, and are fused and integrated with the surrounding expanded resin particles.

  When demolding the foamed resin molded product, the portion of the foamed resin particles that has entered the vapor blowout hole may remain in the vapor blowout hole, so that there is no skin layer on the surface of the molded product. A region may be formed. Further, what remains in the vapor hole, that is, the resin soot as an adhering matter gradually accumulates, and as described above, the vapor hole is clogged. In conventional foamed resin molds, sufficient consideration has not been made in this regard, and as described above, it is common to perform the washing operation of the foamed resin molds before such inconvenience occurs. For this reason, it is the actual situation that the cleaning process is periodically performed at fairly short intervals.

  The present invention has been made in view of the above circumstances, and it is possible to obtain a good foam molded product for each shot while making the interval of the cleaning operation of the foamed resin mold longer than before. It is an object to obtain an improved foamed resin mold.

  A foamed resin mold according to a first aspect of the present invention includes a first mold having a first mold surface and a second mold having a second mold surface, and the first mold surface and the second mold. A molding cavity is formed by the two molding surfaces, the first molding surface is provided with at least one raw material feeder, and the first and second molding surfaces have a plurality of steam holes. The foamable resin particles formed are ejected from the raw material outlet of the raw material feeder to fill the foamable resin particles into the molding cavity, and filled into the foamable resin particles through the plurality of vapor holes. In a foamed resin molding die that molds a foamed resin molded product by bringing into contact with steam, with the molding cavity formed, at least in the region of the second molding surface facing the raw material ejection port of the raw material feeder The steam hole is formed And said that no.

  A foamed resin mold according to the second aspect of the present invention includes a first mold having a first mold surface, a second mold having a second mold surface, and a third mold having a third mold surface. A molding die is provided, and a molding cavity is formed in which both side surfaces are divided by a first molding surface and a second molding surface, and a peripheral side surface is partitioned by a third molding surface. The molding surface is provided with at least one raw material feeder, the first and second molding surfaces are formed with a plurality of vapor holes, and the foamable resin particles are ejected from the raw material outlet of the raw material feeder. In a foamed resin mold, the foamable resin mold is formed by filling foamable resin particles in a molding cavity and contacting the foamable resin particles filled through the plurality of vapor holes with steam. With the cavity formed, at least the raw material feeder In the region of the second mold surface facing the source material jet it is characterized by not formed said vapor hole.

  In the foamed resin molds according to the first and second embodiments described above, the second facing the at least the raw material ejection port of the raw material feeder attached to the molding surface of the first molding die with the molding cavity formed. No steam hole is formed in the area of the molding surface. Therefore, even if the foaming resin particles are ejected from the raw material ejection port with a high momentum and collide with the opposing region of the second molding surface, no steam hole is formed there. As in the mold, it is possible to avoid a situation in which the expandable resin particles enter and accumulate in the steam blowout holes of the core vent attached to the steam holes. In addition, the foamed resin molded product obtained using the foamed resin mold is a non-defective product in which a skin layer is formed on the surface of the molded product facing the raw material outlet of the raw material feeder.

  The expandable resin particles also collide with a region around the region facing the raw material ejection port on the second molding surface. However, since the expandable resin particles in the radially diffused state collide with the surrounding area, the momentum of the expandable resin particles that collide with the surrounding area is the expandable resin that collides with the area facing the raw material ejection port. Smaller than the momentum of the particles. In the steam hole formed in the area around the area facing the raw material jet outlet, the steam blowout formed in the core vent is correspondingly increased compared to the case where it is formed in the area facing the raw material outlet. The extent to which foamable resin particles enter the pores is reduced. Therefore, even if the cleaning interval is longer than that of the conventional foamed resin mold, a good molded product can be obtained for each shot during that period.

  In the present invention, the “raw material outlet of the raw material feeder” refers to an opening at the tip of the jet of the raw material feeder, and when the raw material feeder is a cylindrical body, it is defined by its inner diameter. This is an open area. In addition, “at least the region of the second molding surface facing the material jet port of the raw material feeder” is a region facing the “raw material jet port of the raw material feeder” in the above-described meaning. Of course, it is preferable not to form a vapor hole also in the surrounding area | region close to the area | region which opposes the raw material jet outlet of a raw material feeder. However, if the vapor holes are not formed in a very wide surrounding area, the vapor may not be uniformly supplied to the filled foamed resin particles, so the extent of the vapor holes is not formed. This is preferably set for each actual machine and for each foamed molded product to be molded. Then, when forming the steam hole on the second molding surface, the position of the raw material feeder attached to the first molding surface is taken into consideration and the position satisfying the above conditions is selected to form the steam hole. It becomes.

  In a more preferred embodiment of the foamed resin molding die according to the present invention, in the state where the molding cavity is formed, both the vapor holes formed in the first molding surface and the second molding surface are perpendicular to the molding surface. The positions of the steam holes on both molding surfaces are set so as not to overlap each other. In this aspect, the movement distance of the steam flowing in the molding cavity through the steam hole on the first molding surface side and the steam hole on the second molding surface side is such that both the steam holes are located facing each other. Compared to this, the vapor can be spread evenly in the cavity. As a result, even if the steam hole is not formed in the region of the second molding surface facing the material outlet of the material feeder, it is possible to distribute a sufficient amount of steam to that region, and good foam molding Goods are obtained. Furthermore, the variation in the fused state between the expandable resin particles is further reduced, and a high-strength molded product can be obtained.

  According to the present invention, it is possible to obtain a more improved foamed resin mold that can obtain a good foamed molded product for each shot while making the interval of the cleaning operation of the foamed resin mold longer than before. . In addition, the foamed resin molded product obtained using the foamed resin mold is a non-defective product in which a skin layer is formed on the surface of the molded product facing the raw material outlet of the raw material feeder.

The figure explaining an example of the foaming resin molding die of a 1st form. The figure explaining an example of the foaming resin molding die of a 2nd form. Two figures explaining an example of the core vent attached to a steam hole. The expanded sectional view which shows an example of a steam hole. The figure which shows typically an example of the relationship between a steam hole and a raw material feeder. The figure which shows typically the positional relationship of the steam hole in a 1st and 2nd shaping | molding die.

  Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

  FIG. 1 schematically shows an example of a molding apparatus provided with a foamed resin mold according to the first embodiment of the present invention. The molding apparatus A1 includes a pair of a male mold 1 (first mold) and a female mold 2 (second mold). The male mold 1 is formed with a convex portion constituting the first molding surface 3, and the female mold 2 is formed with a concave portion constituting the second molding surface 4. The male and female molds 1 and 2 are disposed in a state in which the first molding surface 3 and the second molding surface 4 face each other. Then, the male and female molds 1 and 2 are closed with the first molding surface 3 that is the convex part of the male mold 1 inserted into the second molding surface 4 that is the concave part of the female mold 2. Thus, the molding cavity 6 is formed between the opposing surfaces.

  On the first molding surface 3 of the male mold 1, a raw material feeder 10 having a cylindrical portion 11 having an inner diameter D for supplying foamable resin particles into the molding cavity 6 is provided with a raw material jet 12. Are attached to the molding cavity 6 so as to be open, and a plurality of vapor holes 7 are preferably provided at regular pitches in two axial directions perpendicular to each other at the portion facing the molding cavity 6. . Further, a plurality of steam holes 8 are preferably provided at regular pitches in two axial directions perpendicular to each other on the portion of the second molding surface 4 of the female mold 2 facing the molding cavity 6. The inside of the male and female molds 1 and 2 has a hollow structure as a whole, and steam is supplied into the hollow parts 20 and 21 from a steam generating part (not shown), and the steam passes through the steam holes 7 and 8 described above. Then, it is fed into the molding cavity 6.

  FIG. 2 schematically shows an example of a molding apparatus provided with the foamed resin mold according to the second embodiment of the present invention. The molding apparatus A2 includes a first molding die 1 having a flat first molding surface 3, a second molding die 2 having a flat second molding surface 4, and a first molding surface 5b having a third molding surface 5b. 3 molds 5 are provided. The third mold 5 is detachably attached to the flat first mold surface 3 of the first mold 1 in the illustrated example. The 3rd shaping | molding die 5 has the opening part 5a in a surface, and the surrounding side surface which divides the outer periphery of this opening part 5a comprises the said 3rd shaping | molding surface 5b.

  In this molding apparatus A2, the first molding die 1 and the second molding die 2 are fastened with the third molding die 5 in the middle, so that a flat first molding surface 3 and a flat second molding surface are obtained. 4, a molding cavity 6 in which both side surfaces are regulated and the circumferential side surface is regulated by a third molding surface 5b which is a peripheral side wall of the opening 5a of the third molding die 5 is formed.

  In the molding apparatus A2, a raw material feeder having a cylindrical portion 11 having an inner diameter D for supplying foamable resin particles into the molding cavity 6 in the first molding die 1 in the same manner as the molding apparatus A1. 10 is attached so that the raw material ejection port 12 is positioned on the flat first molding surface 3 and opened to the molding cavity 6. A plurality of vapor holes 7 are preferably provided at regular pitches in two axial directions perpendicular to each other in a portion of the flat first molding surface 3 facing the molding cavity 6. A plurality of vapor holes 8 are also preferably provided at regular pitches in two axial directions perpendicular to each other in the portion of the flat second molding surface 4 attached to the molding die 2 that faces the molding cavity 6. . In the figure, reference numeral 9 denotes a reinforcing support. Also in the molding apparatus A2, the inside of the first and second molding dies 1 and 2 has a hollow structure as a whole, and steam is supplied into the hollow parts 20 and 21 from a steam generating part (not shown), The steam passes through the steam holes 7 and 8 and is fed into the molding cavity 6.

  In general, a core vent 30 as shown in FIG. 3 is attached to each of the steam holes 7 and 8 of the molding apparatuses A1 and A2. The core vent 30 is a cylindrical body with one end closed, and includes a closed end surface 31 and a cylindrical main body 32. The outer shape of the cylindrical main body 32 and the inner shape of the steam holes 7 and 8 are the same, and the core vent 30 is press-fitted into the steam holes 7 and 8 so that the closed end surface 31 is on the molding cavity 6 side. Yes. In the core vent 30 </ b> A shown in FIG. 3A, a required number of slits 33 are formed in the closed end surface 31 as steam blowing holes. In the core vent 30 </ b> B shown in FIG. 3B, a large number of through holes 34 are formed in the closed end surface 31 as steam blowing holes. The width of the slit 33 and the diameter of the through hole 34 are made smaller than the average particle diameter of the expandable resin particles used for molding.

  FIG. 4 shows a state in which the core vent 30A shown in FIG. 3A is attached to the steam holes 7 and 8. The molding surfaces 3 and 4 facing the molding cavity 6 and the closed end surface 31 of the core vent 30A are shown in FIG. They are on the same plane. In FIG. 4, 40 is a deposit such as resin waste that may be generated when foam molding is repeatedly performed using the same foamed resin mold, and schematically shows it. In order to remove such deposits 40, a periodic cleaning operation is performed on the foamed resin mold.

  In the foamed resin molding die according to the present invention, when the male molding die 1 and the female molding die 2 are combined to form the molding cavity 6, the second facing the raw material ejection port 12 of the raw material feeder 10. The steam hole 8 is not formed in the region of the molding surface 4. More specifically, in the molding apparatus A1 shown in FIG. 1, the molding cavity 6 is formed by the first molding surface 3 of the first molding die 1 and the second molding surface 4 of the second molding die 2. When formed, the second molding surface 4 of the molding die 2 is opposed to the raw material ejection port 12 having a diameter (inner diameter) D which is the tip of the cylindrical portion 11 of the raw material feeder 10 attached to the first molding die 1. The steam hole 8 is not formed in the region of.

  The same applies to the molding apparatus A2 shown in FIG. 2, and the first molding surface 3 of the first molding die 1, the second molding surface 4 of the second molding die 2, and the third molding die 3rd. When the forming cavity 6 is formed with the forming surface 5b, the diameter (inner diameter) which is the tip of the cylindrical portion 11 of the raw material feeder 10 attached to the first forming die 1 is opposed to the raw material outlet 12 having D. The steam hole 8 is not formed in the region of the second molding surface 4 of the mold 2.

  FIG. 5 shows the second molding surface 4 of the second mold 2 according to the invention. In FIG. 5, a projection view of the cylindrical portion 11 of the raw material feeder 10 attached to the first molding surface 3 of the first molding die 1 when the molding cavity 6 is formed is shown by an imaginary line. An outer diameter line of the cylindrical portion 11 is indicated by 11a, and an inner diameter line of the raw material ejection port 12 is indicated by 12a. As shown in the drawing, the steam hole 8 is not formed inside the inner diameter line 12a of the raw material outlet 12, and in this example, the outer diameter line of the cylindrical portion 11 is also formed inside the 11a. Not formed.

  When the second molding die 2 having the arrangement of the steam holes 8 shown in FIG. 5 is used, the foamable resin particles ejected from the raw material ejection port 12 of the raw material feeder 10 attached to the first molding die 1 are the raw material ejection port. 12 collides with the region of the second molding surface 4 of the second molding die 2 facing 12 with the greatest momentum. However, since the vapor hole 8 is not formed in that region, a situation in which the foamable resin particles enter the vapor blowout hole which is the slit 33 or the through hole 34 of the core vent 30 attached to the vapor hole 8 and accumulate there. Does not occur. The foamable resin particles having a large momentum also collide with the outer diameter line 11a of the cylindrical portion 11 of the raw material feeder 10. However, in this example, the steam hole 8 is not formed in that region, so the steam hole 8 is also formed here. There is no such a situation that the foamable resin particles enter the vapor blowout holes and accumulate there.

  Many steam holes 8 are formed in other regions of the second molding surface 4, but the foamable resin particles ejected from the raw material outlet 12 of the raw material feeder 10 do not directly collide there. Therefore, in that region, a situation in which the expandable resin particles enter the vapor blowing holes of the vapor holes 8 and accumulate there is not generated.

  That is, in the foamed resin molding die according to the present invention, the vapor hole 8 is not formed in the region where the resin soot is most likely to be deposited. Therefore, the cleaning operation interval for removing the resin soot from the steam hole 8 is the most resinous. Compared to the conventional foamed resin mold in which the vapor holes 8 are formed in the region where soot is likely to accumulate, the molding efficiency can be improved by the length of the cleaning operation interval.

  FIG. 6 is a schematic diagram for explaining a more preferable embodiment of the foamed fat molding die according to the present invention, and shows the molding surface when the first molding die 1 and the second molding die 2 are clamped. The state seen from the perpendicular direction is shown. In the figure, ◯ indicates the steam hole 8 formed on the second molding surface 4, and ● indicates the steam hole 7 formed on the first molding surface 3. As shown in the figure, the steam hole 8 (◯) formed in the second molding surface 4 and the steam hole 7 (●) formed in the first molding surface 3 are viewed from a direction perpendicular to the molding surface. The positions of the steam holes on both molding surfaces are set so as not to overlap.

  Thus, by positioning the steam holes 7 and 8 in the first and second molding surfaces 3 and 4, the steam hole 7 on the first molding surface 3 side and the steam hole on the second molding surface 4 side. Since the moving distance of the steam flowing through the molding cavity 6 through 8 is extended as compared with the case where both the steam holes 7 and 8 are opposed to each other, the steam is evenly distributed in the molding cavity 6. Can be made. As a result, the variation in the fused state between the expandable resin particles is further eliminated, and a more uniform and high-strength molded product can be obtained. Moreover, even if the steam hole 8 is not formed in the region of the second molding surface 4 facing the material jet port 12 of the material feeder 10, it is possible to distribute a sufficient amount of steam to the region. The foamed molded product is obtained.

1 ... 1st shaping | molding die,
2 ... Second mold,
3 ... 1st molding surface,
4 ... Second molding surface,
5 ... Third mold,
5a ... third mold opening,
5b ... the third molding surface,
6 ... Molding cavity,
7: Steam holes formed in the first molding surface,
8: Steam holes formed in the second molding surface,
10 ... Raw material feeder,
DESCRIPTION OF SYMBOLS 11 ... Cylindrical part 12 of a raw material feeder ... Raw material outlet D which is an internal diameter part of the cylindrical part of a raw material feeder ... Inner diameter of a raw material feeder (diameter of raw material outlet)

Claims (4)

A first molding die having a first molding surface and a second molding die having a second molding surface are provided, and a molding cavity is formed by the first molding surface and the second molding surface. The first molding surface is provided with at least one raw material feeder, the first and second molding surfaces are formed with a plurality of steam holes, and foamed from the raw material outlet of the raw material feeder. Foam for forming a foamed resin molded product by ejecting the expandable resin particles, filling the foamable resin particles into the molding cavity, and contacting the foamable resin particles filled through the plurality of vapor holes In the resin mold
The foamed resin mold, wherein the steam hole is not formed in at least a region of the second molding surface facing the raw material jet port of the raw material feeder in a state where the molding cavity is molded . A first molding surface having a first molding surface; a second molding die having a second molding surface; and a third molding die having a third molding surface. A molding cavity is formed in which both side surfaces of the molding surface and the peripheral side surface of the third molding surface are defined. The first molding surface is provided with at least one raw material feeder, A plurality of vapor holes are formed in the first and second molding surfaces, the foamable resin particles are ejected from the raw material outlet of the raw material feeder, and the foamable resin particles are filled into the molding cavity, In a foamed resin mold that molds a foamed resin molded product by bringing steam into contact with foamable resin particles filled through a plurality of steam holes,
The foamed resin molding die, wherein the steam hole is not formed at least in the region of the second molding surface facing the raw material jet port of the raw material feeder in a state where the molding cavity is formed. .   In a state where the molding cavity is formed, both of the molding surfaces are formed so that the vapor holes formed in the first molding surface and the second molding surface do not overlap each other when viewed from the direction perpendicular to the molding surface. The foamed resin mold according to claim 1 or 2, wherein the position of the steam hole is set.   Using the foamed resin mold according to any one of claims 1 to 3, the molding cavity is filled with foamable resin particles from a raw material feeder, and steam is supplied to the foamable resin particles through a plurality of steam holes. Foamed resin molded product obtained by contact.

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