CA2217355A1 - Method for die casting three-layer articles and apparatus for carrying out the method - Google Patents
Method for die casting three-layer articles and apparatus for carrying out the method Download PDFInfo
- Publication number
- CA2217355A1 CA2217355A1 CA002217355A CA2217355A CA2217355A1 CA 2217355 A1 CA2217355 A1 CA 2217355A1 CA 002217355 A CA002217355 A CA 002217355A CA 2217355 A CA2217355 A CA 2217355A CA 2217355 A1 CA2217355 A1 CA 2217355A1
- Authority
- CA
- Canada
- Prior art keywords
- needle
- reservoir
- piston
- die
- mold
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000004512 die casting Methods 0.000 title 1
- 239000000463 material Substances 0.000 claims abstract description 106
- 238000000465 moulding Methods 0.000 claims abstract description 18
- 230000004888 barrier function Effects 0.000 claims abstract description 12
- 238000001746 injection moulding Methods 0.000 claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000007789 gas Substances 0.000 claims abstract description 5
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 10
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 10
- 230000005540 biological transmission Effects 0.000 claims description 6
- 238000002347 injection Methods 0.000 claims description 4
- 239000007924 injection Substances 0.000 claims description 4
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 3
- 229920000219 Ethylene vinyl alcohol Polymers 0.000 claims description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 3
- 229920001577 copolymer Polymers 0.000 claims description 3
- 239000004715 ethylene vinyl alcohol Substances 0.000 claims description 3
- 238000005192 partition Methods 0.000 claims description 3
- -1 polyethylene terephthalate Polymers 0.000 claims description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 3
- 239000000155 melt Substances 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 claims 3
- 230000000903 blocking effect Effects 0.000 claims 2
- 229910052782 aluminium Inorganic materials 0.000 claims 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims 1
- 239000004020 conductor Substances 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 claims 1
- 239000002184 metal Substances 0.000 claims 1
- 229910001868 water Inorganic materials 0.000 abstract description 3
- 239000010410 layer Substances 0.000 description 21
- 239000011112 polyethylene naphthalate Substances 0.000 description 5
- 229920003207 poly(ethylene-2,6-naphthalate) Polymers 0.000 description 4
- 239000004014 plasticizer Substances 0.000 description 3
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000011067 equilibration Methods 0.000 description 1
- 235000015203 fruit juice Nutrition 0.000 description 1
- 239000002365 multiple layer Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 230000001360 synchronised effect 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
- 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
- B29C45/2725—Manifolds
-
- 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
-
- 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
- B29C45/1646—Injecting parison-like articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/16—Making multilayered or multicoloured articles
- B29C45/1642—Making multilayered or multicoloured articles having a "sandwich" structure
- B29C45/1646—Injecting parison-like articles
- B29C2045/1648—Injecting parison-like articles the parison core layer being a barrier material
-
- 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
- B29C45/2725—Manifolds
- B29C2045/273—Manifolds stacked manifolds
-
- 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
- B29C2045/2872—Closure devices therefor consisting of needle valve systems with at least three positions, e.g. two different open positions to control the melt flow
-
- 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
- B29C2949/00—Indexing scheme relating to blow-moulding
- B29C2949/07—Preforms or parisons characterised by their configuration
- B29C2949/081—Specified dimensions, e.g. values or ranges
- B29C2949/0811—Wall thickness
- B29C2949/0819—Wall thickness of a layer
-
- 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
Abstract
A method of injection-molding three-layer moldings, especially bottle blanks, having inner and outer layers of a "material A" and of a "material B". Material B can be a material that acts as a barrier against the gases O2, CO2, and SO2, and against water vapor (H2O). The method employs a device that comprises at least one mold and at least one flat hot runner. The mold has several cavities and the hot runner has the same number of dies. Material A is supplied to the cavities (1.1) through an annular gap between the inner (2.1) and the outer (2.2) component of each die. Material B is forced into the cavities through a hollow needle (3) that extends through the center of the inner die component by a piston (4) that is integrated into the die and cannot rotate.
The needle has a port (6) that opens into it at a right angle and remains open as long as the needle remains advanced, in a closing position, and that is blocked when the needle is retracted. A reservoir (3.3) constituted by the hollow inside the needle is charged through the port while the needle is in its closing position.
The needle has a port (6) that opens into it at a right angle and remains open as long as the needle remains advanced, in a closing position, and that is blocked when the needle is retracted. A reservoir (3.3) constituted by the hollow inside the needle is charged through the port while the needle is in its closing position.
Description
CA 022173~ 1997-09-30 = 1 METHOD OF INJECTION-MOLDING THREE-LAYER MOLDINGS
3 The present invention concerns first a method of 4 injection-molding three-layer moldings, especially bottle blanks. They have inner and outer layers of a "material A"
6 and a middle layer of a "material B". Material A can be 7 polyethylene terephthalate (PET) for example. Material B is a 8 material, a copolymer of ethylene and polyvinyl alcohol 9 (EVAL) for example, that acts as a barrier against the gases 10 ~2~ C~2~ and SO2, and against water vapor (H2O). The method 11 employs a device that comprises at least one mold and at 12 least one flat hot runner. The mold has several cavities and 13 the hot runner has the same number of dies. The two materials 14 are supplied to the cavities through separate hot-runner systems. The invention also concerns such a device for 16 carrying out the method.
17 The present invention is not, however, restricted 18 either to bottle blanks or to PET. It can be used for 19 injection molding moldings of any other plastic or combination of plastics for any other purpose. The invention 21 can for example be employed for molding multiple-layer 22 moldings of PET and polyethylene naphthalate (PEN). PEN is, 23 like PET, polyester, although it has much better heat-24 resisting properties, overall mechanical properties, and barrier-forming properties. Although still fairly new, PEN
CA 022173~ 1997-09-30 1 has already been approved by the various governmental 2 authorities as a packaging material in the foodstuffs 3 industry. Due to its outstanding properties, even relatively 4 small portions of PEN by weight of the blank contribute considerably to the quality of the finished bottle. Bottles 6 made of PET or PEN are particular appropriate for bottling 7 fruit juices hot and for storage in hot climates.
8 The middle layer in such blanks constitutes a core, 9 and the inner and outer layer integral skins. The inner layer can also constitute a barrier layer. Such layers, especially 11 those that create a barrier against the gases 02, C02, and 12 S02, and against water vapor (H20), are very important to 13 blanks of this type because they decrease permeability.
14 The inner layers employed in known methods of the aforesaid genus are relatively thick. The thickness makes the 16 blanks considerably more expensive because materials that can 17 act as barriers are substantially more expensive than those 18 that can be employed for outer layers. Another drawback of 19 the known methods is the impossibility of distributing the materials employed for the barrier layers at all uniformly 21 throughout all the cavities in a multiple-cavity mold (a mold 22 with 32 or 48 cavities).
23 Since the material B to be employed as a barrier 24 layer need not be exposed to as much heat as the material A
in the outer layer, the two layers are supplied to the - CA 022173~ 1997-09-30 1 cavities through separate hot-runner systems. This causes 2 considerable problems. One device (known from EO 0 246 512 3 B1) for simultaneously injection molding blanks with several 4 layers accordingly features a separate source and separate ducts. A lot of material B, however, is always left in the 6 die and in the immediately adjacent ducts after each cycle, 7 and the material is exposed to too much heat before being 8 introduced into the cavities.
9 The present invention is intended to eliminate the aforesaid drawbacks and to improve the generic method to the 11 extent that the inner layer of the moldings can be 12 considerably thinner and the molding itself considerably more 13 cost effective to produce and to the extent that the material 14 constituting the inner layer will be uniformly and reproducibly distributed throughout all the cavities.
16 This object is attained in accordance with the 17 present invention in the generic method 18 in that material A is supplied to the cavities 19 through an annular gap between the inner and the outer component of each die and material B is forced into the 21 cavities through a hollow needle that extends through the 22 ~enter of the inner die component by a piston that is 23 integrated into the die and cannot rotate and 24 in that the needle has a port that opens into it at a right angle and re~; n~ open as long as the needle r~A;n~
CA 022173~ 1997-09-30 1 advanced, in a closing position, and that is blocked when the 2 needle is retracted, whereby a reservoir constituted by the 3 hollow inside the needle is charged through the port while 4 the needle is in its closing position.
The charging procedure and the stroke of the piston 6 can be regulated to adjust very precisely and reproducibly 7 from cycle to cycle how much material B is distributed to all 8 the cavities and hence how thick the middle layer will be.
9 The method in accordance with the present invention will also ensure very uniform thickness on the part of the inner layer, 11 the barrier layer.
12 The needle is entirely emptied during each cycle, 13 and material B is accordingly subjected to high heat only 14 during mold emptying and injection, an extraordinarily brief time.
16 One advantageous embodiment of the method in 17 accordance with the present invention is characterized by 18 first supplying enough material A to constitute a 19 single portion through the annular gap between the inner and the outer die component with the needle retracted and the 21 port blocked and with the piston also retracted, 22 then supplying more material A along with material 23 B while the needle remains stationary but the piston 24 advances, then injecting more material A with the needle CA 022173~ 1997-09-30 1 still stationary and its reservoir empty of material B and 2 dwell compressing and decompressing material A, 3 then advancing the needle until it comes into 4 contact with the outer die component, closing the feed, and retracting the needle, charging the reservoir with material 6 B, and 7 finally decompressing material B and removing the 8 molding.
9 The problems that accompany the known methods cannot occur when the method in accordance with the present 11 invention is employed.
12 Another advantageous embodiment of the method in 13 accordance with the present invention comprises 14 first supplying enough material A to constitute a single portion through the annular gap between the inner and 16 the outer die component with the needle retracted and the 17 port blocked and with the piston also retracted, 18 then supplying enough material B to constitute a 19 single portion from the reservoir while the needle re~ins stationary but the piston advances, 21 then supplying both material A and material B with 22 the needle still stationary while the piston advances until 23 it comes into contact with the cone at the needle's outlet 24 then dwell compressing and decompressing material A, CA 022173~ 1997-09-30 1 then advancing the needle until it comes into 2 contact with the outer die component, closing the feed, and 3 retracting the needle, charging the reservoir with material 4 B, and finally decompressing material B and removing the 6 molding.
7 The problems that accompany the known methods can 8 also not occur when this embodiment of the method in 9 accordance with the present invention is employed.
The stroke traveled by the needle and the advanced, 11 emptying, position of the piston are synchronized in the 12 aforesaid embodiments of the method in accordance with the 13 present invention such that the cylindrical entrance to the 14 reservoir will remain blocked once the needle has advanced into the closing position.
16 Still another advanced embodiment of the method in 17 accordance with the present invention comprises 18 simultaneously advancing both the needle and the piston into 19 the closing position once material B has been expelled, forcing all the re~ining material A into the cavities. In 21 this event, a longitudinal groove that provides communication 22 between the port and the reservoir and extends as far as the 23 port in the aforesaid embodiments of the method in accordance 24 with the present invention, also extends somewhat beyond it.
Further embodiments of the method in accordance CA 022173~ 1997-09-30 1 with the present invention are recited in subsidiary claims 4 2 through 8.
3 The device for carrying out the method comprises at 4 least one mold and at least one flat hot runner. The mold has several cavities and the hot runner the same number of dies.
6 A needle slides back and forth in each die.
7 This device attains the object of the present 8 invention 9 in that the needle is hollow and a piston slides back and forth inside it without rotating, whereby the inside 11 of the needle constitutes a reservoir for material B, 12 in that the needle has a port extending into it at 13 a right angle in the vicinity of the hot-runner system for 14 material B and the piston has a longitudinal groove that extends as far as the port, whereby the port and the groove 16 allow material B to flow out of a supply line and into the 17 reservoir, and 18 in that the port is positioned such that the 19 reservoir can be charged only while the needle is in its advanced position, the closing position, the port being 21 blocked as long as the needle is in its retracted position.
22 The hot-runner system for material A is 23 conventional in design and its temperature can be 24 independently controlled. The sole function of the hot-runner system for the barrier material, material B, is to charge the - - CA 022173~ 1997-09-30 1 reservoir. The system is provided with material B from a 2 plasticizer mounted on the mold. This practical measure is 3 possible because of the low proportion of material B.
4 The hot-runner system for material B does not require rheological equilibration because the reservoir is 6 charged subject to a prescribed pressure in accordance with 7 the law of communicating capillaries, m~ning that all the 8 reservoirs in the device will be equally charged in a 9 specified time.
Characteristics of further embodiments of the 11 device in accordance with the present invention will be 12 evident from subsidiary claims 10 through 18.
13 Several embodiments of the method and device in 14 accordance with the present invention will now be specified with reference to the accompanying drawing, wherein 16 Figure 1 illustrates the components of a die in 17 various positions during various steps of a method embodying 18 one injection-molding principle, 19 Figure 2 the pressures that occur over time in the antechamber upstream of a die during that embodiment, 21 Figure 3 the components of a die in various 22 positions during various steps of a method embodying another 23 injection-molding principle, and 24 Figure 4 the pressures that occur over time in the antechamber upstream of a die during that embodiment, CA 022173~ 1997-09-30 1 Figure 5 is a partly sectional top view of a mold, 2 and 3 Figure 6 is a front view of the die-side half of 4 the mold illustrated in Figure 5 as viewed along the direction indicated by arrow VI in that figure.
6 Figures 1 and 3 illustrate by way of example 7 embodiments with a mold 1. Mold 1 is provide with cavities 8 1.1 and an injection-molding die 2. Die 2 comprises an inner 9 component 2.1 and an outer component 2.2. A hollow needle 3 slides back and forth inside inner die component 2.1.
11 Integrated into needle 3 is a piston 4. When piston 4 is 12 retracted, it creates a reservoir 3.1 inside needle 3.
13 Moldings 5 are produced in the cavities 1.1 in mold 1 by the 14 method specified herein.
In the embodiment illustrated by way of example in 16 Figures 1 and 3, a material A is introduced into cavities 1.1 17 through an annular gap between die components 2.1 and 2.2 18 with both needle 3 and piston 4 retracted. A material B is 19 introduced through needle 3.
Figures 1 and 2 illustrate the embodiment of the 21 method recited in Claim 2 and Figures 3 and 4 the embodiment 22 recite in Claim 3.
23 The various steps of the embodiment illustrated in 24 Figures 1 and 3 and in Figures 2 and 4 are sufficiently specified by the call-outs and will not be discussed in CA 022173~ 1997-09-30 1 detail. The pressures relating to material A in Figures 2 and 2 4 are plotted by a continuous line and those relating to 3 material B by a discontinuous line.
4 Materials A and B (cf. Figs. 1 and 3) are supplied to the cavities 1.1 of the mold 1 illustrated in Figure S
6 through dies 2. Each die 2 comprises an inner component 2.1 7 and an outer component 2.2. Accommodated in inner die 8 component 2.1 is a hollow needle 3 that in turn accommodates 9 a piston 4 that cannot rotate. Needle 3 is provided with a port 6 that is closed while in the illustrated position. Port 11 6 is in the vicinity of a longitudinal groove 7 in piston 4.
12 A line 8 that supplies material B communicates with the 13 reservoir 3.1 in needle 3 through groove 7.
14 Dies 2 are secured in a flat hot runner 21. The ends of each piston 4 that point away from a die 2 are 16 fastened to a flat base 10. base 10 travels back and forth 17 subject to a ball-and-screw transmission 11. The screws 12 18 are driven by a variable three-phase servo motor 22 (Fig. 6).
19 This system allows portion-regulated charging of reservoir 3.1 with material B, the barrier material, and following a 21 precise pattern with the material during both continuous and 22 discontinuous injection molding.
23 The whole procedure is made possible by the 24 characteristics of the motor, specifically constant torque over its total speed range, CA 022173~ 1997-09-30 1 high dynamics (from 0 to nominal speed in 25 msec), 2 low friction, 3 high overload capacity, 4 nominal torque even while accelerating and decelerating, 6 very consistent rate of rotation at nominal speeds 7 of 2000 to 8000 rpm, and 8 small size and high output.
Position and speed controls allow precise 11 reproduction of master patterns from cycle to cycle.
12 Needles 3 are all secured in the same base 13.
13 bases 10 and 13 can be driven in and out independently. Base 14 10 is driven by the aforesaid transmission 11 and base 13 by hydraulic cylinders 23.
16 Material B is supplied through tubes 14. Hydraulic 17 cylinders 23 are enclosed in a reflector tube 15 and 18 commlln;cate with a melt distributor 24.
19 The hot-runner system 9 for material B is thermally insulated from the hot-runner system 20 for material A by a 21 partition 25.
22 Also accommodated in mold 1 are stops 18 and 19 23 that establish the zero or farthest-down positions of bases 24 10 and 13.
As will be evident from Figure 6, material A is CA 022173~ 1997-09-30 1 conventionally supplied to hot-runner system 20 (Fig. 5) from 2 an unillustrated machine die through a feed bushing 26 and 3 material B to hot-runner system 9 (Fig. 5) from a plasticizer 4 mounted on mold 1 through another feed bushing 28.
CA 022173~ 1997-09-30 List of parts 1. mold 1.1. cavity 2. die 2.1. inner die component 2.1. outer die component 3. hollow needle 3.1. reservoir 4. piston 5. molding 6. port 7. longitudinal groove 8. material-B supply line 9. material-B hot-runner system 10. piston base 11. ball-and-screw transmission 12. transmission screw 13. needle base 14. material-B tube 15. reflecting tube accommodating material-B tube 16. lower-die plate 17. sheet of reflecting material between 9 and 16 18. piston-base stop 19. needle-base stop 20. material-A hot-runner system -l3-CA 022173~ 1997-09-30 21. hot runner 22. three-phase servo motor 23. hydraulic cylinder 24. material-B melt distributor 25. partition between 9 and 10 26. material-A feed bushing 27. material-B plasticizer 28. material-B feed bushing CA 022173~ 1997-09-30 Figures glossary Dekompression "A" A decompressed Dekompression "B~ B decompressed Dekompression Hohlnadelkolben "B" B needle decompressed ~ekompression Nachdruckkolben "A~ A dwell-pressure piston decompressed Druck Pressure Einspritzen "A" A injected Einspritzen "A" und "B" A and B injected Einspritzen "B" B injected Einspritzen Vorlage "A" Charge A injected Einspritzen Vorlage "B" Charge B injected Entformen: Mold emptied Fu'llen Hohlnadelspeicher "B" und B reservoir charged, remainder Restku'hlzeit cooled Nohlnadel "B" vor B needle advanced Hohlnadel "B" zuru'ck B needle retracted Hohlnadelkolben "B" vor B piston advanced Nohlnadelkolben "B" Endstellung vor B piston fully advanced Nachdrucken "A" A dwell compressed Nachdruckkolben "A" vor A dwell-compression piston advanced Schnecke "A" stop A screw stopped Schnecke "A" vor A screw advanced Versiegeln Fu'llen "B" Close and charge with B
Zeit Time
6 and a middle layer of a "material B". Material A can be 7 polyethylene terephthalate (PET) for example. Material B is a 8 material, a copolymer of ethylene and polyvinyl alcohol 9 (EVAL) for example, that acts as a barrier against the gases 10 ~2~ C~2~ and SO2, and against water vapor (H2O). The method 11 employs a device that comprises at least one mold and at 12 least one flat hot runner. The mold has several cavities and 13 the hot runner has the same number of dies. The two materials 14 are supplied to the cavities through separate hot-runner systems. The invention also concerns such a device for 16 carrying out the method.
17 The present invention is not, however, restricted 18 either to bottle blanks or to PET. It can be used for 19 injection molding moldings of any other plastic or combination of plastics for any other purpose. The invention 21 can for example be employed for molding multiple-layer 22 moldings of PET and polyethylene naphthalate (PEN). PEN is, 23 like PET, polyester, although it has much better heat-24 resisting properties, overall mechanical properties, and barrier-forming properties. Although still fairly new, PEN
CA 022173~ 1997-09-30 1 has already been approved by the various governmental 2 authorities as a packaging material in the foodstuffs 3 industry. Due to its outstanding properties, even relatively 4 small portions of PEN by weight of the blank contribute considerably to the quality of the finished bottle. Bottles 6 made of PET or PEN are particular appropriate for bottling 7 fruit juices hot and for storage in hot climates.
8 The middle layer in such blanks constitutes a core, 9 and the inner and outer layer integral skins. The inner layer can also constitute a barrier layer. Such layers, especially 11 those that create a barrier against the gases 02, C02, and 12 S02, and against water vapor (H20), are very important to 13 blanks of this type because they decrease permeability.
14 The inner layers employed in known methods of the aforesaid genus are relatively thick. The thickness makes the 16 blanks considerably more expensive because materials that can 17 act as barriers are substantially more expensive than those 18 that can be employed for outer layers. Another drawback of 19 the known methods is the impossibility of distributing the materials employed for the barrier layers at all uniformly 21 throughout all the cavities in a multiple-cavity mold (a mold 22 with 32 or 48 cavities).
23 Since the material B to be employed as a barrier 24 layer need not be exposed to as much heat as the material A
in the outer layer, the two layers are supplied to the - CA 022173~ 1997-09-30 1 cavities through separate hot-runner systems. This causes 2 considerable problems. One device (known from EO 0 246 512 3 B1) for simultaneously injection molding blanks with several 4 layers accordingly features a separate source and separate ducts. A lot of material B, however, is always left in the 6 die and in the immediately adjacent ducts after each cycle, 7 and the material is exposed to too much heat before being 8 introduced into the cavities.
9 The present invention is intended to eliminate the aforesaid drawbacks and to improve the generic method to the 11 extent that the inner layer of the moldings can be 12 considerably thinner and the molding itself considerably more 13 cost effective to produce and to the extent that the material 14 constituting the inner layer will be uniformly and reproducibly distributed throughout all the cavities.
16 This object is attained in accordance with the 17 present invention in the generic method 18 in that material A is supplied to the cavities 19 through an annular gap between the inner and the outer component of each die and material B is forced into the 21 cavities through a hollow needle that extends through the 22 ~enter of the inner die component by a piston that is 23 integrated into the die and cannot rotate and 24 in that the needle has a port that opens into it at a right angle and re~; n~ open as long as the needle r~A;n~
CA 022173~ 1997-09-30 1 advanced, in a closing position, and that is blocked when the 2 needle is retracted, whereby a reservoir constituted by the 3 hollow inside the needle is charged through the port while 4 the needle is in its closing position.
The charging procedure and the stroke of the piston 6 can be regulated to adjust very precisely and reproducibly 7 from cycle to cycle how much material B is distributed to all 8 the cavities and hence how thick the middle layer will be.
9 The method in accordance with the present invention will also ensure very uniform thickness on the part of the inner layer, 11 the barrier layer.
12 The needle is entirely emptied during each cycle, 13 and material B is accordingly subjected to high heat only 14 during mold emptying and injection, an extraordinarily brief time.
16 One advantageous embodiment of the method in 17 accordance with the present invention is characterized by 18 first supplying enough material A to constitute a 19 single portion through the annular gap between the inner and the outer die component with the needle retracted and the 21 port blocked and with the piston also retracted, 22 then supplying more material A along with material 23 B while the needle remains stationary but the piston 24 advances, then injecting more material A with the needle CA 022173~ 1997-09-30 1 still stationary and its reservoir empty of material B and 2 dwell compressing and decompressing material A, 3 then advancing the needle until it comes into 4 contact with the outer die component, closing the feed, and retracting the needle, charging the reservoir with material 6 B, and 7 finally decompressing material B and removing the 8 molding.
9 The problems that accompany the known methods cannot occur when the method in accordance with the present 11 invention is employed.
12 Another advantageous embodiment of the method in 13 accordance with the present invention comprises 14 first supplying enough material A to constitute a single portion through the annular gap between the inner and 16 the outer die component with the needle retracted and the 17 port blocked and with the piston also retracted, 18 then supplying enough material B to constitute a 19 single portion from the reservoir while the needle re~ins stationary but the piston advances, 21 then supplying both material A and material B with 22 the needle still stationary while the piston advances until 23 it comes into contact with the cone at the needle's outlet 24 then dwell compressing and decompressing material A, CA 022173~ 1997-09-30 1 then advancing the needle until it comes into 2 contact with the outer die component, closing the feed, and 3 retracting the needle, charging the reservoir with material 4 B, and finally decompressing material B and removing the 6 molding.
7 The problems that accompany the known methods can 8 also not occur when this embodiment of the method in 9 accordance with the present invention is employed.
The stroke traveled by the needle and the advanced, 11 emptying, position of the piston are synchronized in the 12 aforesaid embodiments of the method in accordance with the 13 present invention such that the cylindrical entrance to the 14 reservoir will remain blocked once the needle has advanced into the closing position.
16 Still another advanced embodiment of the method in 17 accordance with the present invention comprises 18 simultaneously advancing both the needle and the piston into 19 the closing position once material B has been expelled, forcing all the re~ining material A into the cavities. In 21 this event, a longitudinal groove that provides communication 22 between the port and the reservoir and extends as far as the 23 port in the aforesaid embodiments of the method in accordance 24 with the present invention, also extends somewhat beyond it.
Further embodiments of the method in accordance CA 022173~ 1997-09-30 1 with the present invention are recited in subsidiary claims 4 2 through 8.
3 The device for carrying out the method comprises at 4 least one mold and at least one flat hot runner. The mold has several cavities and the hot runner the same number of dies.
6 A needle slides back and forth in each die.
7 This device attains the object of the present 8 invention 9 in that the needle is hollow and a piston slides back and forth inside it without rotating, whereby the inside 11 of the needle constitutes a reservoir for material B, 12 in that the needle has a port extending into it at 13 a right angle in the vicinity of the hot-runner system for 14 material B and the piston has a longitudinal groove that extends as far as the port, whereby the port and the groove 16 allow material B to flow out of a supply line and into the 17 reservoir, and 18 in that the port is positioned such that the 19 reservoir can be charged only while the needle is in its advanced position, the closing position, the port being 21 blocked as long as the needle is in its retracted position.
22 The hot-runner system for material A is 23 conventional in design and its temperature can be 24 independently controlled. The sole function of the hot-runner system for the barrier material, material B, is to charge the - - CA 022173~ 1997-09-30 1 reservoir. The system is provided with material B from a 2 plasticizer mounted on the mold. This practical measure is 3 possible because of the low proportion of material B.
4 The hot-runner system for material B does not require rheological equilibration because the reservoir is 6 charged subject to a prescribed pressure in accordance with 7 the law of communicating capillaries, m~ning that all the 8 reservoirs in the device will be equally charged in a 9 specified time.
Characteristics of further embodiments of the 11 device in accordance with the present invention will be 12 evident from subsidiary claims 10 through 18.
13 Several embodiments of the method and device in 14 accordance with the present invention will now be specified with reference to the accompanying drawing, wherein 16 Figure 1 illustrates the components of a die in 17 various positions during various steps of a method embodying 18 one injection-molding principle, 19 Figure 2 the pressures that occur over time in the antechamber upstream of a die during that embodiment, 21 Figure 3 the components of a die in various 22 positions during various steps of a method embodying another 23 injection-molding principle, and 24 Figure 4 the pressures that occur over time in the antechamber upstream of a die during that embodiment, CA 022173~ 1997-09-30 1 Figure 5 is a partly sectional top view of a mold, 2 and 3 Figure 6 is a front view of the die-side half of 4 the mold illustrated in Figure 5 as viewed along the direction indicated by arrow VI in that figure.
6 Figures 1 and 3 illustrate by way of example 7 embodiments with a mold 1. Mold 1 is provide with cavities 8 1.1 and an injection-molding die 2. Die 2 comprises an inner 9 component 2.1 and an outer component 2.2. A hollow needle 3 slides back and forth inside inner die component 2.1.
11 Integrated into needle 3 is a piston 4. When piston 4 is 12 retracted, it creates a reservoir 3.1 inside needle 3.
13 Moldings 5 are produced in the cavities 1.1 in mold 1 by the 14 method specified herein.
In the embodiment illustrated by way of example in 16 Figures 1 and 3, a material A is introduced into cavities 1.1 17 through an annular gap between die components 2.1 and 2.2 18 with both needle 3 and piston 4 retracted. A material B is 19 introduced through needle 3.
Figures 1 and 2 illustrate the embodiment of the 21 method recited in Claim 2 and Figures 3 and 4 the embodiment 22 recite in Claim 3.
23 The various steps of the embodiment illustrated in 24 Figures 1 and 3 and in Figures 2 and 4 are sufficiently specified by the call-outs and will not be discussed in CA 022173~ 1997-09-30 1 detail. The pressures relating to material A in Figures 2 and 2 4 are plotted by a continuous line and those relating to 3 material B by a discontinuous line.
4 Materials A and B (cf. Figs. 1 and 3) are supplied to the cavities 1.1 of the mold 1 illustrated in Figure S
6 through dies 2. Each die 2 comprises an inner component 2.1 7 and an outer component 2.2. Accommodated in inner die 8 component 2.1 is a hollow needle 3 that in turn accommodates 9 a piston 4 that cannot rotate. Needle 3 is provided with a port 6 that is closed while in the illustrated position. Port 11 6 is in the vicinity of a longitudinal groove 7 in piston 4.
12 A line 8 that supplies material B communicates with the 13 reservoir 3.1 in needle 3 through groove 7.
14 Dies 2 are secured in a flat hot runner 21. The ends of each piston 4 that point away from a die 2 are 16 fastened to a flat base 10. base 10 travels back and forth 17 subject to a ball-and-screw transmission 11. The screws 12 18 are driven by a variable three-phase servo motor 22 (Fig. 6).
19 This system allows portion-regulated charging of reservoir 3.1 with material B, the barrier material, and following a 21 precise pattern with the material during both continuous and 22 discontinuous injection molding.
23 The whole procedure is made possible by the 24 characteristics of the motor, specifically constant torque over its total speed range, CA 022173~ 1997-09-30 1 high dynamics (from 0 to nominal speed in 25 msec), 2 low friction, 3 high overload capacity, 4 nominal torque even while accelerating and decelerating, 6 very consistent rate of rotation at nominal speeds 7 of 2000 to 8000 rpm, and 8 small size and high output.
Position and speed controls allow precise 11 reproduction of master patterns from cycle to cycle.
12 Needles 3 are all secured in the same base 13.
13 bases 10 and 13 can be driven in and out independently. Base 14 10 is driven by the aforesaid transmission 11 and base 13 by hydraulic cylinders 23.
16 Material B is supplied through tubes 14. Hydraulic 17 cylinders 23 are enclosed in a reflector tube 15 and 18 commlln;cate with a melt distributor 24.
19 The hot-runner system 9 for material B is thermally insulated from the hot-runner system 20 for material A by a 21 partition 25.
22 Also accommodated in mold 1 are stops 18 and 19 23 that establish the zero or farthest-down positions of bases 24 10 and 13.
As will be evident from Figure 6, material A is CA 022173~ 1997-09-30 1 conventionally supplied to hot-runner system 20 (Fig. 5) from 2 an unillustrated machine die through a feed bushing 26 and 3 material B to hot-runner system 9 (Fig. 5) from a plasticizer 4 mounted on mold 1 through another feed bushing 28.
CA 022173~ 1997-09-30 List of parts 1. mold 1.1. cavity 2. die 2.1. inner die component 2.1. outer die component 3. hollow needle 3.1. reservoir 4. piston 5. molding 6. port 7. longitudinal groove 8. material-B supply line 9. material-B hot-runner system 10. piston base 11. ball-and-screw transmission 12. transmission screw 13. needle base 14. material-B tube 15. reflecting tube accommodating material-B tube 16. lower-die plate 17. sheet of reflecting material between 9 and 16 18. piston-base stop 19. needle-base stop 20. material-A hot-runner system -l3-CA 022173~ 1997-09-30 21. hot runner 22. three-phase servo motor 23. hydraulic cylinder 24. material-B melt distributor 25. partition between 9 and 10 26. material-A feed bushing 27. material-B plasticizer 28. material-B feed bushing CA 022173~ 1997-09-30 Figures glossary Dekompression "A" A decompressed Dekompression "B~ B decompressed Dekompression Hohlnadelkolben "B" B needle decompressed ~ekompression Nachdruckkolben "A~ A dwell-pressure piston decompressed Druck Pressure Einspritzen "A" A injected Einspritzen "A" und "B" A and B injected Einspritzen "B" B injected Einspritzen Vorlage "A" Charge A injected Einspritzen Vorlage "B" Charge B injected Entformen: Mold emptied Fu'llen Hohlnadelspeicher "B" und B reservoir charged, remainder Restku'hlzeit cooled Nohlnadel "B" vor B needle advanced Hohlnadel "B" zuru'ck B needle retracted Hohlnadelkolben "B" vor B piston advanced Nohlnadelkolben "B" Endstellung vor B piston fully advanced Nachdrucken "A" A dwell compressed Nachdruckkolben "A" vor A dwell-compression piston advanced Schnecke "A" stop A screw stopped Schnecke "A" vor A screw advanced Versiegeln Fu'llen "B" Close and charge with B
Zeit Time
Claims (20)
1. A method for injection-molding three-layer moldings, particularly bottle blanks with inner and outer layers of a first material and a middle layer of a second material forming a barrier against gases corresponding to O2, CO2 and SO2, and against water vapor; comprising the step of: providing at least one mold and at least one hot runner plate; providing a plurality of cavities in said mold and injection die nozzles in said hot runner plate, said injection die nozzles corresponding in number to said cavities; supplying said first and second materials to said cavities through separate hot-runner systems; supplying said first material through an annular gap between an inner and an outer component of each die nozzle; forcing said second material into said cavities through a hollow needle extending through a center of the inner die component by a non-rotatable piston integrated into the die nozzle; providing a port in said needle, said port having an opening at a right angle to said needle;
holding said opening open as long as said needle remains advanced in a closing position; blocking said opening when said needle is retracted; charging a reservoir formed by a hollow inside sad needle through said portion while said needle is in the closing position.
holding said opening open as long as said needle remains advanced in a closing position; blocking said opening when said needle is retracted; charging a reservoir formed by a hollow inside sad needle through said portion while said needle is in the closing position.
2. A method as defined in claim 1, including the steps of:
first supplying sufficient said first material to comprise a single portion through said annular gap between said inner and outer component when said needle is retracted and said port is blocked and said piston is also retracted; supplying thereafter additional said first material together with said second material while said needle remains stationery and said piston advances;
injecting thereafter additional said first material while said needle remains stationery and said reservoir is empty of said second material; compressing thereafter said firs material and subsequently decompressing said first material; advancing thereafter said needle until contacting said outer component, closing supply of said first material, retracting said needle, and charging said reservoir with said second material; and decompressing finally said second material and removing the molding from the mold.
first supplying sufficient said first material to comprise a single portion through said annular gap between said inner and outer component when said needle is retracted and said port is blocked and said piston is also retracted; supplying thereafter additional said first material together with said second material while said needle remains stationery and said piston advances;
injecting thereafter additional said first material while said needle remains stationery and said reservoir is empty of said second material; compressing thereafter said firs material and subsequently decompressing said first material; advancing thereafter said needle until contacting said outer component, closing supply of said first material, retracting said needle, and charging said reservoir with said second material; and decompressing finally said second material and removing the molding from the mold.
3. A method as defined in claim 1, including the steps of:
first supplying sufficient said first material to comprise a singular portion through said annular gap between said inner and said outer component when said needle is retracted and said portion is blocked and said piston is also retracted; supplying thereafter sufficient said second material to comprise a single portion from said reservoir while said needle remains stationary and said piston advances; supplying thereafter both said first material and said second material while said needle remains stationary and said piston advances until contacting with a cone of an outlet of said needle; compressing thereafter and subsequently decompressing said first material; advancing thereafter said needle until contacting said outer component and closing the supply, retracting said needle, and charging said reservoir with said second material; and decompressing finally said second material and removing the molding from the mold.
first supplying sufficient said first material to comprise a singular portion through said annular gap between said inner and said outer component when said needle is retracted and said portion is blocked and said piston is also retracted; supplying thereafter sufficient said second material to comprise a single portion from said reservoir while said needle remains stationary and said piston advances; supplying thereafter both said first material and said second material while said needle remains stationary and said piston advances until contacting with a cone of an outlet of said needle; compressing thereafter and subsequently decompressing said first material; advancing thereafter said needle until contacting said outer component and closing the supply, retracting said needle, and charging said reservoir with said second material; and decompressing finally said second material and removing the molding from the mold.
4. A method as defined in claim 1, wherein said needle and said piston are advanced simultaneously and in synchronization into a closing position after said second material has been forced out.
5. A method as defined in claim 1, wherein said reservoir after being charged is decompressed by retracting said piston immediately before opening the mold.
6. A method as defined in claim 1, wherein the amount of material charged in said reservoir is dependent on the amount of advance of said piston; and actuating said piston by a ball-and-screw transmission having a screw connected to a variable three-phase servo motor.
7. A method as defined in claim 6, wherein either the volume of said reservoir or the amount of said second material to be charged in said reservoir is dependent on a layer of said second material in an unstretched molding being substantially .10 to 0.20 mm thick and a wall of said blank after being completed in fabrication is substantially 10 to 20 µm thick.
8. A method as defined in claim 6, wherein the amount of said second material to be charged in said reservoir is dependent on the proportion of said second material in the molding in the range of 1.5% to 3% by weight of the total molding.
9. Apparatus for injection-molding three-layer moldings, particularly bottle blanks with inner and outer layers of a first material and a middle layer of a second material forming a barrier against gases corresponding to O2, CO2 and SO2, and against water vapor; comprising: at least one mold and at least one hot runner plate; said mold having a plurality of cavities;
injection die nozzles in said hot runner plate and corresponding in number to said cavities; separate hot-runner systems for supplying said first and second materials to said cavities; each die nozzle having an inner and an outer component, said first material being supplied through an annular gap between said inner and said outer component; a hollow needle extending through a center of the inner die component by a non-rotatable piston integrated into the die nozzle for forcing said second material into said cavities; said needle having a portion at a right angle to said needle; means for holding said opening open as long as said needle remains advanced in a closing position; means for blocking said opening when said needle is retracted; a reservoir formed by a hollow inside said needle and charged through said port while said needle is in the closing position, said needle sliding back and forth in each die nozzle, said piston sliding back and forth inside said needle and having a longitudinal groove extending as far as said port, said port and said groove allowing said second material to flow out of a supply line and into said reservoir; said port having a position for charging said reservoir only while said needle is advanced in said closing position, said port being blocked as long a said needle is in retracted position.
injection die nozzles in said hot runner plate and corresponding in number to said cavities; separate hot-runner systems for supplying said first and second materials to said cavities; each die nozzle having an inner and an outer component, said first material being supplied through an annular gap between said inner and said outer component; a hollow needle extending through a center of the inner die component by a non-rotatable piston integrated into the die nozzle for forcing said second material into said cavities; said needle having a portion at a right angle to said needle; means for holding said opening open as long as said needle remains advanced in a closing position; means for blocking said opening when said needle is retracted; a reservoir formed by a hollow inside said needle and charged through said port while said needle is in the closing position, said needle sliding back and forth in each die nozzle, said piston sliding back and forth inside said needle and having a longitudinal groove extending as far as said port, said port and said groove allowing said second material to flow out of a supply line and into said reservoir; said port having a position for charging said reservoir only while said needle is advanced in said closing position, said port being blocked as long a said needle is in retracted position.
10. Apparatus as defined in claim 9, including a first flat base for securing all needles; a second flat base for securing all pistons, said first base and said second base traveling in and out independently of each other.
11. Apparatus as defined in claim 10, wherein said first base and said second base are rectangular with four outer corners guided inside the mold.
12. Apparatus as defined in claim 10, including at least one hydraulic cylinder for actuating said second base.
13. Apparatus as defined in claim 10, including a ball-and-screw transmission with a screw connected to a variable three-phase sevo motor for actuating said first base.
14. Apparatus as defined in claim 9, including bent tubes o high heat conducting material for supplying said second material to said die nozzles from a melt distributor and simultaneously compensating for thermal expansion.
15. Apparatus as defined in claim 14, including an aluminum reflector tube for holding loosely each of said bent tubes.
16. Apparatus as defined in claim 9, including a partition for thermally insulating the hot-runner system associated with said second material from the hot-runner system associated with said first material.
17. Apparatus as defined in claim 9, including a sheet of reflecting metal between the hot-runner system associated with said second material and a bottom-die plate.
18. Apparatus as defined in claim 10, including stops in said mold to form farthest-down positions for said first base and said second base.
19. A method as defined in claim 1, wherein said first material is polyethylene terephthalate (PET) and said second material is a copolymer of ethylene and polyvinyl alcohol (EVAL).
20. Apparatus as defined in claim 9, wherein said firs material is polyethylene terephthalate (PET) and said second material is a copolymer of ethylene and polyvinyl alcohol (EVAL).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19640662A DE19640662C1 (en) | 1996-10-02 | 1996-10-02 | Injection moulding of bottle preforms |
| DE19640662.5-16 | 1996-10-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2217355A1 true CA2217355A1 (en) | 1998-04-02 |
Family
ID=7807685
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002217355A Abandoned CA2217355A1 (en) | 1996-10-02 | 1997-09-30 | Method for die casting three-layer articles and apparatus for carrying out the method |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5935614A (en) |
| EP (1) | EP0839629A1 (en) |
| CA (1) | CA2217355A1 (en) |
| DE (1) | DE19640662C1 (en) |
Families Citing this family (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0887169A1 (en) * | 1997-06-27 | 1998-12-30 | Altoplast AG | Method for producing a multilayer preform and preform produced according to the method |
| US6352426B1 (en) | 1998-03-19 | 2002-03-05 | Advanced Plastics Technologies, Ltd. | Mold for injection molding multilayer preforms |
| TWI250934B (en) | 1997-10-17 | 2006-03-11 | Advancsd Plastics Technologies | Barrier-coated polyester articles and the fabrication method thereof |
| 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 |
| CH692573A5 (en) * | 1997-11-04 | 2002-08-15 | Otto Hofstetter Ag Werkzeug Un | A method for producing multilayer preforms. |
| US6305563B1 (en) * | 1999-01-12 | 2001-10-23 | Aptargroup, Inc, | One-piece dispensing structure and method and apparatus for making same |
| US6655945B1 (en) | 1999-03-18 | 2003-12-02 | Mold Masters Limited | Apparatus and method for multi-layer injection molding |
| US6440350B1 (en) | 1999-03-18 | 2002-08-27 | Mold-Masters Limited | Apparatus and method for multi-layer injection molding |
| US6398537B2 (en) | 1999-04-02 | 2002-06-04 | Mold-Masters Limited | Shuttle system for an apparatus for injection molding |
| US6808820B2 (en) | 2000-09-05 | 2004-10-26 | Advanced Plastics Technology Ltd. | Multilayer containers and preforms having barrier properties utilizing recycled material |
| BR0210476A (en) * | 2001-06-18 | 2004-08-10 | Becton Dickinson Co | Multilayer Containers and Multilayer Container Forming Process |
| US6884061B2 (en) * | 2002-09-18 | 2005-04-26 | Mold-Masters Limited | Metering device for a nozzle of an injection molding apparatus |
| US7175419B2 (en) * | 2002-12-03 | 2007-02-13 | Mold-Masters Limited | Hot runner co-injection nozzle |
| US7175420B2 (en) * | 2003-02-13 | 2007-02-13 | Mold-Masters Limited | Valve gated injection molding system with independent flow control |
| US20040166189A1 (en) * | 2003-02-25 | 2004-08-26 | Mold-Masters Limited | Injection molding system with flow control |
| WO2005102668A2 (en) | 2004-04-16 | 2005-11-03 | Advanced Plastics Technologies Luxembourg S.A. | A bottle, a method of forming the bottle, a liquid dispensing system and an extruded profile |
| EP1943074A1 (en) | 2005-08-30 | 2008-07-16 | Advanced Plastics Technologies Luxembourg S.A. | Methods and systems for controlling mold temperatures |
| US7458795B2 (en) * | 2006-02-24 | 2008-12-02 | Incoe Corporation | Co-injection nozzle assembly |
| EP1997603A1 (en) * | 2007-05-31 | 2008-12-03 | Alliance for business solutions A4BS | Modified hot runner systems for injection blow molding |
| JP2012232463A (en) * | 2011-04-28 | 2012-11-29 | Yoshino Kogyosho Co Ltd | Preform injection molding device, injection molding method, and synthetic resin bottle body |
| KR20170029860A (en) * | 2015-09-08 | 2017-03-16 | 삼성전자주식회사 | Case for mobile phone and injection mold for the same |
| CA3162732A1 (en) * | 2019-12-23 | 2021-07-01 | Husky Injection Holding Systems Ltd. | Injection molding of multilayer articles with post-pullback pressure monitoring |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| CH566207A5 (en) * | 1972-12-07 | 1975-09-15 | Siemag Siegener Masch Bau | |
| 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 |
| US4174413A (en) * | 1976-07-27 | 1979-11-13 | Asahi-Dow Limited | Multi-layered molded articles |
| US4946365A (en) * | 1983-04-13 | 1990-08-07 | American National Can Company | Apparatus for injection molding and injection blow molding multi-layer articles |
| US4657496A (en) * | 1984-06-04 | 1987-04-14 | Gifu Husky Co., Ltd. | Hot-runner mold for injection molding |
| JPS61235126A (en) * | 1985-04-12 | 1986-10-20 | Nissei Ee S B Kikai Kk | Multi-layer vessel and manufacture thereof |
| US4717324A (en) * | 1986-05-12 | 1988-01-05 | Husky Injection Molding Systems, Inc. | Coinjection of hollow articles and preforms |
| DE3644523A1 (en) * | 1986-09-25 | 1988-07-14 | Agfa Gevaert Ag | METHOD FOR PRODUCING AN INJECTION MOLDING TOOL |
| AT391833B (en) * | 1988-10-03 | 1990-12-10 | Engel Gmbh Maschbau | Injection nozzle for injection-moulding machines |
| US4990301A (en) * | 1989-01-25 | 1991-02-05 | Continental Pet Technologies, Inc. | Method and apparatus for injection molding of multilayer preforms |
| US5536164A (en) * | 1995-05-05 | 1996-07-16 | Electra Form, Inc. | Flexible hot manifold assembly for injection molding machines |
-
1996
- 1996-10-02 DE DE19640662A patent/DE19640662C1/en not_active Expired - Fee Related
-
1997
- 1997-08-19 EP EP97114279A patent/EP0839629A1/en not_active Withdrawn
- 1997-09-30 CA CA002217355A patent/CA2217355A1/en not_active Abandoned
- 1997-10-01 US US08/941,907 patent/US5935614A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0839629A1 (en) | 1998-05-06 |
| US5935614A (en) | 1999-08-10 |
| DE19640662C1 (en) | 1998-03-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |