+

WO1993004838A1 - Procede de moulage par injection dans une machine de moulage par injection - Google Patents

Procede de moulage par injection dans une machine de moulage par injection Download PDF

Info

Publication number
WO1993004838A1
WO1993004838A1 PCT/JP1992/001075 JP9201075W WO9304838A1 WO 1993004838 A1 WO1993004838 A1 WO 1993004838A1 JP 9201075 W JP9201075 W JP 9201075W WO 9304838 A1 WO9304838 A1 WO 9304838A1
Authority
WO
WIPO (PCT)
Prior art keywords
synthetic resin
injection molding
plasticized synthetic
mold
cavity
Prior art date
Application number
PCT/JP1992/001075
Other languages
English (en)
Japanese (ja)
Inventor
Akira Yokota
Original Assignee
Komatsu Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Komatsu Ltd. filed Critical Komatsu Ltd.
Publication of WO1993004838A1 publication Critical patent/WO1993004838A1/fr

Links

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

Definitions

  • the present invention relates to an injection molding method for an injection molding machine in which a plasticized synthetic resin having a high melt viscosity and a low fluidity is injected and filled into a mold cavity from within a cylinder of an injection molding machine body.
  • Injection molding enables molding with high dimensional accuracy, and among various injection molding materials, for example, ultra-high molecular weight polyethylene, fluororesin, etc. have impact resistance, abrasion resistance, self-lubrication, chemical resistance, etc. Due to its superiority, it is being widely used for various machine parts, household goods, and other applications.
  • plasticizable synthetic resins such as ultrahigh molecular weight polyethylene and fluororesin have high melt viscosity and extremely low fluidity, and are difficult to mold using ordinary injection molding methods.
  • the plasticized synthetic resin is injected from the thin cylinder of the injection molding machine into the cavity of the desired molded product volume of the mold through the gate of the mold. At the end of the injection filling, the plasticized synthetic resin in the gate section is solidified with a constant so-called holding pressure in order to inject a fixed amount of plasticized synthetic resin into the cavity. Fill the plasticized synthetic resin over a period of time until constant.
  • the plasticized synthetic resin is injected and charged so that the average resin pressure inside the cavity of the plasticized synthetic resin to be injected is about 300 to 500 Iig / cn] 2. merely being, also about from 300 to 5 () 0 kg / contraction amount due to cooling because cni an average ⁇ pressure of 2 is large it I phase ⁇ , injecting a predetermined amount of resin into wire carrier within Activity Takashi ⁇ As described above, it is necessary to fill the plasticized synthetic resin with a constant holding pressure until the gate portion solidifies as described above.
  • the present invention has been made in order to solve such a problem, and it is an object of the present invention to provide an injection molding method for an injection molding machine in which laminar separation does not occur.
  • the injection molding method of the injection molding machine according to the present invention achieves the above-mentioned object. 9 Basically,
  • the plasticized synthetic resin is rapidly and rapidly applied under a reduced pressure into a cavity having a target molded product volume of the mold or exceeding the target molded product volume.
  • Injection-filling is performed so that the plasticized synthetic resin to be injected-filled has a relatively high resin pressure, and after this injection-filling, the inside of the cylinder of the injection molding machine body and It is characterized in that it comprises an injection filling step of stopping the flow of the plasticized synthetic resin between the inside of the mold cavity and the flow immediately and immediately.
  • the plasticized synthetic resin When the plasticized synthetic resin is injected and filled into the mold cavity from inside the cylinder of the injection molding machine, the plasticized synthetic resin is set at high speed and high pressure. Thus, the plasticized synthetic resin is injected and filled without giving time to cool and solidify.
  • the injection Takashi ⁇ is the ⁇ pressure Canon the Activity of plasticized synthetic resin is a relatively high average resin pressure, e.g., 1000 ⁇ 1500 kg / cm 2 approximately in so as to plasticize the synthetic resin injection charging ⁇ Therefore, since there is almost no shrinkage due to cooling and there is no need to consider the amount of shrinkage, basically, no pressure is required to inject and fill a predetermined amount of resin into the cavity.
  • the plasticized synthetic resin starts to solidify in the cavity, a predetermined amount of the plasticized synthetic resin has already been injected and filled into the cavity. After the injection filling, the plasticized synthetic resin flows into or out of the cavity between the cylinder of the injection molding machine body and the cavity of the mold. The flow of plasticized synthetic resin is stopped because it stops instantly and stops quickly. Therefore, since the plasticized synthetic resin of a predetermined amount injected and filled in the cavity does not move, it does not solidify in layers sequentially from the wall surface side of the cavity. No state separation occurs.
  • the quick stop including the instantaneous flow of the plasticized synthetic resin may be performed as follows.
  • the mold is formed after uniformization of the resin pressure distribution of the plasticized synthetic resin injected and filled into the cavity of the mold after a quick stop including the instantaneous flow of the plasticized synthetic resin.
  • a compression step may be provided in which a pressing force is applied to the movable mold to compress the plasticizable synthetic resin injected and filled in the cavity of the mold to a target molded product volume. . By performing such compression, the precision of the molded article can be improved.
  • the plastic pressure distribution of the plasticized synthetic resin injected and filled in the mold cavity is compressed after it is uniformed, the molded product will be like an optical lens. If, a uniform refractive index is obtained.
  • the uniformization of the resin pressure distribution of the plasticized synthetic resin is also performed by shrinkage due to cooling of the plasticized synthetic resin, elastic recovery stress, and the like.
  • plasticized synthetic resin having a high melt viscosity and a low fluidity examples include ultrahigh molecular weight polyethylene and fluororesin.
  • This ultra-high molecular weight polyethylene is obtained, for example, by Ziegler polymerization, has a much larger molecular weight than ordinary polyethylene, and has an extremely high melt viscosity among plasticized synthetic resins used for injection molding.
  • it is known as a resin that is more difficult to mold than other plasticized synthetic resins.
  • the fluororesin is a resin containing fluorine, such as a tetrafluoroethylene resin, a tetrafluoroethylene copolymer, a hexafluoropropylene copolymer resin, and a trifluorochloroethylene resin.
  • ultra high molecular weight polymers there is no particular limitation on the temperature at the time of injection of styrene, fluororesin, or the like, as long as it is substantially higher than the melting point of the resin and lower than the decomposition temperature of the resin.
  • FIG. 1 to 4 are drawings for explaining a preferred embodiment of an injection molding method for an injection molding machine according to the present invention
  • FIGS. 1 to 3 are semi-illustrated longitudinal sectional views of the whole of the injection molding machine of the first embodiment, enlarged longitudinal sectional views of relevant parts, and the injection pressure of the plasticized synthetic resin mold. A graph showing a change over time,
  • FIG. 4 is a half-illustrated longitudinal sectional view of the entire injection molding machine of the second embodiment.
  • HIZEX Million 3400 M which is an ultra-high molecular weight polyethylene
  • the injection temperature is set within a range of 170 to 240 t, which is substantially higher and lower than the decomposition temperature of the resin.
  • FIG. 1 shows the overall outline of the injection molding machine 1
  • an injection molding machine body 11 is joined at a nozzle portion 12 to a mold 10 for molding an injection molded product.
  • the pelletized or powdered material resin of the plasticized synthetic resin supplied from the material hopper 14 is melted and mixed in the heated cylinder 13. While kneading, the molten plasticized material resin is measured and the flow path 15 formed in the nozzle part 12 is further pierced, and further, as shown in FIG. Via the gate section 17, the mold 10 A screw 19 for injection charging is provided inside the W3PT JP9 tee 18.
  • the rotation of the screw 19 for melting and kneading the material resin is performed by a screw rotation motor 20.
  • the screw 19 and the screw rotation motor 20 are mounted on a base 21.
  • the base 21 controls a flow control valve 22 and an electromagnetic relief valve 23 by a control device 24.
  • a control device 24 controls the pressure oil supplied and discharged from the pressure oil source 25 to the hydraulic screw device 27 via the pipeline 26, it is driven right and left in FIG.
  • the pressing of the hydraulic oil to the hydraulic screw device 27 is performed by applying a predetermined pressing force to the screw 19 for setting the plasticized synthetic resin in the cylinder 13 to a predetermined injection pressure. It is performed via the base 21 by supply and discharge.
  • control device 24 has a stroke set value set in the stroke setter 28 and a screw measured by the screw position detector 29 engaged with the base 21.
  • the result of comparison with the user position value is provided by the comparator 30.
  • the control device 24 Based on the comparison result, the control device 24 performs the control operation of the flow control for the flow control valve 22 and the control of the pressure value setting control for the electromagnetic relief valve 23 according to a predetermined program.
  • the control of moving forward and backward toward the nozzle portion 12 and applying a predetermined pressing force is performed.
  • the control of the rotation or stop of the screw rotation motor 20 is also performed by the control device 24 in connection with the advance and retreat of the screw 19 and the like.
  • the mold 10 is an intermediate mold 32 for forming the cavity 18 with the fixed mold 31 joined to the nozzle 12 of the injection molding machine main body 1 1.
  • the movable mold 33, and the movable mold 33 advances and retreats to make the capacity of the desired cavity. It contracts and expands to the tee volume.
  • the movable mold 33 is engaged with a piston rod 35 of a compression cylinder 34, and the piston rod 35 is also controlled by a control device 24 to perform an excitation switching control for an electromagnetic switching valve 36 and an electromagnetic relief valve.
  • the pressure value setting control for 37 By controlling the pressure value setting control for 37, the pressure oil supplied from the pressure oil source 38 to the compression cylinder 34 via lines 39a and 39b is controlled to drive left and right in Fig. 1. Is done.
  • a return pin 40 is provided on the front side of the movable mold 33, and the return pin 40 comes into contact with the intermediate mold 32 when the movable mold 33 advances, thereby restricting the advance of the movable mold 33. As a result, the desired molded product volume of the capital 18 is secured.
  • a stop 41 is provided behind the movable mold 33, and the movable mold 33 comes into contact with the stop 41 when the movable mold 33 is retracted. This restricts the further expansion of the capacity of the Capability 18.
  • the intermediate mold 32, the movable mold 33 and the stopper 41 are integrally brought close to the fixed mold 31 by a known means, and the mold is closed.
  • the solenoid a of the electromagnetic switching valve 36 is excited, and the set pressure value of the electromagnetic relief valve 37 is set and controlled to the highest value in the settable range.
  • the highest pressure oil is supplied to the piston side 34a of the compression cylinder 34. With this supplied pressure oil, the pressure value of the hydraulic pressure in the piston side 34a of the compression cylinder 34 rises to the maximum value, and the screw rod 35 is driven rightward in FIG.
  • the movable die 33 is moved forward by the application of the pressing force until the re-injection pin 40 contacts the intermediate die 32. In this way, the capacity of the cavity 18 is ensured to the desired molded product volume (
  • the plasticized synthetic resin is introduced into the cavity 18 at high speed and high pressure, preferably for a short time of 0.1 to 0.8 seconds.
  • the set pressure value of the electromagnetic relief valve 23 is set to a high value, and pressurized oil is supplied from the pressurized oil source 25 to the hydraulic screw device 27. With the supplied pressure oil, the screw 19 is applied with a pressing force that is driven to the left in FIG. 1 and is advanced by a predetermined stroke set value set in the stroke setting device 28. The advance by the predetermined stroke set value is performed by controlling the flow rate of the pressure oil by the flow rate control valve 22.
  • the average resin pressure of the plasticized synthetic resin injected and filled into the cavity 18 of the desired molded product is a plasticized synthetic resin that has been melt-plasticized with a fixed amount of resin. , 500 kg / cm 2 at high pressure and high speed.
  • the solenoid a of the solenoid-operated switching valve 36 is de-energized and the compression cylinder 34 is compressed by passing the piston side 34a and the piston rod 35 side to the tank.
  • the intermediate mold 32, the movable mold 33 and the stopper 41 are separated from the fixed mold 31 by a known means, and the mold is moved. Open 10.
  • the solenoid a of the electromagnetic switching valve 36 is excited to supply the pressure oil from the pressure oil source 38 to the piston side 34a of the compression cylinder 34, and the piston rod 35 is moved to the position shown in FIG.
  • the solenoid a is deenergized
  • the solenoid b is energized
  • the solenoid relief valve b is energized.
  • Pressure oil is supplied from the source 38 to the screw rod 35 side of the compression cylinder 34, and the piston rod 35 is driven to the left in FIG. 1 to retreat the movable mold 33 to prepare for the next molding cycle.
  • the flow path 15 of the nozzle section 12 of the injection molding machine main body 11 is provided as a flow path opening / closing means that can prevent the flow of the plasticized synthetic resin between the inside of the cylinder 13 and the inside of the cavity 18.
  • a closing valve 50 is provided. The opening / closing operation of the closing valve 50 is performed by controlling the driving device 52 for driving the operating lever 51 engaged with the closing valve 50 by the control device 24.
  • the closing valve 50 is immediately closed to block the flow of the plasticized synthetic resin.
  • the inside of the cylinder 13 and the inside of the cavity 18 are immediately filled.
  • the flow of the plasticized synthetic resin between them is stopped.
  • the plasticizing synthetic resin is reduced by lowering the holding pressure in balance with the decrease in the resin pressure accompanying the progress of cooling, and in the second embodiment, by closing the shut-off valve 50. The flow is stopped.
  • a constant holding pressure is applied to the plasticized synthetic resin injected into the cavity 18 for a short time, for example, 0 to: L. 5 seconds, preferably 0.
  • the flow of the plasticized synthetic resin between the inside of the cylinder 13 and the inside of the cavity 18 may be stopped.
  • the plasticized synthetic resin is originally filled so that the resin pressure in the cavity 18 becomes a relatively high resin pressure. Since there is almost no shrinkage due to cooling and there is no need to consider the amount of shrinkage, the specified amount of resin is injected into the CAPTI 18 precisely, and the resin pressure inside the cavities 18 is reduced. It is sufficient time to balance the amount of resin charged in each cavity 18 in the case of a multi-cavity mold 10 with balance.
  • a predetermined amount of plasticized synthetic resin is injected and filled into the cavity 18 having a target molded product volume.
  • a predetermined amount of plasticized synthetic resin is injected and filled into the tee 18 exceeding the target molded product volume, and then the plasticized synthetic resin in the gate 17 is solidified into the movable mold 33.
  • the mechanism and hydraulic circuit of the injection molding machine 1 when setting the cavity volume of the cavity 18 so as to exceed the target molded product volume, the mechanism and hydraulic circuit of the injection molding machine 1 are changed within a range obvious to those skilled in the art. Needless to say, you need to do that.
  • the resin pressure distribution of the plasticized synthetic resin in the cavity 18 is made uniform, if the molded product is an optical lens or the like, A uniform refractive index can be obtained.
  • the uniformization of the resin pressure distribution of the plasticized synthetic resin in the cavity 18 is also performed by the elastic recovery stress of the plasticized synthetic resin and further by the shrinkage of the plasticized synthetic resin due to cooling.
  • the state of injection of the plasticized synthetic resin into the cavity 18 was not clarified, but the plasticized synthetic resin having a high melt viscosity and low fluidity was subjected to high speed and high pressure. In order to inject at, the powder is inevitably injected into the cavity 18.
  • the weight or shape variation among the molded products is reduced.
  • a molded article of excellent quality and appearance which does not occur and which does not cause layering or separation can be obtained.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)

Abstract

Procédé de moulage par injection dans une machine de moulage par injection permettant de procéder à l'injection et au chargement d'une résine synthétique plastique à viscosité fondue élevée et à faible fluidité. On injecte ladite résine dans la cavité d'un moule métallique dont le volume est égal ou supérieur à celui d'un produit moulé obtenu à partir du cylindre de la machine de moulage par injection, et cette injection s'effectue rapidement et sous pression élevée dans un laps de temps très court, par exemple de 0,1 à 1,0 secondes, afin d'assurer une pression de résine relativement élevée et comprise entre 1000 et 1500 kg/cm2. A la suite de l'injection et du chargement, on arrête rapidement ou instantanément, au besoin, l'écoulement de la résine synthétique plastique entre l'intérieur du cylindre de la machine de moulage par injection proprement dite, et l'intérieur de la cavité du moule métallique, ceci afin d'empêcher toute délamification.
PCT/JP1992/001075 1991-08-28 1992-08-26 Procede de moulage par injection dans une machine de moulage par injection WO1993004838A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP21707391 1991-08-28
JP3/217073 1991-08-28

Publications (1)

Publication Number Publication Date
WO1993004838A1 true WO1993004838A1 (fr) 1993-03-18

Family

ID=16698413

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP1992/001075 WO1993004838A1 (fr) 1991-08-28 1992-08-26 Procede de moulage par injection dans une machine de moulage par injection

Country Status (1)

Country Link
WO (1) WO1993004838A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6164421A (ja) * 1984-09-06 1986-04-02 Matsushita Electric Ind Co Ltd 分割樹脂鏡胴の製造方法
JPS6241853B2 (fr) * 1982-05-09 1987-09-04 Tekunopurasu Kk
JPH03254912A (ja) * 1990-03-05 1991-11-13 Komatsu Ltd 超高分子量ポリエチレンの射出成形方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6241853B2 (fr) * 1982-05-09 1987-09-04 Tekunopurasu Kk
JPS6164421A (ja) * 1984-09-06 1986-04-02 Matsushita Electric Ind Co Ltd 分割樹脂鏡胴の製造方法
JPH03254912A (ja) * 1990-03-05 1991-11-13 Komatsu Ltd 超高分子量ポリエチレンの射出成形方法

Similar Documents

Publication Publication Date Title
JPH0761662B2 (ja) 射出成形方法と装置
JP2770131B2 (ja) 射出成形方法及び射出成形機
WO1997015432A1 (fr) Procede de moulage par injection avec preplastification
EP1360056B1 (fr) Dispositif de dosage pour machine a mouler les matieres plastiques
US6875383B2 (en) Method and apparatus for injection molding
KR102386613B1 (ko) 물품을 미세성형하기 위한 방법
JP4871956B2 (ja) 成形方法及び成形装置
US20210268703A1 (en) Injection device and injection control method
JPH0490322A (ja) 射出圧縮成形方法
JP2883140B2 (ja) 射出成形機の充填量検出方法
WO1993004838A1 (fr) Procede de moulage par injection dans une machine de moulage par injection
JPH07299850A (ja) 射出成形方法
JPH0615707A (ja) 射出成形機の射出成形方法
US20060125151A1 (en) Pressure and temperature guidance in an in-mold coating process
JP2947852B2 (ja) 超高分子量ポリエチレンの射出成形方法
WO1993001926A1 (fr) Procede de moulage par injection-compression dans une machine de moulage par injection
JP6429923B2 (ja) 可塑化装置とプランジャ式射出装置とからなる射出装置の運転方法
JP2011240602A (ja) 射出成形方法、およびその装置
JPH0780226B2 (ja) 超高分子量ポリエチレンの射出圧縮成形方法
JP3232550B2 (ja) 射出圧縮成形における型締圧力の制御方法
US20060012062A1 (en) Method and apparatus for metering and controlling dispense rate
JP2024035492A (ja) 射出成形機および射出装置
JPH0639886A (ja) 射出成形方法
Gornik Microinjection Molding Machines
Haaxma Injection Molding

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA DE US

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载