JP2001047467A - Grain-like molded article and method and apparatus for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a grain-like molded article having a straight grain pattern near to nature. SOLUTION: A first material 24 and a second material 25 are used as molten resins in an incompletely mixed state and, before the molten resins enter a cavity, they are brought to such a state that the second material 25 flows along the resin supply end of the cavity and allowed to go toward the resin supply end of the cavity to generate a plurality of branched flows 26 arranged in the direction along the resin supply end of the cavity and these branched flows 26 are allowed to meet with each other. By this constitution, the respective branched flows 26 are brought to an almost constant width state while made adjacent to each other before the molten resins enter the cavity and a plurality of the stabilized branched flows 26 are supplied to the cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a woodgrain molded article, a method for producing a woodgrain molded article, and an apparatus for producing a woodgrain molded article.

[0002]

2. Description of the Related Art As a method of manufacturing a molded article made of synthetic resin, there is a method of forming a grain pattern on the surface of the molded article as disclosed in Japanese Patent Application Laid-Open No. 8-276644. According to this one
With the synthetic resin, it is possible to mass-produce a molded article having a woody feeling close to that of natural wood.

[0003]

However, the grain pattern of the molded article obtained by the above molding method is a plate grain pattern,
It is not possible to obtain a molded article having a straight-grained pattern showing a sense of quality.

The present invention has been made in view of the above circumstances, and a first technical problem is to provide a method for producing a woodgrain-like molded product having a straight-grain pattern close to nature. A second technical problem is to provide an apparatus for producing a woodgrain shaped article having a straight-grain pattern close to nature. A third technical problem is to provide a woodgrain-like molded product having a natural grain pattern.

[0005]

In order to achieve the first technical object, the present invention (the invention of claim 1) provides:
In a method for producing a woodgrain-like molded product in which a molten resin containing a first material and a second material having a color different from the first material is supplied to a cavity to form a woodgrain pattern, the molten resin may be a first resin. Using a material and a second material in an incompletely mixed state, before the molten resin enters the cavity,
The molten resin is supplied along the cavity resin supply end in an incompletely mixed state, and from that state, a plurality of branch streams are arranged in the direction along the cavity resin supply end while directing the molten resin toward the cavity resin supply end. And a plurality of the separated streams are merged. Preferred embodiments of the first aspect are as described in the second to fifth aspects.

In order to achieve the second technical problem, in the present invention (invention of claim 6), a runner is connected to a cavity resin supply end via a gate,
In a woodgrain-like molded product manufacturing apparatus in which molten resin is supplied into the cavity from the cavity resin supply end through the gate, the runner is extended along the cavity resin supply end, and the gate is A plurality of dividers for sequentially forming a plurality of branch flow generating passages in the direction of extension of the runner at the entrance of the gate to make the molten resin a plurality of branch flows in a parallel state; and an outlet of the gate from the plurality of dividers. And a converging space portion formed over the portion and merging the plurality of diverging flows. Preferred embodiments of the sixth aspect are as described in the seventh to eleventh aspects.

In order to achieve the third technical object, according to the present invention (claim 12), the first material and the second material having a different color from the first material are incomplete. After the molten resin contained in the mixed state is supplied to the cavity through the gate under a plurality of branch flows, the molten resin is solidified to form a product portion formed in the cavity and a gate corresponding resin portion formed in the gate. And a plurality of diversion traces are formed at least on the surface of the product part, and the diversion traces extend in the widthwise inner side of the diversion traces in the extending direction of the diversion traces. A first material solidification portion in which the first material solidifies, and a second material solidification portion in which the second material solidifies so as to extend in the extending direction of the first material solidification portion on both sides in the width direction of each branch mark. Part and a grain of wood adapted to have In a molded product, the gate-corresponding resin portion includes a plurality of branch flow generation passage traces as the plurality of branch flow generation traces, and a film-shaped portion continuous with the plurality of branch flow generation passage traces and connected to the product portion. It has a configuration to have. A preferred aspect of the twelfth aspect is as described in the thirteenth aspect.

[0008]

According to the first aspect of the present invention, a molten resin in which the first material and the second material are in an incompletely mixed state is used, and the molten resin is not mixed before the molten resin enters the cavity. In a completely mixed state, the molten resin is supplied along the cavity resin supply end, and from that state, the molten resin is generated in a plurality of branch streams arranged in the direction along the cavity resin supply end while facing the cavity resin supply end. Stabilizes a plurality of sub-streams before entering the cavity and downstream of the merge point of the plurality of sub-streams (to allow each sub-stream to flow with a substantially constant width while adjoining each other). Thereafter, a pattern flow having a substantially constant width (a pattern line having a substantially constant width) can be stably formed by the second material (as each branch flows with a substantially constant width while adjoining each other, the pattern flow in each branch flows). The material (tip portion) also flows to the downstream side and spreads in the width direction until it is regulated by the adjacent branch flow, and the second material is extended in the width direction both sides of each branch flow in the flow direction of the branch flow. The plurality of divided flows in the separated state can be supplied to the cavity. For this reason, since a plurality of divided flows in a stable state can be supplied into the cavity, a natural grain pattern can be reliably formed in the product portion formed in the cavity. Moreover, in this case, before the molten resin enters the cavity, a plurality of branch streams are generated and merged, so that a plurality of branch stream generation path traces as a path trace for generating a plurality of branch streams are, of course, plural. In the early stage of the occurrence of a shunt (immediately after ejection), vortices and the like caused by vortices that are likely to occur due to the separation of adjacent shunts are formed in the part of the molded product other than the product part (resin part corresponding to the gate). Will be located. For this reason, by separating the product part from the molded product, a plurality of diversion-producing passage traces and swirl traces and the like can be reliably eliminated in the product part, so that the product can be made more like a woodwork product. Further, since the pattern is formed in accordance with the number of shunts (two pattern lines are formed for one shunt), the number of pattern lines can be freely increased or decreased in the cavity by adjusting the number of shunts. Thus, various straight-grain patterns can be formed as desired. further,
Since the straight-grain pattern is formed based on the branch flow, the straight-grain pattern can be formed on the entire (periphery) by simply setting the branch flow for moldings of various shapes (eg, elbow shape, cap shape, etc.). It can be formed. Furthermore, since the grain pattern is formed by a regular method based on the branch flow, the quality of the molded article (the grain pattern formation state) is made uniform,
The yield can be increased. In addition, the second material is fed to the first material while being in an incompletely mixed state, and the flow is used so that the second material follows the cavity resin supply end before the molten resin enters the cavity. As a molding machine, any molding machine may be used as long as it has a function of sending molten resin to the cavity side (a screw-type injection molding machine, a plunger-type molding machine, and a single-head injection machine). The cost of equipment can be reduced by using a general-purpose molding machine irrespective of the type of the molding machine or the multi-head injection molding machine).

According to the second aspect of the present invention, when a plurality of partial flows are generated, the undivided flow is caused to flow while overlapping with the plurality of partial flows, so that the plurality of partial flows are formed before the molten resin enters the cavity. Not only can it be stabilized by merging, but also at the time of the occurrence of multiple shunts, the multiple shunts can be provided with flow resistance in an overlapping relationship with the flow that is not shunted. The generation of a flow can be suppressed, and a plurality of divided flows can be quickly made into a balanced flow (a flow that forms a pattern line (formed of a second material) having a substantially constant width for each divided flow). become. For this reason, in the product part formed in the cavity, it is possible to more surely form a natural grain pattern.

According to the third aspect of the present invention, since the side on which the non-divided flow flows is set as the surface side of the woodgrain shaped article, a plurality of divided flows are transmitted to the non-divided flow layer. The pattern lines are formed relatively slowly (by pulling the flow that is not diverted by a plurality of shunts), and a very natural, straight grain pattern with a blurry feeling can be formed on the surface of the product part formed in the cavity. become.

According to the fourth aspect of the present invention, since the side on which the plurality of divided flows flow is set as the surface side of the woodgrain-shaped molded product, the flow balanced with the relationship with the non-divided flow (relational flow). By doing so, it is possible to clearly form the straight grain pattern on the surface of the product part formed in the cavity based on the plurality of shunts, while ensuring the formation of a natural grain pattern.

According to the fifth aspect of the present invention, before the molten resin enters the cavity, all of the molten resin supplied toward the cavity is changed into a plurality of partial flows. A plurality of divergent streams having the (second material)) sharpened are supplied to the cavities, so that a grain pattern close to nature can be extremely sharply expressed in a product portion formed in the cavities.

According to the sixth aspect of the present invention, the molten resin is sent out in an incompletely mixed state of the first material and the second material, so that the second material flows along the cavity resin supply end in the runner. Such a state can be achieved, and from that state, the molten resin is generated in a plurality of branch streams arranged in the direction along the cavity resin supply end while facing the cavity resin supply end with the plurality of partitions, and the A plurality of branches can be merged in the merge space, and the apparatus can implement the manufacturing method according to claim 1. For this reason, it is possible to provide an apparatus for manufacturing a woodgrain-like molded product that can surely form a nearly natural grain pattern in a product portion formed in the cavity.

According to the seventh aspect of the present invention, the gate is provided with the entrance space so as to be continuous with the junction space while overlapping the plurality of partitions in the region where the plurality of partitions exist. Therefore, when a plurality of shunts are generated, the flow that is not shunted flows while overlapping the plurality of shunts, so that the manufacturing method according to claim 2 can be performed using the device.

According to the eighth aspect of the present invention, since the gate is constituted by an opening and closing mold and the plurality of partition portions are provided in the mold constituting the back side of the woodgrain molded product among the opening and closing molds, The device according to claim 7, wherein not only can the concrete device be obtained, but also the pattern lines are formed by the transmission of a plurality of divided flows to the non-divided flow layer, and a very natural-looking straight-grain pattern with a blurry feel Can be formed on the surface of the product portion formed in the cavity, and the manufacturing method according to claim 3 can be carried out using the apparatus.

According to the ninth aspect of the present invention, the gate is constituted by an opening and closing mold, and the plurality of partition portions are provided in a mold constituting the surface of the woodgrain molded product among the opening and closing molds. The straight-grain pattern can be clearly displayed on the surface of the product section formed in the cavity based on the plurality of stable branch flows.
Can be implemented.

According to the tenth aspect, the gate has:
At the entrance of the gate, since only a plurality of partitions are provided, when generating a plurality of branches,
All of the molten resin supplied toward the cavity is changed into a plurality of branch flows by the plurality of partition portions, and the manufacturing method according to claim 5 can be performed by the apparatus.

According to the eleventh aspect of the present invention, both ends in the extending direction of the runner are disposed so as to surround the cavity resin supply end, and the outlet of the gate is provided on the cavity resin supply end side and on both sides of the cavity. Therefore, even in a three-dimensional molded product in which the product part (molded product) has a side wall, a plurality of shunts forming a straight-grain pattern line can be appropriately supplied to a region corresponding to the side wall. Thus, even a three-dimensional molded product having side walls can form a nearly natural grain pattern.

According to the twelfth aspect of the present invention, it is not only possible to obtain a natural-looking straight-grained pattern simply by the action of a plurality of shunts in the manufacturing stage or the like. In the manufacturing stage, a film-like portion is formed in the manufacturing stage by having a plurality of branch-flow occurrence passage traces as a plurality of branch-flow occurrence passage traces and a film-like portion continuous with the plurality of branch-flow generation passage traces and connected to the product portion. By using the portion as a flow adjustment space, it is possible to stabilize a plurality of divided flows (a flow state where a pattern line (formed of the second material) having a substantially constant width is formed for each divided flow). In addition, not only the traces of the plurality of diverted passages but also the vortex traces caused by vortices and the like which are likely to be generated due to the separation of the adjacent diverted flows at the initial stage of the generation of the divided flows (immediately after the ejection), are included in the molded product. Being located in a part other than the product part (resin part corresponding to the gate), by separating the product part from the molded product, it is possible to surely eliminate a plurality of diversion-causing passage traces and vortex traces in the product part become. For this reason, with the said molded article, a product part can be obtained as a woodworking product which has a very natural and straight grain pattern. Further, in the woodgrain-shaped molded article, since a pattern is formed in accordance with the number of shunts (2 for one shunt)
One pattern line is formed), and the number of pattern lines can be freely increased or decreased by adjusting the number of shunts, and various straight-grain patterns can be formed as desired. Furthermore, since a straight-grain pattern is formed based on the diversion trace, a straight-grain pattern can be formed for molded products of various shapes (eg, elbow shape, cap shape, etc.) only by setting the diversion flow at the time of molding. Become. For this reason, a molded product equivalent to an expensive woodworking product can be provided at low cost. Furthermore, since a straight-grain pattern is formed on the basis of the diversion trace, a pattern line having a substantially constant width in the thickness direction is formed not only on the surface but also on the inside in the thickness direction based on the effect of diversion at the time of molding. That is, in the wood-grained injection-molded product, even if worn, the straight-grain pattern can be prevented from disappearing.
For this reason, in the woodgrain-shaped molded article, it is possible to not only enhance the reliability of holding the grain-grain pattern, but also to show the grain-grain pattern as well as the natural wood, and to sufficiently cope with the familiarity based on wear. Become.

According to the thirteenth aspect of the present invention, the gate-corresponding resin portion is provided in a region where a plurality of branch flow generation passage traces exist.
Since it is provided with the inlet film-shaped portion so as to be continuous with the film-shaped portion while overlapping the plurality of branch-flow-generating passage traces, the portion of the film-shaped portion is flow-adjusted space at the stage of manufacturing the woodgrain-like molded product. In addition to being able to be used as a part, the flow of the molten resin (which does not form a plurality of divided flows) serving as the inlet film-shaped portion regulates a plurality of divided flows to some extent (regulation based on flow resistance), and stabilizes the flow of each divided flow in a stable and balanced manner. It is possible to increase the certainty that the product has been taken. For this reason, it is possible to further increase the certainty that the product part of the woodgrain-shaped molded product has a nearly natural grain pattern.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 13 show a first embodiment. In this first embodiment, reference numeral 1 in FIGS. 1 and 2 denotes an injection molded product according to this embodiment immediately after molding,
The molded article 1 immediately after the molding has a long flat product part 2 in which the molten resin is solidified, and a gate corresponding resin part which is attached to the product part 2 (the resin solidified in the gate). ) 3, a runner-compatible resin portion (resin solidified in the runner) 4 connected to the gate-compatible resin portion, and a sprue-compatible resin portion (resin solidified in the sprue) 5 connected to the runner-compatible resin portion 5
And are to have.

As the molten resin used for the molded article 1, a resin in which a second material is contained in a first material is used. The first material and the second material have different colors, and a state before the second material is completely mixed with the first material, that is, an incompletely mixed state is used in the molding stage. It is supposed to be. Specifically, as the first material, an ABS resin (ABS: acrylonitrile-
Butadiene-styrene, or AAS, AES or the like obtained by polymerizing acrylic or ethylene in place of butadiene of ABS),
TPE (thermoplastic elastomer) resin (olefin type,
Various resins such as nylon, urethane and the like are used alone or in combination. As the second material, various resins such as PP (polypropylene) resin, PBT (polybutylene terephthalate) resin, PET (polyethylene terephthalate) resin and the like are used. Resins are to be used alone or in combination. Further, the first material and the second material contain a colorant, a pigment, wood flour, etc. in addition to various resins, and the content is appropriately determined according to the type of the target grain pattern. It has become. The weight ratio of the second material to the first material is preferably about the second material / first material = 5/100,
When wood flour is added, the proportion of wood flour added is
The range of 5 to 50% with respect to the amount of the material and the second material (more preferably, about 10% from the viewpoint of a feeling of wood, moldability, and the like)
It is preferable to add with.

The elongated flat product part 2 is formed as a molded product 1
After removal of the gate-compatible resin portion 3, the runner-compatible resin portion 4, and the sprue-compatible resin portion 5, the panel-shaped product portion is to be used for various applications. As shown in FIG. 1, a plurality of branch marks 6 based on a plurality of branch flows of the molten resin are formed in the molded article 2. Each of the above-mentioned shunt traces 6 basically has a substantially constant width,
It is sequentially formed in the width direction of the product part 2 (vertical direction in FIG. 1), and each branch mark 6 is extended in the extending direction of the product part 2 (left-right direction in FIG. 1). This each branch trace 6
Is constituted by a first material solidification unit 7 and a second material solidification unit 8, and the first material solidification unit 7 and the second material solidification unit 8 are provided not only on the surface of the product unit 2 but also inside the product unit 2. Is formed. The first material solidification portion 7 is solidified on the inner side in the width direction (vertical direction in FIG. 1) of each branch mark 6 so as to extend in the direction in which the branch mark 6 extends.
The material solidification section 7 occupies substantially the entirety in each branch trace 6. The second material solidification unit 8 is solidified so as to extend in the direction in which the first material solidification unit 7 extends on both sides in the width direction of each branch mark 6, and the second material solidification unit 7 It is formed with a smaller line width than the first material solidified portion 7. In this case, since the incompletely mixed state of the second material with respect to the first material is under an unstable flow state, the color at each branch mark 6 (the first and second material solidification units 7 and 8) The shading of the color and the like may be slightly different, which may give rise to a natural woodiness. In the present embodiment, in addition, a pattern line having a blurred feeling (the second material solidified portion 8) is used. It is actively formed, and this will also make it look like a natural grain.

The runner-compatible resin portion 4 is disposed at a certain interval (for example, 5 mm to 10 mm) with respect to the product portion 2 outside one end side in the extending direction of the product portion 2. The portion 4 has a substantially semi-circular cross section and extends over the entire width of the product portion 2 (vertical direction in FIG. 1). The sprue-compatible resin portion 5 is provided on the side opposite to the product portion 2 with respect to the runner-compatible resin portion 4, and the sprue-compatible resin portion 5 continues to a central portion in the extending direction of the runner-compatible resin portion 4.

As shown in FIGS. 1 to 6, the gate corresponding resin portion 3 is formed in a flat film shape as a whole.
In addition, the connection to the product part 2 is made to extend over substantially the entire extending direction of the runner-compatible resin 4 (the width direction of the product part 2), and is connected so as to straddle the lower part of the runner-compatible resin part 4 and the lower part of the product part 2. are doing. Specifically, at the entrance (the right end in FIG. 1) of the gate corresponding resin portion 3, an entrance film-shaped portion 3 a and a plurality of branch flow occurrence passage traces 3 b are provided in a state of being overlapped. Also exit (Fig. 1
On the middle, left end) side, the main film-shaped portion 3c is provided integrally with the inlet film-shaped portion 3a and the plurality of branch flow generation passage traces 3b. Inlet film part 3a
Is a flow of the molten resin which is not divided is solidified at the entrance of the gate 21, and the entrance film-like portion 3a
Is made flat with a thickness of about half of the main film-shaped portion 3c, and in this state, is connected to the lower part of the runner-compatible resin portion 4. The plurality of branch flow generation passage traces 3b are traces of passages that generate a plurality of branch flows from the molten resin, in which the molten resin is solidified, and the plurality of branch flow generation passage traces 3b are formed of the product part 2.
Are arranged at equal intervals in the width direction. The main film-shaped portion 3c is formed by solidifying molten resin on the outlet side from the inlet film-shaped portion 3a and the plurality of branch flow generation passage traces 3b. While maintaining the same thickness as that of the branch flow generation path trace portion 3b, it has a flat shape and continues from the inlet film-shaped part 3a and the plurality of branch flow generation path trace parts 3b to the lower part of the product section 2.

As shown in FIG. 1, the plurality of branch marks 6 extend (are formed) also to the gate corresponding resin portion 3. Each of the diverging traces 6 is, in the main film-shaped portion 3c,
It is formed so as to be continuous with each branch trace 6 of the product part 2, and the branch branch generation path trace part 3b is located at the center in the width direction of each branch trace 6 in the main film part 3c.

Next, a manufacturing method for manufacturing the molded article 1 (product part 2) and a manufacturing apparatus for implementing the manufacturing method will be described. First, before describing the manufacturing method, a manufacturing apparatus for performing the manufacturing method will be described, and the manufacturing method will be described together with the operation of the manufacturing apparatus.

As shown in FIG. 7, the manufacturing apparatus 9 for manufacturing the molded product 1 includes a molding machine 10 and a mold 11.
In the present embodiment, a general-purpose screw injection molding machine is used as the molding machine 10. The molding machine 10 melts the solid pellets 12 for the first material and the solid pellets 13 for the second material, which are sequentially supplied to the inside, in a cylinder 14 to melt the resin 15 (FIG. 7).
Has a function of sending out the molten resin 15 to the mold 11 with a predetermined pressure (programmed injection pressure). When the molten resin 15 is generated, the cylinder 14 is used. The second material is set to be in an incompletely mixed state with the first material based on the temperature adjustment and the like in the inside. In this case, as the injection conditions, for example, cylinder temperature: 235 ° C., maximum injection pressure: 1500 Kg / cm 2, screw diameter of the injection molding machine: 46 mm, etc. are used.

The mold 11 has an upper mold 16 and a lower mold 17 as shown in FIGS. 7 and 8, and the lower molds 16 and 17 are further moved by a mold clamping mechanism (not shown). When the mold is clamped, a cavity 18, a sprue 19, a runner 20, and a gate 21 are formed therein. In this case, in the present embodiment, the upper mold 16 is set so as to form the front side of the molded article 1, and the lower mold 17 is set so as to form the back side of the molded article 1. As the operating conditions, for example, a mold temperature: 60 ° C., a mold clamping force: 150 t, and the like are used. The cavity 18 forms a space corresponding to the long flat product part 2. The cavity 18 holds a space having a constant width and a constant thickness, and is opposed to the cavity resin supply end 22 and the cavity resin supply end 22. A resin reaching end 23 is formed. The sprue 19 is provided on the molding machine 10.
The sprue 19 is connected to the runner 20, and the sprue 19 is configured to guide the molten resin 15 to the runner 20. In this case, a bent portion (bent path) that changes the flow direction of the molten resin 15 may be formed in the sprue 19. The runner 20 constitutes a runner connecting the sprue 19 and the gate 21,
In the present embodiment, the runner 20 has a substantially semicircular cross section and extends along the cavity resin supply end 22 while facing the cavity resin supply end 22 (see FIG. 11).

The gate 21 constitutes a flat runner connecting the runner 20 and the cavity 18 so as to form the gate corresponding resin portion 3. The gate 21 communicates the lower part of the cavity resin supply end 22 and the lower part of the runner 20 in an overlapping state, and the communication part (connection part) of the gate 21 to the lower part of the runner 20 is substantially in the extending direction of the runner 20. The communication portion (connection portion) of the gate 21 to the lower portion of the cavity 18 is formed over substantially the entire cavity resin supply end 22.

As shown in FIGS. 8 to 10, the gate 21 is provided with a plurality of partitions 60 and an entrance space 61 at an entrance (right end in FIGS. 7 and 8). A merging space 62 is provided on the outlet side (the left end in FIGS. 7 and 8) with respect to the inlet. Multiple partitions 6
Numerals 0 are provided on the lower mold 17 in a protruding state, and the respective partition portions 60 are sequentially arranged in the extending direction of the runner 20 at predetermined intervals. A space between the adjacent partitions 60 constitutes a plurality of branch generation passages 63 for generating a plurality of branch flows from the molten resin 15, and the molten resin solidified in the plurality of branch flow generation passages 63. As a result, the branch flow generation passage trace 3b is formed. The entrance space 61 is secured so as to overlap above the plurality of partitions 60, and the thickness of the entrance space 61 is substantially half the thickness of the entrance of the gate 21 (substantially the same thickness as the partition 60). Is). The molten resin 15 solidified in the entrance space 61 forms the entrance film-shaped portion 3a. The junction space 62 includes the plurality of partitions 60 and the entrance space 61.
Further on the outlet side, the thickness is substantially the same as the thickness of the plurality of partition portions 60 and the entrance space portion 61. The merge space portion 62 maintains the state, and the plurality of partition portions 60 and the entrance space portion 61 to the cavity 18 (the exit side of the gate 21). Due to the molten resin 15 solidified in the joining space 61, the main film-shaped portion 3b is formed.
Is formed.

Next, a method of manufacturing the molded article 1 (product part 2) will be described together with the operation of the manufacturing apparatus. First, in the molding machine 10, the solid pellet 1 for the first material is used.
The solid material pellets 13 for the second material and the second material are supplied into the cylinder 14 at predetermined supply speeds, and
When the molten resin 15 composed of and the second material 25 is generated, the molten resin 15 is continuously sent to the mold 11 side. Thereby, the second material 2 of the molten resin 15
5 rides on the flow of the molten resin 15 and the second material 2
5 is a plurality of linear flows along the flow of the molten resin 15. As shown in FIG. 11, the flow of the plurality of linear second materials 25 further flows to the runner 20 via the sprue 19 based on the delivery flow of the molten resin 15, and the second material 25 The flow 25 shows a flow shape extending in the direction in which the runner 20 (cavity resin supply end 22) extends. In this case, when the sprue 19 or the like has a bent portion (bent path), pulsation of the molten resin 15 and the like are suppressed.

When the molten resin 15 is filled in the runner 20, the molten resin 15 is supplied to the gate 21 under the injection pressure as shown in FIG. In the gate 21, the molten resin 15 is converted into a non-divided flow 64 and a plurality of divided flows 26 based on the inlet space 61 and the plurality of divided flow passages 63 (the plurality of partitions 60). The undivided stream 64 and the plurality of split streams 26
It will flow to the junction space 62 while overlapping vertically.

Each of the above-mentioned split streams 26 will be specifically described. Each of the branch streams 26 is formed by a corresponding one of the branch stream generation passages 63.
As shown in FIG. 12, the air flows into the confluence space 62 in a parabolic shape,
Flows in the merging space 62 while spreading in the width direction (vertical direction in FIG. 12) (see the phantom line in FIG. 12). For this reason, each adjacent branch 26 joins at a predetermined flow position from the branch generation passage 63 (the junction point is indicated by a point P in FIG. 12), and each branch 26 has a substantially constant width while adjacent to each other. It will flow with the flow of. Thereafter, each branch 26 flows in the width direction to the outlet of the gate 21 while spreading in the width direction until being regulated by the adjacent branch 26, and accordingly, the second branch in each branch 26. Material 25 (tip) is also shown in FIG.
As shown in FIG. 5, the second material 25 flows to the exit side of the gate 21 and expands in the width direction until it is regulated by the adjacent branch flow 26. It is extended in the flow direction. This allows
In each branch 26, downstream from the junction P,
A pattern flow of substantially constant width (pattern line of substantially constant width) is stably formed by the second material 25. On the other hand, since the speed of each of the divided streams 26 is reduced by the respective divided stream generation passages 63, the speed of each of the divided streams 26 is not increased.
Is relatively faster than the speed of
Are to flow in a manner to pull the stream 64 which is not diverted. For this reason, based on the relative speed difference between the plurality of split streams 26 and the undivided stream 64, the plurality of split streams 2
6 is transmitted relatively slowly to the undivided flow 64, during which the second material 25 is effectively diffused, and in the undivided flow 64, the upper mold contact surface side (forming) The closer to (product surface side), the more grainy the flow of the grain pattern (the second material 25), which is very close to a natural tree, is formed.

The non-divided flow 64 flowing over the plurality of divided streams 26 is subjected to flow resistance (shear resistance) to the plurality of divided streams 26 via an overlapping surface of the plurality of divided streams 26 and the undivided stream 64. )
Abrupt changes in the plurality of branches 26 are suppressed. For this reason, at the start of the injection molding, as shown in FIG. 12, the adjacent diverting streams 26 that have just exited the respective diverting passages 63 are still separated from each other. Is each diverted stream 26
And the formation of the vortex S is suppressed, and the merging point P of each branch 26 is determined by the branch generation passage 6.
3 and is located relatively short from
The process (stream) leading to becomes smooth. And each branch 2
After the merging of 6, even if a force that tries to disturb each branch 26 due to a difference in momentum of the branch 26, an external factor, or the like is applied, the flow 64 that is not branched is generated based on the resistance with the plurality of branches 26. That action will be suppressed. As a result, the reliability of maintaining a pattern flow having a substantially constant width (a pattern line having a substantially constant width) for each branch 26 is enhanced (improving stability),
In the flow 64 that is not divided, the above-described straight-grain pattern flow is reliably formed. Moreover, in the present embodiment, in addition to the resistance (shear resistance) between the undivided flow 64 and the plurality of divided flows 26 at the gate 21 inlet, the gate 21 is formed as an overlap gate, and the overlap gate is used. Since the flow resistance can be expected, only a part of the molten resin is prevented from being supplied to the gate 21 earlier, and the molten resin (the undivided flow 64 and the plurality of divided flows 26) is controlled at substantially the same timing. It will enter the gate 21 (the junction space 62).

The stable flow of the molten resin 15 as described above passes through the junction space 62 and the gate 21 (the junction space 6).
The resin flows into the cavity 18 from the cavity resin supply end 23, which maintains a state substantially the same as the flow width in 2).
As a result, the molten resin reaches the cavity resin reaching end 23 in a stable state in the cavity 18, and also in the cavity 18, a straight-grained flow is formed in the molten resin, and The closer the contact is to the side, the more the grain pattern flow is more like a natural tree with a blurry feel.

Thereafter, when the supply of the molten resin 15 into the cavity 18 is completed (filled), the upper and lower dies 16 and 17 are opened after the molten resin 15 is solidified. Then, the above-mentioned molded article 1 is taken out as a molded article.

Therefore, in the first embodiment, a plurality of stable and balanced divided streams 26 are formed by utilizing the plurality of divided streams 26, the merging space 62, the undivided stream 64, and the like. By setting the flow on the surface side of the molded product 1 to the non-divided flow 64, at least on the surface of the product portion 2 of the molded product 1, it is possible to reliably obtain the molded product 1 having a blurred-feeling natural grain pattern. Can be done. Moreover, in this case, even if a vortex based on the vortex S is formed on the molded article 1, the vortex is formed on the gate corresponding resin part 3 different from the product part 2, and the gate corresponding resin part 3 is formed. By removing the product 1 from the product 1, it is possible to prevent the product portion 2 from having a vortex. At this time, since the branch flow generation path trace 3b is also formed in the gate corresponding resin part 3,
By removing the gate-corresponding resin portion 3 from the molded article 1, it becomes possible to remove the branch flow generation path trace 3b together with the vortex trace. In addition, in obtaining the product part 2, the number of pattern flows of the second material 25 can be freely increased or decreased by adjusting the number of branch flows 26 (2 on both sides in the width direction of one branch flow 26).
(A pattern line of two second materials 25 is formed), and various straight-grain patterns can be formed as desired. Further, the molten resin 15 is applied to the second material 2 with respect to the first material 24.
5 so as to be in an incompletely mixed state and sent out to the cavity resin supply end 22, and utilizing the flow, the second
Since the material 25 has a flow shape extending along the cavity resin supply end 22 just before the cavity resin supply end 22, it is not necessary to form a pattern with a multi-head injection molding machine or the like. It can be used, and equipment cost can be reduced.

FIGS. 14 and 15 show a second embodiment, and FIGS.
17 shows a third embodiment, FIGS. 18 to 22 show a fourth embodiment, FIGS. 23 to 26 show a fifth embodiment, and FIGS. 27 to 29 show a sixth embodiment. In each of the embodiments, the same reference numerals are given to the same components as those already described or described above, and description thereof will be omitted.

In the second embodiment shown in FIGS. 14 and 15, a plurality of partitions 60 are provided on the upper
6 are provided with a plurality of diverting passages 6 by a plurality of partitions 60.
3 are formed. On the other hand, between the plurality of partitions 60 and the lower mold 17, at the time of mold clamping, the entrance space 61.
In the second embodiment, the plurality of branch flow generating passages 63 (the plurality of partitions 60) and the inlet space 61 overlap in a state opposite to that of the first embodiment. . Therefore, in this manufacturing apparatus, the molten resin 1
5 is supplied into the gate 21, at the entrance of the gate 21, a plurality of shunts 26 and a non-shunted stream 64 are generated in a vertical relationship. It flows toward the confluence space 62 side in an overlapped state while keeping the surface of the molded article 1). Therefore, in the second embodiment, a stable and balanced straight-grain pattern can be formed in the product part 2 by using the merging space portion 62 and the undivided flow 64 as in the first embodiment,
The influence of the plurality of shunts greatly affects the surface of the product part 2, and a straight grain pattern can be clearly displayed on at least the surface of the product part 2.

In the third embodiment shown in FIGS. 16 and 17, a plurality of partition portions 60 are provided on the lower mold 17 and the upper mold 1 is provided.
When the mold 6 and the lower mold 17 are clamped, only a plurality of branch flow generating passages 63 are formed at the entrance of the gate 21. Therefore, in this manufacturing apparatus, the molten resin 15
Is supplied into the gate 21, at the entrance of the gate 21, all of the molten resin 15 is changed to only the plurality of branch streams 26, and the plurality of branch streams 26 are combined into the merge space 62.
Will flow to the side. Therefore, in the third embodiment, the influence of the flow of the plurality of diversions 26 can be exerted on the entire product unit 2 while securing the stability after that by the merging of the plurality of diversions 26, and the product unit 2 (2) A natural grain pattern on the surface can be clearly displayed.

In the fourth embodiment shown in FIGS. 18 to 22, as shown in FIGS. 18 and 19, the product portion 2 of the molded product 1 has a gutter shape having a circular cross section and one end thereof. The opening is rounded and closed, and the gate corresponding resin portion 3 and the runner corresponding resin portion 4 are disposed so as to surround one end of the product portion 2. In the product part 2 of the molded article 1, a plurality of second material solidification parts 8 are formed at predetermined intervals in a circumferential direction of the product part 2, and each of the second material solidification parts 8 is formed of the product part 2. It extends in the extending direction, and extends continuously along one end thereof along the round shape. As shown in FIG. 20, this product part 2
After removal of the gate corresponding resin portion 3, the runner corresponding resin portion 4, etc., the end of the handrail 41 is used as a cover for the support member.

In order to mold such a molded article 1, a space (cavity 18) for forming the product part 2 is formed inside the mold 11 (the upper mold 16 and the lower mold 17) as shown in FIG. On the other hand, the rounded one end side (FIG. 21)
A runner 20 and a gate 21 are arranged on the middle and right end side (cavity resin supply end 22) so as to surround the cavity resin supply end 22, as shown in FIG.
One outlet faces both sides of the cavity 18. Thereby, even if the product part 2 has a peripheral wall (side wall) in addition to the closed end, the plurality of shunts 26 forming the straight-grain pattern line are formed as shown in FIG. (Cavities) can be supplied in an appropriate and stable state, and even a gutter-like product portion 2 having a peripheral wall can be formed with a nearly natural grain pattern.

In the fifth embodiment shown in FIGS. 23 to 26, as shown in FIGS. 23 and 24, the product portion 2 of the molded product 1 is a long box-shaped cover, The corresponding resin portion 3 and the runner corresponding resin portion 4 are disposed so as to surround one longitudinal end of the product portion 2. In the product part 2 of the molded article 1, not only the top wall 65 but also the side wall 6
6, a plurality of second material solidified portions 8 are formed so as to extend in the direction in which the product portion 2 extends.
As shown in FIG. 25, after removing the gate corresponding resin portion 3, the runner corresponding resin portion 4, and the like from the molded product 1, the molded product 1 is used as an upper end cover of the ladder 67.

In order to mold such a molded article 1, a space (cavity 18) for forming the product part 2 is formed inside the mold 11 (the upper mold 16 and the lower mold 17) as shown in FIG. On the other hand, a runner 20 and a gate 21 are disposed on one end side in the longitudinal direction (the right end side (cavity resin supply end 22 in FIG. 26) of FIG. 26) so as to surround the cavity resin supply end 22, and the outlet of the gate 21 is provided. Part is cavity 1
8 on both sides. Thus, even in a box-like shape in which the product part 2 has the side wall 66, the plurality of branch streams 26 forming the straight-grain pattern line are formed not only in the space region (cavity) corresponding to the top wall 65 but also in the space region corresponding to the side wall. (Cavities) can be supplied in an appropriate and stable state, and the natural grain pattern can be formed even in the box-shaped product portion 2 having the side wall 66.

In the sixth embodiment shown in FIGS. 27 to 29, as shown in FIGS. 27 and 28, the product portion 2 of the molded product 1 is a relatively deep box-shaped cover, The corresponding resin portion 3 and the runner corresponding resin portion 4 are disposed so as to surround one end of the product portion 2. This molded product 1
Also in the product part 2 of FIG. 2, a plurality of second material solidified parts 8 are formed not only on the top wall 65 but also on the side wall 66 so as to extend in the direction in which the product part 2 extends. 2
As shown in FIG. 9, after removing the gate corresponding resin portion 3, the runner corresponding resin portion 4, and the like from the molded product 1, the molded product 1 is used as a cover of a support member of the handrail 41.

A mold 11 for molding such a molded article 1
The upper mold 16 and the lower mold 17 have basically the same structure as the fourth and fifth embodiments. Therefore, this sixth
In the embodiment, further description regarding the mold will be omitted.

Although the embodiments have been described above, the present invention includes the following aspects. 1) The contents of the upper mold 16 and the lower mold 17 in each embodiment are reversed, and the lower mold 17 side is the surface side of the molded article 1. 2) The mold is not limited to the upper and lower molds 16 and 17.

It is to be noted that the object of the present invention is not limited to the specified one, but also includes providing what substantially corresponds to what is described as preferred or advantageous.

[Brief description of the drawings]

FIG. 1 is a plan view showing a molded product immediately after molding in a first embodiment.

FIG. 2 is an enlarged side view of FIG.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 4 is an enlarged sectional view taken along line BB of FIG. 1;

FIG. 5 is an enlarged sectional view taken along line CC of FIG. 1;

FIG. 6 is an enlarged sectional view taken along line DD of FIG. 1;

FIG. 7 is an explanatory diagram illustrating the manufacturing apparatus according to the first embodiment.

FIG. 8 is a partially enlarged cross-sectional view showing a mold according to the first embodiment.

FIG. 9 is an enlarged sectional view taken along line EE of FIG. 8;

FIG. 10 is an enlarged sectional view taken along line FF of FIG. 9;

FIG. 11 is an explanatory diagram illustrating a flow of a molten resin in a mold.

FIG. 12 is an explanatory diagram illustrating a flow of a molten resin in a gate.

FIG. 13 is an explanatory diagram illustrating that a pattern flow of a second material is generated for each branch after a plurality of branches merge.

FIG. 14 is an explanatory diagram illustrating a second embodiment.

FIG. 15 is an enlarged sectional view taken along line GG of FIG. 14;

FIG. 16 is an explanatory diagram illustrating a third embodiment.

FIG. 17 is an enlarged sectional view taken along line HH of FIG. 16;

FIG. 18 is a perspective view showing a molded product according to a fourth embodiment from the front side.

FIG. 19 is a perspective view showing a molded product according to a fourth embodiment from the back side.

FIG. 20 is a perspective view showing a handrail using a product part (cover) according to the fourth embodiment.

FIG. 21 is a perspective view showing a mold according to a fourth embodiment.

FIG. 22 is an explanatory diagram showing a plan view of a flow of a molten resin (a plurality of branch flows) in a mold according to a fourth embodiment.

FIG. 23 is a perspective view showing a molded product according to a fifth embodiment from the front side.

FIG. 24 is a view showing a molded product according to the fifth embodiment from the back side.

FIG. 25 is a partial perspective view showing a ladder using a product part (cover) according to the fifth embodiment.

FIG. 26 is a perspective view showing a mold according to a fifth embodiment.

FIG. 27 is a perspective view showing a molded product according to a sixth embodiment from the front side.

FIG. 28 is a view showing a molded product according to the sixth embodiment from the back surface side.

FIG. 29 is a perspective view showing a handrail using a product part (cover) according to the sixth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molded product 2 Product part 3 Resin part corresponding to a gate 3a Inlet film part 3b Rear part of a split flow generation passage 3c Main film part 4 Resin part corresponding to a runner 5 Resin part corresponding to a sprue 6 Trace of branch flow 7 First material solidification part 8 Second material solidification Part 9 Manufacturing apparatus 11 Mold 15 Molten resin 16 Upper mold 17 Lower mold 18 Cavity 21 Gate 22 Cavity resin supply end 26 Branch flow 60 Partition section 61 Inlet space 62 Merging space 63 Split flow generating passage 64 Flow not split

 ──────────────────────────────────────────────────続 き Continued from the front page F term (reference) 4F206 AA03 AA11 AA13 AA24 AA29 AA31 AB12 AF08 AG01 JA07 JB28 JF01 JF46 JL02 JM01 JM04 JN01 JN14 JQ81

Claims (13)

[Claims] 1. A method for producing a woodgrain-like molded product, wherein a molten resin containing a first material and a second material having a different color from the first material is supplied to a cavity to form a woodgrain pattern. As the resin, a material in which the first material and the second material are in an incompletely mixed state is used. Before the molten resin enters the cavity, the molten resin is in an incompletely mixed state along the cavity resin supply end. And supplying the molten resin from the state to the plurality of branch streams arranged in the direction along the cavity resin supply end while facing the cavity resin supply end, and merging the plurality of branches. Manufacturing method of preform. 2. The method for producing a woodgrain-like molded product according to claim 1, wherein, when the plurality of shunts are generated, a stream that is not shunted is overlapped with the plurality of shunts. 3. The method for producing a woodgrain-shaped product according to claim 2, wherein the side on which the non-divided flow flows is set as the surface side of the woodgrain-shaped product. 4. The method for producing a woodgrain-like molded product according to claim 2, wherein a side on which the plurality of divergent flows flows is set as a surface side of the woodgrain-like molded product. 5. The method for manufacturing a woodgrain-like molded product according to claim 1, wherein, when the plurality of divided flows are generated, all of the molten resin supplied to the cavity is changed to the plurality of divided flows. . 6. A woodgrain-like molded product manufacturing apparatus in which a runner is connected to a cavity resin supply end via a gate, and a molten resin is supplied into the cavity from the cavity resin supply end via the runner and the gate. A runner is extended along the cavity resin supply end, and the gate sequentially forms a plurality of branch generation passages in an extending direction of the runner at an entrance portion of the gate to form the molten resin in a parallel state. A woodgrain-like molding, comprising: a plurality of partitions for a plurality of branches; and a joining space formed from the plurality of partitions to the outlet of the gate to merge the plurality of branches. Product manufacturing equipment. 7. The device according to claim 6, wherein the gate is provided in a region where the plurality of partitions exist.
An apparatus for producing a woodgrain-like molded product, wherein an inlet space is provided so as to be continuous with the junction space while overlapping the plurality of partitions. 8. The gate according to claim 7, wherein the gate is constituted by an opening / closing die, and the plurality of partition portions are provided in a mold of the opening / closing die that constitutes a back surface side of a woodgrain molded product. A woodgrain injection molded article manufacturing apparatus, characterized in that: 9. The gate according to claim 7, wherein the gate is constituted by an opening / closing die, and the plurality of partition portions are provided in a die of the opening / closing die that constitutes a surface side of a woodgrain molded product. A woodgrain injection molded article manufacturing apparatus, characterized in that: 10. The apparatus according to claim 6, wherein the gate is provided with only the plurality of partitions at an entrance of the gate. 11. The cavity resin supply end according to claim 6, wherein both ends in the extending direction of the runner are disposed so as to surround the cavity resin supply end, and the outlet of the gate is provided on the cavity resin supply end side. An apparatus for producing a woodgrain molded article, characterized in that it faces both sides. 12. A molten resin containing a first material and a second material having a color different from the first material in an incompletely mixed state is supplied to the cavity through the gate under a plurality of branch flows. After solidification, the product part formed in the cavity and the gate corresponding resin part formed in the gate are integrally connected, and a plurality of diversion traces are formed on at least the surface of the product part. A first material solidification portion in which the first material solidifies so that the branch mark extends in the widthwise inner side of each branch mark in the direction in which the branch mark extends, and at both sides in the width direction of each branch mark; And a second material solidification part in which the second material solidifies by extending in the direction of extension of each of the first material solidification parts. , The traces of the plurality of diverted passages A plurality of the diversion occurring passage ATOBE, and a film-like portion that is continuous with the plurality of shunt occurrence passage Keigo connected to the product portion, it woodgrain molded article characterized by the Te. 13. The device according to claim 12, wherein the gate-corresponding resin portion is continuous with the film-shaped portion while overlapping with the plurality of branch flow generation passage traces in an existence region of the plurality of branch flow generation passage traces. A woodgrain-like molded product comprising an inlet film portion.