WO2009103805A1 - Procédé et dispositif de moulage par injection-compression de préformes - Google Patents

Procédé et dispositif de moulage par injection-compression de préformes Download PDF

Info

Publication number
WO2009103805A1
WO2009103805A1 PCT/EP2009/052068 EP2009052068W WO2009103805A1 WO 2009103805 A1 WO2009103805 A1 WO 2009103805A1 EP 2009052068 W EP2009052068 W EP 2009052068W WO 2009103805 A1 WO2009103805 A1 WO 2009103805A1
Authority
WO
WIPO (PCT)
Prior art keywords
cavities
melt
cores
cavity
metering
Prior art date
Application number
PCT/EP2009/052068
Other languages
German (de)
English (en)
Inventor
Stefan Bock
Original Assignee
Netstal-Maschinen Ag
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 Netstal-Maschinen Ag filed Critical Netstal-Maschinen Ag
Publication of WO2009103805A1 publication Critical patent/WO2009103805A1/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
    • B29C45/02—Transfer moulding, i.e. transferring the required volume of moulding material by a plunger from a "shot" cavity into a mould cavity
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
    • B29C45/561—Injection-compression moulding
    • 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
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/28—Closure devices therefor
    • B29C45/2806—Closure devices therefor consisting of needle valve systems
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/461—Injection of measured doses
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/53—Means for plasticising or homogenising the moulding material or forcing it into the mould using injection ram or piston
    • B29C45/54—Means for plasticising or homogenising the moulding material or forcing it into the mould using injection ram or piston and plasticising screw
    • 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
    • B29C45/64—Mould opening, closing or clamping devices
    • B29C45/68—Mould opening, closing or clamping devices hydro-mechanical
    • B29C45/681—Mould opening, closing or clamping devices hydro-mechanical using a toggle mechanism as mould clamping device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/25—Solid
    • B29K2105/253—Preform

Definitions

  • the invention relates to a method for compression injection molding of preforms by means of an injection molding machine with a movable tool carrier plate having a mold half with cores and a stationary tool carrier plate, which is associated with a mold half with a plurality of mold cavities, wherein the melt on the side of the stationary tool carrier plate on metered valves are introduced into the mold cavity or cavities and the cores are so far penetrated into the cavities before completion of the melt dosage that the cavities are at least substantially closed to the outside.
  • the invention further relates to a device for compression injection molding of preforms by means of an injection molding machine, a movable and a stationary tool carrier plate with a mold cavity with a plurality of mold cavities, wherein the movable mold half is formed with a core carrier plate and with cores and the melt supply into the cavities arranged on the side of the stationary tool carrier plate and the injection nozzle to the mold cavities or cavities valve-closed is closed.
  • preforms are produced in the classical spheroidal casting process by means of injection molding machines with a horizontal axis.
  • injection molding machines with a horizontal axis.
  • the raw material is fed in granular form via a funnel to a plasticizing unit and prepared.
  • a valve between the plasticizing screw and an injection piston is opened and metered into a melt deposit placed upstream of the injection piston.
  • the melt is injected in batches by way of hot runner nozzles into each of the cavities of the injection mold.
  • the injection piston generates a sufficient hydraulic pressure over the required time.
  • the preform is cooled rapidly. After, for example, 14 seconds, the mold halves are opened by withdrawing the core side of the tool or the corresponding movable mold half and the preforms are removed from the open mold halves.
  • the corresponding technology has reached a high level today, so that up to 200 preforms with the highest quality can be produced in short cycle times.
  • JP 620 90 210 proposes for a vertical press. A portion of processed melt is placed in the still open mold halves, and then the mold halves are closed with respect to the outer contours of the mold. As a next step, a plunger moves with the complementary bottom shape of the Container is formed, with a corresponding compression pressure and gives the molded parts the definitive shape.
  • EP 567 870 shows a hydraulic press for the production of plastic parts in the compression method. Again, the machine axis or the direction of movement of the movable mold half is vertical. In each case, a metered portion of melt is inserted into the open lower half of the mold and the exact part shape is produced by closing the molds. About appropriate control medium, the closing movement or the speed profile of the upper mold half can be controlled.
  • JP 202 21 0808 proposes to produce preforms with an analogous concept.
  • liquid melt is metered into the open cavity. Thereafter, the core, which generates the interior of the preform, retracted into the cavity and at the same time closed the mold.
  • the amount of melt is chosen so large that with closed mold halves, the cavities are completely filled. It is not known to the applicant whether this solution could ever be put into practice.
  • JP 2001 000 219518 is another solution for the automated production of preforms.
  • the core is retracted before introducing the liquid melt in upright cavities. Thereafter, the melt is metered from below into the cavity via a valve-controlled spray nozzle, the core with the movable mold half is completely retracted, at the same time the mold is closed and the compression pressure is applied.
  • the exact dosage can be adjusted by equalizing flows between the cavity and the valve needle vestibule.
  • the patents GB 2 430 642 and GB 2 430 643 show two further solutions for the compression injection molding of preforms.
  • the injection mandrel moves horizontally in the direction of the solid mold half.
  • the hot melt is on the side of the cavity via a controllable injection valve according to the injection cycle in the Cavity introduced.
  • the solution is based on several plates, which are movable to the open side of the cavities. It is proposed a movable plate with the cores and a displaceable relative to the plate with the cores neckring plate.
  • the plate with the cavities is formed with a sealing contact with a cylindrical outer portion of the cores.
  • the object of the invention was therefore to search for solutions which allow 50 to 200 and more preforms to be produced by the compression spraying method in one cycle, without any qualitative losses with respect to comparably large injection molding machines of the prior art, for example according to WO 2004 / 073953, with the aim of shortening the machine cycle time for the production of preforms over the prior art.
  • the method according to the invention is characterized in that the cores occupy a filling or metering position around the cores to produce a ring flow, and the melt is introduced for each cavity in a predosed amount.
  • the inventive device is characterized in that by means of the cores, the open Preformtime are lockable to the outside and the Device has a control device for positioning the core carrier plate or the cores in a metering position and pre-metered amounts of melt are introduced into the cavities, wherein the compression pressure for the production of the part shape in the individual cavities can be generated via the cores.
  • mold cavities are at least substantially closed to the outside before metering and the cores are moved into a filling or metering position
  • melt is introduced as a ring flow of a pre-metered amount of melt into the cavity, preferably until it is completely filled
  • Compression pressure preferably on a second stop. It is not mandatory that the cores occupy an exact position in the metering position.
  • the cores can be moved via a control device within a filling area in such a way that the annular inflow of the melt into the cavity is optimized. For example, with the flow pressure of the melt, the core can be pushed back slightly until completion of the dosage. It is important that after completion of the dosage, the cavity is filled with the pre-dosed amount of melt and the cores occupy a predeterminable dosing position before the compression pressure starts.
  • the compression pressure is built up and maintained for several seconds.
  • a hot plastic mass at a pressure of about 1000 bar is such a strong elastic material that it is more than 10% compressible equal to a spring. Due to the fact that the metering pressure can be chosen much lower with, for example, 50 to 200 bar, the metering is correspondingly less affected by the compression behavior of the melt mass. This means that the dosage is better controllable and thus can be brought to a higher accuracy.
  • Another advantage is that the sealing behavior of the cores and cavities with increasing compression pressure is better because on the one hand on the outer sealing surfaces applied a higher sealing pressure and on the other hand, the sealing length with the deeper penetration of the cores is greater.
  • the decisive advantage of the new invention is that, on the one hand with pre-dosed quantities a) the dosage for all preforms can be brought to a higher level with respect to the dosing accuracy with respect to an exact and equal dosage for each of the mold cavities, b) the dosing time can be massively shortened. This is because the dosage is prepared immediately before each mold cavity or each cavity and the predosing during the time Preforment casserole and the next dosing phase is prepared. A particularly important point is that a pre-metered identical amount of melt is simultaneously introduced into each of the mold cavities. This also has the great advantage that, for example, an exact final metering by a correction from a shrinkage compensation space is possible.
  • the new invention allows a number of particularly advantageous embodiments. It is for the claims 2 to 12 and 14 to 27 reference.
  • the injection molding machine is designed as a horizontal machine, with horizontally movable mold half.
  • the first melt jet In a horizontal position of the machine or the mold cavity meets after opening a valve needle, the first melt jet symmetrically directly to the top of the cores and is then deflected into a ring flow.
  • part of this melt may adhere to the tip, with the advantage that this particularly delicate batch cools down first.
  • the injection molding machine can also be designed as a vertical machine.
  • the second movement for the compression pressure can be delayed, but with the maximum possible closing force close to the extended position of the toggle lever on a second adjustable stop or stop.
  • the drive of the movable mold half hydraulically or electrically, in particular via a linear drive or a servomotor take place.
  • the core movement with maximum accuracy controlled repeatable regulated in the phase of cavity filling and selectively positioned without mechanical stop or programmed as a movement sequence.
  • the dosage is prepared for each one dosing for each shot and for each mold cavity in an upstream dosing antechamber.
  • the pre-metering quantity in the metering antechamber is codetermined by a double valve associated with each mold cavity, which valve is designed as an injection valve on one end side and as a feed valve on the other end side of a valve needle.
  • the injection valve is alternately opened in the mold cavity or in the entrance to the dosing antechamber in a shrinkage compensation chamber and the opposite each output closed.
  • the individual metering antechambers can be designed as metering cylinders to which a piston plate with a respective ejection piston moves relatively for each metering antechamber, so that the pre-metered melt quantity is introduced identically and at the same time over the shortest possible path into all mold cavities.
  • the introduction of the melt into the cavities is controlled to be intersecting with the retraction movement of the cores into the cavities.
  • the ejection piston the pre-metering quantity is determined.
  • this dosing antechamber is additionally preceded by a shrinkage compensation chamber for each mold cavity, so that during the first shrinkage phase of the preform still melt can flow into the mold cavity.
  • the input into the shrinkage compensation chamber is closed.
  • the metering of the melt can take place in the mold cavity itself.
  • the cores are controlled so far introduced into the cavities until a pre-definable dosing set is. This presupposes that the movable tool carrier plate for the metering position is positionally and wegêt / -geregelt, so that adjusts a desired metering in the cavity.
  • the mold cavity can be filled in essentially any repeatable way and thus the exact pre-metering of the melt quantity can be achieved.
  • a high metering pressure of, for example, 50 to 250 bar, preferably 100 to 200 is required so that the melt can be introduced at high speed into the most distant cavity areas of the cavity, in particular the threaded portion of the preforms, and further that all cavities have the same filling conditions to have. Fast filling prevents premature local cooling of the melt in the edge area of the cavities.
  • the compression pressure In contrast to the relatively low dosing pressure, usually less than 200 bar, the compression pressure should be brought to 300 to 600 bar.
  • the new solution takes advantage of the compression pressure very much advantage.
  • a plasticizing screw itself since it primarily has the task of melt processing, a pressure pump with a poor efficiency.
  • the mechanical pressure generation during compression molding with the cores is optimal in relation to the required energy.
  • FIG. 1 shows a schematic overview of an injection molding machine for the production of preforms of the prior art
  • FIG. 2a shows the tool and injection side of a device according to the invention
  • FIGS. 2 b to 2 e show four different positions of the tool or of the tool
  • FIG. 2b shows a start position with open shapes.
  • the Figure 2c shows the neck rings, already retracted.
  • FIG. 2d shows the end of the pre-metering, and
  • FIG. 2e shows a situation in the compression phase; the form drive with toggle levers and a closed
  • Mold schematically the angle range ⁇ for the closing process until the end of the filling or dosing; the angular range ⁇ of the compression phase; c three positions when retracting a neck ring and a core into a cavity;
  • Figure 4a shows the neck ring and the core in the retracted position; in Figure 4b, the neck ring is already in a sealing position; in the figure 4c, the core is retracted in a metering position;
  • c schematically three positions for the metering and the compression phase; schematically shows the melt supply into the cavity with a Dosiervorraum and a shrinkage compensation space for the melt for a preform; shows a second adjustable stop; shows a first adjustable stop; schematically shows an injection molding machine with vertical
  • Ax a combination of an inventive solution with an extruder and a Fi-Fo-melt storage. Ways and embodiments of the invention
  • FIG. 1 shows an entire injection molding machine of the prior art for the production of preforms 10 with a machine bed 1, on which a fixed tool carrier plate 2 and an injection unit 3 and a support plate 4 are mounted.
  • a movable tool carrier plate 5 is supported axially displaceably on the machine bed 1.
  • the fixed tool carrier plate 2 and the support plate 4 are interconnected by four bars 6, which enforce the movable tool carrier plate 5 and lead.
  • a drive unit 7 Between the support plate 4 and the movable tool carrier plate 5 is a drive unit 7 for generating the closing movement and the closing pressure.
  • the fixed tool carrier plate 2 and the movable tool carrier plate 5 each carry a mold half 8 and 9, in each of which a plurality of cores 24 and cavities 60 is arranged, which together form the mold cavities for producing a corresponding number of sleeve-shaped injection molded parts.
  • the sleeve-shaped injection-molded parts 10 adhere to the cores 24.
  • the preforms 10 are still in a semi-solid state at this time and are indicated by broken lines.
  • the same injection-molded parts 10 in the finished cooled state are shown in FIG. 1 at the top left, where they are just dropped from a post-cooling device 19.
  • the upper spars 6 are shown interrupted for the purpose of better showing the details between the open mold halves.
  • FIG. 1 shows the four most important handling phases for the preforms 10 after completion of the injection process:
  • A is the removal of the injection molded parts or preforms 10 from the two mold halves 8, 9.
  • the still semi-rigid sleeve-shaped parts are thereby received by a in the space between the open mold halves 8, 9 and a lowered into the position "A” removal device 11 and with this in the position "B” raised (receiving device 11 'in Figure 1).
  • B is the transfer position of the removal device 11 with the preforms 10 at a transfer gripper 12 ("B” in Fig. 1).
  • C is the transfer of the preforms 10 from the transfer gripper 12 to a
  • FIG. 1 shows, as it were, snapshots of the four main steps for handling after removal from the mold halves 8, 9.
  • the sleeve-shaped preforms 10 arranged vertically one above the other are taken over by the transfer gripper 12 or 12 'and by pivoting the transfer device in the direction of the arrow P in a position horizontally next to each other, according to the phase "C" brought.
  • the transfer gripper 12 consists of a pivotable about an axis 13 holding arm 14, which carries a holding plate 15 to the parallel spacing a support plate 16 is arranged for cores 24.
  • the support plate 16 can be raised by means of two hydraulic devices 17 and 18 parallel to the holding plate 15, so that in the position "B" the sleeve-shaped injection molded parts 10 are retrieved from the removal device 11 and pushed by the pivoted to the position "C" position in the overlying Nachkühl uncomfortable 19 can be.
  • the respective transfer takes place by increasing the distance between the holding plate 15 and the support plate 16.
  • the still semi-rigid preforms 10 are ready-cooled in the aftercooling device 19 during three to four cycles and then, after a displacement of the Nachkssel owned 19, in the position "D" expelled and thrown on a conveyor belt 20.
  • FIGS. 2a to 2e show the solution according to the invention.
  • the cores 24 are extended.
  • the tool is in open position.
  • the movable tool carrier plate 5 is at the far left.
  • the neck rings 62 are shown with the Neckringaniplatte 80 in disengaged position, immediately after the removal of the preforms of a previous injection cycle.
  • the neckring support plate 80 is supported or guided on the movable tool carrier plate 5 and can perform its own driving movement via a drive 23, not shown.
  • the movable tool carrier plate 5 is fixedly connected to a core carrier plate 81, so that the cores 24 are moved directly with the positive locking.
  • the mold cavity 82 may also be slidably guided on the spars 6.
  • a hot runner plate 83 which is part of a two-part tool, consisting of the hot runner plate 83 and the mold cavity 82. These two plates are relatively displaceable. As will be explained below, with the corresponding relative movement, melt can be metered into the mold cavities.
  • the mold cavity 82 can be moved for this purpose by a drive 23 which is supported on the movable tool carrier plate 5.
  • the drive 23 presses the cavity plate 82 in the direction of the hot runner plate 83, wherein a spring 84 is tensioned ( Figure 2b). With the relaxation of the spring 84, the mold cavity 82 is moved to the left and filled a Dosiervorraum 70 with new melt during the opening movement of the positive connection.
  • the injection unit 3 consists of a plasticizing unit 31 with a plasticizing screw 32, a feed hopper 26 for the granulate feed and an injection nozzle 28 with corresponding drives 35.
  • 33 denotes a reservoir for additives which are metered into the plasticizing space by means of a pump 34 , It is important that with a plasticizing screw 32 in the zone X a good mixing is achieved.
  • the plasticizing screw 32 performs by means of motor 35 a rotary movement and a linear displacement.
  • the entire injection unit 3 can be moved horizontally, as indicated by arrow 36, so that the injection nozzle 28 is moved into or out of contact with the hot runner plate 83.
  • FIG. 2b shows the injection molding tool in the starting situation for one injection cycle, wherein the mold halves are open and the cores 24 are in the retracted position.
  • FIG. 2c already shows the preparation of a spraying cycle.
  • the neck rings 62 have penetrated into the inlet region of the cavities 60 and close the corresponding outer edge. The valve is still in closed position.
  • FIG. 2d shows, as a subsequent step, the metering process, the first phase of the injection process.
  • the cores 24 are retracted, as shown by arrow 85, into a filling or metering position of the cores 24 within the cavities 60. At the same time, this is the beginning of the melt dosage into the cavities 60 according to arrow 86.
  • FIG. 2e already shows the compression phase as a third phase.
  • the cores 24 are pressed according to double arrow 87 by a compression path in the cavity 60 with filled melt.
  • the valves are already closed. After the start of the compression phase, a new dosing quantity is prepared for the next injection cycle.
  • FIG. 3a shows the form-locking side with the two tool halves 8, 9 in the closed position.
  • the horizontal displacement is accomplished by a column nut adjustment and primarily needed for adaptation for different thicknesses.
  • the toggle mechanism 40 consists of a crosshead 41 and four tab connections 42, further comprising four 5-point toggle levers, each of the 5-point toggle lever having a first toggle lever 43 and a second toggle lever 44. Both are connected via a common knee joint 45.
  • the knee lever 43 are connected via bearings 46 at articulation points 47 with the drive support plate 4.
  • the knee lever 44 are connected via bearings 48 at articulation points 49 with the movable tool carrier plate 5.
  • the crosshead 41 is via the tab connection 42 via joints 50 and 52 with the respective knee levers 43 in engagement.
  • the tab connection 42 may be formed as a longer lever, so that the power transmission ratio is improved.
  • the toggle drive 55 consists of a cylinder 56 and a piston rod 51.
  • the cylinder 56 is connected via a flange to the crosshead 41.
  • the Piston rod 51 has a piston rod end bearing 53, which is connected via a piston rod abutment 54 with the drive support plate 4.
  • FIG. 3b schematically shows an angle range ⁇ for the closing process until the end of the metering phase.
  • FIG. 3c shows the angular range ⁇ of the compression phase.
  • Figures 4a to 4c show schematically three situations when retracting a core 24 and the neck ring 62, 62 ', 62 "in a cavity 60.
  • the cavity 60 is determined in the cylindrical part by a cooling sleeve 61.
  • the outer contour, in particular the entire threaded portion of the preform 10 is determined by a neck ring 62.
  • the entire inner shape of the preform 10 is formed by the core 24 ( Figure 4c).
  • the core 24 moves with the movable mold half 8 in a horizontal direction. The same applies to the neck ring 62, 62 ', 62 ", as far as the retraction movement into the cavity 60 is concerned.
  • the neck ring 62 In order to free the threaded portion of the preform 10, the neck ring 62 must be split so that the two halves can move transversely to the horizontal motion, as shown in FIG. 4a. At the beginning of an injection cycle, the neck ring 62 is first closed and closed to the cavity 60 until a tight seal is achieved (FIG. 4b). Finally, the core 24 moves into the cavity 60 ( Figure 4c).
  • FIGS. 5a to 5g show seven situations according to the new solution with the compression molding method.
  • FIGS. 5a and 5c correspond to FIGS. 4a and 4b.
  • FIG. 5 c shows that the cores 24 are not yet completely retracted into the cavity 60.
  • FIG. 5d shows the same core position as in FIG. 5c; however, a metered amount of melt (dotted) has already been injected into the cavity 60.
  • the compression phase is expressed in FIG. 5e (preform black).
  • FIG. 5f shows the core 24 already extended and
  • FIG. 5g shows the release of the preform 10.
  • Figures 6a to 6e show a preferred embodiment in which the melt is predosed before injection into the cavity 60.
  • the dosing room 70 has a cylindrical shape, so that a corresponding piston 71 analogous to a piston pump can make a presettable displacement movement.
  • the metering antechamber 70 is filled.
  • the injection opening 103 is closed with the valve needle tip 104.
  • a shrinkage compensation chamber 75 also remains fully filled.
  • the core 24 is already moving into a metering position.
  • the metering antechamber 70 is preceded by a shrinkage compensation chamber 75.
  • FIG. 6b shows the beginning of the dosage.
  • the metering antechamber 70 and the shrinkage compensation chamber 75 are filled.
  • FIG. 6 c shows the actual filling phase or metering phase of the cavity 60.
  • the valve needle 73 is retracted to the right.
  • the injection nozzle 74 is open.
  • the filling opening 115 is closed with the rear valve seat 106.
  • the piston 71 is already shifted to the right according to arrow 116 and is in the process of displacing the melt in the metering antechamber 70 and metering it into the cavity 60.
  • FIG. 6d shows the phase of the shrinkage compensation after the compression phase.
  • the valve 106 is in the retracted position and closes the filling opening 107.
  • the compression pressure prevails both in the shrinkage compensation chamber 75 and in the cavity 60.
  • a compensating flow, at least during the first cooling or shrinking phase of the preform 10, takes place via the free connecting passage 117 , Thus, the shrinkage is compensated by the melt under compression in the heated shrinkage compensation space 75.
  • FIG. 6 e shows the situation at the end of the cooling or shrinking phase.
  • the valve needle tip 104 has already closed the injection opening 103.
  • the metering antechamber 70 and the shrinkage compensation chamber 75 can be refilled for the next injection cycle.
  • the great advantage of a solution according to FIGS. 6a to 6e lies in the fact that during the mold opening and closing of the mold again a pre-metered amount of melt can be provided. This results in a time saving for an injection cycle of 1 to 3 seconds. With a preform with 4 mm wall thickness and 25 grams of weight is expected in the latest state of the art with about 14 seconds cycle time, with the hold time about 6 seconds and the remaining cooling time about 3 seconds.
  • the shrinkage can be up to 8% in extreme cases.
  • the dosing phase itself can be reduced to 1/2 - 1 second.
  • the injection of the melt from the chambers into the cavities 60 must be initiated.
  • a damping of any kind such as a spring 84 to drive, which generates a higher back pressure against the closing forces than needed for injecting the melt from the melt chambers for filling the cavities 60
  • Hydraulic cylinders would be conceivable, which would accompany the entire stroke and close the valve in the desired position by means of a displacement transducer. These cylinders could also absorb the closing movement in a short construction to initiate the injection stroke, but after the injection process this would be a complete closure If the closing unit moves to the said damping, the force builds up on the piston plate and the melt is now forced into the cavities 60 (FIG.
  • the tool After completion of the cooling time, the tool is opened in a known manner. With the opening stroke of the closing unit, the refilling of the melt chambers can be initiated at the same time and the damping can be returned to its starting position, depending on the design.
  • the piston plate is pushed by the inflowing melt back into a presettable position.
  • the closure needles are controlled such that they keep the nozzles closed during the filling process in order to prevent the melt from flowing into the cavities 60 due to the filling pressure (FIG. 6e).
  • a shot pot can basically be dispensed with with the new solution.
  • a much cheaper extruder can be used in conjunction with a Fi-Fo melt storage according to patent application no. 0268/08 25.2.2008.
  • energy is saved on both solutions, since the injection process is no longer performed by a separate drive but by the already existing closing movement.
  • the content of this application is explained as an integral part of the present application.
  • the piston plate must be designed so that it can be heated with integrated cartridges. These can be arranged, for example, in the pistons or heating plates in a sandwich construction. It is also important to ensure that the leakage material, which is likely to occur in chip form, can fall out of the individual pistons free.
  • the cleaning process Hesse fine air ducts in the piston significantly improve from which the Leckagematehal can be blown out at intervals still to be determined by means of air blasts.
  • the amount of leakage late neck will be very small anyway due to the small expected pressures as described above. In addition, this amount can be determined constructively by the design of the gap. Without leakage, however, can not be worked because the material also acts as a lubricant.
  • FIG. 7 a the cavity 60 is used as a metering antechamber 70 by a predetermined retraction of the core 24.
  • the cavity 60 On the open end side of the preform 10, the cavity 60 is substantially sealed by the neck ring 62 and the core 24.
  • the melt is injected into the cavity 60 at a preselectable melt pressure and the valve is closed at the metering end (FIG. 7c). Only now does the compression phase begin, in which the core 24 is pressed into the cavity 60 with full closure force and the melt is compacted.
  • a nozzle heating belt 63 is arranged to the injection nozzle 28 .
  • FIG. 8a shows a particularly advantageous embodiment of the melt dosage according to FIGS. 6a to 6e.
  • the device has for this purpose a metering antechamber 70 which is connected to a melt transfer channel 100 and an extruder, according to arrow 101.
  • a valve needle 105 is arranged, which according to Figure 8a, the injection port 103 with the valve needle tip 104 closed.
  • the valve needle 105 has a valve body 106, which closes the valve seat 107 in the opposite position.
  • the valve needle 105 is actuated by a piston 108, which within a cylinder 109 by means of a Pneumatikmediunns 112 and valves 110 and 111 is controlled in the required cycle of the injection cycle.
  • the pneumatic medium 112 is shown with larger dots and the melt with fine dots.
  • the melt is heated, at least in the metering antechamber 70, in the melt transfer channel 100 by means of heating elements 113.
  • FIG. 8a shows an interplay between refilling the metering antechamber 70 and transferring the metering chamber volume into the cavity 60. For this purpose, the entire device 114 moves to the right. Because the melt transfer into the cavities 60 takes place independently of the flow in the melt transfer channel 100, the time previously required for filling the cavity 60 can be saved. This time saving can be on the order of 1 to 4 seconds, which means a considerable increase in productivity with a total cycle time of, for example, 12 seconds.
  • FIG. 8b shows the arrangement of two adjustable wedges 64, 65 between the hot runner plate 83 and the plate 67 as a second stop.
  • the second stop can be adjusted, this by means of a controlled drive 66.
  • the exact dosage or the way of Dosierkolbens 71 can be preset.
  • FIG. 9 shows diagrammatically a Sphtzgiessmaschine with vertical axis 120. From the function, however, correspond to all parts of a machine with a horizontal axis.
  • FIG. 10 shows a combination of the new invention with an extruder 89 and a multiplicity of miniature shot pots 90, whose most important components are: a metering antechamber 70, a valve needle 105, displacement piston 95 and a pneumatic cylinder 109.
  • the extruder 89 performs a constant rotating movement out.
  • the displacement piston 95 performs primarily a linear movement in the rhythm of the injection cycle. Analogously, the displacement piston 95 moves in time with the piston 108 and the valve needle 105.
  • Additives 33 can by means of a Pump 34 are supplied to the plasticization.
  • the extruder 89 may be shorter than the plasticizing screw 32 according to FIG. 2a.
  • the extruder 89 consists of an extruder screw 91 and an extruder barrel 92.
  • the granules are fed via a feed hopper 26 to the extruder 89.
  • the drive motor 93 may be a simple electric motor, since it only has to ensure a rotary movement for the extruder screw 91.
  • the peculiarity of this solution is that immediately after the extruder 89 a Fi-Fo memory 94 is arranged.
  • the fi-fi accumulator 94 has the peculiarity that the melt leaving the extruder 89 first also leaves the Fi-Fo accumulator 94 first and is fed into the melt transfer passage 100.
  • a displacement piston 95 moves according to arrow 96 from top to bottom and vice versa.
  • the displacement piston 95 is primarily axially driven, but may additionally perform a rotary motion, especially if it is a mixer.
  • the Fi-Fo function also applies to the melt flowing directly from the extruder 89 into the Fi-Fo reservoir 94.
  • discharging the melt from the Fi -Fo storage 94 flows the melt from the extruder 89 as a parallel flow with the Extruderaustrag and is fed directly into the dosing Vorraum 90, 70.

Abstract

La présente invention concerne un procédé et un dispositif de moulage par injection-compression de préformes (10) au moyen d'une presse d'injection comprenant une plaque porte-outil mobile (5) qui présente un demi-moule (8) doté de noyaux (24), et une plaque porte-outil fixe (2) à laquelle est associé un demi-moule doté de plusieurs cavités de moulage (60). Les noyaux (24) adoptent une position de remplissage ou de dosage afin de produire un écoulement annulaire autour des noyaux (24). Avant la fin du dosage de matière fondue, les noyaux (24) pénètrent dans les cavités de moulage (60) jusqu'à ce que les cavités de moulage soient au moins sensiblement fermées par rapport à l'extérieur. La matière fondue est introduite dans les cavités de moulage (60) de façon dosée alors que le moule n'est pas encore complètement fermé, les vannes sont fermées et la pression de compression est créée au moyen des noyaux (24).
PCT/EP2009/052068 2008-02-21 2009-02-20 Procédé et dispositif de moulage par injection-compression de préformes WO2009103805A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CH00248/08 2008-02-21
CH2482008 2008-02-21
CH00623/08 2008-04-22
CH6232008 2008-04-22

Publications (1)

Publication Number Publication Date
WO2009103805A1 true WO2009103805A1 (fr) 2009-08-27

Family

ID=40874742

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2009/052068 WO2009103805A1 (fr) 2008-02-21 2009-02-20 Procédé et dispositif de moulage par injection-compression de préformes

Country Status (1)

Country Link
WO (1) WO2009103805A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITMI20131556A1 (it) * 2013-09-20 2015-03-21 Magic Mp Spa Gruppo di formatura di preforme di contenitori in materiale termoplastico
EP4008518A1 (fr) * 2020-12-01 2022-06-08 Sacmi Imola S.C. Presse de moulage par injection pour le moulage de préformes

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4243620A (en) * 1975-06-13 1981-01-06 Motosacoche S.A. Method of manufacturing an object in plastics material and object obtained thereby
DE3133872A1 (de) * 1981-08-27 1983-03-17 Deutsche Solvay-Werke Gmbh, 5650 Solingen "verfahren und vorrichtung zur herstellung von formteilen oder gegenstaenden aus kunststoff"
JPS5949896B2 (ja) * 1978-12-05 1984-12-05 凸版印刷株式会社 多層延伸中空容器の製造方法
US5662856A (en) * 1995-07-12 1997-09-02 Imesco, Inc. Low-pressure method for the preparation of hollow plastic articles
US5833899A (en) * 1997-09-23 1998-11-10 Wunderlich; Ernst Dieter Method for the preparation of method articles by single and multi-layer compression and apparatus therefor
JP2003025397A (ja) * 2001-07-19 2003-01-29 Toyo Seikan Kaisha Ltd プリフォームの射出圧縮成形法
DE10239339A1 (de) * 2002-08-28 2004-03-11 Sig Blowtec Gmbh & Co. Kg Vorrichtung zum Zwischenspeichern von plastifiziertem Kunststoff
WO2005018905A1 (fr) * 2003-08-16 2005-03-03 Im-Pak Technologies Limited Pieces moulees en plastique
US20080265466A1 (en) * 2005-10-03 2008-10-30 Im-Pak Technologies Limited Injection Impact Compression Moulding

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4243620A (en) * 1975-06-13 1981-01-06 Motosacoche S.A. Method of manufacturing an object in plastics material and object obtained thereby
JPS5949896B2 (ja) * 1978-12-05 1984-12-05 凸版印刷株式会社 多層延伸中空容器の製造方法
DE3133872A1 (de) * 1981-08-27 1983-03-17 Deutsche Solvay-Werke Gmbh, 5650 Solingen "verfahren und vorrichtung zur herstellung von formteilen oder gegenstaenden aus kunststoff"
US5662856A (en) * 1995-07-12 1997-09-02 Imesco, Inc. Low-pressure method for the preparation of hollow plastic articles
US5833899A (en) * 1997-09-23 1998-11-10 Wunderlich; Ernst Dieter Method for the preparation of method articles by single and multi-layer compression and apparatus therefor
JP2003025397A (ja) * 2001-07-19 2003-01-29 Toyo Seikan Kaisha Ltd プリフォームの射出圧縮成形法
DE10239339A1 (de) * 2002-08-28 2004-03-11 Sig Blowtec Gmbh & Co. Kg Vorrichtung zum Zwischenspeichern von plastifiziertem Kunststoff
WO2005018905A1 (fr) * 2003-08-16 2005-03-03 Im-Pak Technologies Limited Pieces moulees en plastique
US20080265466A1 (en) * 2005-10-03 2008-10-30 Im-Pak Technologies Limited Injection Impact Compression Moulding

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 198501, Derwent World Patents Index; AN 1985-004354, XP002538521 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITMI20131556A1 (it) * 2013-09-20 2015-03-21 Magic Mp Spa Gruppo di formatura di preforme di contenitori in materiale termoplastico
EP4008518A1 (fr) * 2020-12-01 2022-06-08 Sacmi Imola S.C. Presse de moulage par injection pour le moulage de préformes

Similar Documents

Publication Publication Date Title
EP1558434B1 (fr) Procede et dispositif pour le traitement ulterieur et le refroidissement de preformes
EP0647514A1 (fr) Moule d'injection
EP2207663B1 (fr) Dispositif de soufflage-étirage et procédé de fabrication de préformes
DE2034163A1 (de) Spntzgußmaschine
EP2252446B1 (fr) Procédé et dispositif de moulage par injection-compression de préformes
DE102005037116B3 (de) Verfahren zur Herstellung eines Formteils, insbesondere Spritzgießverfahren
WO2009103805A1 (fr) Procédé et dispositif de moulage par injection-compression de préformes
EP0207932B1 (fr) Dispositif pour le moulage assisté en pression, en particulier le moulage par injection, de pièces moulées
EP1420930B1 (fr) Procede et dispositif de production automatique de plaques minces
AT517860B1 (de) Verfahren und Vorrichtung zur Herstellung zumindest eines Formteils
EP1804995B1 (fr) Procede d'estampage par injection de materiau thermoplastique
WO2009103803A1 (fr) Procédé de préparation d'une masse fondue et unité de plastification
DE3541382C2 (fr)
DE2327268A1 (de) Verfahren und vorrichtung zum herstellen von formkoerpern aus expandierbarem polystyrolschaum
DE1291104B (de) Spritzgiessform zum Herstellen von Gegenstaenden aus thermoplastischem Kunststoff
DE2419509C3 (de) Verfahren und Vorrichtung zum Herstellen von Formteilen
DE3803793C1 (en) Apparatus and process for producing mouldings from plastic
DE1040229B (de) Vorrichtung zum Formen von hohlen Gegenstaenden aus organischen thermoplastischen Kunststoffen
DE1554999C (de) Vorrichtung zum Herstellen von Form teilen durch Gießen von flüssigen Zwei oder Mehrkomponenten Kunststoffen in For men
DE1479777C3 (de) Vorrichtung zum Spritz-Blas-Formen eines hohlen Gegenstandes aus thermoplastischem Kunststoff
DE1554999B2 (de) Vorrichtung zum herstellen von formteilen durch giessen von fluessigen zwei- oder mehrkomponenten-kunststoffen in formen
AT407725B (de) Verfahren zur herstellung eines formkörpers aus kunststoff
DE2154441C3 (de) SpritzgieBeinrichtung zur Herstellung von Gegenständen aus Kunststoff, mit mehreren auf einer geschlossenen Bahn angeordneten Formeinheiten
DE2010994A1 (en) Transfer moulding with reduced material wastage
DE2855200A1 (de) Verfahren und vorrichtung zum formen von kunststoffgegenstaenden

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09713566

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09713566

Country of ref document: EP

Kind code of ref document: A1