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
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/02—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles
  • B29C43/04—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles using movable moulds
  • B29C43/06—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles using movable moulds continuously movable in one direction, e.g. mounted on chains, belts
  • B29C43/08—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles using movable moulds continuously movable in one direction, e.g. mounted on chains, belts with circular movement, e.g. mounted on rolls, turntables
• • 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
  • B29C31/00—Handling, e.g. feeding of the material to be shaped, storage of plastics material before moulding; Automation, i.e. automated handling lines in plastics processing plants, e.g. using manipulators or robots
  • B29C31/04—Feeding of the material to be moulded, e.g. into a mould cavity
  • B29C31/06—Feeding of the material to be moulded, e.g. into a mould cavity in measured doses, e.g. by weighting
  • B29C31/065—Feeding of the material to be moulded, e.g. into a mould cavity in measured doses, e.g. by weighting using volumetric measuring chambers moving between a charging station and a discharge station
  • B29C31/068—Feeding of the material to be moulded, e.g. into a mould cavity in measured doses, e.g. by weighting using volumetric measuring chambers moving between a charging station and a discharge station of the piston type
• • 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
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/32—Component parts, details or accessories; Auxiliary operations
  • B29C43/34—Feeding the material to the mould or the compression means
• • 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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/16—Cooling
  • B29C2035/1616—Cooling using liquids
• • 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
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/16—Cooling
  • B29C2035/1658—Cooling using gas
  • B29C2035/1666—Cooling using gas dried air
• • 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
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/32—Component parts, details or accessories; Auxiliary operations
  • B29C43/34—Feeding the material to the mould or the compression means
  • B29C2043/3466—Feeding the material to the mould or the compression means using rotating supports, e.g. turntables or drums
• • 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
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/32—Component parts, details or accessories; Auxiliary operations
  • B29C43/36—Moulds for making articles of definite length, i.e. discrete articles
  • B29C2043/3676—Moulds for making articles of definite length, i.e. discrete articles moulds mounted on rotating supporting constuctions
  • B29C2043/3678—Moulds for making articles of definite length, i.e. discrete articles moulds mounted on rotating supporting constuctions on cylindrical supports with moulds or mould cavities provided on the periphery
  • B29C2043/3681—Moulds for making articles of definite length, i.e. discrete articles moulds mounted on rotating supporting constuctions on cylindrical supports with moulds or mould cavities provided on the periphery opening and closing axially, i.e. parallel to the rotation axis
• • 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
  • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material

Definitions

• the present invention relates to a process for the continuous production by injection-compression of preforms for the manufacture of packaging, such as bottles, made of synthetic material by means of an extruder as well as an installation for implementing the method.
• Synthetic packages for example PET bottles, are produced by stretch-blow molding of a preform generally by two methods, namely:
• the "two-step” method makes it possible to manufacture several preforms at a time, but the preforms when they arrive at the blower are at room temperature and they must be heated up to the blowing temperature which is the same. 100 ° C order, which on the one hand requires specific management of preforms (storage, transport, manipulation) and on the other hand makes production more expensive.
• the method "in one step” saves energy since the preforms, when they arrive at the blowing stations, are at a temperature of the order of 60 ° C which saves the energy needed to heat the preforms of the ambient temperature at 60 ° C.
• the manufacture of the preform requires the transformation of the thermoplastic synthetic material, in this case PET, to obtain the preform from a cooled mold.
• the perfectly dried granules (approximately 160 ° C. for a few hours) are converted by a melt extruder to approximately 270 ° C.
• injection pressure usually exceeds 1000 bar.
• This technique involves high stress Mecani ⁇ cal on the material and a workhorse in terms of the mold clamping force and injection pressure.
• a shutter system is required to close the injection threshold at the end of the hold phase.
• Compression Injection An exact amount of hot material is injected into the mold by a doser as the mold's movable punch moves back to facilitate the transfer of the material into the mold, the completed injection the punch performs the compression process for form the preform.
• the injection pressure remains below 500 bar, the mechanical stresses low.
• the present invention aims to improve the production of preforms to make it continuous and better adapted to the rate of blowing machines, especially rotary.
• the invention can be used even in the "two-step" method, the preform production according to the invention being faster.
• An injection metering device is in the form of a piston movable relative to a cylinder and is a syringe capable of receiving and then injecting the melt.
• the dosing wheel equipped with a rotating connection with the extruder which is fixed, rotates continuously and ensures the filling of each injection valve on a complete revolution. Dosers injection arrive empty on the metering wheel and come out filled with a quantity of material calculated according to the weight of the preform.
• the dosing wheel ensures a radial distribution of the molten material through channels which feed the injection feeders during filling.
• a poppet valve is opened and passes the material to the injection feeder.
• the piston of the injection metering device is prestressed by a cylinder to ensure a back pressure during filling of the injection metering device.
• the poppet valve is closed again and the cylinder pulls the piston of the injection metering device onto a calculated stroke to decompress the material inside the injection metering device.
• An injection-compression module supports a preform mold with a footprint. Each injection-compression module executes a cycle during one turn of the injection-compression wheel to manufacture a preform according to the following sequence: closure of the mold then injection of the melt into the mold with recoil of the punch of the mold, then compressing the material by the punch, then cooling the material for a calculated time, then opening the mold, then ejecting the preform.
• the mold of the injection-compression module is provided on its end opposite the punch of an injection threshold (hole for the entry of the melt). The end of the "syringe" constituting the dispenser is placed facing the injection threshold and under the thrust of the metering piston the material enters the mold.
• the piston remains in place and closes the injection threshold until the solidification of the injected material and the withdrawal of the preform.
• the filling through the injection threshold is through a circuit in which the molten material is pushed and when the dose is injected into the mold of the injection-compression module a valve must close for until solidification of the solid matter.
• the management of this circuit with the melt and the valves is complicated.
• the method according to the invention using the metering device which remains in place until removal of the preform solves this problem.
• each injection-compression module executes the injection-compression cycle described above to manufacture a preform recovery of the preform by means of handling and passage of each dosing device. injection on the dosing wheel for new filling.
• the advantage of this process is the continuous production of preforms at high speed which allows to feed downstream a rotary blower for the formation of packaging which also works at high speed.
• the preforms leaving the machine for producing the preforms are at a temperature of approximately 60 ° C. and it is sufficient to heat them to bring them to the blowing temperature which is approximately 100 ° C., which can be achieved more rapidly and with a saving of energy.
• the preform is transferred and cooled in cooling molds located on the cooling wheel of the preforms.
• the supported preforms are conveyed directly to a blowing installation for forming the packages.
• the invention also relates to an installation for implementing the method according to claim 4.
• the installation is characterized by the fact that a third wheel, the preform cooling wheel, located in the vertical of the synchronously rotating injection-compression wheel is provided with preform cooling molds.
• preforms need to be stored before being moved to a blower, cooling may be required.
• Figure 1 is a schematic perspective view of an installation according to the invention.
• Figure 2 is a section of the metering wheel in a plane passing through the axis of rotation of said wheel.
• Fig. 3 is an enlarged view of a detail of Fig. 2.
• Figure 4 is a perspective view of part of the installation showing some details.
• Figure 5 is a perspective view of an injection-compression device.
• Figure 6 is a sectional view of a metering and injection-compression module assembled.
• FIG. 1 we have schematically represented the main elements of the installation for the implementation of the method according to the invention.
• a hopper and dryer of the PET granules feed an extruder 2.
• the extruder feeds a metering wheel 3 on which metering devices are located (not shown)
• An injection-compression wheel 4 supporting modules of injection-compression 5 is disposed after the metering wheel 3.
• preform cooling is provided by means of a wheel preform cooling device 6 provided with a set of devices 61 blowing air on the preforms before they are taken over for storage.
• the metering wheel 3 is provided with housings 36 in which metering units 7 are placed.
• Each metering device 7 comprises a tubular portion 71 in which A tubular portion 71 terminates in an orifice 73 through which the extruded material is pushed into the metering device 7 and thereafter it will exit to feed the injection-compression devices.
• the housings 36 communicate with a shutter 31, 32 ( Figure 2, 3). Said shutter comprises a seat 32 and a piston 31.
• Each seat 32 communicates through a radial opening with a radial channel 34 of the metering wheel 3 and is also provided with an orifice facing the orifice 73 of the metering device 7.
• All the radial channels 34 are supplied with extruded material through an axial channel 33 of the wheel 3 itself fed by the extruder 2.
• a metering device 7 When a metering device 7 is placed in a housing 36, the piston 31 moves back to free the passage and let the extruded material pass through the doser. The entry of the extruded material under pressure causes the piston 72 to retract.
• the piston 31 goes back down and blocks the passage to the doser. The piston 72 during the filling is subjected to a back pressure, and after filling back to decompress the extruded material.
• the amount of the material in the dispenser is a function of several parameters such as the feed pressure, the diameter of the orifice 73, the time during which the shutter 31, 32 remains open ...
• Several feeders are arranged The metering wheel 3.
• Each metering device must be filled about two-thirds of the circumference of the dosing wheel 3. Then, it is transferred to the injection-compression wheel 4 and replaced by an empty metering device from the latter wheel. 4.
• FIG. 4 shows the metering wheel 3 with the proportioners 7 mounted on a vertical support, two transfer wheels 8 and 9 disposed on vertical supports and the injection-compression wheel 4 with the injection devices. compression 5 regularly distributed on its periphery.
• the wheel 8 is provided with radial arms 81 with a gripping device 82. Each arm 8 grasps a metering device 5 full of the wheel 3 and brings it into an injection-compression device 5 of the wheel 4.
• the wheel 9 is also provided with radial bars 91, 92 identical to the radial arms 81, 82 to enter the empty dosers 7 of the wheel 4 and bring them to the wheel 3 for a new filling.
• the four wheels 3,4,8 and 9 turn in the same direction.
• the gripping devices 82, 92 may be grippers controlled by a cam specific to each wheel 8, 9 or other equivalent devices to seize the moment a full or empty doser and leave it on the wheel 4 or 3.
• Each injection-compression device 5 is fixed on the wheel 4 by a radial support 51.
• the lower part of the device 5 comprises a cylinder 52.
• Above the piston 51 of the gripping means 53 hold the doser 7.
• the driver 7 Under the action of a spring 54 the driver 7 is housed in the lower part of a die or mold 55.
• Under the action of the cylinder 52 the piston 72 of the metering device 7 injects the material into the mold 55.
• piston 72 of the metering device 7 (FIG 6) is provided with a pin 721 which is inserted into the orifice 73 of the metering device and closes the injection threshold 551 of the mold 55 when all of the extruded material passes into the mold 55.
• a punch 56 secured to a moving part 57 comes into the mold 55 to form the preform.
• the upper part of the preform with the screw thread (for the production of preforms intended to become bottles the) is formed in the upper part of the punch 56.
• This part is formed of two complementary jaws 58, 59.
• the metering wheel 3 in one embodiment comprises 24 metering units while the injection-compression wheel 4 comprises 48 devices 5.
• the described installation allows a continuous high rate.
• the preforms are at the outlet of the continuous wheel 4 on a blowing installation that saves heating energy, or are stored for blowing later.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Robotics (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
• Forging (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37575312

Family Applications (1)

Country Status (8)

Families Citing this family (1)

Family Cites Families (16)

• 2006
  • 2006-04-14 FR FR0603334A patent/FR2899836B1/fr not_active Expired - Fee Related
• 2007
  • 2007-04-03 EP EP07734221A patent/EP2007562A1/de not_active Withdrawn
  • 2007-04-03 WO PCT/IB2007/000901 patent/WO2007119139A1/fr active Application Filing
  • 2007-04-03 BR BRPI0711533-4A patent/BRPI0711533A2/pt not_active IP Right Cessation
  • 2007-04-03 RU RU2008144968/05A patent/RU2426643C2/ru not_active IP Right Cessation
  • 2007-04-03 CA CA2647840A patent/CA2647840C/fr not_active Expired - Fee Related
  • 2007-04-03 CN CN2007800134983A patent/CN101421087B/zh not_active Expired - Fee Related
  • 2007-04-03 US US12/296,591 patent/US7993564B2/en not_active Expired - Fee Related

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