WO1992003274A1 - Fabrication directe - Google Patents

Fabrication directe Download PDF

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Publication number
WO1992003274A1
WO1992003274A1 PCT/US1991/005591 US9105591W WO9203274A1 WO 1992003274 A1 WO1992003274 A1 WO 1992003274A1 US 9105591 W US9105591 W US 9105591W WO 9203274 A1 WO9203274 A1 WO 9203274A1
Authority
WO
WIPO (PCT)
Prior art keywords
resin
screw
melt
particles
resins
Prior art date
Application number
PCT/US1991/005591
Other languages
English (en)
Inventor
Philip Strubing Blatz
Paul Noel Richardson
Pallatheri Manackal Subramanian
Ronald Luther Saxton
Original Assignee
E.I. Du Pont De Nemours And Company
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 US07/655,485 external-priority patent/US5130076A/en
Application filed by E.I. Du Pont De Nemours And Company filed Critical E.I. Du Pont De Nemours And Company
Priority to BR919106791A priority Critical patent/BR9106791A/pt
Priority to AU85396/91A priority patent/AU647527B2/en
Priority to CA002089267A priority patent/CA2089267C/fr
Priority to KR1019930700570A priority patent/KR930701281A/ko
Publication of WO1992003274A1 publication Critical patent/WO1992003274A1/fr

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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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/58—Details
    • B29C45/60—Screws
    • 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
    • B29C45/03—Injection moulding apparatus
    • 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
    • B29B7/00—Mixing; Kneading
    • B29B7/30—Mixing; Kneading continuous, with mechanical mixing or kneading devices
    • B29B7/34—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices
    • B29B7/38—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary
    • B29B7/40—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with single shaft
    • B29B7/42—Mixing; Kneading continuous, with mechanical mixing or kneading devices with movable mixing or kneading devices rotary with single shaft with screw or helix
    • B29B7/428—Parts or accessories, e.g. casings, feeding or discharging means
    • B29B7/429—Screws
    • 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
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/47—Means for plasticising or homogenising the moulding material or forcing it into the mould using screws
    • B29C45/50—Axially movable screw
    • 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
    • B29C48/505—Screws
    • B29C48/56—Screws having grooves or cavities other than the thread or the channel
    • 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

Definitions

  • This invention relates to the direct
  • Post consumer plastics such as polyester resins
  • polyester resins can be recycled by melt fabrication to produce articles which can serve in utilities usually less demanding than the same articles molded from virgin resin.
  • the reason for this less demanding utility may arise from the presence of contaminants accompanying the post consumer plastic. Efforts are made to remove all contaminants, but this is an elusive goal under the current state of recycle technology.
  • the injection molded test bars were prepared in two steps, first, compounding of the random copolymer into the matrix resin to form molding pellets (hereinafter referred to as pre-compounding), followed by injection molding to form articles as the second step.
  • This sequence of steps was selected in the Epstein patents because of the need to achieve a very fine dispersion of the random copolymer within the resin matrix in order to realize optimum toughening in the molded articles, e.g., impact test bars.
  • the second step injection molding, takes the molding pellets, melts them and injects the molten resin into the test bar mold.
  • the dispersion is accomplished in the pre-compounding step and the fabrication is
  • Example 168 of Epstein II departs from this combination of operations by extruding a film from a blend of 66 nylon with a fumaric acid-grafted EPDM and subjecting the extruded film to stretching or thermoforming.
  • injection molding such as that used in common single-stage injection molding machines does not lend itself to making a fine
  • the screw rotates and retracts under the pressure of the molten resin being forced by the screw into the forward end of the barrel, i.e., adjacent the injection port of the barrel. During this rotation, the resin feed to the injection molding machine becomes melted and
  • the screw remains stationary and retracted while the mold opens and the molded article is removed from the mold.
  • a typical molding cycle might take 43 seconds, consisting of 20 seconds screw forward time, 20 seconds hold time, and 3 seconds mold open time. Of the 20 seconds hold time, typically only a portion of it is screw rotation time, e.g., 5 seconds whereby it is apparent that the screw rotates for only a small fraction of the time of molding cycle.
  • pre-compounding has served as the standard for resin feed of incompatible resins to injection molding machines.
  • Verbraak et al. reports testing eight different screws for dispersive mixing and summarizes the results of this testing as follows: "A reasonable morphology was achieved only
  • the blend of polypropylene/EPDM is not very tough to begin with, especially from the point of view of applications demanding room temperature impact toughness of 300 J/m and higher. Verbraak et al. does not disclose his dispersive mixing to achieve this desired toughness result.
  • Back pressure is usually adjusted as low as possible which yields the result of a well-compacted melt which is free from bubbles or voids (p. 399).
  • the use of increased back pressure will result in improved mixing, but accompanied by disadvantages of long screw recovery times, high pressures on the resin melt which may result in nozzle drooling, and increased wear of the injection molding machine (p. 399).
  • Du Pont Information Bulletin A-88012 (1973) provides information on the use of back pressure in injection molding. Back pressure is disclosed to be helpful for acrylic resins as a way of preventing air pick-up in the screw which cause black streaks in the molded part.
  • polyoxymethylene (Delrin ® ), back pressure may help produce a more uniform melt temperature and in color mixing, but is not needed for most molding and could cause nozzle leakage.
  • EPO 0 340 873 Al discloses a mixing device with distributive mixing action for an extruder and injection molding machine, which is useful for mixing viscous materials such as melted plastics and rubber, materials such as soap and clay in addition to
  • U.S. Pat. 4,912,167 discloses an improvement in melt blends of polyester resin with an epoxide copolymer, the improvement involving the incorporation of metal salts of certain acids or certain
  • the metal salts being selected from the group consisting of Al +++ , Cd ++ , Co ++ , Cu ++ , Fe ++ , In +++ , Mn ++ , Nd +++ , Sb +++ , Sn ++ , and Zn ++ .
  • Al +++ , Cd ++ , Co ++ , Cu ++ , Fe ++ , In +++ , Mn ++ , Nd +++ , Sb +++ , Sn ++ , and Zn ++ The nature of this improvement is disclosed to be increased melt strength and increased melt
  • Verbraak et al. discloses an unsuccessful attempt to perform dispersive mixing in an injection molding machine.
  • the polymers used in Verbraak et al., polypropylene and ethylene-propylene-diene elastomer, are fairly compatible as indicated by the similarity of their solubility parameters of
  • thermoplastic resins which would be especially useful for upgrading post consumer
  • the present invention satisfies this need by providing a process for the direct fabrication of incompatible resins, i.e., the pre-compounding step can be eliminated, and the incompatible resins can be compounded sufficiently within the injection molding machine and then directly molded to produce articles of modified resins all without causing degradation of any of the resins used.
  • the process for the direct fabrication of articles from incompatible resins comprises
  • thermoplastic resin which is incompatible with said first resin, this incompatibility being characterized by a difference of at least 2 (J/cm 3 ) 1/2 between the solubility parameters of the first and second resins, said particles having at least one dimension of at least 2 mm, said first resin being present in a major proportion and said second resin being present in a minor proportion.
  • This process is adaptable to being carried out in the typical single-stage injection molding machine which uses a single screw rotating and
  • the periodic shearing and periodic forcing steps are alternating, i.e., while the molten resin is being forced into the pre-determined shape in the mold, the screw is not rotating and therefore the melt within the barrel is not being subjected to shear.
  • the process of the present invention is also applicable to injection blow molding wherein the same alternating relationship between the shearing and forcing steps is observed.
  • the pre-determined shape is subsequently also subjected to blow molding within a second mold to produce the article desired.
  • the process of the present invention is also applicable to injection molding in a two stage machine wherein a single screw is used to melt resin and force it through a check valve into an injection cylinder. A ram then forces this molten resin into the mold.
  • the screw does not reciprocate, but it does stop rotation during the times the injection cylinder is filled with molten resin, and the ram injects the molten resin into the mold and the ram remains in the forward position to maintain pressure on the resin in the mold until it solidifies,
  • the screw reciprocates similarly to the operation of a single-stage injection molding machine.
  • the forward thrust of the screw injects molten resin into the injection cylinder rather than the mold, and the ram then forces the molten resin into the mold.
  • the screw can rotate to melt resin, until the screw reciprocates to its back position, which gives a faster cycle time as compared to a single-stage machine.
  • the shearing and forcing steps are
  • the process of the present invention is also applicable to extrusion blow molding, wherein the forcing of the sheared melt into the pre-determined shape is done by extrusion of a tube.
  • a mold closes around the tube.
  • the mold is then transferred to a blow molding station for blow molding into the article desired.
  • the extruder screw is stopped, during which time the melt within the extruder is not being subjected to shear.
  • the periodic shearing and forcing steps are simultaneous.
  • the process of the present invention process either a finished article having generally the shape desired or an intermediate article which is blow molded to the finished article.
  • the process of the present invention is also
  • the process of the present invention is accomplished by fitting the screw used in the
  • injection molding injection blow molding, or
  • the present process may also be described as being applicable to modifying polyamide and polyester resins as the matrix resins with incompatible resins which impart greater utility, notably toughness, to the matrix resins.
  • Polyester resin is becoming increasingly available as post consumer plastic, and the process of the present invention is especially applicable to upgrading the properties of such resin.
  • Another embodiment of the present invention solves this problem by providing much more consistently high toughness results when these resins are used.
  • This embodiment may be described as a process for the direct
  • copolymer elastomer to finely disperse the melt of the copolymer elastomer within the melt of the polyester resin, said shearing being carried out in the presence of adjuvant for said toughening of said articles incorporated into said melt, and
  • elastomer within the melt of polyester resin is preferably the same as in the other embodiments described hereinbefore, namely, the shear rate and shear time of the periodic shearing step being
  • Fig. 1 is a schematic side elevation in cross-section of an injection molding machine useful for carrying out a process of the present invention, with the embodiment of the screw shown in the
  • FIG. 2 shows the injection molding machine of Fig. 1 with the screw in the rammed or forward position.
  • Fig. 3 is a side view, in enlargement and indeterminate length, of the embodiment of screw shown in Figs. 1 and 2 useful for carrying out the process of the present invention.
  • Fig. 4 shows in enlargement as compared to Fig. 3 one of the plurality of shearing sections making up the dispersion section of the screw of Fig. 3.
  • Fig. 5 is a cross section taken along line 5-5 of Fig. 4.
  • Fig. 6 shows in enlargement one embodiment of barrier flight for use in the shearing sections of the screw.
  • Fig. 7 shows in side elevation another embodiment of dispersive mixing section for a screw which can be used in an injection molding machine for carrying out the process of the present invention.
  • Fig. 8 shows a cross section of the dispersive mixing section of Fig. 7 taken along line 8-8 of Fig. 7.
  • Fig. 9 shows a graph of impact strength vs.
  • the resin feed to the process of the present invention comprises a major proportion of a first thermoplastic resin and a minor proportion of a second thermoplastic resin which is incompatible with the first resin.
  • a first thermoplastic resin With respect to the total weight of these resins, about 55 to 95% can be the first resin and correspondingly, about 5 to 45% can be the second resin.
  • the weight proportions of these resins are about 10 to 40% second resin and more preferably about 10 to 25% second resin, and even more preferably, about 10 to 20% second resin with the remainder being first resin, since the second resin component will usually be the more expensive resin as compared to the cost of the first resin, it is desired to use as small a proportion of the second resin as is possible to accomplish the modification desired, which will generally be no greater than about 20 wt. % of the combined weight of the first and second resins.
  • the first resin is provided in the form of particles and the second resin is provided in the form of particles essentially separate from the particles of first resin, i.e., the resins are in different particles.
  • the particles have bulk as indicated by their having at least one dimension which is at least about 2 mm.
  • the particles are melt derived, either from virgin or recycle polymer. As such they will typically be in the form of pellets melt cut or cut from a previously extruded strand from the original manufacture of the resin. Dry flake of the resin is another particle form, but pellets are normally preferred for use of handling. Nevertheless, for post consumer plastics, the recycle form of the resin will typically be flakes obtained by chopping up the recycle articles such as bottles.
  • the first and second resins are also
  • the second resin is reduced to very fine particle sizes within the first resin matrix by the process of the present invention, the second resin nevertheless remains as particles, and does not
  • the incompatibility between the resins in the molten state is manifested by the high interfacial tension of the molten particles of the second resin in the melt of the first resin.
  • This high interfacial tension makes it difficult to break up the second resin particles into fine particles, i.e., the molten particles of the second resin want to retain their particle size rather than break up into much smaller particles.
  • the incompatibility between the first and second resins used in the present invention can be also characterized by difference between solubility parameters.
  • Solubility parameter is a measure of the cohesive energy density of the resin.
  • the solubility parameter is proportional to the strength of attraction between the molecules making up the resin. The closer the solubility parameters of two different' resins, the more miscible they are with one another. The converse is true as the difference between solubility parameters increases.
  • Solubility parameter of resins can be measured by determination of maximum swelling of the resin in a series of solvents having different solvent action on the resin, with the solubility parameter of the solvent giving the maximum swelling action being the solubility parameter of the resin. Solubility parameters for many polymers are disclosed in the literature, see for example Table 4, pp, 362-367 of the Polymer Handbook by J. Brandrup and E. H. Immergut, Interscience
  • solubility parameter from the formula ⁇ pF 1 /M wherein p is the density of the resin, ⁇ F 1 is the sum of the molar attraction constants of all the chemical groups in the polymer repeat unit, and M is the molecular weight of the repeat unit in the
  • solubility parameter for the ethylene/n-butyl acrylate/glycidyl methacrylate copolymer used in Examples 1-6, 23 and 24 and having the following mole %'s of each comonomer 90.3, 8.3, and 1.4, respectively is calculated as follows:
  • the molecular weights of the 3 monomers are: ethylene 28.
  • solubility parameter for the resin is the sum of these values in proportion to the mole % of the comonomer present X resin density, as follows:
  • EPDM 1,4-hexadiene copolymer
  • incompatibility for example characterized by a difference between solubility parameters of at least 2 (J/cm 3 ) 1/2 and more preferably at least 3 (J/cm 3 ) 1/2 .
  • the solubility parameter is 16.2 (J/cm 3 ) 1/2 , and for 68% by wt.
  • the solubility parameter is 16.4 (cal/cm 3 ) 1/2 .
  • the spread between the solubility parameters for all these EPDM polymer, including the 1,4-hexadiene EPDM described above, is 0.22 (J/cm 3 ) 1/2 .
  • the dispersion obtained by the process of the present invention can be characterized by the second resin present as a discrete phase within the matrix of first resin, with the particles (areas of discrete phase) of second resin preferably being smaller than about 5 microns, which corresponds to a 5000X reduction in the size of the second resin particles fed to the process.
  • the second resin also preferably has a number average particle size within the matrix of less than about 1 micron. Number average particle size is measured by the procedure disclosed in U.S. Pat. 4,753,980 in col. 6, lines 10-44.
  • Preferred first resins used in the process of the present invention are polyesters, polyamides, polyacetals, and polyarylates.
  • polyesters include polyethylene terephthalate (PET), copolymers of PET and polyethylene isophthalate, cyclohexyl dimethanol/terephthalic acid copolymer, cyclohexyl dimethanol/ethylene glycol/terephthalic acid
  • copolymers polyethylene 1,4-dicarboxynaphthenate, polybutylene terephthalate, and polycarbonates.
  • polyacetals examples include the oxymethylene
  • polyarylates include the polymers derived from polymerization of bisphenol A with isophthalic and terephthalic acids, preferably a mixture of about 50% of each acid (wt. basis).
  • polyamides include conventional semicrystalline nylons such as nylon 6, nylon 66, nylon 69, nylon 6/10, nylon 6/12, nylon 11, nylon 12, nylon copolymers such as 6/66, 66/6, 6/610, 6/612, and recently introduced nylon 4/6, and nylon 12/12.
  • Amorphous nylons such as the copolymers of
  • the first resin can be a single resin or a blend of compatible resins.
  • second resin The selection of second resin and its amount will depend on the first resin used and the effect desired from the modification of the first resin.
  • the second resin is an elastomer which when finely dispersed within the first resin, significantly improves toughness of the first resin by a factor of at least 3X and preferably at least 5X. Toughness improvements of 10X and higher are obtainable by the process of the present invention.
  • the molecular weight of the first resin should be
  • Elastomers are those thermoplastic resins which at room temperature exhibit substantial
  • deformability e.g., stretchability and substantially immediate complete recovery of original dimension upon release of the force causing the deformation. They also typically exhibit a glass transition temperature (Tg) below ambient temperature (20oC).
  • second resins include ethylene copolymers wherein ethylene is copolymerized with one or more of such monomers as vinyl acetate, alkyl (meth)acrylate, such as methyl, ethyl, or butyl (meth) aerylates
  • (meth) acrylic acid, (meth)acrylamide, carbon monoxide, or glycidyl (meth)acrylate examples include ethylene/n-butyl acrylate/carbon monoxide, ethylene/n-butyl acrylate/glycidyl
  • ethylene/(meth)acrylate copolymer may include grafted acid, anhydride or glycidyl groups. Additional ethylene copolymers include ionomers and
  • ethylene/propylene and ethylene/propylene/diene elastomers with or without grafted acid or anhydride groups examples include styrene copolymer-based elastomers such as
  • styrene-ethylenebutene block copolymers with or without grafted acid anhydride, or glycidyl groups, styrene/butadiene block copolymer, styrene/acrylic ester/acrylonitrile copolymer.
  • additional second resins include the block copolyetherester elastomers such as those derived from polymerization of 1,4-butylene terephthalate with poly(tetramethylene ether) glycol terephthalate, such as the copolymers made from 25:75 weight proportion of these monomers.
  • the second resins can also be a blend of compatible resins.
  • Preferred elastomers are the
  • ethylene/glycidyl (meth)acrylate copolymers which also contain C 1 -C 6 alkyl (meth)acrylate, preferably n-butyl acrylate, wherein the amount of glycidyl
  • (meth)acrylate constitutes about 1 to 10 wt. % of the copolymer, preferably about 2.5 to 7 wt. %, and the alkyl (meth)acrylate constitutes about 15 to 35 wt. % of the copolymer, and the ethylene constitutes about 55 to 84 wt. % of the copolymer to total 100%.
  • the relationship of the first and second resin to one another is such that the
  • dispersion of the extremely fine particles of second resin within the matrix of first resin in articles fabricated by the process of the present invention is also accompanied by the particles adhering to the matrix, despite the incompatibility of the resins. This adhesion promotes the toughening of the
  • polyester and epoxide copolymer elastomers
  • this gelation is believed to be a manifestation of reaction between the polyester resin matrix and the dispersed fine particles of the
  • the first and/or second resins can contain the usual compounding ingredients, e.g. antioxidants, stabilizers, colorants, and fine particulate inorganic extenders and fillers.
  • antioxidants e.g. antioxidants, stabilizers, colorants, and fine particulate inorganic extenders and fillers.
  • the first step is to combine the particles of first and second resin. This can be done by simultaneously. feeding the particles as individual streams or a dry mixed blend to the feed hopper 4 of an injection molding machine 2 (Figs. 1 and 2).
  • the resins present in the particles are pre-conditioned, e.g, dried, as may be required, depending on the resins being used.
  • a typical dry condition is such that the dried resin has a moisture content of less than about 0.02 wt. % when the resin is polyester and less than about 0.05 wt. % when the resin is
  • the injection molding machine includes a barrel portion 6, defining a heated cylindrical chamber 8 and a hydraulic cylinder portion 10.
  • a plasticating screw 12 is positioned axially within the chamber 8 and extends into the hydraulic cylinder portion 10 of the machine, where the screw terminates with a cylinder head 14.
  • the screw has a helical flight 16 for advancing the particle feed from hopper 4 along the length of chamber 8 towards the forward end of the barrel portion 6 which is equipped with an injection nozzle 17. During this advancement the resin
  • the melt condition means that the resin is heated above its softening point.
  • the melt condition means that the resin is heated above its melt
  • the molten combination of resins is next received by the dispersion section 18 of the screw which consists of three shear sections 20 separated by intervening transverse mixing channels 22. Further details of the screw will be described later herein with reference to Figs. 3 to 6.
  • the dispersion section 18 which may be called the dispersion head of the screw 12 reduces the size of the molten particles of second resin and finely disperses them within the molten first resin.
  • the forward position of the screw 12 is shown in Fig. 2. This position is representative of the forward time of the injection molding cycle, in which the screw 12 forces an amount of molten resin through the nozzle 17 into the mold 24 which is merely shown as a box because of the conventionality of this aspect. During this time, including the time the screw is maintained in the forward position to
  • the forward position of the screw 12 is obtained by applying hydraulic pressure by conventional means against the face 15 of the cylinder head 14 of the screw.
  • the nose 26 of the screw generally conforms to the interior shape of the nozzle so as to minimize the amount of molten resin remaining in the cylindrical chamber.
  • the nose 26 may also be equipped with a conventional check valve (not shown) to prevent molten resin from back flow within the cylindrical chamber when the screw rams forward and is held in the forward position.
  • the screw Upon completion of the screw forward time, the screw commences rotation, for example via gear 28 mounted on the screw 12 and engaged with conventional gear driving means (not shown). During this rotation, the particle feed is subjected to additional melting as it advances along the screw 12 and to shear as the resultant melt traverses the dispersion section 18 of the screw.
  • FIG. 1 shows the screw 12 in the retracted position and the presence of molten resin 30 in the forward end of the chamber.
  • the amount of the molten resin 30 present in the forward end of the chamber is the amount necessary to fill the pre-determined shape provided by the mold.
  • the screw rotates during the retraction and when it reaches the retracted position, the rotation of the screw is stopped.
  • This retraction time and the time spent in the retracted position to permit the molded article to cool to solidification is the hold time of the injection molding cycle.
  • the screw rotates only during its retraction during the hold time.
  • the screw is also standing still while the mold is opened and the molded article removed
  • shearing of the resin melt is only periodic during the injection molding cycle and the forcing of the sheared melt into the shapes (articles) desired is periodic, with these actions alternating with one another, and with considerable additional portion of the injection molding cycle being taken up with the screw standing still, i.e., not rotating and therefore not shearing the melt.
  • the retraction of the screw is retarded so as to extend the rotation time of the screw. This is accomplished by applying pressure to the face 15 of cylinder head 14 of the screw during the hold time of the molding cycle. The effect of this retardation is to extend the shearing time for the molten resin.
  • the back pressure on the screw Is about 0.3 MPa (50 psi). In operation of the process of the present invention, the back pressure will generally be at least 1.5 MPa.
  • the high degree of shear necessary to accomplish the fine dispersion desired is obtained by the use of the dispersion section on the screw at the rotation speed and spill clearance which provides this shear.
  • the check valve present in the two-stage injection molding machine between the screw barrel and the injection chamber shears the molten resin as it is forced by the screw into the injection cylinder, to supplement the shear and thus the dispersion provided by the
  • the shear time in the molding operation comprises at least about 15% and more preferably at least about 20% or at least about 25% of the molding cycle, with the choice of minimum shear time depending on the particular molding operation.
  • the shear time is at least 30% of the cycle time.
  • Figs. 3 to 6 show details of one embodiment of screw design for accomplishing the necessary shear.
  • Screw 12 has a helical bearing flight 16 and a root 32 which forms in sequence extending in the direction of resin movement along the chamber 8, a feed section 34, a transition section 36, and a
  • metering section 38 which are designed to deliver a steady flow of molten resin to the dispersion section 18 of the screw.
  • the feed, transition, and metering sections are conventional screw features and can have many different designs to accomplish this delivery.
  • the root 32 has a constant diameter over several turns of flight 16 for receiving the resin particles.
  • the transition section 36 it has a root of increasing diameter, and in the metering section 38, the root returns to a constant diameter corresponding to the largest root diameter of the transition zone.
  • the channel 40 formed by the helical flight 16 and root 32 coupled with the interior wall of chamber 8 decreases in volume within the transition section 36.
  • Rotation of the screw in the direction causing the resin particles to advance from the feed section 34 through the transition section 36 causes the resin particles to become compacted to provide heating of the particles from several sources, the heat from barrel 6 and the heat generated within the chamber by compaction of particles within channel 40 and movement within these compacted particles caused by the relative movement of the particles as they are wiped along the wall of the heated barrel 6 by the helical bearing flight 16.
  • Substantial melting of the resin particles is desired by the time the resins reach the metering section 38, where the resins may be exposed to additional heating from the barrel and motion of the resins within the shallow channel 40 present in this section.
  • the dispersion section 18 is designed to intensify the shear of the polymer during the next portion of its advancement along the chamber.
  • the dispersion section 18 consists of three
  • shearing sections 20 spaced apart from one another along the length of the screw to form transverse mixing channels 22 between adjacent sections 20.
  • each shearing section 20 comprises a plurality of bearing flights 42 and a plurality of barrier flights 44 interleaved with one another, each extending from the screw 12 and in the embodiment shown, each forming a helix angle with respect to the axis of the screw at 60o.
  • the length of each shearing section is about the same as the diameter of the flight 42, which is the same as the diameter of the helical flight 16.
  • the spacing between the bearing flights and barrier flights form a corresponding plurality of interleaved entrance channels 46 and exit channels 48 extending along the axis of the screw and having the same helix angle as the bearing and barrier flights.
  • Means are provided for closing the entrance or upstream end 50 of each exit channel, and means are provided for closing the exit end or downstream end 52 of each entrance channel.
  • the closure means consists of a eeb extending from the corresponding ends of the bearing flights and having the same diameter thereas so that the resins being plasticated do not pass over the closed ends 50 and 52 of channels 46 and 48. Instead, the resins are forced by the metering section 38 of the screw 12 into the entrance or upstream ends 54 of the entrance channels 46. In this way, the metered resins are divided into a plurality of streams of resin corresponding to the number of entrance channels present.
  • the resins are forced along the length of the entrance channels 46, filling their volume with resin until the resin reaches the closed downstream ends 52 of these channels.
  • the bearing flights 42 form the force or leading side of the entrance channels 46, and the barrier flights 44 form the aft or trailing side of the entrance channels, with reference to the direction of rotation of screw 12. As shown best in Fig. 5, the barrier flights 44 are spaced further from the
  • the entrance channels 46 in effect overflow with resin over the barrier flights 44 through the clearances 56 (spill clearance) to enter the trailing exit channels.
  • any particles of resin present are subjected to shear and heating to cause the particles to melt and break down into small particles.
  • the width of the clearance 56 (spill clearance) between the barrier flight and wall of the barrel 6 is
  • the entrance channels are wider and therefore have greater volume than the exit channels, which provides greater residence time of the resins in the entrance channels to promote the softening and melting of the resins prior to shearing within clearance 56 in case there are non-melted particles.
  • Fig. 6 shows one embodiment for shaping each barrier flight 44 so as to promote attenuation and thus break down of polymer particles.
  • the entry side of the clearance 56 from the entrance channel 46 is tapered away from the wall of the barrel 6 to form a wedge shaped opening 58 to the clearance 56.
  • the resin melt moves into the clearance 56, it becomes subjected to greater and greater shear arising from compression between the decreasing space within the wedge-shaped opening 58 and the wall of the barrel.
  • the resins Upon leaving the exit channels of shearing section 20, the resins enter the adjacent transverse mixing channel 22, where the streams of resin from the preceding exit channels 48 become united by the rotation of screw 12.
  • the number of shearing sections 20 is preferably at least 2 and more preferably at least 3, the number of such sections depending on the amount of shear that can be built into each dispersion section and the particular dispersion task to be accomplished within the
  • the number of bearing and barrier flights per shearing section 20 will generally be from four to eight of each.
  • the dispersion section 18 accomplishes both shear and mixing of the resultant fine particles of second resin within the first resin.
  • the dispersion section 18 under the conditions of plastication, achieves a shear rate of at least about 300 sec -1 within the molten resin, more preferably at least about 450 sec -1 , and even more preferably at least about 900 sec -1 for thorough dispersion of the second resin within the first resin.
  • Shear rate is the circumferential speed of the screw divided by the spill clearance (clearance 56).
  • the circumferential speed of the screw is the screw diameter X 3.14159 X rpm.
  • the spill clearance is the difference between the radius of the barrel or cylindrical chamber and the barrier flight radius.
  • the circumference of the screw will be 139.7 mm.
  • the circumferential speed is 13970 mm/min or 232.8 mm/sec.
  • the present invention achieves this result by judicious choice of shear time and shear intensity conditions for the particular combination of first and second resin being processed. Shear intensity will depend on the melt viscosity of the resins being sheared, the screw rotation speed, the clearance 56 and the number of such clearances.
  • the clearance 56 will be selected from the range of about 0.15 to 0.7 mm to obtain the result desired.
  • the lower spill clearance will be no greater than about 0.35 mm.
  • the relative melt viscosities of the first and second resins under plasticating conditions in the dispersion section also contribute to the shear present in the dispersion section 18 to cause the molten particles of second resin to break down into smaller particles, and these smaller particles to break down into even smaller particles within the dispersion section.
  • the first and second resins are selected so that their melt viscosities at plasticating temperature produces the shear between resins described above, so as to achieve the best dispersion result possible for the plasticating conditions used.
  • the melt viscosities of the first resins will be within the range of about 5:1 to 1:5 of one another, i.e., the melt viscosity of the first resin can be from five times greater to 1/5 of the melt viscosity of the second resin. More preferably, the range of relative melt viscosities is about 2:1 to 1:2 and even more preferably about 1:1.
  • the forcing of the molten resin through the check valve between the screw barrel and the injection chambers subjects the molten resin to high shear to augment the shear achieved by the dispersion head of the screw.
  • the process of the present invention can also be carried out in extrusion blow molding wherein that the screw does not reciprocate. Instead it is the periodic rotation of the screw that forces an amount of molten resin into the shape desired.
  • extrusion blow molding a blow-mold is then closed about the extruded shape (parison), and the mold is next transferred to a blowing station. During this mold closing and mold transfer, the screw does not rotate. In this
  • the fine dispersion of second resin within first resin is achieved by shear rate and shear time but without the possibility of extending the shear time by retarding retraction of the screw.
  • Figs. 7 and 8 show another design of a dispersion head that can be used in the present invention.
  • This head 70 forms the forward end of a screw 72 having a helical bearing flight 74 only partially shown, which can be the same as screw 12, with head 70 forming the dispersion section to take the place of dispersion section 18.
  • Head 70 is commonly available as a Maddock head for use in mixing colorant into thermoplastic resin. It has a plurality of bearing flights 76 and barrier flights 78
  • each shear section 20 of dispersion section 18 has a greater number of flights and channels.
  • the spill clearance 86 is defined by the smaller radius of the barrier flights 78 as compared to the bearing flights 76 and the distance between the barrier flights and the interior wall of the barrel.
  • Webs 84 extend from the bearing flights to close the exit end of the entrance channels and the entrance end of the exit channels and to define the sides of the spill clearance.
  • the nose 88 of the dispersion head 70 can be equipped with a conventional check valve (not shown) so that the screw using this head can be used in injection molding involving reciprocation of the screw.
  • Polyester resins particularly polyethylene terephthalate, are moisture sensitive such that the presence of moisture during melt
  • the toughening effect of the copolymer elastomer on the polyester resin can be enhanced by incorporation of adjuvant into the melt blend of these polymers.
  • This incorporation can be carried out by adding the adjuvant to the melt blend, whereby the shearing of the melt blend disperses the adjuvant therein.
  • the incorporation can be carried out by adding the adjuvant to the feed of polymer particles to the direct fabrication process.
  • the adjuvant can be in the form of finely divided particulate material which can be dry mixed with the polymer particle feed.
  • the adjuvant can also be normally liquid (at room temperature), which state lends itself to either mixing with the polymer
  • the adjuvant does not contain any water.
  • the adjuvant needs to be dispersible in the polymer melt.
  • the adjuvant in the dry form has a melting point which is less than the temperature of the melt blend of polymers.
  • the temperature of the melt blend will generally be at least 240oC.
  • the adjuvant is preferably neat, i.e., without dilution in a liquid solvent or dispersant, so that such diluents do not have to be disposed of and will not interfere with the direct fabrication process.
  • the shearing of the melt blend disperses the adjuvant therein so that preferably, it is no longer visible in the blend or in the articles fabricated therefrom, even under
  • a number of compounds incorporated into the melt blend provides the adjuvant effect, i.e., the toughness of articles molded from the melt blend is high with much greater consistency than when the adjuvant is not present.
  • the toughness of the articles molded in accordance with the embodiment of the present invention is at least 500 J/m and more preferably at least 700 J/m.
  • adjuvants include zinc salts and zinc complexes.
  • zinc salts include the zinc salts of fatty acids which are saturated and have the general formula CH3 (CH 2 )n COOH wherein n is 4 to 27, preferably 7 to 19.
  • Examples of such zinc salts are zinc valerate, zinc octanoate, zinc laurate, and zinc stearate, with zinc stearate being preferred.
  • Zinc octanoate is an example of normally liquid
  • zinc stearate is a solid at room temperature but melts at about 130oC.
  • zinc complexes are zinc acetyl acetonate and zinc diethyldithiocarbonate.
  • Additional adjuvants include certain salts of certain other metals, including tin stearate, copper stearate and cerium stearate.
  • Stearic acid is not an adjuvant. The same is true for the Na, K, Li, Ca, Mg, Al, Co, and Ni stearates.
  • Zn salicylate is an adjuvant but zinc benzoate and zinc citrate are not.
  • ZnCO 3 is an adjuvant but ZnO is not.
  • Zinc acetate is not an adjuvant apparently because it is not dispersible in the melt blend, i.e., the zinc acetate end up as "clumps" thereof in
  • the effect of the adjuvant on the toughness of articles molded from the melt blend of polyester resin and copolymer elastomer, as previously described is to provide more consistently high toughness results than without the adjuvant being present.
  • the adjuvant makes the direct fabrication process more "forgiving" insofar as being able to tolerate polymer degration, presence of impurities, and other variabilities in feed composition and processing conditions that would otherwise only give occasionally high toughness results.
  • the reason for the adjuvant effect of more consistently high toughness is unknown, as is the reason why seemingly closely related
  • the compounds are not adjuvants. Apparently, however, the adjuvant aids in the reaction between the polyester resin and the copolymer elastomer.
  • the adjuvant effect for particular compounds may also depend on the amount of shear to which the melt blend incorporating the adjuvant is subjected. At low shear, characterized by a screw back pressure of only about 0.3 MPa, the adjuvant effect may not be obtained, but is obtained when screw back pressure is increased to increase shear time, or other measures to increase shear intensity are taken.
  • the adjuvants especially zinc stearate provides good results even at low screw back pressure.
  • the adjuvant provides a two fold effect to the direct fabrication process.
  • the adjuvant increases the consistency of the direct fabrication result of high toughness for the polyester
  • the adjuvant also reduces the amount of shear that is necessary to achieve the fine dispersion of the copolymer elastomer within the polyester resin, and promotes interaction therebetween which produces adhesion between these polymers.
  • One manner of reducing shear time is to reduce the back pressure on the melt processing screw, which is used in direct fabrication molding to increase shear time. This may also lead to shorter molding cycles.
  • the amount of adjuvant used will generally be about 0.05 to 2.0% based on the weight of the
  • polyester resin plus the copolymer elastomer is preferably about 0.1 to 0.5 wt. % thereof.
  • the process of the present invention in its many embodiments is useful to directly fabricate a wide variety of articles such as containers for many different utilities. Normally the process of the present invention will be practiced by combining the first and second resins for the first time at the start of the practice of the process which ends up with directly fabricated articles of predetermined shape, either finished articles as in the case of injection molded articles or intermediates such as a tubular parison for subsequent blow molding into the finished article. This saves the fabricator the need and expense to undertake precompounding. It is
  • the resin supplier may wish to provide the second resin, ordinarily the minor resin component, to the fabricator in the form of a concentrate in a first resin, within which the second resin may be the major or minor resin component, ultimately to end up as the minor resin component in the fabricated article.
  • the second resin is low melting and moisture sensitive, the concentrate with the higher melting first resin gives a more
  • the concentrate will generally be supplied as pellets containing both the first and second resin for
  • the pellets containing both the first and second resins will constitute a minor proportion of the feed to the direct fabrication process, and more
  • the fabricator then subjects the combination of concentrate particles with first resin particles to the melting/shearing process to produce the fine dispersion of second resin particles within the matrix of first resin hereinbefore described.
  • polyester compositions used in these Examples were as follows: (a) 42 lbs. (19.1 kg) of PET recycle soda bottle flake (about 6 to 9 mm in lateral dimension and .05 to 1 mm thick) which was vacuum dried 18 hours at 100oC, and (b) 8.3 lbs. (3.8 kg) of pellets (3.5 mm diameter, 3.5 mm long) of 76.75% by wt. ethylene/28% by wt. n-butyl acrylate/5.25% by wt. glycidyl methacrylate copolymer elastomer which was vacuum dried 18 hours at 40oC.
  • injection molding machine was continuously blanketed with nitrogen.
  • the injection molding machine was a 6 ounce (0.17 kg), 125 ton (1.11 MN) machine containing a 4.44 cm diameter screw.
  • the screw was the screw described in Fig. 3, except that the screw had four shearing sections 20, in which the clearance 56 was 0.15 mm (0.006 in.) and each dispersion section 18 had 6 barrier flights.
  • the temperatures used were as follows: Barrel rear, 175oC; barrel center, 260oC;
  • Izod impact strength was measured for each Example on the flex bars produced by the 10th, 20th, 30th, 40th and 50th injection molding shots.
  • the flex bars were cut in half, one half representing the gate end and the other half representing the far end of the injection molded flex bar.
  • the test results were averaged to represent the result for each Example. These results are shown in Table I and are plotted as curve 90 in the graph of Fig. 9.
  • the times expressed for molding cycle are the fill/hold/and eject times.
  • Example 7 but the increase becomes much greater for a given screw rotation time using the screw with the dispersion section.
  • the high average impact strength obtained for Example 7 is believed to be spurious, resulting from an almost 3X difference between impact strength of flex bars molded at the 10th shot vs. the 20th shot.
  • the screw of U.S. Pat. 3,006,029 used for Comparative Examples 7-13 had no dispersion section.
  • the increased screw rotation time represents increasing shear time
  • curve 92 the increased screw rotation represents increased mixing time, with insufficient shear to obtain the fine dispersion of second resin within the first resin necessary to achieve high toughening.
  • the polyamide composition used in these Examples was as follows: 81% by wt. nylon 66 which was vacuum dried; 10% by wt. ethylene/propylene/diene copolymer elastomer grafted with 1.8% maleic anhydride groups; and 9% by wt. ethylene/propylene/l,4-hexadiene copolymer elastomer.
  • These components are available from Du Pont as Zytel ® 101, anhydride grafted E/P rubber and Nordel ® 3781, respectively.
  • the three components were each in the form of pellets of about 3.5 mm in diameter X 3.5 mm in length and they were drum tumbled for 10 minutes under a nitrogen
  • Moldings were produced on the injection molding machine using the following molding machine temperatures; barrel rear, 261oC, barrel center 281oC, barrel front 281oC, nozzle, 280oC, mold temperature 90oC.
  • the screw used for this direct molding operation was the screw of Fig. 3, except that there were four shearing sections 20, used in Examples 1-6 operating at 100 rpm to produce a shear rate of 1528 sec -1 .
  • the results are shown in Table III.
  • the number average particle size of the second resins in the nylon was less than 1 micron.
  • Surlyn ® 8270 is a zinc neutralized copolymer of ethylene/23.5% by wt. n-butyl acrylate/9% by wt.
  • methacrylic acid and is an elastomer methacrylic acid and is an elastomer.
  • the same injection molding machine and screw (Fig. 3, except there were four shearing sections 20,) as Examples 1-6 was used to mold samples from this dry blend of flake and pellets.
  • the molding conditions used were as follows: Temperatures; barrel rear, 175oC; barrel center, 260oC; barrel front, 260oC; nozzle, 260oC; screw speed, 100 rpm; ram speed, fast; mold
  • the shear rate was 1528 sec -1 .
  • PET Since PET has a notched Izod impact strength of about 25 J/m, it is apparent from Table IV that considerable toughening of PET resin is obtained by the incorporation of this ionomer into the resin, with this toughening increasing with increasing shear time. In these Examples, the number average particle size of the ionomer in the PET matrix was about 1 micron.
  • a two-stage injection molding machine equipped with a reciprocating screw having the Maddock dispersion head of Fig. 7 and 8 was used to injection mold one liter flower pot type containers using a 4-cavity hot runner mold.
  • the flower pot had a 1.2 mm thick wall and a 1.4 mm thick base.
  • the feed to the injection molding machine consisted of a dry tumbled (under N2 blanket) mixture of the following
  • temperatures from rear to the forward of the extrusion barrel were 232oC, 249oC, 277oC and 278oC, and 279oC at the nozzle.
  • the mold temperatures were 38oC for the core and 51.7oC for the cavity.
  • the extruder was a 70 mm diameter 24/1 length to diameter ratio, equipped with a screw having a 3/1 compression ratio and the Maddock head.
  • the Maddock head had a spill clearance of 0.635 mm and the screw operated at 125 rpm to give a shear rate of 651 sec -1 .
  • the molding cycle was 18 sec; the screw rotation time was only 3 sec.; giving a shear time of only 17% of the total cycle time.
  • the molded flower pot containers were tested for toughness by being filled with water and capped at room temperature and were dropped against a solid surface from a height of 122 cm. When the drop angle was 45oC, i.e., the filled container struck the surface at the corner between its wall and bottom, none of five containers tested failed (none broke). This test was repeated for the same containers molded the same way from the same composition, except the composition was pre-compounded, so that pellets of the mixed composition were fed to the 2-stage injection molding machine. Five of the containers were tested by the same drop test and all survived.
  • Example 23 was repeated except that the containers molded were a 2 gallon pail liner about 22.9 cm in diameter and 27.9 cm tall, having a 2.3 mm wall thickness and each weighing about 0.9 kg.
  • the barrel temperatures were as follows: rear, 230oC;
  • the nozzle center, 260oC; and forward 260oC.
  • the screw rotation time was 16 sec.
  • the impact strength of the wall of the container was tested by the Gardner impact test (ASTM D-3029).
  • the directly fabricated containers had a toughness of 55.1 J as compared to greater than 59.0 J for pre-compounded containers.
  • the directly fabricated containers exhibited an impact strength of 24.4 J as compared to 35.3 J for the pre-compounded containers.
  • particle size (of the ethylene elastomer) in the bottom of the pails revealed that for the directly fabricated pails the particle size range was 0.1 to 6.0 microns and the number average particle size was 0.6 micron.
  • the pre-compounded parts the
  • the cause of this variability may be due to impurities in the recycle PET coming from the post-consumer source of these flakes, variability in the PET flake itself because of the different sources of the PET resin from which the consumer plastic was originally made, insufficient drying of the PET flake before feeding to the direct fabrication process and/or a combination of these phenomena.
  • montanate-containing bars was 176.3 J/m which although less than the 535 J/m average for the zinc
  • stearate-containing test bars still produced more than 2X improvement when no additive was present.
  • the 30 carbon atoms fatty acid zinc salt is not preferred.
  • the 12 carbon atom-containing zinc salt (zinc laurate) gave great improvement, averaging 492 J/m.
  • the calcium and sodium montanate additive-containing bars gave little to no improvement as compared to when no additive was present.
  • the zinc stearate-containing test bars were about 9X tougher than the bars containing no additive and the zinc citrate additive.
  • the citrate additive contains 6 carbon atoms.
  • Zn stearate is compared to articles molded from melt blends in which no adjuvant is present and with other compounds incorporated into the melt blends, some of which compounds act .as adjuvants and some of which do not.
  • the melt blend used in this series of experiments was derived from
  • ZnO seems to have made the molded article weaker while Zn benzoate provides some improvement, but less than desired.
  • the zinc octoate liquid was poured over the flake of PET and copolymer elastomer pellets in the wt. % indicated and then the zinc octoate was drum tumbled with these resins to obtain the blend, including antioxidant, for feed to the injection molding machine.
  • Table XI represents a second series of experiments which includes moldings with no additive and with Zn stearate for purposes of comparison with the other compounds tested as additives.

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  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
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Abstract

Fabrication en fusion avec précompoundage d'une pluralité de résines thermoplastiques à l'aide d'une vis (12) comportant une section de dispersion (18), dans des machines de moulage par injection. Le constituant mineur de résine peut être un élastomère, lequel durcit le composant principal de la résine. On améliore cet effet en augmentant la contre-pression exercée sur la vis (18) utilisée dans la machine de moulage par injection (2), afin de prolonger la rotation de la vis et ainsi le temps de cisaillement par la section de dispersion (18).
PCT/US1991/005591 1990-08-27 1991-08-15 Fabrication directe WO1992003274A1 (fr)

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BR919106791A BR9106791A (pt) 1990-08-27 1991-08-15 Fabricacao direta
AU85396/91A AU647527B2 (en) 1990-08-27 1991-08-15 Direct fabrication of articles from incompatible resins
CA002089267A CA2089267C (fr) 1990-08-27 1991-08-15 Fabrication directe
KR1019930700570A KR930701281A (ko) 1990-08-27 1991-08-15 직접 성형 가공법

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US62358190A 1990-12-07 1990-12-07
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US07/655,485 US5130076A (en) 1990-08-27 1991-02-14 Direct fabrication
US655,485 1991-02-14

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WO2009134653A1 (fr) * 2008-04-30 2009-11-05 E. I. Du Pont De Nemours And Company Surfaces de matière plastique ayant des caractéristiques de surface améliorées
DE102011101852A1 (de) * 2011-05-18 2012-11-22 Reifenhäuser GmbH & Co. KG Maschinenfabrik Plastifiziereinrichtung für Kunststoffe
US8722761B2 (en) 2008-04-30 2014-05-13 E I Du Pont De Nemours And Company Plastic surfaces having improved surface characteristics
RU169414U1 (ru) * 2016-03-21 2017-03-16 Федеральное государственное автономное образовательное учреждение высшего образования "Крымский федеральный университет имени В.И. Вернадского" Экструдер для переработки строительных и полимерных материалов
WO2017085500A3 (fr) * 2015-11-19 2017-07-27 Petainer Large Container Ip Limited Procédés et produits de moulage par injection-soufflage avec bi-étirage
DE102016015310A1 (de) * 2016-12-22 2018-06-28 Wittmann Battenfeld Gmbh Plastifiziereinheit einer Kunststoffverarbeitungsmaschine

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JP4182702B2 (ja) * 2002-07-30 2008-11-19 日産自動車株式会社 リサイクル樹脂製品の製造方法及び自動車用樹脂部品
CN106671389A (zh) * 2016-12-02 2017-05-17 余国庆 一种用于多种橡胶回收的塑化机螺杆

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WO2009134653A1 (fr) * 2008-04-30 2009-11-05 E. I. Du Pont De Nemours And Company Surfaces de matière plastique ayant des caractéristiques de surface améliorées
US8722761B2 (en) 2008-04-30 2014-05-13 E I Du Pont De Nemours And Company Plastic surfaces having improved surface characteristics
DE102011101852A1 (de) * 2011-05-18 2012-11-22 Reifenhäuser GmbH & Co. KG Maschinenfabrik Plastifiziereinrichtung für Kunststoffe
WO2017085500A3 (fr) * 2015-11-19 2017-07-27 Petainer Large Container Ip Limited Procédés et produits de moulage par injection-soufflage avec bi-étirage
RU169414U1 (ru) * 2016-03-21 2017-03-16 Федеральное государственное автономное образовательное учреждение высшего образования "Крымский федеральный университет имени В.И. Вернадского" Экструдер для переработки строительных и полимерных материалов
DE102016015310A1 (de) * 2016-12-22 2018-06-28 Wittmann Battenfeld Gmbh Plastifiziereinheit einer Kunststoffverarbeitungsmaschine

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JPH06500508A (ja) 1994-01-20
KR930701281A (ko) 1993-06-11
JP3220141B2 (ja) 2001-10-22
CA2089267C (fr) 2002-01-29
EP0546085A1 (fr) 1993-06-16
AU647527B2 (en) 1994-03-24
AU8539691A (en) 1992-03-17
BR9106791A (pt) 1993-06-15
CA2089267A1 (fr) 1992-02-28
EP0546085A4 (en) 1993-09-15
NZ239519A (en) 1992-12-23

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