CA1268013A - Device for manufacturing molded articles of plastics material - Google Patents
Device for manufacturing molded articles of plastics materialInfo
- Publication number
- CA1268013A CA1268013A CA000547481A CA547481A CA1268013A CA 1268013 A CA1268013 A CA 1268013A CA 000547481 A CA000547481 A CA 000547481A CA 547481 A CA547481 A CA 547481A CA 1268013 A CA1268013 A CA 1268013A
- Authority
- CA
- Canada
- Prior art keywords
- closing needle
- duct
- plastics material
- opening
- closing
- 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.)
- Expired - Lifetime
Links
- 239000004033 plastic Substances 0.000 title claims abstract description 55
- 229920003023 plastic Polymers 0.000 title claims abstract description 55
- 239000000463 material Substances 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 7
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 34
- 238000004891 communication Methods 0.000 claims abstract description 6
- 230000006872 improvement Effects 0.000 claims description 2
- 238000006073 displacement reaction Methods 0.000 description 5
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- 238000007789 sealing Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000001746 injection moulding Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- -1 for example Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 230000007704 transition Effects 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
- B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
- B29C44/34—Auxiliary operations
- B29C44/36—Feeding the material to be shaped
- B29C44/38—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length
- B29C44/42—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length using pressure difference, e.g. by injection or by vacuum
- B29C44/424—Details of machines
- B29C44/425—Valve or nozzle constructions; Details of injection devices
-
- 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
- B29C45/16—Making multilayered or multicoloured articles
- B29C45/1603—Multi-way nozzles specially adapted therefor
- B29C45/1606—Multi-way nozzles specially adapted therefor using a rotatable valve
-
- 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
- B29C45/16—Making multilayered or multicoloured articles
- B29C45/1642—Making multilayered or multicoloured articles having a "sandwich" structure
-
- 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
- B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
- B29K2105/043—Skinned foam
Abstract
ABSTRACT OF THE DISCLOSURE
A device for manufacturing molded articles of plastics material which have an outer skin of a plastics material free of expanding agents and a porous core of a plastics material containing an expanding agent includes an extruder head with a main duct in communication with a discharge opening. Two feed ducts for the two plastics materials lead angularly offset into the main duct at locations axially spaced from the discharge opening and from each other. A closing needle is axially movably placed in the main duct. The two feed ducts can be separated from the main duct by means of the closing needle. The closing needle defines a connecting duct extending essentially in axial direction. The connecting duct ends at the end face of the closing needle and at the circumference of the closing needle radially toward the more remote feed duct. In the closed axial position of the closing needle and in an at least partially open axial position of the closing needle, the radial circumferential opening of the connecting duct is located approximately on the same level as the inner radial outlet opening of the more remote feed duct.
The closing needle is rotatable about the longitudinal axis of the extruder head relative to the outlet opening in any axial position of the closing needle.
A device for manufacturing molded articles of plastics material which have an outer skin of a plastics material free of expanding agents and a porous core of a plastics material containing an expanding agent includes an extruder head with a main duct in communication with a discharge opening. Two feed ducts for the two plastics materials lead angularly offset into the main duct at locations axially spaced from the discharge opening and from each other. A closing needle is axially movably placed in the main duct. The two feed ducts can be separated from the main duct by means of the closing needle. The closing needle defines a connecting duct extending essentially in axial direction. The connecting duct ends at the end face of the closing needle and at the circumference of the closing needle radially toward the more remote feed duct. In the closed axial position of the closing needle and in an at least partially open axial position of the closing needle, the radial circumferential opening of the connecting duct is located approximately on the same level as the inner radial outlet opening of the more remote feed duct.
The closing needle is rotatable about the longitudinal axis of the extruder head relative to the outlet opening in any axial position of the closing needle.
Description
BACKGROUND OF T~E INVENTION
1. Field of the Invention The present invention relates to a device for manufacturing molded articles of plastics material which~have an outer skin preferably of a plastics material free of expanding agents and a core, preferably a porous core of plastics material containing an expanding agent. The device includes an extruder head with a main duct in communication with a discharge opening. Two feed ducts for the two plastics materials lead angularly offset into the main duct at locations axially spaced from the discharge opening and from each other. A closing needle is placed axially movable in the main duct. The two feed ducts can be separated from the main duct by means of the closing needle. The closing needle defines a connecting duct extending essentially in axial direction. The connecting duct ends, on the one hand, at the end face of the closing needle and, on the other hand, at the circumference of the closing needle radially toward the more remote feed duct.
1. Field of the Invention The present invention relates to a device for manufacturing molded articles of plastics material which~have an outer skin preferably of a plastics material free of expanding agents and a core, preferably a porous core of plastics material containing an expanding agent. The device includes an extruder head with a main duct in communication with a discharge opening. Two feed ducts for the two plastics materials lead angularly offset into the main duct at locations axially spaced from the discharge opening and from each other. A closing needle is placed axially movable in the main duct. The two feed ducts can be separated from the main duct by means of the closing needle. The closing needle defines a connecting duct extending essentially in axial direction. The connecting duct ends, on the one hand, at the end face of the closing needle and, on the other hand, at the circumference of the closing needle radially toward the more remote feed duct.
2. Description of the Prior Art An extruder head of the above-described type is already known from German Offenlegungsschrift 3,247,000. This extruder head is characterized in that, in the closed position ~2~8~13 of the closing needle and seen in axial direction from the discharge opening, the connecting duct provided in the closing needle emerges radially from the closing needle,in front of the more remote feed duct. This extruder head is additionally characterized in th~t the distance between the front edge of the inner radial outlet opening of the connecting duct and the free end face of the closing needle is greater than the smallest axial distance between the front edge oE the front feed duct and the front edge of the rear duct, on the one hand, and smaller than the greatest axial distance be-tween the front edge of the front feed duct and the rear edge of the rear feed duct, on the other hand.
Compared to other known extruder heads as disclosed, for example, in German Utility Model ~,034,352, the extruder head according to German Offenlegungsschrift 3,247,000 has the advantage that in an extruder head which is structurally as complicated, it is possible during the injection procedure to effect a continuous transition from one plastics material to the other plastics material and vice-versa, without requiring the use of special locking devices. Moreover, it is possible, if necessary, to inject into a mold a plastics r.laterial without expanding agent as well as a plastics material containing an expanding agent separately from each other without the use of special locking devices.
1, .
Compared to other known extruder heads as disclosed, for example, in German Utility Model ~,034,352, the extruder head according to German Offenlegungsschrift 3,247,000 has the advantage that in an extruder head which is structurally as complicated, it is possible during the injection procedure to effect a continuous transition from one plastics material to the other plastics material and vice-versa, without requiring the use of special locking devices. Moreover, it is possible, if necessary, to inject into a mold a plastics r.laterial without expanding agent as well as a plastics material containing an expanding agent separately from each other without the use of special locking devices.
1, .
-3- 1 ~26~0~3 The device of the type described above for manufacturing molded articles from plastics material is deficient in that, when an injection molding procedure is carried ~ut with the plastics material containing an expanding agent, a so-called afterpressure can be exerted on the plastics material already in the mold only if an intermediate stop means is provided in the feed range for the plastics material with an expanding agent, i.e., if the extruder head is operated with a spec~al control in order to achieve sealing.
It has been found that, due to the sluggish movements resulting from this type of control, the reproducibility of the desired result, i.e., sealing, is not always ensured.
Another deficiency of known devices for manufacturing molded particles of plastics material as disclosed, for example, in German patent 2,342,789, is that, due to the subsequent injection with plastics material free of expanding agents, the respective closing needle must press the plastics material in front of it into the sprue. While this can be done easily in foamed molded articles having relatively thick walls, this cannot be achievea in molded articles having thin walls because the sprue has usually at this time already hardened.
126~)13 It is an object of the present invention to further develop a device for the manufacture of molded articles of plastics material of the above-specified type.
Another object is to make it possible to operate plastics material flows having different temperatures and different types of plastics material, for example, plastics material free of expanding agents and plastics material containing an expanding agent.
In accordance with the present invention there is provided a device of the above-specified type the improvement comprising, in the closed axial position of the closing needle as well as in at least partially open axial position of the closing needle, the radial circumferential opening of the connecting duct is located approximately on the same level as the inner radial outlet opening of the more remote feed duct. In addition, the closing needle, or its radial circumferential opening, is rotatable about the longitudinal axis of the extruder head relative to the outlet opening in any axial position of the closing needle.
~L268013 The device according to the present inven~ion has the particular advantage that the supply of plastics material free of expanding agent used for forming the compact outer skin of the molded articles can be interrupted with the aid of the closing needle without the respective plastics material being displaced into the sprue of the mold.
In accordance with another Eeature of the presen-t invention, the axial width of the radial circumferential opening of the connecting duct at the closing needle is approximately twice the axial width of the outlet opening at the corresponding feed duct.
As a result, the connecting duct remains connected to the corresponding feed duct at least over a portion of the distance of axial displacement of the closing needle. As a result, it is possible simultaneously to feed plastics material containing expanding agent and plastics material free of expanding agent into the mold connected to the extruder head.
The operation of the extruder head according to the present invention is optimized if the angle of rotation of the closing needle in the extruder head is limited. Thus, the connecting duct in the closing needle can be connected to or separated from the corresponding Eeed duct in a very simple manner.
~ . I
'. I
- ~26c~L3 The extruder head according to the present invention is of particularly simple c~nstruction if the radial circumferential opening of the connecting duct~is formed directly in the closing neecle. However, it may be advantageous in some cases t~ provide the radial circumferential opening for the connecting duct in a sleeve which is mounted rotatably on -the circumference of the closing needle. In this situa-tion, the closing needle itselE only has to be moved axially, ~hile tle sleeve containing the radial circumferential opening may be seated so as to be rotatable within the housing of the extruder head.
In accordance with anol er advantageous structural feature of the present invention, the axial distance between the two openings of the two feed ducts into the main duct is approximately twice the axial width of the openings of the feed ducts.
In accordance with another feature of the present invention, the translational and rotational movements of the closing needle are carried out optionally either simultaneously or one after the other. However, it is also possible to couple, or make capable of coupling, the translational and the rotational movements of the closing needle.
.
Finally, the closing needle may be arranged in the housing of the extruder head so as to be movable only in axial direction, while the sleeve is mounted so as to be rotatable only by a limited angle.
The device according to the present invention can be used as a machine nozzle as well as a nozzle for a hot duct system for a multiple component injection molding process.
For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the drawings and descriptive matter in which there is illustrated and described by way of example, a preferred embodiment of the invention.
In the drawings:
Figures 1 through 6 are longitudinal sectional views of the extruder head according to the present invention, showing the portions of the extruder head which are essential for the present invention in different positions of operation.
30~3 DETAILED DESCRIPTION OF THE INVENTION
The drawings show of a device for manufac!turing molded articles of plastics material having a compact outer skin of plastics material free of expanding agent and a porous core of plastics material containing an expanding agent, only an extruder head 1 whlch is connected through a nozzle 2 to a sprue bushing 3 of an injection mold, not shown.
\
A main duct 5 which receives a closing needle 6 extends from the nozzle 2 coaxially through a housing 4 through of the extruder head 1. Closing needle 6 includes a shaft 7 extending rearwardly through the extruder head 1, The shaft 7 is engaged by a displacement drive, not shown, which can be actuated, for example, by a pressure medium, particularly a hydraulic medium.
The end of the closing needle 6 defines a sealing cone 8 which interacts with an appropriately shaped sealing cone 9 in nozzle 2 when the closing needle 6 is in the advanced sealing position, as clearly illustrated in Figs. 1, 5 and 6.
At a distance from nozzle 2 which contains an outlet opening 10 opens a feed duct 11 into main duct 5 of housing 4.
At the opening into the main duct 5, the feed duct 11 is inclined at a predetermined angle, for example, of 30 to 40. 1.
The feed duct 11 is connected at its other end leading out of il the extruder head 1 to an injection unit, not shown.
, i _ ~6B~13 A-t a distance from nozzle 2 which is smaller than the distance of the opening of feed duct 11 into main duct 5 from throttle 2, another feed duct 12 opens into main duct 5 also at a predetermined angle of, for example, 30 to 40 . This feed duct 12 also preferably extends toward the rear out of extruder head 1 and is connected at this other end to an injection unit, not shown.
Openings 1~ and 14 of the two feed ducts 11 and 12 in-to main duct 5 are preferably located on circumferentially \
opposite portions of main duct 5 and are axially offset relative to each other by a di.stance 15 which preferably is twice the size of the axial width of the two openings 13 and 14 of the ducts 11 and 12, respectively.
Dimension 16 of the possible axial displacement of the closing needle 6 is selected at least of such a magnitude that the cross-sectional area of the opening 14 of the duct 12 into main duct 5 can be fully closed, as illustrated in Figs. 1, 2 and 5, 6, while this cross-sectional area may also be almost completely open, as illustrated in Figs. 3 and ~.
Closing needle 6 defines a connecting duct 17 which extends coaxially to the long.itudinal axis of the extruder head. The opening 18 of connecting duct 17 at the free end of closing needle 6 is provided in axial alignment with the discharge opening 10 of nozzle 2.
. .
,. I
1~80~3 The other end of the connecting duct 17 extends under a predetermined angle of inclination of, for example, 30 to 40, radially toward the circumference of closing needle 6 and forms a circumferential opening 19 whose axial width 20 is greater than t~e axial width of outlet opening 13 at the corresponding feed duct 11. It has been found advantageous if the axial width 20 of the radial circumferential opening 19 is selected approximately twice the axial width of the outle-t opening 13 of the duct 11. As a result, it is ensured that the flow can be maintained between the duct 11 and connecting duct 17 even during an axial displacement of closing needle 6, as can be clearly seen from a comparison of Figs. 2 and 4 of the drawing.
On the other hand, to ensure that the flow connection between the feed duct 11 and the connecting duct 17 can be interrupted at any time, closing needle 6 is not only axially displaceable but also mounted rotatably in housing 4 or main duct 5 of extruder head 1. The angle of possible rotation of the needle 6 can be limited in such a way that, in one angular position, the radial circumferential opening 19 of connec-ting duct 17 is separated from the outlet opening 13 of feed duct 11, as illustrated in Figs. 1, 3 and 6, while, in the other angular position, openinqs 19 and 13 are in communication, as shown in Figs. 2, 4 and 5.
f ~L~6~
An angle of rota-tion of closing needle 6 of, for example, 90 should be sufficient in most cases for effecting and interrupting the flow connection of the feed duct 11 with the connecting duct 17.
In the simplest case, the axial displacement and the angular rotation of closing needle 6 are effected and controlled independently from each other by separate drives.
It is then possible, if desired, to carry out the translational and the rotational movements of closing needle 6 either simultaneously or one after the other.
However, it is also easily possible to couple the translational and the rotational movement of the closing needle 6 and to control the movements in a predetermined relationship. For this purpose, it is easily possible to utilize cam drives or crank drives which can be adapted to different requirements.
It would also be conceivable to provide the closing needle 6 in the housing 4 of extruder head 1 so as to be only axially movable and to provide a sleeve around the closing needle 6 which is mounted in the housing 4 of extruder head 1 in such a way that it is rotatable but axially immovable.
This sleeve would then include the radial circumferential opening 19 having an axial width 20 which, depending upon its position of rotation, effects or interrupts the flow connection between feed duct 11 and connecting duct 17.
;l I
~268013 In the extruder head 1 illustrated in the drawing, feed duct 11 in housing 4 and connecting duct 17 in closing needle 6 serve for feeding the plastics material melt free of expanding agents, while the plastic material melt containing an expanding agent is fed to main duct 5 through feed duct 12.
In the position of operation of the extruder head 1 illustrated in Fig. 1, i.e., in the closed initial position of closing needle 6, the two melt flows are conducted through feed ducts 11 and 12 only to the circumference of closing needle 6. Accordingly, the flows cannot reach either the main duct 5 or the nozzle 2.
In the position of operation illustrated in Fig. 2, the closing needle 6 is still in its advanced closing position.
However, closing needle 6 has been turned in circumferential direction, so that outlet opening 13 of feed duct 11 is in communication through radial circumferential opening 19 with connecting duct 17 in closing needle 6. Thus, the plastics material free cf expandin~ agent present in feed duct 11 can reach the mold only through the connecting duct 17 and the discharge opening 10 of nozzle 2.
As soon as a certain amount of plastics material free of expanding agents has reached the mold, closing needle 6 is axially retracted from the position shown in Fig. 2 into the position shown in Fig. 3. As a result, the outlet opening 14 of feed duct 12 into main duct 5 is released and, simultaneously, the opening 18 of connecting duct 17, is , .
~6~
pulled into the main duct 5 from the discharge opening lO of nozzle 2. In this position, plastics material free of expanding agent and plastics material containing an expanding agent are simultaneously fed through main duct 5 into the discharge opening lO of nozzle 2.
Closing needle g is now rotated in its axial position illustrated in Fig. 3 about its longitudinal axis into the initial position, so that the outlet opening 13 of feed duct ll is no longer in communication with the radial circum-ferential opening l9 of connecting duct 17. Thus, the supply of plastics material free of expanding agent is interrupted, so that now only plastics material containing an expanding agent is conducted from feed duct 12 into main duct 5 and\from main duct 5 through discharge opening lO of nozzle 2 into the mold.
As soon as the desired or required amount of plastics material containing an expanding agent has been injected into the mold, the closing needle 6 is rotated as well as axially moved from the position according to Fig. 4, so that initially the position of operation according to Fig. 3 and then the position of operation according to Flg. 5 are reached. In the position of operation according to Fig. 5, the plastics material free of expanding agent exerts the necessary afterpressure on the molded ar-ticle in the mold, so that the space of the mold is filled in the optimum manner. Simul-taneously, the plastics material free of expanding agent .
6~
still in the discharge opening 10 of throttle 2 is flushed out, so that the extruder head is prepared for -the next shot.
The closing needle 6 is now rotated into the position according to Fig. 6, so that the position of operation shown in Fig. 1 is again reached.
Af-ter the cooling time has elapsed, the mold can be opened and the molded article can be taken out of the mold.
It should be pointed out that the positions of operation illustrated in Figs. 1 through 6 are not required in all cases. For example, if an operation is carried out in which the nozzle for plastics material free of expanding agent is always open, the extruder head 1 only assumes the positions of operation illustrated in Figs. 2, 3 and 5 of the drawing\.
In molded articles of plastics material having an outer skin and core, preferably a plastics material free of expanding agent is used for the skin which ensures a smooth compact sheathing of the core, while generally a plastics material containing an expanding agent is used for the core in order to obtain a porous structure thereof. ~Iowever, if it is desired in certain situations, the plastics materials can also be used in the opposite manner or the use of two plastics materials either free of expanding agent or containing an expanding agent is possible.
lZ6~
The present invention is not limited to a device in which only two feed ducts lead into the main duct. It is also possible to use more than two plastics materia~s if the extruder head and the plastics material are appropriately modified.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
It has been found that, due to the sluggish movements resulting from this type of control, the reproducibility of the desired result, i.e., sealing, is not always ensured.
Another deficiency of known devices for manufacturing molded particles of plastics material as disclosed, for example, in German patent 2,342,789, is that, due to the subsequent injection with plastics material free of expanding agents, the respective closing needle must press the plastics material in front of it into the sprue. While this can be done easily in foamed molded articles having relatively thick walls, this cannot be achievea in molded articles having thin walls because the sprue has usually at this time already hardened.
126~)13 It is an object of the present invention to further develop a device for the manufacture of molded articles of plastics material of the above-specified type.
Another object is to make it possible to operate plastics material flows having different temperatures and different types of plastics material, for example, plastics material free of expanding agents and plastics material containing an expanding agent.
In accordance with the present invention there is provided a device of the above-specified type the improvement comprising, in the closed axial position of the closing needle as well as in at least partially open axial position of the closing needle, the radial circumferential opening of the connecting duct is located approximately on the same level as the inner radial outlet opening of the more remote feed duct. In addition, the closing needle, or its radial circumferential opening, is rotatable about the longitudinal axis of the extruder head relative to the outlet opening in any axial position of the closing needle.
~L268013 The device according to the present inven~ion has the particular advantage that the supply of plastics material free of expanding agent used for forming the compact outer skin of the molded articles can be interrupted with the aid of the closing needle without the respective plastics material being displaced into the sprue of the mold.
In accordance with another Eeature of the presen-t invention, the axial width of the radial circumferential opening of the connecting duct at the closing needle is approximately twice the axial width of the outlet opening at the corresponding feed duct.
As a result, the connecting duct remains connected to the corresponding feed duct at least over a portion of the distance of axial displacement of the closing needle. As a result, it is possible simultaneously to feed plastics material containing expanding agent and plastics material free of expanding agent into the mold connected to the extruder head.
The operation of the extruder head according to the present invention is optimized if the angle of rotation of the closing needle in the extruder head is limited. Thus, the connecting duct in the closing needle can be connected to or separated from the corresponding Eeed duct in a very simple manner.
~ . I
'. I
- ~26c~L3 The extruder head according to the present invention is of particularly simple c~nstruction if the radial circumferential opening of the connecting duct~is formed directly in the closing neecle. However, it may be advantageous in some cases t~ provide the radial circumferential opening for the connecting duct in a sleeve which is mounted rotatably on -the circumference of the closing needle. In this situa-tion, the closing needle itselE only has to be moved axially, ~hile tle sleeve containing the radial circumferential opening may be seated so as to be rotatable within the housing of the extruder head.
In accordance with anol er advantageous structural feature of the present invention, the axial distance between the two openings of the two feed ducts into the main duct is approximately twice the axial width of the openings of the feed ducts.
In accordance with another feature of the present invention, the translational and rotational movements of the closing needle are carried out optionally either simultaneously or one after the other. However, it is also possible to couple, or make capable of coupling, the translational and the rotational movements of the closing needle.
.
Finally, the closing needle may be arranged in the housing of the extruder head so as to be movable only in axial direction, while the sleeve is mounted so as to be rotatable only by a limited angle.
The device according to the present invention can be used as a machine nozzle as well as a nozzle for a hot duct system for a multiple component injection molding process.
For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the drawings and descriptive matter in which there is illustrated and described by way of example, a preferred embodiment of the invention.
In the drawings:
Figures 1 through 6 are longitudinal sectional views of the extruder head according to the present invention, showing the portions of the extruder head which are essential for the present invention in different positions of operation.
30~3 DETAILED DESCRIPTION OF THE INVENTION
The drawings show of a device for manufac!turing molded articles of plastics material having a compact outer skin of plastics material free of expanding agent and a porous core of plastics material containing an expanding agent, only an extruder head 1 whlch is connected through a nozzle 2 to a sprue bushing 3 of an injection mold, not shown.
\
A main duct 5 which receives a closing needle 6 extends from the nozzle 2 coaxially through a housing 4 through of the extruder head 1. Closing needle 6 includes a shaft 7 extending rearwardly through the extruder head 1, The shaft 7 is engaged by a displacement drive, not shown, which can be actuated, for example, by a pressure medium, particularly a hydraulic medium.
The end of the closing needle 6 defines a sealing cone 8 which interacts with an appropriately shaped sealing cone 9 in nozzle 2 when the closing needle 6 is in the advanced sealing position, as clearly illustrated in Figs. 1, 5 and 6.
At a distance from nozzle 2 which contains an outlet opening 10 opens a feed duct 11 into main duct 5 of housing 4.
At the opening into the main duct 5, the feed duct 11 is inclined at a predetermined angle, for example, of 30 to 40. 1.
The feed duct 11 is connected at its other end leading out of il the extruder head 1 to an injection unit, not shown.
, i _ ~6B~13 A-t a distance from nozzle 2 which is smaller than the distance of the opening of feed duct 11 into main duct 5 from throttle 2, another feed duct 12 opens into main duct 5 also at a predetermined angle of, for example, 30 to 40 . This feed duct 12 also preferably extends toward the rear out of extruder head 1 and is connected at this other end to an injection unit, not shown.
Openings 1~ and 14 of the two feed ducts 11 and 12 in-to main duct 5 are preferably located on circumferentially \
opposite portions of main duct 5 and are axially offset relative to each other by a di.stance 15 which preferably is twice the size of the axial width of the two openings 13 and 14 of the ducts 11 and 12, respectively.
Dimension 16 of the possible axial displacement of the closing needle 6 is selected at least of such a magnitude that the cross-sectional area of the opening 14 of the duct 12 into main duct 5 can be fully closed, as illustrated in Figs. 1, 2 and 5, 6, while this cross-sectional area may also be almost completely open, as illustrated in Figs. 3 and ~.
Closing needle 6 defines a connecting duct 17 which extends coaxially to the long.itudinal axis of the extruder head. The opening 18 of connecting duct 17 at the free end of closing needle 6 is provided in axial alignment with the discharge opening 10 of nozzle 2.
. .
,. I
1~80~3 The other end of the connecting duct 17 extends under a predetermined angle of inclination of, for example, 30 to 40, radially toward the circumference of closing needle 6 and forms a circumferential opening 19 whose axial width 20 is greater than t~e axial width of outlet opening 13 at the corresponding feed duct 11. It has been found advantageous if the axial width 20 of the radial circumferential opening 19 is selected approximately twice the axial width of the outle-t opening 13 of the duct 11. As a result, it is ensured that the flow can be maintained between the duct 11 and connecting duct 17 even during an axial displacement of closing needle 6, as can be clearly seen from a comparison of Figs. 2 and 4 of the drawing.
On the other hand, to ensure that the flow connection between the feed duct 11 and the connecting duct 17 can be interrupted at any time, closing needle 6 is not only axially displaceable but also mounted rotatably in housing 4 or main duct 5 of extruder head 1. The angle of possible rotation of the needle 6 can be limited in such a way that, in one angular position, the radial circumferential opening 19 of connec-ting duct 17 is separated from the outlet opening 13 of feed duct 11, as illustrated in Figs. 1, 3 and 6, while, in the other angular position, openinqs 19 and 13 are in communication, as shown in Figs. 2, 4 and 5.
f ~L~6~
An angle of rota-tion of closing needle 6 of, for example, 90 should be sufficient in most cases for effecting and interrupting the flow connection of the feed duct 11 with the connecting duct 17.
In the simplest case, the axial displacement and the angular rotation of closing needle 6 are effected and controlled independently from each other by separate drives.
It is then possible, if desired, to carry out the translational and the rotational movements of closing needle 6 either simultaneously or one after the other.
However, it is also easily possible to couple the translational and the rotational movement of the closing needle 6 and to control the movements in a predetermined relationship. For this purpose, it is easily possible to utilize cam drives or crank drives which can be adapted to different requirements.
It would also be conceivable to provide the closing needle 6 in the housing 4 of extruder head 1 so as to be only axially movable and to provide a sleeve around the closing needle 6 which is mounted in the housing 4 of extruder head 1 in such a way that it is rotatable but axially immovable.
This sleeve would then include the radial circumferential opening 19 having an axial width 20 which, depending upon its position of rotation, effects or interrupts the flow connection between feed duct 11 and connecting duct 17.
;l I
~268013 In the extruder head 1 illustrated in the drawing, feed duct 11 in housing 4 and connecting duct 17 in closing needle 6 serve for feeding the plastics material melt free of expanding agents, while the plastic material melt containing an expanding agent is fed to main duct 5 through feed duct 12.
In the position of operation of the extruder head 1 illustrated in Fig. 1, i.e., in the closed initial position of closing needle 6, the two melt flows are conducted through feed ducts 11 and 12 only to the circumference of closing needle 6. Accordingly, the flows cannot reach either the main duct 5 or the nozzle 2.
In the position of operation illustrated in Fig. 2, the closing needle 6 is still in its advanced closing position.
However, closing needle 6 has been turned in circumferential direction, so that outlet opening 13 of feed duct 11 is in communication through radial circumferential opening 19 with connecting duct 17 in closing needle 6. Thus, the plastics material free cf expandin~ agent present in feed duct 11 can reach the mold only through the connecting duct 17 and the discharge opening 10 of nozzle 2.
As soon as a certain amount of plastics material free of expanding agents has reached the mold, closing needle 6 is axially retracted from the position shown in Fig. 2 into the position shown in Fig. 3. As a result, the outlet opening 14 of feed duct 12 into main duct 5 is released and, simultaneously, the opening 18 of connecting duct 17, is , .
~6~
pulled into the main duct 5 from the discharge opening lO of nozzle 2. In this position, plastics material free of expanding agent and plastics material containing an expanding agent are simultaneously fed through main duct 5 into the discharge opening lO of nozzle 2.
Closing needle g is now rotated in its axial position illustrated in Fig. 3 about its longitudinal axis into the initial position, so that the outlet opening 13 of feed duct ll is no longer in communication with the radial circum-ferential opening l9 of connecting duct 17. Thus, the supply of plastics material free of expanding agent is interrupted, so that now only plastics material containing an expanding agent is conducted from feed duct 12 into main duct 5 and\from main duct 5 through discharge opening lO of nozzle 2 into the mold.
As soon as the desired or required amount of plastics material containing an expanding agent has been injected into the mold, the closing needle 6 is rotated as well as axially moved from the position according to Fig. 4, so that initially the position of operation according to Fig. 3 and then the position of operation according to Flg. 5 are reached. In the position of operation according to Fig. 5, the plastics material free of expanding agent exerts the necessary afterpressure on the molded ar-ticle in the mold, so that the space of the mold is filled in the optimum manner. Simul-taneously, the plastics material free of expanding agent .
6~
still in the discharge opening 10 of throttle 2 is flushed out, so that the extruder head is prepared for -the next shot.
The closing needle 6 is now rotated into the position according to Fig. 6, so that the position of operation shown in Fig. 1 is again reached.
Af-ter the cooling time has elapsed, the mold can be opened and the molded article can be taken out of the mold.
It should be pointed out that the positions of operation illustrated in Figs. 1 through 6 are not required in all cases. For example, if an operation is carried out in which the nozzle for plastics material free of expanding agent is always open, the extruder head 1 only assumes the positions of operation illustrated in Figs. 2, 3 and 5 of the drawing\.
In molded articles of plastics material having an outer skin and core, preferably a plastics material free of expanding agent is used for the skin which ensures a smooth compact sheathing of the core, while generally a plastics material containing an expanding agent is used for the core in order to obtain a porous structure thereof. ~Iowever, if it is desired in certain situations, the plastics materials can also be used in the opposite manner or the use of two plastics materials either free of expanding agent or containing an expanding agent is possible.
lZ6~
The present invention is not limited to a device in which only two feed ducts lead into the main duct. It is also possible to use more than two plastics materia~s if the extruder head and the plastics material are appropriately modified.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
Claims (11)
1. A device for manufacturing molded articles of plastics material having an outer skin and a core, the device including an extruder head defining a discharge opening and a main duct in communication with the discharge opening, the extruder head further defining two feed ducts for the plastics materials of the outer skin and of the core, the two feed ducts leading angularly offset into the main duct at locations axially spaced from the discharge opening and from each other, a closing needle placed axially movable in the main duct, the two feed ducts capable of being separated from the main duct by means of the closing needle, the closing needle having an end face and a circumference and defining a connecting duct extending essentially in axial direction, the connecting duct being at the end face of the closing needle and at the circumference of the closing needle radially toward the feed duct located more remote from the discharge opening, the improvement comprising, in a closed axial position of the closing needle as well as in an at least partially open axial position of the closing needle, the radial circumferential opening of the connecting duct being located approximately on the same level as the inner radial outlet opening of the more remote feed ducts, wherein the closing needle and its radial circumferential opening are rotatable about the longitudinal axis of the extruder head relative to the outlet opening in any axial position of the closing needle.
2. The device according to claim 1, wherein the plastics material for the outer skin is free of expanding agent and the other plastics material contains an expanding agent to form a porous core.
3. The device according to claim 1, wherein the axial width of the radial circumferential opening of the connecting duct at the closing needle is approximately twice the axial width of the outlet opening at the corresponding feed duct.
4. The device according to claim 1, wherein the closing needle is rotatable in the extruder head by a limited angle of rotation.
5. The device according to claim 1, wherein the radial circumferential opening of the connecting duct is formed in the closing needle.
6. The device according to claim 1, comprising a sleeve mounted rotatably on the circumference of the closing needle, the radial circumferential opening of the connecting duct being formed in the sleeve.
7. The device according to claim 1, wherein the axial distance between the two openings of the two feed ducts into the main duct is approximately twice the axial width of the opening of the feed ducts.
8. The device according to claim 1, wherein the closing needle is capable of carrying out translational and rotational movements simultaneously.
9. The device according to claim 1, wherein the closing needle is capable of carrying out translational and rotational movements one after the other.
10. The device according to claim 1, wherein translational and rotational movements of the closing needle are capable of being coupled.
11. The device according to claim 6, wherein the closing needle is capable of being moved only axially, and the sleeve is mounted so as to be rotatable only a limited angle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19863632185 DE3632185A1 (en) | 1986-09-23 | 1986-09-23 | DEVICE FOR PRODUCING PLASTIC MOLDED BODIES |
| DEP3632185.0 | 1986-09-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1268013A true CA1268013A (en) | 1990-04-24 |
Family
ID=6310090
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000547481A Expired - Lifetime CA1268013A (en) | 1986-09-23 | 1987-09-22 | Device for manufacturing molded articles of plastics material |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4789318A (en) |
| EP (1) | EP0261350B1 (en) |
| JP (1) | JP2505490B2 (en) |
| AT (1) | ATE62445T1 (en) |
| CA (1) | CA1268013A (en) |
| DE (2) | DE3632185A1 (en) |
| ES (1) | ES2021648B3 (en) |
Families Citing this family (35)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364256A (en) | 1986-01-28 | 1994-11-15 | Ophthalmic Research Group International, Inc. | Apparatus for the production of plastic lenses |
| US5529728A (en) | 1986-01-28 | 1996-06-25 | Q2100, Inc. | Process for lens curing and coating |
| US6201037B1 (en) | 1986-01-28 | 2001-03-13 | Ophthalmic Research Group International, Inc. | Plastic lens composition and method for the production thereof |
| US6730244B1 (en) | 1986-01-28 | 2004-05-04 | Q2100, Inc. | Plastic lens and method for the production thereof |
| US5415816A (en) | 1986-01-28 | 1995-05-16 | Q2100, Inc. | Method for the production of plastic lenses |
| US5169648A (en) * | 1987-10-09 | 1992-12-08 | Battenfeld Gmbh | Apparatus for injection molding articles of thermoplastic materials |
| DE3734164C3 (en) * | 1987-10-09 | 1999-09-09 | Battenfeld Gmbh | Process for injection molding molded parts from thermoplastic materials and device for carrying out the process |
| NL8801096A (en) * | 1988-04-27 | 1989-11-16 | Hartman Holding B V | NOZZLE AND AN INJECTION MOLDING FOR TWO-COMPONENT INJECTION MOLDING. |
| JPH0545400Y2 (en) * | 1988-07-25 | 1993-11-19 | ||
| US4890994A (en) * | 1988-09-30 | 1990-01-02 | Hoover University, Inc. | Apparatus for forming a parison with a view stripe |
| AT391833B (en) * | 1988-10-03 | 1990-12-10 | Engel Gmbh Maschbau | Injection nozzle for injection-moulding machines |
| DE3912426A1 (en) * | 1989-04-12 | 1990-10-18 | Mannesmann Ag | METHOD AND DEVICE FOR PRODUCING MULTI-COMPONENT INJECTION MOLDING PARTS |
| JPH0767715B2 (en) * | 1990-11-20 | 1995-07-26 | 三晶技研株式会社 | Hot runner type synthetic resin mold |
| DE4108654A1 (en) * | 1991-03-16 | 1992-09-17 | Basf Ag | THERMOPLATICALLY DEFORMABLE, MULTI-LAYERED PANEL, ESPECIALLY FOR THE INTERIOR REMOVAL OF AIRCRAFT AND OTHER MASS TRANSPORT |
| US5112212A (en) * | 1991-05-02 | 1992-05-12 | Husky Injection Molding Systems Ltd. | Shooting pot with combined valve and piston |
| CA2068543C (en) * | 1992-05-11 | 1999-11-09 | Jobst Ulrich Gellert | Coinjection molding apparatus having rotary axial actuating mechanism |
| US5514214A (en) | 1993-09-20 | 1996-05-07 | Q2100, Inc. | Eyeglass lens and mold spin coater |
| FR2717733B1 (en) * | 1994-03-25 | 1996-04-26 | Renault | Plastic injector. |
| US5650178A (en) * | 1994-11-23 | 1997-07-22 | Bemis Manufacturing Company | Co-injection manifold for injection molding |
| DE19606045C2 (en) * | 1996-02-19 | 1997-11-27 | Krupp Ag Hoesch Krupp | Process for the injection molding of three-layer moldings and device for carrying out the process |
| US6022498A (en) | 1996-04-19 | 2000-02-08 | Q2100, Inc. | Methods for eyeglass lens curing using ultraviolet light |
| US6280171B1 (en) | 1996-06-14 | 2001-08-28 | Q2100, Inc. | El apparatus for eyeglass lens curing using ultraviolet light |
| DE19649467A1 (en) * | 1996-11-29 | 1998-06-10 | Incoe Int Inc | Hot channel co-injection system with outstanding control of melt flows |
| CA2219247C (en) | 1997-10-23 | 2006-12-05 | Mold-Masters Limited | Injection molding apparatus having a melt bore through the front end of the pin |
| US6391231B1 (en) | 1998-11-23 | 2002-05-21 | Younger Mfg. Co. | Method for side-fill lens casting |
| AU2001238716A1 (en) * | 2000-02-29 | 2001-09-12 | Bemis Manufacturing Company | Co-injection apparatus for injection molding |
| US6964748B2 (en) * | 2000-11-30 | 2005-11-15 | Bemis Manufacturing Company | Co-injection methods using endothermic-blowing agents and products made therefrom |
| US7168943B2 (en) * | 2003-08-29 | 2007-01-30 | Mold-Masters Limited | Guided valve pin for an injection molding apparatus |
| US7390184B2 (en) * | 2005-11-09 | 2008-06-24 | Centoco Plastics Limited | Dual injection manifold |
| GB2466432B (en) * | 2008-12-16 | 2010-11-03 | Crompton Mouldings Ltd | A moulding method and moulding machine |
| JOP20140215B1 (en) * | 2013-07-10 | 2023-03-28 | Esco Group Llc | Connector to facilitate lifting of wear parts |
| DE102013015800A1 (en) | 2013-09-24 | 2015-03-26 | Wittmann Battenfeld Gmbh | injection molding machine |
| DE102014002728B3 (en) | 2014-03-03 | 2015-05-21 | Wittmann Battenfeld Gmbh | Nozzle system of an injection molding machine injection unit |
| JP7135409B2 (en) * | 2018-04-27 | 2022-09-13 | セイコーエプソン株式会社 | Three-dimensional modeling apparatus and three-dimensional model manufacturing method |
| DE102020109197A1 (en) | 2020-04-02 | 2021-10-07 | STG Stanztechnik GmbH & Co. KG | Channel system for the continuous injection of a plasticized molding compound into a molding tool, injection molding device and a method for controlling and regulating a continuous injection process of such an injection molding device |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3349435A (en) * | 1965-09-21 | 1967-10-31 | Danadyne Inc | Precision die for manufacture of foamed plastics and the like |
| US3733156A (en) * | 1968-12-06 | 1973-05-15 | Ici Ltd | Injection moulding machines |
| US3666389A (en) * | 1969-11-24 | 1972-05-30 | Dominion Gasket & Mfg Co Ltd | Extrusion apparatus for making conduit pipe |
| US3894823A (en) * | 1971-09-07 | 1975-07-15 | Robert Hanning | Apparatus for injection molding of parts of synthetic material |
| US3694123A (en) * | 1971-11-11 | 1972-09-26 | Du Pont | Apparatus for making a tube of plastic film |
| DE2342789C2 (en) * | 1973-08-24 | 1981-10-08 | Schloemann-Siemag AG, 4000 Düsseldorf | Device for the discontinuous production of multilayer moldings |
| CH566207A5 (en) * | 1972-12-07 | 1975-09-15 | Siemag Siegener Masch Bau | |
| DE2259818C3 (en) * | 1972-12-07 | 1978-05-18 | Schloemann-Siemag Ag, 4000 Duesseldorf | Injection molding device for producing a molded body with a core made of foamed and an outer skin made of unfoamed thermoplastic material |
| DE2449758A1 (en) * | 1974-10-19 | 1976-04-29 | Schloemann Siemag Ag | METHOD AND DEVICE FOR MANUFACTURING PLASTIC MOLDED PARTS WITH A FOAMED CORE AND AN UNFOAMED OUTER SKIN |
| US4117955A (en) * | 1977-04-13 | 1978-10-03 | Beloit Corporation | Multi-port valved nozzle for co-injection molding |
| US4422838A (en) * | 1979-12-27 | 1983-12-27 | Ishikawajima-Harima Jukogyo Kabushiki Kaisha | Extrusion head for use in blow molding machine |
| DE8034352U1 (en) * | 1980-12-23 | 1982-06-24 | Battenfeld Maschinenfabriken Gmbh, 5882 Meinerzhagen | Device for the production of plastic moldings |
| JPS58179632A (en) * | 1982-04-14 | 1983-10-20 | Meiki Co Ltd | Sandwich molding equipment |
| DE3247000A1 (en) * | 1982-12-18 | 1984-06-20 | Battenfeld Maschinenfabriken Gmbh, 5882 Meinerzhagen | Device for producing plastic moulded articles |
| DE3305931A1 (en) * | 1983-02-21 | 1984-08-23 | Battenfeld Maschfab | Apparatus for discontinuously producing multilayer mouldings from plastic |
| SE435598B (en) * | 1983-04-12 | 1984-10-08 | Dziewanowski Andre | PROCEDURE AND DEVICE FOR MANUFACTURING EXTRUDED Pipes |
-
1986
- 1986-09-23 DE DE19863632185 patent/DE3632185A1/en active Granted
-
1987
- 1987-07-30 DE DE8787111027T patent/DE3769255D1/en not_active Expired - Lifetime
- 1987-07-30 AT AT87111027T patent/ATE62445T1/en not_active IP Right Cessation
- 1987-07-30 ES ES87111027T patent/ES2021648B3/en not_active Expired - Lifetime
- 1987-07-30 EP EP87111027A patent/EP0261350B1/en not_active Expired - Lifetime
- 1987-09-10 US US07/095,855 patent/US4789318A/en not_active Expired - Lifetime
- 1987-09-22 JP JP62236371A patent/JP2505490B2/en not_active Expired - Lifetime
- 1987-09-22 CA CA000547481A patent/CA1268013A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| ES2021648B3 (en) | 1991-11-16 |
| EP0261350B1 (en) | 1991-04-10 |
| DE3769255D1 (en) | 1991-05-16 |
| EP0261350A3 (en) | 1989-06-28 |
| JPS6389318A (en) | 1988-04-20 |
| JP2505490B2 (en) | 1996-06-12 |
| US4789318A (en) | 1988-12-06 |
| DE3632185C2 (en) | 1991-12-12 |
| DE3632185A1 (en) | 1988-03-31 |
| EP0261350A2 (en) | 1988-03-30 |
| ATE62445T1 (en) | 1991-04-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1268013A (en) | Device for manufacturing molded articles of plastics material | |
| US5895667A (en) | Device for injection molding articles of plastics material which contain hollow spaces | |
| EP0310914B1 (en) | Method of injection moulding formed parts of thermoplastic resins, and for carrying out this method | |
| US4582224A (en) | Nozzle for mixing at least two flowable reaction components | |
| EP0043543B1 (en) | Device for producing multi-layer moulded thermoplastic articles | |
| US5219512A (en) | Improved pressure-holding chamber type injection molding process and apparatus for injection molding of products | |
| US6419116B1 (en) | Molding nozzle gate valve | |
| JP2544400B2 (en) | Injection head for producing multi-layer moldings from thermoplastic synthetic resin materials | |
| US5200127A (en) | Method and apparatus for gas assisted injection molding | |
| US3945784A (en) | Injection moulding machinery | |
| US5169648A (en) | Apparatus for injection molding articles of thermoplastic materials | |
| JPH0525650B2 (en) | ||
| JPH07276415A (en) | Injection molding method for circular hollow piece | |
| US6533447B2 (en) | Plasticizing apparatus for a pre-plasticization-type injection molding machine | |
| JPH0768601A (en) | Runnerless mold | |
| GB1564340A (en) | Feed screw assembly for a plasticizing machine for plasticceed screw assembly for a plasticizing machine for plasticizable masses particularly plastics or rubber | |
| JP2858180B2 (en) | Multi-layer molding resin injection device | |
| US3807925A (en) | Nozzle for injection molding | |
| DE10022288C2 (en) | Device for producing a workpiece to be tempered | |
| JP2002521238A (en) | Molding apparatus and molding method | |
| JP3595384B2 (en) | Two-color injection molding nozzle of injection molding machine | |
| DE4311196A1 (en) | Plastics injection nozzle with needle valve | |
| JPH06320590A (en) | Large capacity injection method and apparatus utilizing extrusion molding machine | |
| JPS6138010B2 (en) | ||
| JPH05269794A (en) | Injection molding machine for sandwich molding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |