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
  • 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
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/06—PE, i.e. polyethylene
  • B29K2023/0608—PE, i.e. polyethylene characterised by its density
  • B29K2023/065—HDPE, i.e. high density polyethylene
• • 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
  • B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• • 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
  • B29L2031/7172—Fuel tanks, jerry cans
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K15/00—Arrangement in connection with fuel supply of combustion engines or other fuel consuming energy converters, e.g. fuel cells; Mounting or construction of fuel tanks
  • B60K15/03—Fuel tanks
  • B60K15/03177—Fuel tanks made of non-metallic material, e.g. plastics, or of a combination of non-metallic and metallic material
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31855—Of addition polymer from unsaturated monomers

Definitions

• the present invention relates to a process for the implementation by extrusion blow molding of an HDPE (high density polyethylene) as well as fuel tanks capable of being obtained using this process.
• HDPE high density polyethylene
• the increasing use of plastics has posed a problem for the environment for many years.
• laws were intended to impose a minimum weight rate of recycling of plastics used.
• the fuel tank which is often produced by extrusion blow molding of high density polyethylene (HDPE)
• HDPE high density polyethylene
• the extrusion-blowing technique is only applicable to resins having good melt strength and being very homogeneous, which is generally not the case with resins recycled following the degradation undergone by the resin. during its lifetime and / or its recovery (reprocessing).
• the resins and in particular the HDPE are stabilized so as to limit their degradation during their lifetime as a solid object, but this stabilization is not however sufficient during the use of used resins. It is therefore known to add to these resins, during their use, one or more stabilizers in order to allow this use and subsequent use without damage.
• a stabilization generally does not make it possible to obtain, at the outlet of the extruder, a product suitable for processing by blowing. Indeed, most of the recycled resins, even when stabilized, have in the molten state an unacceptable lengthening under their own weight, which makes manipulation of the parisons impossible during blowing.
• EP 1095978 describes the extrusion of compositions comprising HDPE, at least one polyfunctional polymer or oligomer having a glass transition temperature below 10 ° C (polysiloxane) and an epoxide polyfunctional, under conditions involving a reduction in the Melt Index (MI).
• polysiloxane polysiloxane
• MI Melt Index
• the present invention therefore relates to a process for the implementation by extrusion blow molding of a used high density polyethylene (HDPE) in particulate form, according to which the used HDPE is extracted in admixture with a polyfunctional epoxide, and then the extradate to a blowing operation.
• HDPE high density polyethylene
• the HDPE which can be used by the process according to the present invention can be a homopolymer of ethylene or a copolymer of ethylene with a monomer such as propylene, butene, hexene or octene, in particular a content generally greater than 2% or even 4% and generally not exceeding 10% or even 8%. It is preferably a copolymer of ethylene and hexene having a hexene content of between 4 and 8%.
• This resin can for example be obtained by using a Phillips catalyst or a Ziegler catalyst. Phillips type resins are preferred.
• the density of this resin is generally greater than or equal to 930, preferably greater than or equal to 940, or even 945 g / kg. Resins with an MI (measured at 190 ° C according to ISO 1133) less than or equal to 1 g / 10 min under a load of 5 kg, and greater than or equal to 1 under a load of 21.6 kg, give good results .
• used resin according to the present invention is meant a resin having already undergone at least one shaping by melting (other than a simple granulation) and having had a non-negligible lifetime in this form, during which it has undergone non-negligible degradation (and in particular, oxidation) phenomena.
• the present invention is particularly suitable for "aged" resins, having been polymerized and used months or even years before (20 to 25 for example) and having even been used in an aggressive chemical and / or thermal environment, such than the constituent resins of used fuel tanks.
• the HDPE is in particulate form i.e. in the form of particles (powder, granules, fragments ...) so that it can actually be introduced into the extruder and melted.
• the extradate can be used as it is or in admixture with used resin but not additive (i.e. not having been extruded in admixture with a polyfunctional epoxide) and / or with "virgin” resin.
• “virgin” resin according to the present invention is meant a resin which has not undergone any shaping by melting (with the exception of any granulation) and which has not undergone significant degradation.
• the extradate is advantageously used in admixture with used non-additive or virgin resin in weight proportions of 60:40 to 40:60.
• Used HDPEs of different origins can also be used as a mixture, and optionally also diluted with virgin resin, in the same proportions as those described above.
• the polyfunctional epoxide according to the present invention is preferably of the same type as those described in patent applications WO 94/29377, WO 97/30112, WO 00/26286 and EP 1095978.
• this epoxide is combined with a phenol hindered and to a phosphite (as described in WO 94/29377), to an aromatic secondary amine (as described in WO 97/30112), or to a polyfunctional polymer or oligomer with a glass transition temperature below 10 ° C ( as described in EP 1095978).
• additives can also be incorporated into the HDPE during the implementation process according to the present invention.
• stabilizers such as the above-mentioned phenols and phosphites
• carbon black etc.
• the extrusion mixed with the polyfunctional epoxide is preferably carried out under high shear stresses making it possible to obtain a significant reduction in MI (measured at 190 ° C. according to the ISO standard). 1133 and under a suitable load to obtain a value greater than or equal to 1 g / 10 min).
• significant reduction of the ML is generally meant a reduction of at least 5%, preferably at least 10%, or even at least 15% of the MI compared to its initial value (before extrusion).
• the HDPE can be extradited in a single screw or twin screw extraditor.
• Twin screw extraders are preferred because they induce a higher shear rate, which allows the material to melt more quickly.
• the profile of the screw or screws of these extradeurs will be adapted in a manner known to those skilled in the art.
• kneading elements will be introduced as soon as possible into the screws.
• these kneading elements are introduced from the first third of the screws. It is also possible, in the case of single screw extradeurs which are less kneading, to use a grooved sheath.
• the polyfunctional epoxide is advantageously premixed with virgin resin in powder form ("fluff”) and is then introduced with the resin to be stabilized into the extradeuse, through the main hopper.
• the extrusion conditions (rotation speed, temperature profile %) are to be optimized according to the chosen screw profile, taking into account the torque available on the chosen machine.
• the extradeuse is advantageously provided with a filter of suitable dimensions to effectively filter the flow of molten material, without excessively increasing the pressure.
• the shaping by extrusion blow molding can be done in a single step, i.e. that the melted HDPE leaving the extradeuse where it was added is directly put in the form of a parison and that this is then directly blown, in line with the extraditor used for additivation.
• the HDPE is granulated at the outlet of the extraditor where it has been additivated, and it is subsequently subjected to shaping by extrusion blow molding, optionally in admixture with used resin not additivated and or with virgin resin.
• the extrusion-blowing parameters (screw speed, temperature, etc.) used in this case are similar to those used for virgin resin.
• the method according to the present invention is intended for the manufacture of hollow bodies intended to contain or convey fuel.
• fuel denotes both petrol and diesel or any other fuel used in internal combustion engines.
• the hollow bodies are tanks or fuel pipes.
• the process according to the present invention applies particularly well to HDPEs coming from used fuel tanks, and which have already been implemented by extrusion blow molding. According to this variant of the invention, it is possible to mix an HDPE coming from a petrol tank with an HDPE coming from a diesel tank.
• Fuel tanks generally include metallic elements (such as the fuel filter cartridge, the ball of the non-return valve, the pump rotor, etc.) which must be separated from the HDPE before subjecting it to the method according to this variant of the invention.
• metallic elements such as the fuel filter cartridge, the ball of the non-return valve, the pump rotor, etc.
• the reservoir is generally ground before subjecting its constituent resin to the process according to this variant of the invention.
• the present invention also relates to petrol tanks capable of being obtained by the method described above and having a substantially identical F / C ratio at the surface and at the core in the tank.
• This F / C ratio can for example be measured by XPS (X-Ray Photoelectron Spectroscopy).
• XPS X-Ray Photoelectron Spectroscopy
• a normal measurement at the surface gives the F / C ratio at heart and an oblique measurement (or measurement at 60 °) gives the F / C ratio at the surface.
• the present invention is illustrated in a non-restrictive manner by the following example:
• Used fuel tanks have undergone the following stages: - shredding in a water atmosphere to avoid explosions
• the resin obtained in step 1 is extruded with 0.5% of Recycloblend ® 660 in a co-rotating twin-screw extender (BC 45) rotating at 111 RPM and using the following screw and temperature profile.
• the MI (190 ° C, 21.6 kg) of the resin was 6.4 g / 10 min before this extrusion and 5.6 g / 10 min after, a reduction of 13%.
• the fresh product prepared in step 3 was blown under standard conditions on a BAT 1000 type blow-molding machine.
• the tanks are produced in continuous extrusion under the following conditions: head: BKC 400; fiher 500mm; mold: X74. These tanks were re-shredded and re-blown 3 times.
• step 3 40% of the fresh product (step 3) was mixed with 60% of the regrind product (step 4). The mixture was blown under the same conditions as those of step 4. At the end of the blowing, fluorine was injected into the tank. Eltex RSB 714 supplemented with antioxidant N0060 was also extruded and blown as in step 4.
• the atomic F / C ratio was measured on the 3 samples. A measurement was taken perpendicular to the surface (normal: 0 °) and in obstruction relative to the surface (angle of 60 °). The normal measurement (0 °) gives an idea of the "bulk"concentration; the measurement at 60 ° is an indication of the surface concentration. The higher the F / C ratio, the more chemically carbon fluoride there is: a ratio of 2 indicates that we are in the presence of -CF 2 - groups.
• the sample recycled with Recycloblend ® 660 has the highest concentration of Fluorine. In addition, this concentration seems to be constant depending on the thickness. The fluorine layer seems to be the most constant. With regard to the fluorine concentration of the virgin resin, this seems to be overall lower but slightly higher at the surface. TJ is therefore a little more fluorine on the surface but this content decreases rapidly with depth (shallower layer). Regarding the recycled resin containing only antioxidant, it has a lower concentration both in surface and in depth.
• the recycled resin containing the Recycloblend ® is better than the virgin resin and is better than the recycled resin containing the standard antioxidant.
• the viscosity at 190 ° and at the stress of 1 sec -1 was measured on a 0.3 / 1 fiher.
• the flow essentially has an elongational component.
• the viscosities were measured on the starting resins, after the 3 blowing / grinding cycles and after mixing with the "fresh" resin.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Extraction Or Liquid Replacement (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8867372

Family Applications (1)

Country Status (5)

Families Citing this family (5)

Family Cites Families (18)

• 2001
  • 2001-09-14 FR FR0112016A patent/FR2829720B1/fr not_active Expired - Fee Related
• 2002
  • 2002-09-13 EP EP02772309A patent/EP1429908A1/de not_active Withdrawn
  • 2002-09-13 JP JP2003528375A patent/JP2005502506A/ja active Pending
  • 2002-09-13 US US10/489,687 patent/US20040241473A1/en not_active Abandoned
  • 2002-09-13 WO PCT/EP2002/010389 patent/WO2003024692A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events