JPH06293040A - Hollow injection molding method - Google Patents
Hollow injection molding methodInfo
- Publication number
- JPH06293040A JPH06293040A JP10599593A JP10599593A JPH06293040A JP H06293040 A JPH06293040 A JP H06293040A JP 10599593 A JP10599593 A JP 10599593A JP 10599593 A JP10599593 A JP 10599593A JP H06293040 A JPH06293040 A JP H06293040A
- Authority
- JP
- Japan
- Prior art keywords
- hollow
- hollow portion
- molten resin
- hollow part
- pressurized gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000001746 injection moulding Methods 0.000 title claims abstract description 10
- 239000011347 resin Substances 0.000 claims abstract description 35
- 229920005989 resin Polymers 0.000 claims abstract description 35
- 238000002347 injection Methods 0.000 claims description 23
- 239000007924 injection Substances 0.000 claims description 23
- 238000007599 discharging Methods 0.000 claims description 4
- 238000000465 moulding Methods 0.000 abstract description 12
- 238000001816 cooling Methods 0.000 abstract description 10
- 230000000694 effects Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 46
- 238000000034 method Methods 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/1703—Introducing an auxiliary fluid into the mould
- B29C45/1704—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/1703—Introducing an auxiliary fluid into the mould
- B29C45/1704—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
- B29C2045/1718—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles sealing or closing the fluid injection opening
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、金型キャビティ内に射
出した溶融樹脂中に加圧ガスを圧入して中空部を形成す
る中空射出成形方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow injection molding method for forming a hollow portion by pressurizing a pressurized gas into a molten resin injected into a mold cavity.
【０００２】[0002]
【従来の技術】従来、金型キャビティ内に射出した溶融
樹脂中に加圧ガスを圧入して中空部を成形する中空射出
成形方法と共に、加圧ガス圧入後再度溶融樹脂を射出し
て中空部を密閉することも知られている（特公昭５７−
１４９６８号）。2. Description of the Related Art Conventionally, along with a hollow injection molding method of pressurizing a pressurized gas into a molten resin injected into a mold cavity to mold a hollow portion, the molten resin is injected again after the pressurized gas is injected and the hollow portion is injected. It is also known to seal the
14968).
【０００３】[0003]
【発明が解決しようとする課題】ところで、上記中空射
出成形において、中空部を形成するために圧入される加
圧ガスは、溶融樹脂を押し退け移動させながら中空部を
拡大していくため、中空部末端付近は熱溜りとなりやす
い。従って、中空部末端付近以外の部分が十分冷却され
た状態で中空成形品を金型から取り出した場合でも、取
り出した後に中空部末端付近の冷却が進行して、当該部
分の表面に熱収縮によるひけを生じやすい。By the way, in the above hollow injection molding, the pressurized gas that is press-fitted to form the hollow portion expands the hollow portion while pushing away the molten resin to move the hollow portion. Heat tends to accumulate near the ends. Therefore, even when the hollow molded product is taken out from the mold in a state where the portion other than the vicinity of the hollow end is sufficiently cooled, cooling near the hollow end is progressed after taking out and the surface of the portion is affected by heat shrinkage. Prone to sink marks.
【０００４】一方、加圧ガス圧入後再度溶融樹脂を射出
して中空部を密閉し、中空部に高圧の加圧ガスを閉じ込
めた状態とした場合、上記中空部末端付近の冷却が不十
分のまま取り出すと、中空成形品に亀裂を生じるおそれ
がある。On the other hand, when the molten resin is injected again after pressurizing the pressurized gas to seal the hollow portion and the high pressure gas is confined in the hollow portion, the cooling around the end of the hollow portion is insufficient. If it is taken out as it is, the hollow molded product may be cracked.
【０００５】このようなことから、加圧ガスの圧入を伴
う中空射出成形においては、加圧流体を圧入して中空部
を形成した後、中空部末端付近まで十分に冷却固化して
から中空成形品を取り出しているため、成形サイクルが
長くなって成形効率が低下する問題がある。From the above, in hollow injection molding with pressurization of a pressurized gas, after pressurizing fluid is press-fitted to form a hollow portion, it is sufficiently cooled and solidified near the end of the hollow portion, and then hollow molding is performed. Since the product is taken out, there is a problem that the molding cycle becomes long and the molding efficiency is lowered.
【０００６】本発明は、このような従来の問題点に鑑み
てなされたもので、金型キャビティ内に射出した溶融樹
脂中に加圧ガスを圧入する中空射出成形において、中空
部末端付近の冷却が遅れることによる成形サイクルの遅
延を防止し、成形の効率化を図ることを目的とする。The present invention has been made in view of such conventional problems, and in hollow injection molding in which a pressurized gas is injected into a molten resin injected into a mold cavity, cooling near the end of the hollow portion is performed. The purpose of the present invention is to prevent the delay of the molding cycle due to the delay of molding and to improve the efficiency of molding.
【０００７】[0007]
【課題を解決するための手段】このために本発明では、
図１に示されるように、金型キャビティ１内に射出して
溶融樹脂中に加圧ガスを圧入して中空部２を形成する中
空射出成形方法において、射出路３を介して圧入した中
空部２内の加圧ガスを射出路３を介して排出した後、再
び溶融樹脂を射出して、中空部２を密閉すると共に中空
部２内を大気圧よりやや高い圧力に加圧し、しかる後に
中空成形品を金型４から取り出すこととしているもので
ある。To this end, in the present invention,
As shown in FIG. 1, in the hollow injection molding method of forming a hollow portion 2 by injecting a pressurized gas into a molten resin by injecting it into a mold cavity 1, the hollow portion press-fitted through an injection passage 3. After the pressurized gas in 2 is discharged through the injection path 3, the molten resin is injected again to seal the hollow portion 2 and pressurize the inside of the hollow portion 2 to a pressure slightly higher than the atmospheric pressure, and then to the hollow portion. The molded product is to be taken out of the mold 4.
【０００８】[0008]
【実施例及び作用】まず、本発明の方法では、図１
（ａ）に示されるように、金型キャビティ１内への溶融
樹脂の射出と加圧ガスの圧入を行い、中空部２を形成す
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS First, in the method of the present invention, FIG.
As shown in (a), the hollow resin 2 is formed by injecting the molten resin into the mold cavity 1 and pressurizing the pressurized gas.
【０００９】溶融樹脂は、金型キャビティ１内を満たす
に十分な量を射出するフルショットでも、金型キャビテ
ィ１内を満たすに足りない量を射出するショートショッ
トでもよい。The molten resin may be a full shot for injecting a sufficient amount to fill the mold cavity 1 or a short shot for injecting an insufficient amount to fill the mold cavity 1.
【００１０】加圧ガスの圧入は、ショートショットの場
合、射出すべき溶融樹脂を射出し終ってから開始して
も、溶融樹脂の射出途中で開始してもよい。また、フル
ショットの場合は溶融樹脂の射出完了後に開始され、冷
却に伴う樹脂の体積収縮に応じて圧入されることにな
る。In the case of a short shot, the pressurization of the pressurized gas may be started after the completion of the injection of the molten resin to be injected or during the injection of the molten resin. Further, in the case of full shot, it is started after the injection of the molten resin is completed, and the resin is press-fitted according to the volume shrinkage of the resin accompanying cooling.
【００１１】加圧ガスとしては、例えば空気や炭酸ガス
等でもよいが、窒素等の不活性ガスが好ましい。The pressurized gas may be, for example, air or carbon dioxide gas, but an inert gas such as nitrogen is preferable.
【００１２】本発明における加圧ガスの圧入は、射出路
３を介して行われるものである。この射出路３とは、金
型キャビティ１内に流入するまでに溶融樹脂が通る、金
型４に形成された溶融樹脂の通路のことで、具体的には
スプルー３ａやランナー３ｂが挙げられる。The pressurization of the pressurized gas in the present invention is performed through the injection passage 3. The injection path 3 is a passage for the molten resin formed in the mold 4 through which the molten resin flows before it flows into the mold cavity 1, and specifically includes the sprue 3a and the runner 3b.
【００１３】図１に示される方法における加圧ガスの圧
入は、射出ノズル５に内蔵されたガスノズル６によって
行われるもので、この場合の加圧ガスは、射出された溶
融樹脂と同様に、スプルー３ａからランナー３ｂを通っ
て金型キャビティ２へと圧入されることになる。The pressurization of the pressurized gas in the method shown in FIG. 1 is carried out by the gas nozzle 6 incorporated in the injection nozzle 5, and the pressurized gas in this case is the sprue like the injected molten resin. It will be press-fitted into the mold cavity 2 from 3a through the runner 3b.
【００１４】加圧ガスの圧入により中空部２を形成した
後、図１（ｂ）に示されるように、中空部２内の加圧ガ
スの排出を行う。この加圧ガスの排出は、圧入時と同様
に樹脂通路３を介して行われるもので、図１（ｂ）にお
ける加圧ガスは、圧入時とは逆にランナー３ｂからスプ
ルー３ａへと逆流して、ガスノズル６から回収タンク
（図示されていない）へと回収されるものとなってい
る。また、中空部２内の加圧ガスの排出は、このような
回収をせずに、射出ノズルを金型４から離し、加圧ガス
を大気に放出することで行うこともできる。After the hollow portion 2 is formed by pressurizing the pressurized gas, the pressurized gas in the hollow portion 2 is discharged as shown in FIG. 1 (b). This pressurizing gas is discharged through the resin passage 3 as in the press-fitting, and the pressurizing gas in FIG. 1 (b) flows backward from the runner 3b to the sprue 3a contrary to the press-fitting. Then, the gas is collected from the gas nozzle 6 to a collection tank (not shown). Alternatively, the pressurized gas in the hollow portion 2 can be discharged by separating the injection nozzle from the mold 4 and discharging the pressurized gas to the atmosphere without performing such collection.
【００１５】この加圧ガスの排出は、加圧ガスを圧入
し、中空部２内の圧力を保持したまま金型キャビティ１
内の樹脂をある程度冷却した後に行われるが、特に中空
部末端７付近の冷却が不十分な段階で行われる。加圧ガ
スの排出を行うタイミングは、成形する中空成形品の材
質、大きさ、肉厚、中空部２の大きさ等に応じて定めれ
ばよいが、中空部末端７付近以外の箇所における樹脂は
金型４から取り出し得る状態にまで冷却しておくことが
好ましい。。The discharge of the pressurized gas is performed by injecting the pressurized gas and maintaining the pressure in the hollow portion 2 in the mold cavity 1
This is performed after the resin inside has been cooled to some extent, but particularly at a stage where the vicinity of the hollow end 7 is insufficiently cooled. The timing at which the pressurized gas is discharged may be determined according to the material, size, wall thickness, size of the hollow portion 2 and the like of the hollow molded product to be molded, but the resin at a location other than the vicinity of the hollow end 7 Is preferably cooled to a state where it can be taken out from the mold 4. .
【００１６】中空部１内の加圧ガスを排出した後、金型
キャビティ１内の樹脂の冷却を続行しつつ、図１（ｃ）
に示されるように、再び溶融樹脂を少量射出する。この
溶融樹脂の再射出は、一旦降圧した中空部２内の圧力を
大気圧よりやや高い圧力まで昇圧すると共に、中空部２
を密閉して、金型４から中空成形品を取り出した後も中
空部２内の当該圧力を維持できるようにするものであ
る。After discharging the pressurized gas in the hollow portion 1, while continuing to cool the resin in the mold cavity 1, FIG.
Inject a small amount of molten resin again as shown in FIG. This re-injection of the molten resin raises the pressure in the hollow portion 2 that has once been reduced to a pressure slightly higher than atmospheric pressure, and
Is sealed so that the pressure in the hollow portion 2 can be maintained even after the hollow molded product is taken out from the mold 4.
【００１７】即ち、上記溶融樹脂の再射出により、射出
路３内へと通じていた中空部２は閉塞される。また、射
出路３内に残存していたガスもしくは大気が中空部２内
に押し込まれると共に、射出された溶融樹脂の一部が中
空部２内に入り込んで中空部２を狭めることによって、
中空部２内の圧力が高められることになる。That is, by the re-injection of the molten resin, the hollow portion 2 communicating with the injection passage 3 is closed. Further, the gas or the atmosphere remaining in the injection passage 3 is pushed into the hollow portion 2, and a part of the injected molten resin enters the hollow portion 2 to narrow the hollow portion 2,
The pressure inside the hollow portion 2 is increased.
【００１８】このような再射出を行った後中空成形品を
取り出すと、中空部末端７付近の冷却が不十分であって
も、取り出された中空成形品の内側からの保圧効果が残
存しているので、当該中空部末端７付近の冷却に伴うひ
けの発生が防止される。また、中空部２内に残存する圧
力は再射出する溶融樹脂量によって制御できると共に、
高い圧力を要しないので、取り出し後の成形品の変形や
亀裂発生の心配もないものである。When the hollow molded article is taken out after such re-injection, the pressure holding effect from the inside of the taken out hollow molded article remains even if the cooling in the vicinity of the hollow end 7 is insufficient. Therefore, the sink mark caused by cooling around the hollow end 7 is prevented. Further, the pressure remaining in the hollow portion 2 can be controlled by the amount of molten resin to be re-injected, and
Since high pressure is not required, there is no concern about deformation or cracking of the molded product after taking it out.
【００１９】溶融樹脂再射出後の中空部２内の圧力は大
気圧の１．１〜１．３倍であることが好ましい。この中
空部２内の圧力が低過ぎると、中空部末端７付近が冷却
不十分なまま中空成形品を取り出した時の当該部分のひ
けを防止しにくくなる。逆に中空部２内の圧力が高過ぎ
た場合、取り出した中空成形品の中空部末端７付近が冷
却不十分であると、内圧によって当該部分が変形したり
破裂しやすくなる。The pressure inside the hollow portion 2 after the re-injection of the molten resin is preferably 1.1 to 1.3 times the atmospheric pressure. If the pressure in the hollow portion 2 is too low, it becomes difficult to prevent sink marks in the hollow portion 2 when the hollow molded product is taken out with insufficient cooling near the end 7 of the hollow portion. On the contrary, if the pressure in the hollow portion 2 is too high and the hollow end portion 7 of the hollow molded product taken out is insufficiently cooled, the portion is likely to be deformed or burst due to the internal pressure.
【００２０】図１における加圧ガスの圧入と排出は、射
出ノズル５に内蔵されたガスノズル６を用いて行われる
が、このようなガスノズル６を用いずに行うこともでき
る。The pressurization and discharge of the pressurized gas in FIG. 1 are performed using the gas nozzle 6 built in the injection nozzle 5, but it is also possible to perform without using such a gas nozzle 6.
【００２１】即ち、射出ノズル５とは別個に、射出路３
に開口する加圧ガス流路（図示されていない）を金型４
に設けておくことで、加圧ガス流路を介して加圧ガスの
圧入と排出を行うことができる。この場合、加圧ガス排
出後の溶融樹脂の再射出は、射出ノズルから分岐通路
（図示されていない）を経てこの加圧ガス流路に溶融樹
脂を導くことで行うことができる。That is, separately from the injection nozzle 5, the injection path 3
Pressurized gas flow path (not shown) opening to the mold 4
By disposing the pressure gas, it is possible to pressurize and pressurize the pressurized gas through the pressurized gas flow path. In this case, the re-injection of the molten resin after discharging the pressurized gas can be performed by guiding the molten resin from the injection nozzle to the pressurized gas flow path through a branch passage (not shown).
【００２２】上記の場合、中空部２内の加圧ガスの排出
時に、前述と同様に回収タンク（図示されていない）へ
と加圧ガスを回収することも可能である。また、中空部
２内の加圧ガスの排出時に、切り換え弁（図示されてい
ない）を切り換えて、加圧ガス流路８を大気に解放する
ことで、中空部２内の加圧ガスを大気に放出することも
可能である。In the above case, when the pressurized gas in the hollow portion 2 is discharged, it is also possible to recover the pressurized gas into a recovery tank (not shown) as described above. When the pressurized gas in the hollow portion 2 is discharged, the switching valve (not shown) is switched to open the pressurized gas passage 8 to the atmosphere, so that the pressurized gas in the hollow portion 2 is released to the atmosphere. It is also possible to release it.
【００２３】[0023]
【発明の効果】本発明は、以上説明した通りのものであ
り、中空部末端７付近が冷却不十分な状態で中空成形品
を取り出してもひけや変形、更には亀裂を生じないの
で、冷却時間を短縮することができ、成形サイクルを短
くすることで成形効率を向上させることができるもので
ある。EFFECTS OF THE INVENTION The present invention is as described above, and even if a hollow molded article is taken out in a state where the hollow end 7 is insufficiently cooled, sink marks, deformation, and cracks do not occur. The time can be shortened and the molding efficiency can be improved by shortening the molding cycle.
【００２４】ちなみに、同じ中空成形品について、全体
を十分冷却してから取り出す従来の方法による場合と、
本発明の方法により中空部末端７付近が冷却不十分なま
ま取り出し場合とで成形時間を比較したところ、前者で
は１サイクル８５秒要したのに対し後者では１サイクル
５０秒で、３５秒短縮可能であった。また、後者である
本発明の方法によった場合、中空成形品にひけ、変形及
び破裂は発生しなかったのに対し、前者である従来の方
法での成形サイクルを５０秒にすると、中空部末端７付
近の表面でひけが発生した。By the way, with respect to the same hollow molded article, the conventional method in which the whole is sufficiently cooled and then taken out,
When the molding time was compared with the case of taking out with insufficient cooling in the vicinity of the hollow end 7 by the method of the present invention, one cycle required 85 seconds for the former, whereas one cycle 50 seconds for the latter, 35 seconds can be shortened. Met. Further, in the case of the latter method of the present invention, sink marks, deformation and rupture did not occur in the hollow molded article, whereas when the molding cycle of the former conventional method was 50 seconds, the hollow portion A sink mark occurred on the surface near terminal 7.
【図１】本発明の一実施例を示す説明図である。FIG. 1 is an explanatory diagram showing an embodiment of the present invention.
１ 金型キャビティ ２ 中空部 ３ 射出路 ３ａ スプルー ３ｂ ランナー ４ 金型 ５ 射出ノズル ６ ガスノズル ７ 中空部末端 1 Mold Cavity 2 Hollow Part 3 Injection Path 3a Sprue 3b Runner 4 Mold 5 Injection Nozzle 6 Gas Nozzle 7 Hollow End
Claims (1)
に加圧ガスを圧入して中空部を形成する中空射出成形方
法において、射出路を介して圧入した中空部内の加圧ガ
スを射出路を介して排出した後、再び溶融樹脂を射出し
て、中空部を密閉すると共に中空部内を大気圧よりやや
高い圧力に加圧し、しかる後に中空成形品を金型から取
り出すことを特徴とする中空射出成形方法。1. A hollow injection molding method for forming a hollow portion by injecting a pressurized gas into a molten resin by injecting it into a mold cavity, and injecting a pressurized gas in the hollow portion, which is pressed in through an injection passage. After discharging through the passage, the molten resin is injected again to seal the hollow portion and pressurize the inside of the hollow portion to a pressure slightly higher than the atmospheric pressure, and then the hollow molded product is taken out from the mold. Hollow injection molding method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10599593A JPH06293040A (en) | 1993-04-09 | 1993-04-09 | Hollow injection molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10599593A JPH06293040A (en) | 1993-04-09 | 1993-04-09 | Hollow injection molding method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06293040A true JPH06293040A (en) | 1994-10-21 |
Family
ID=14422305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10599593A Withdrawn JPH06293040A (en) | 1993-04-09 | 1993-04-09 | Hollow injection molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06293040A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008087484A1 (en) * | 2007-01-11 | 2008-07-24 | Itw Automotive Products Gmbh & Co. Kg | Method for injection molding of hollow articles of plastic material |
-
1993
- 1993-04-09 JP JP10599593A patent/JPH06293040A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008087484A1 (en) * | 2007-01-11 | 2008-07-24 | Itw Automotive Products Gmbh & Co. Kg | Method for injection molding of hollow articles of plastic material |
| US7998395B2 (en) | 2007-01-11 | 2011-08-16 | Itw Automotive Products Gmbh & Co. Kg | Method for injection molding of hollow articles of plastic material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3118645B2 (en) | Gas assisted injection molding method and apparatus for injection molded articles | |
| JPH0720637B2 (en) | Injection molding method and apparatus for hollow molded article | |
| JPH0735058B2 (en) | Hollow molding method | |
| KR100870596B1 (en) | Die cast apparatus and casting method | |
| JPH06293040A (en) | Hollow injection molding method | |
| JPH08229992A (en) | Hollow molding device | |
| JPH0872109A (en) | Method and device for injection molding synthetic resin molded article | |
| JP2001047472A (en) | Mold for injection molding | |
| JP2537985B2 (en) | Plastic molding method | |
| JPH0824990A (en) | Method and device for completing casting process after weightless casting of especially easily oxidizable metal or alloy in casting mold particularly in green sand mold | |
| JP3407987B2 (en) | Storage method of resin molding die and resin sealing method of electronic component | |
| US7998395B2 (en) | Method for injection molding of hollow articles of plastic material | |
| JPH08252661A (en) | Metal injection molding method and apparatus | |
| JP2005053074A (en) | Valve gate type injection molding method | |
| JP3418495B2 (en) | Injection molding method | |
| JPH10291227A (en) | Blow molding and its forming method | |
| JPH08216178A (en) | Injection and compression hollow molding method and apparatus | |
| JP2002192572A (en) | Mold | |
| JP3287694B2 (en) | Injection molding method for thermoplastic resin molded articles and mold equipment for injection molding | |
| JP2874835B2 (en) | Gas injection molding die and gas injection molding method using the same | |
| JPH0478510A (en) | Production of hollow resin product | |
| JPH06218517A (en) | Casting method | |
| JPS5924492Y2 (en) | Synthetic resin injection mold | |
| JP3423427B2 (en) | Injection molding method for automotive door handle cover | |
| JPH0929774A (en) | Injection molding method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000704 |