EP4288260A1 - Procédé de production d'un matériau plastique à base de pet recyclé destiné à être utilisé dans un procédé de moulage par injection à paroi mince et corps creux produit dans le procédé de moulage par injection à paroi mince - Google Patents

Procédé de production d'un matériau plastique à base de pet recyclé destiné à être utilisé dans un procédé de moulage par injection à paroi mince et corps creux produit dans le procédé de moulage par injection à paroi mince

Info

Publication number
EP4288260A1
EP4288260A1 EP22708433.2A EP22708433A EP4288260A1 EP 4288260 A1 EP4288260 A1 EP 4288260A1 EP 22708433 A EP22708433 A EP 22708433A EP 4288260 A1 EP4288260 A1 EP 4288260A1
Authority
EP
European Patent Office
Prior art keywords
pet
injection molding
chain breaker
acid
chain
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.)
Pending
Application number
EP22708433.2A
Other languages
German (de)
English (en)
Inventor
Robert Siegl
Benjamin Haas
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alpla Werke Alwin Lehner GmbH and Co KG
Original Assignee
Alpla Werke Alwin Lehner GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CH00117/21A external-priority patent/CH718330A1/de
Priority claimed from CH070736/2021A external-priority patent/CH719268A1/de
Application filed by Alpla Werke Alwin Lehner GmbH and Co KG filed Critical Alpla Werke Alwin Lehner GmbH and Co KG
Publication of EP4288260A1 publication Critical patent/EP4288260A1/fr
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/0026—Recovery of plastics or other constituents of waste material containing plastics by agglomeration or compacting
    • B29B17/0042—Recovery of plastics or other constituents of waste material containing plastics by agglomeration or compacting for shaping parts, e.g. multilayered parts with at least one layer containing regenerated plastic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B9/00—Making granules
    • B29B9/10—Making granules by moulding the material, i.e. treating it in the molten state
    • 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
    • B29C45/0001—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor characterised by the choice of 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D22/00—Producing hollow articles
    • B29D22/003—Containers for packaging, storing or transporting, e.g. bottles, jars, cans, barrels, tanks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/02—Separating plastics from other materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/04—Disintegrating plastics, e.g. by milling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B2017/001—Pretreating the materials before recovery
    • B29B2017/0015—Washing, rinsing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/02—Separating plastics from other materials
    • B29B2017/0213—Specific separating techniques
    • B29B2017/0255—Specific separating techniques using different melting or softening temperatures of the materials to be separated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/02—Separating plastics from other materials
    • B29B2017/0213—Specific separating techniques
    • B29B2017/0268—Separation of metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/02—Separating plastics from other materials
    • B29B2017/0213—Specific separating techniques
    • B29B2017/0286—Cleaning means used for separation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
    • B29B17/04—Disintegrating plastics, e.g. by milling
    • B29B2017/042—Mixing disintegrated particles or powders with other materials, e.g. with virgin materials
    • 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
    • B29C2045/0091—Pellets or granules, e.g. their structure, composition, length, height, width
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/285—Feeding the extrusion material to the extruder
    • B29C48/287—Raw material pre-treatment while feeding
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/69—Filters or screens for the moulding 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/50—Details of extruders
    • B29C48/76—Venting, drying means; Degassing 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/0005—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor characterised by the 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
    • B29C49/04—Extrusion blow-moulding
    • 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
    • B29K2067/003—PET, i.e. poylethylene terephthalate
    • 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
    • B29K2105/0094—Condition, form or state of moulded material or of the material to be shaped having particular viscosity
    • 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
    • B29K2105/26—Scrap or recycled material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/712—Containers; Packaging elements or accessories, Packages
    • B29L2031/7158—Bottles
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

  • the present invention relates to a method for producing a rPET plastic material for use in a thin-wall injection molding process according to the preamble of claim 1 and a hollow body produced in the thin-wall injection molding process.
  • the standard PET types used today for the production of bottles in a stretch blow molding process are predominantly linear PET types (no branched) with a low copolymer content of less than 5% by weight and an intrinsic viscosity (IV) between 0.72 and 0. 86 dl/g (according to ASTM D 4603).
  • IV intrinsic viscosity
  • thin-wall injection molding requires viscosities of between 0.5 and 0.7 dl/g. This means that the material produced in the standard PET recycling process and also the usual regenerated materials cannot be used for the injection molding process.
  • PET materials are known as new goods with a viscosity of 0.5 to 0.7 dl/g (ASTM D4603), which is designed precisely for these applications.
  • ASTM D4603 a viscosity of 0.5 to 0.7 dl/g
  • Packaging manufacturers who want to use exactly this material will still have to prove a recycling share of 25% to 50% in the future, depending on which legal regulation or voluntary commitment is binding for the distributor until 2025 or 2030.
  • a much higher recycling content of 40 to 100% is usually required for polyester applications.
  • a PET recycling material with a viscosity of 0.5 to 0.7 dl/g is required for injection-moulded packaging. This sounds very simple at first, since PET can be broken down to the planned viscosity very easily using water and heat.
  • the PET will degrade exactly as planned to a viscosity of 0.5 to 0.7 dl/g, but the material will be damaged by this degradation (hydrolysis ) whitish cloudy and partially crystalline. Sometimes there are also bubbles.
  • the uncontrolled crystallization causes sink marks, cavities and severely warped parts, which are also much too brittle for the final application as packaging due to the low viscosity and high internal stress.
  • the main PET recycling stream available on the market consists largely of PET bottles, which were made from a material with a viscosity of approx. 0.72 to 0.86 dl/g in a stretch blow molding process (ISBM process).
  • the viscosity of this recycling stream is too high for injection molding of thin-walled parts.
  • the recycling goods on the market from the main stream mainly contain PET ISBM bottles with a copolymer content of 2 to 3%. This proportion of copolymer varies greatly, depending on whether the recycled goods contain many films and deep-drawn items, PET-G or returnable bottles. In general, the copolymer content is too unstable to be able to produce stable, thin-walled injection molded parts from rPET that should not crystallize uncontrollably.
  • the average viscosity in the recycled goods is around 0.02 to 0.09 dl/g lower than starting material, but must be decontaminated under heat and vacuum (or nitrogen) to be suitable for food contact. This decontamination can take place in a dryer before the recycling extruder, in the recycling extruder or after the recycling extruder in a so-called SSP process. Combinations are also common.
  • PET can be broken down in a targeted manner by adding mono-ethylene glycol (glycolysis).
  • WO001997020886A1 discloses a method that uses glycolysis and subsequent purification to recycle previously used polyester materials. Recycled PET is contacted with 1.1 to 10 moles of ethylene glycol per mole of dicarboxylic acid in the polyester at a temperature in the range of 150 to 300°C for between 10 minutes and 4 hours to depolymerize the polyester and produce a reaction mixture containing monomeric and contains oligomeric dihydroxy species. Excess ethylene glycol is then removed and the reaction mixture dissolved in a hot solvent. The hot solution is then filtered to remove unwanted impurities. Thereafter, the solution is cooled and the dihydroxy species precipitated as a solid.
  • PET transesterifies through the addition of low-molecular esters or polyesters (cross- and trans-esterfication) and that the viscosity adjusts under heat by exchanging polyesters in the chain.
  • a polyester with the monomers A and B and a second polyester with the monomers B and C can be converted by transesterification into a third copolyester which contains monomers of types A, B and C in its chains.
  • IPA isophthalic acid
  • DEG diethylene glycol
  • NDC naphthalenedicarboxylic acid
  • FDCA furandicarboxylic acid
  • the object of the present invention is to provide an rPET material that is particularly suitable for thin-wall injection molding and primarily comes from rPET that comes from the collection of post-consumer PET articles, in particular from bias-molded PET bottles, is won.
  • Another goal is to propose an rPET material that can be compressed at 500 to 3000 bar, ideally spraying at approx. up to 1 in 500 for thin-wall injection molding.
  • a further aim is that the material can be processed in such a way that it remains transparent, ie essentially crystal clear, and that no crystallization of the material scatters the light so that the contents can no longer be seen.
  • viscosity means the intrinsic viscosity (IV) measured according to ASTM 4603-03 standard.
  • pure-type PET is understood to mean that PET has been sorted within the scope of today's technological possibilities, so that the proportion by weight of non-type plastic is less than 2%, preferably less than 1% and particularly preferably less than 0.5%.
  • rPET is used here as an abbreviation for recycled post-consumer PET.
  • ISBM-PET means PET (including PET copolymers) that is suitable for use in an ISBM process, i.e. has an IV between 0.72 dl/g and 0.86 dl/g (viscosity measurement according to ASTM D4603).
  • chain breaker is understood to mean chemical compounds which are suitable for degrading PET or for being incorporated into the polymer chain as a copolymer.
  • the invention relates to a method for producing a rPET plastic material for use in a thin-wall injection molding process with a wall thickness (L) to flow path (D) ratio of 1:100 to 1:350, which comprises the following process steps: a) sorting, washing and crushing of post-consumer PET articles, ie PET bottles mostly produced using the ISBM process, the PET material of which has an intrinsic viscosity of between 0.72 and 0.86dl/g according to ASTM D4603, b) removal of contamination such as metal or paper, before, at the same time as or after process step a), c) subsequent drying of the comminuted PET material, d) melting of the crushed and dried PET material and preferably decontamination thereof in a degassing resp. Recycling extruder and subsequent granulation, and e) production of a thin-walled injection molded article from the PET material in an injection molding process.
  • the object is achieved with a method according to the preamble of claim 1 in that a chain breaker is added to the granulated material and the melt of granulate and chain breaker is reactively extruded and injected directly into an injection mold, the process being conducted in such a way that the intrinsic viscosity of the injection molded article is lowered to 0.5 to 0.7 dl/g and preferably to 0.5 to 0.65 dl/g during extrusion and a thin-walled injection molded article is obtained in an injection molding process in which the ratio of wall thickness (L) of the injection molded article to the flow path (D) from 1 to 100 to 1 to 350 resp. is up to 1 to 500 in thin-wall injection molding.
  • This process has the advantage that rPET from a conventional PET recycling stream, in particular from bias-molded PET bottles, can also be made usable for the production of thin-walled injection molded articles.
  • the temperature during extrusion, the dwell time of the material in the extruder and the amount of chain breaker are advantageously selected such that the extruded material has an intrinsic viscosity (IV) greater than 0.5 dl/g, in particular between 0.52 and 0.68 dl/g and preferably between 0.55 and 0.65 dl/g.
  • IV intrinsic viscosity
  • a PET bottle stream is preferably used that contains particularly little contamination from polymers other than PET (e.g. PA blends).
  • PA blends e.g. PA blends
  • particularly little is understood to mean that the proportion of PA blends, radical scavengers and other additives such as oxygen scavengers, acetaldehyde scavengers, UV absorbers, slip additives, infrared absorbers etc. is less than 10% by weight, preferably less than 5% by weight, and more preferably less than 3% by weight.
  • either a specific amount of monoethylene glycol or a specific amount of water is used as a chain breaker.
  • the IV can be reduced to such an extent by splitting the PET molecules directly during the actual injection molding process that thin-walled articles can be produced.
  • PET recycling material used for the extrusion is preferably used with a water content of between 100 and 1000 ppm and preferably between 300 and 1000 ppm water. That means that the preceding drying and decontamination is preferably carried out in such a way that the desired water content is set.
  • the PET recycling material can also be enriched with water again after drying and/or decontamination (process steps c) and/or d)).
  • the granulated material can also be added between 50 and 1000 ppm monoethylene glycol, respectively. be added. This also leads to the desired reduction in intrinsic viscosity during the spraying process.
  • the chain breakers used are compounds which can be incorporated into the PET polymer molecules and thus lead to a higher proportion of copolymer.
  • the intrinsic viscosity can be reduced and the rate of crystallization slowed down to such an extent that thin-walled, transparent and strip-free articles can be injection molded. This effect was unexpected since it had to be assumed that the material would become cloudy. Furthermore, it was expected that bubbles and small cracks would form in the injection molded article, similar to when water is used in the degradation of the rPET.
  • the proportion of copolymers during extrusion can be increased by at least 1%, preferably at least 2% and particularly preferably by at least 3%, and the viscosity of the material can be reduced.
  • the proposed method uses the effect that higher proportions of copolymer change the PET molecule chain in such a way that crystallization is thereby inhibited or suppressed.
  • a chain breaker is monoethylene glycol.
  • monoethylene glycol is already part of the PET chain. The addition of monoethylene glycol breaks the chain, but does not increase the proportion of copolymer.
  • Diols which can be incorporated into the chain as a copolymer, are advantageously used as chain breaker.
  • Preferred diols are diethylene glycol, propylene glycol and/or butylene glycol, but also cyclic polyalcohols such as 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane (spirol glycol) .
  • dicarboxylic acids are used as chain breakers. These are also very suitable for reducing the chain lengths.
  • Preferred dicarboxylic acids as chain breakers are isophthalic acid, 2,5-furandicarboxylic acid and/or
  • Naphthalene dicarboxylic acid as these can be incorporated into the polymer chain as a copolymer.
  • diesters are used as chain breakers.
  • diesters examples include dimethyl isophthalate and/or bis(hydroxyethyl) isophthalate.
  • the diols, dicarboxylic acids, diesters can each be used individually or as mixtures.
  • PET copolymer chains with 2 to 20 monomers containing isophthalic acid (IPA), furandicarboxylic acid (FDCA), naphthalenedicarboxylic acid or diethylene glycol are advantageously used as chain breaker.
  • IPA isophthalic acid
  • FDCA furandicarboxylic acid
  • naphthalenedicarboxylic acid or diethylene glycol is expediently between 3 and 10% by weight.
  • Caffeine is the trivial name for 1,3,7-trimethyl-2,6-purinedione (short form 1,3,7-trimethylxanthine).
  • the chain breakers are advantageously added in process step f) before or during the melting of the granules.
  • the post-consumer PET material used has a maximum copolymer content of about 3% and preferably a maximum of 2.5% prior to drying and recycling in process step d).
  • Process step f) is preferably carried out in such a way that the total proportion of copolymer in the rPET is increased to 2.5 to 8%, preferably to 3.0 to 8% and particularly preferably to 3.5% to 8%.
  • An increased proportion of copolymer leads to a lowering of the IV and at the same time a slowing down of the crystallization rate, which makes the injection molding of thin-walled articles possible in the first place.
  • the post-consumer incoming goods are advantageously decontaminated by degassing the volatile contaminants at elevated temperatures between 70° and 330°C, preferably between 180 and 220°C, before the recycling extruder, i.e. process step d), and/or in the recycling extruder and/or after the recycling extruder, through a vacuum of less than 0.2 bar absolute, or
  • Nitrogen flushing takes place between 0.1 sec and 20 hours, preferably for 4 to 10 hours.
  • the granules can optionally be degassed under reduced pressure in an SSP reactor at a temperature of 180 to 220° C. and for 1 to 15 hours, preferably 4 to 10 hours.
  • a polymerization (polycondensation) takes place at the same time.
  • Decontamination under heat and vacuum can take place in the extruder and in the subsequent SSP reactor.
  • nitrogen can also be used to remove contamination.
  • heat and vacuum or a protective gas atmosphere e.g. nitrogen
  • a protective gas atmosphere e.g. nitrogen
  • the material is preferably decontaminated by subsequent treatment in the SSP reactor, its viscosity is not increased to such a high level that it becomes a PET which is well suited for the stretch blow molding process, but rather below a viscosity of ⁇ 0.72 dl /g exits the SSP.
  • the material is preferably decontaminated before the actual injection molding process step f) to such an extent that it is suitable for applications in the food and/or consumer goods sector.
  • a masterbatch is advantageously produced from the chain breaker, and this masterbatch is metered directly into the intake of the injection molding machine. This has the advantage that the proportion of chain breaker can be controlled very well and there is good mixing in the extruder.
  • the comminuted PET recycling material is preferably dried at temperatures between 60 and 180° C. for 1 to 8 hours.
  • the intrinsic viscosity of the material used is advantageously reduced by 0.05 to 0.3 dl/g, preferably 0.1 to 0.25 dl/g, as a result of the reactive extrusion in process step f).
  • the crystallization percentage of the treated rPET injection molded part is reduced by at least 10% compared to the untreated material without increased copolymer content.
  • the temperature during extrusion and the amount of chain breaker are chosen such that the extruded material has an IV greater than 0.5 dl/g and in particular between 0.5 and 0.7 dl/g.
  • the residence time of the polyester material in the injection molding unit or recycling extruder is advantageously between 20 and 400 seconds, preferably between 30 and 300 seconds. and more preferably between 40 and 200 seconds. With the above residence times, the IV of the polyester material can be lowered by 0.05 to 0.3 dl/g in the presence of a chain breaker during extrusion.
  • the extruded melt is filtered before granulation.
  • the extruded melt is pressed through a perforated filter with a perforation size between 30 ⁇ m and 300 ⁇ m and preferably between approximately 50 ⁇ m and 100 ⁇ m.
  • a perforation size between 30 ⁇ m and 300 ⁇ m and preferably between approximately 50 ⁇ m and 100 ⁇ m.
  • the rPET material is degassed and decontaminated during the extrusion in method step d).
  • the melt is divided into thin layers or strands in the extruder.
  • the surface of the material is increased and decontamination can be carried out very quickly.
  • the extrusion takes place in a vacuum or in a protective gas atmosphere, in particular under nitrogen.
  • Another embodiment of the method involves an alternative form of injection molding or a mixed form of injection molding in the sense of compression molding.
  • Another embodiment of the method involves an alternative form of injection molding or a mixed form of injection molding in the sense of spray foaming.
  • Post-consumer PET material is used for the process, which has a viscosity of between about 0.7 and about 0.86 dl/g.
  • a PET bottle flow is preferably used that has particularly little contamination from polymers other than PET (e.g. PA Blends) contains.
  • PA Blends polymers other than PET
  • particularly little is understood to mean that the proportion of PA blends, radical scavengers and other additives such as oxygen scavengers, acetaldehyde scavengers, UV absorbers, slip additives, infrared absorbers etc. is less than 10% by weight, preferably less than 5% by weight, and more preferably less than 3% by weight.
  • post-consumer PET bottles are sorted according to type, washed, cut and contamination such as metal, paper, etc. is removed.
  • contamination such as metal, paper, etc. is removed.
  • the collected PET material is first sorted by color and then foreign plastics are preferably sorted out.
  • the cut PET flakes are dried.
  • the rPET is in a degassing resp. Recycling extruder decontaminated and granulated.
  • a chain breaker is added to the granules, and the granules are then reactively extruded.
  • the rPET degrades rapidly in the injection unit during extrusion, i.e. the average molecular weight of the rPET and thus the intrinsic viscosity decrease.
  • the addition of the chain breaker is primarily intended in the injection molding unit, but can also be added in the recycling extruder or, in rare cases, as an alternative.
  • Chain Breaker not only in the extruder of the injection molding machine, but already in the extruder of the recycling machine, the recycling material can be broken down in a targeted manner in the extrusion process and enriched with copolymers.
  • Regrind from post-consumer PET bottles with an average IV of 0.72 dl/g and an average copolymer content of 1% isphthalic acid and 1.3% diethylene glycol are mixed with 0.5% diethylene glycol in the recycling extruder and extruded at an average temperature of 290°C.
  • the viscosity was reduced much more than usual to a value of only 0.58 dl/g. Due to a subsequent SSP (6h 220°C, in order to achieve food contact compliance, the granules have only built up to 0.72 dl/g. These granules are dried under 50ppm water content and an injection molding machine together with a second amount of diethylene glycol (0. 2%) was added.Surprisingly, the PET was able to break down again to a viscosity of only 0.55 dl/g and a preform with a wall thickness of only 1mm and a flow path of 120mm could be injected.
  • ground material from post-consumer bottles is built up into granules for the stretch blow molding process with a viscosity of an SSP of 0.76 dl/g.
  • the dried granulate 180°C-6h, dried air, 2m 2 air/kgPET dew point -35°C
  • the diethylene glycol degraded the PET to a viscosity of 0.61 dl/g, and surprisingly, a preform with only 1mm wall thickness and 120mm flow path could be injected.
  • the invention provides a process by which previously used polyester materials, including either production waste polyester materials and/or post-consumer polyester materials, can be conveniently and efficiently recovered and purified.
  • the collected PET material is first sorted by color, preferably re-sorted, cut into small pieces (ground), washed, dried, extruded and preferably decontaminated at the same time, granulated, and if necessary built up and decontaminated again and then in the presence of chain breakers into one thin-walled article extruded.
  • the subject matter of the invention is a process in which a starting material for injection molding is made from a recycled post-consumer PET with a viscosity between 0.72 and 0.86 dl/g according to ASTM D4603 and a maximum copolymer content of approx. 3% by weight with a viscosity between 0.50 and 0.7 dl/g is produced using Chain Breaker.
  • the shredded and dried PET material is melted and decontaminated to such an extent that it is suitable for applications in the food and consumer goods sectors.
  • a chain breaker is added to the rPET material in the melt of the recycling extruder and/or preferably in the melt of the injection unit in order to reduce the viscosity and enrich the PET with copolymers.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Polyesters Or Polycarbonates (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Abstract

L'invention concerne un procédé, dans lequel un matériau de départ pour un moulage par injection présentant une viscosité entre 0,50 et 0,7 dl/g est produit à l'aide d'un agent d'interruption de chaîne à partir d'un PET post-consommateur recyclé présentant une viscosité entre 0,72 et 0,86 dl/g selon la norme ASTM D4603 et une fraction de copolymère d'au plus environ 3 %. Dans le procédé, le matériau PET broyé et séché est fondu et décontaminé à un degré tel qu'il est approprié pour des applications dans le secteur alimentaire et le secteur de biens de consommation. Un agent d'interruption de chaîne est ajouté au matériau PET recyclé dans la masse fondue de l'extrudeuse de recyclage et/ou de préférence dans la masse fondue de l'unité d'injection afin de réduire la viscosité et d'enrichir le PET par des copolymères.
EP22708433.2A 2021-02-08 2022-02-08 Procédé de production d'un matériau plastique à base de pet recyclé destiné à être utilisé dans un procédé de moulage par injection à paroi mince et corps creux produit dans le procédé de moulage par injection à paroi mince Pending EP4288260A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH00117/21A CH718330A1 (de) 2021-02-08 2021-02-08 Verfahren zur Herstellung eines rPET-Kunststoffmaterials zur Verwendung in einem Dünnwand-Spritzgussverfahren und im Dünnwand-Spritzgussverfahren hergestellter Hohlkörper.
CH070736/2021A CH719268A1 (de) 2021-12-17 2021-12-17 Mehrweg-Kunststoffflasche.
PCT/EP2022/052961 WO2022167679A1 (fr) 2021-02-08 2022-02-08 Procédé de production d'un matériau plastique à base de pet recyclé destiné à être utilisé dans un procédé de moulage par injection à paroi mince et corps creux produit dans le procédé de moulage par injection à paroi mince

Publications (1)

Publication Number Publication Date
EP4288260A1 true EP4288260A1 (fr) 2023-12-13

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EP22708433.2A Pending EP4288260A1 (fr) 2021-02-08 2022-02-08 Procédé de production d'un matériau plastique à base de pet recyclé destiné à être utilisé dans un procédé de moulage par injection à paroi mince et corps creux produit dans le procédé de moulage par injection à paroi mince

Country Status (5)

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US (1) US20240100742A1 (fr)
EP (1) EP4288260A1 (fr)
MX (1) MX2023008392A (fr)
WO (1) WO2022167679A1 (fr)
ZA (1) ZA202306904B (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3722219A1 (fr) * 2019-04-12 2020-10-14 Societe Anonyme des Eaux Minerales d'Evian Et en Abrege "S.A.E.M.E" Récipient à paroi mince fabriqué à partir d'un matériau recyclé
CH719622A1 (de) * 2022-04-22 2023-10-31 Alpla Werke Alwin Lehner Gmbh & Co Kg Verfahren zur Herstellung eines rPET-Kunststoffmaterials zur Verwendung in einem Dünnwand­ Spritzgussverfahren und im Dünnwand-Spritzgussverfahren hergestellte Behälter, wie Becher, Schalen, Wannen oder Stegverpackungen.
EP4286129A1 (fr) * 2023-02-28 2023-12-06 The Procter & Gamble Company Contenants à haute teneur en matériau recyclé

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Publication number Priority date Publication date Assignee Title
US5635584A (en) 1995-12-07 1997-06-03 Eastman Chemical Company Process including glycolysis and subsequent purification for recycling polyester materials
US5780128A (en) * 1996-04-15 1998-07-14 Pepsico Inc. Polyethylene preform and container
FR2828129A1 (fr) * 2001-07-31 2003-02-07 Perrier Vittel Man Technologie Procedes de fabrication de preformes et de contenants en pet tels que bouteilles alimentaires, contenants et preformes intermediaires obtenus
JP5079239B2 (ja) * 2006-02-02 2012-11-21 株式会社リコー 再生ｐｅｔ材料を用いたトナーボトルの成形方法
BR112012017646A2 (pt) * 2010-01-18 2016-03-29 Invista Tech Sarl composição de poliéster, artigo moldado por injeção-sopro com estiramento e método para apriomorar resistência á rachadura por tensão caústica
AU2010101182A4 (en) * 2010-07-14 2010-12-09 Basf Se Polyester resin composition and a process for manufacturing the same
JP2014198422A (ja) * 2013-03-29 2014-10-23 株式会社 資生堂 射出延伸ブローボトル及び射出延伸ブローボトルの製造方法
CH713339A1 (de) * 2017-01-03 2018-07-13 Alpla Werke Alwin Lehner Gmbh & Co Kg PET-Regranulat mit hoher intrinsischer Viskosität und Verfahren zu dessen Herstellung.

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ZA202306904B (en) 2024-08-28
MX2023008392A (es) 2023-08-03
WO2022167679A1 (fr) 2022-08-11
US20240100742A1 (en) 2024-03-28

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