DK156162B - PROCEDURE FOR MANUFACTURING A CONTAINER OF A MOLECULAR ORIENTED THERMOPLASTIC MATERIAL AND APPARATUS FOR EXERCISING THE PROCEDURE - Google Patents

Description

DK 156162 B

The present invention relates to a method of the kind set forth in the preamble of claim 1 for producing a container of molecularly oriented thermoplastic material and the method according to the invention is peculiar to the characterizing part of claim 1.

The invention further relates to an apparatus for carrying out the method.

It is known to orient thermoplastic materials in 10 systems in which such materials are inflated to hollow objects such as containers. Such a molecular orientation is highly desirable when the thermoplastic material is of such a nature that an orientation can be developed therein, thereby providing an appropriate means of improving the strength properties of the finished container. Alternative methods for increasing the strength include changing the chemical structure of the thermoplastic material during the synthesis by strength-increasing modifiers, or by increasing the wall thickness of the finished product. The former may adversely affect other properties of the material, while the latter is rather costly, especially when the thermoplastic material is one of the newly developed low permeability nitrile-based plastics known as LOPAC®. , which is a registered trademark of the Monsanto Company. Therefore, it would be desirable to develop such an orientation during the molding operation, since the plastic material must in all cases be shaped in some way to obtain the shape of the finished product.

Generally, in order to become molecularly oriented, a thermoplastic material must be heated to a certain temperature range, after which the material is stretched to develop.

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Figure 2 shows the orientation, the said temperature range being below the temperature at which the thermoplastic material is extruded, but where the temperature range is considerably above room temperature.

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The known technique for developing such a molecular orientation, as disclosed, for example, in U.S. Patent No. 3,470,282, is based on injection molding of the thermoplastic material followed by temperature conditioning and stretching in axial and radial law. -in the inflation tool. Although this technique is generally satisfactory, it is not without disadvantages. As is well known, it is desirable to produce a predetermined distribution of the wall thickness in the thermoplastic material prior to the final blow-up to compensate for the differences in stretching that occur at the blow-up and as a result thereof. obtain a uniformly distributed wall thickness in the finished product, or alternatively to impart a wall thickness different to the wall thickness of the other areas to provide a particular area of the finished product. When the blank is formed by injection molding, the position of the entire injection molding surface, which corresponds to the shape of the blanket, must be checked to obtain a predetermined blank, whereas only the positioning of the much less important surfaces defining an annular outlet needs to be checked for variation of the wall thickness of the blank as the blank is formed by extrusion. In addition, very high temperatures and pressures are required and, as a result, 30 strong injection molding equipment, and such temperatures and pressure conditions may be destructive in the event of decomposition when the thermoplastic material is of the heat sensitive type. When the thermoplastic material is relatively viscous and 35

DK 156162 B

Furthermore, it may happen that it will not be possible to inject this material into narrow injection holes in the mold tool or, in other ways, the size of the container which it is possible to design. of such materials may be limited, since the material will not flow sufficiently into the relatively narrow and deep injection mold without adversely displacing the inner facet loss. It has also been found that by transferring a injection molded blank to the blowing tool, the blank may have a tendency to unwanted shrinkage and contraction, which is likely due to the flow orientation developed in the thermoplastic material during injection molding.

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Other prior art, such as that disclosed in U.S. Patent No. 3,294,885 and other related patents, indicates a reheating of the thermoplastic material for orientation temperature after an initial cooling and prior to stretching. Although such a technique is generally considered satisfactory under certain conditions, if the blank is designed in such a way that the wall thickness is varied as set forth above, it may be difficult to achieve a relatively uniform temperature through the full wall thickness which may vary more or less in the material without the use of a special zone heating arrangement. Furthermore, if significant temperature gradients exist across the cross-section of the blank, the degree of stretching and, as a consequence, the molecular orientation may vary, that is, the hot and thin sections will extend to a greater extent than the thicker and cooler sections, whereby the desired orientation and material distribution may be less desirable. Others 35

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4 problems have arisen in the prior art in those areas where the thermoplastic material has orientation temperature, for example in the design of the final shape of the container and / or the design of a welded closure.

5 Special heated mold parts and / or multi-arm closure mechanisms, as described, for example, in ÜS Patent No. 3,430,290, have previously been used.

With the present invention, a method for forming multi-axis orientation in an inflated blank has been developed which overcomes the aforementioned difficulties of the prior art.

The invention discloses a method for producing a multi-axis oriented container having a controlled distribution of wall thickness, which method comprises extruding a molecular oriented thermoplastic blank at a temperature above that at a substantially molecular orientation. 20, the thickness of one part of the blank will be increased relative to another part of the extrusion, after which the blank of variable wall thickness is subjected to temperature conditioning. Hereby the temperature of the blank is brought within the range where there is a generally molecular orientation, the temperature of the part of the blank where the thickness is increased more than in other parts of the blank. The temperature-conditioned blank is extended such that a non-axial orientation is developed, the extension causing the thick strip parts to be stretched more than the other belt parts. This reduces the wall thickness of the thick parts and approaches the thickness of the other parts. Finally, there is an expansion of the thus extended blank in a radial direction outwardly against the walls of a cavity of an up-35

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5, a blow molding tool similar to the shape the container is to have and during the formation of a radial orientation in said container.

More specifically, the method discloses the closure of separate sections of a conditioning molding tool at a portion of the varying wall thickness of the blank just after the blank is extruded and while still at its extrusion temperature by clamping the open end into the joint between the sections of the conditioning molding tool and by introducing liquid under pressure into the closed closed molding mold during an expanded expansion of the blank outwardly to contact the cooled surfaces of a cavity to form a preform of varying wall thickness and with an outer layer of reduced temperature. This outer layer is capable of supporting itself during transfer to later stages of the process. The present process is particularly useful for treating nitrile group-containing 2u thermoplastic polymers, wherein at least 60% by weight of the thermoplastic material has been polymerized from a nitrile group-containing monomer such as methacrylonitrile comprising the thermoplastic material. at least one polymerized comonomer with at least one ethylenically unsaturated bond in its molecular structure, such as styrene.

The apparatus for carrying out the method according to the invention comprises a blanket conditioning mold tool 30 prior to a temperature conditioning change. The conditioning molding tool has an interior cavity which corresponds to (but is smaller in surface area than) the cavity of the final molding tool, and which includes devices for cooling the walls of this interior cavity.

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The invention will be described in more detail below with reference to the drawing, in which: 1-5 partly in section and schematically show pictures of a combination of apparatus parts, and so show successive steps in the method according to the invention.

Referring now to the drawings, FIG. 1-5, various parts of a composite apparatus combination for the production of multi-axis oriented containers have a controlled distribution of wall thickness.

The first part of this apparatus combination is shown in FIG. 1, and comprises an arrangement generally designated 10 to form a blank 12. The surface arrangement 10 comprises an extrusion head 14 with an axially movable mandrel 16 within it. The head 14 has an end portion which can converge inwardly as shown at 20 18 and cooperates with the top portion 20 at the front end of the mandrel 16 to form an annular extrusion outlet opening between the inner surface 112 of the end portion 18 and the outer surface 110 of the top portion 20. "Extrusion" used hereinafter is used to define the pressing of a thermoplastic material at an elevated temperature through an annular outlet opening formed by surface members such as a top portion 20 and an end portion 18 of an extrusion head to form an elongated free open skin 30 tubular blank, such as, for example, 12.

An arrangement generally designated 22 is intended to control the wall thickness of the thermoplastic material upon its conversion to the blank 12. The control 35

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Preferred arrangement 22 preferably includes the System shown and described in full detail in U.S. Patent No. 3,697,632. Such an arrangement in the embodiment shown in FIG. 1, a housing 24 is rigidly connected to the upper portion of the mandrel 16 and a plunger 26 to the mandrel 16 which can be moved back and forth in the housing 24 by supply of pressurized fluid on each side of the piston 26 through tubes 28 and 30.

10 Located below the surface arrangement 10 and the arrangement 22 there is a blanket conditioning molding tool, generally designated 32 in FIG. 2. The conditioning molding tool 32 comprises separable sections 34 and 36, and together form an internal cavity 15 when the sections are assembled in a closed position.

The cavity 38 corresponds to (but smaller in surface area than) the cavity within which the finished container is to be formed. 1 shows the arrangement according to FIG. 2, the cavity 38 is in the form of an extended cylinder having a portion 40 above its 20 center which is in the form of the neck end of a bottle and the neck end may have threaded portions 39 and a shoulder portion 41. Also included as part of the cavity 38 is provided. a holding section 42 immediately up to the neck end portion 40, a neck bone holding section 25 at the upper end of the cavity 38 and a bottom bone holding section 46 at the lower end of the molding tool 32. The shaping tool 32 further comprises arrangement for controlling the surface temperature of the wall of the mold. the inner cavity 38, the arrangement comprising a series of internal ducts 43 through which a suitable cooling medium can circulate to reduce the surface temperature of the cavity 38.

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An arrangement generally designated 48 serves to expand the blank 12 into the cavity 38, which in the example shown comprises a hollow needle 50 mounted on a piston 52. This may work in a bore formed in the forming mold section 36 by means of a pressurized liquid which is passed through the duct 54.

A temperature conditioning arrangement generally shown as 56 according to FIG. 3 is arranged below the conditioning tool 32 to bring the temperature of the blank 12 within the range at which, in the main case, molecular orientation takes place by stretching.

An arrangement 56 in the example shown in FIG. 3 comprises a housing 58 having an inlet 60 and an outlet 62 therein for passage of temperature-conditioned air to reduce the temperature of one or more thermoplastic deformed members 80 to the desired orientation temperature. Such preformed members are arranged in holders 64 carried by the carrier plate 66, which can be rotated by means of 20 drive means 68 which may comprise an electric motor 70 and an associated gear exchange 72. An arrangement 74 can be arranged (Fig. 3 ) for transferring a blanket portion, when formed into a preformed blank, from the conditioning molding tool 32 to the temperature-conditioning arrangement 56. The transferring means 74 may comprise a pair of claws 76 and 78 closable about the projecting holding section 42 shown in FIG. preformed workpiece 80.

The final molding tool 82 (Fig. 4) is arranged 30 below the conditioning molding tool 38 and has an internal cavity 84, the shape of which corresponds to the shape of the container to be molded herein. The final molding tool 82 comprises separable sections 86 and 88 which together define the cavity 35 in a closed position.

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9 84. The mold tool 82 in the embodiment shown in FIG. 4, has an open end 90 which allows shaft 96 to project into cavity 84, and the molding tool is further provided with a cooling arrangement for controlling the surface temperature of the wall of cavity 84. Such cooling arrangement may also comprise a series of channels 92 , through which a suitable cooling medium can circulate in known manner.

10 is arrangement 94 (Fig. 4) which can act through opening 90 of the final molding tool 82 is arranged for longitudinal stretching of the preformed workpiece 80 for the full radial expansion of the final molding cloth 82. Such a stretching arrangement may comprise an axially movable shaft 96 having a foot portion 98 at the front end of the shaft and having a hollow passage 100 inside.

Another arrangement, separate from the first expanding arrangement 48, and operating in the conditioning molding tool 38, is arranged for expansion of the blank portion of the preformed workpiece 80 in the final molding tool 82. Such a second arrangement comprises a source of pressurized fluid (not shown) connected via conventional leads to passage 100 of shaft 96.

A resilient sealing member 102 supported on the bearing ring 104 is arranged to press with pressure against the upper surface portion 106 around the aperture 90 of the connecting molding tool 82 to seal the internal part thereof. of the preformed blank 80 from the surroundings during the shaping of the container.

In carrying out the process, a molecularly orientable thermoplastic material 100 (Fig. 1), such as a nitrile group-containing polymer, consisting of 35

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10 90% polymerized methacrylonitrile and 10% polystyrene pressed through the extrusion head 14 by means of a conventional extruder (not shown) against the surface arrangement 10. Although the preferred material of Exercise 5 of the process of the invention is such a nitrile group-containing polymer, any molecularly oriented thermoplastic material is used. Typical alternative thermoplastic materials include polymerized 1-olefins, soin for example polyethylene and polypropylene, as well as polyvinyl chloride. The polymer 108 is pressed between the outer surface 110 of the top portion 20 and the inner surface 112 of the end portion 18 of the extruder head 14 in a continuous manner to form an extended, free and hollow strip portion 12 with an open end at a temperature which is 15 resembles that at which a substantially molecular orientation occurs by stretching. Such a temperature for the nitrile group-containing polymer used is within the range of 204-260 ° C.

As the thermoplastic material 108 is forced through the surface arrangement 10, the plunger 26 is pressurized upwardly by means of a fluid which is passed through the tube 30 to increase the size of the opening between the top part 20 and the end part 18, thereby providing a 25 Increasing the thickness of the wall of the blank 12 by its extrusion, as shown in FIG. 1. Such an upward movement must occur at exactly the time of extrusion, where the strip portion forming the portion 115 of the bottle 114 (Fig. 5) up to its neck end 30 45 runs out of the outlet. Such a predetermined increase in wall thickness is easily obtainable by the technique described in ÜS Patent No. 3,697,632. A downward movement of the top portion 20 decreases the size of the opening and thus causes a reduction 35

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11 of the thickness of the wall of the extruded blank 12.

When a sufficient portion of blank 12 has been extruded to fill the desired space between sections 34 and 36 of mold 38, sections 34 and 36 are brought together against a portion of blank 12, and as this occurs, The open end 116 of the blanket is clamped by clamping surfaces 118 in the joint between sections 36 and 34. Thus, the variable wall thickness blank 10 is closed within the conditioning molding tool 32. The other end of the blanket portion can be separated from the extruder head 14 by a conventional used knife arrangement (not shown) or can be isolated from the head 14 by being squeezed between clamping surfaces 120 in the upper part of the mold tool 32. As will be understood since the temperature of the thermoplastic material of the blank 12 is relatively high in this step in the process, there will be no difficulty in forming a close welding of the end (s) between the surfaces of the clamping surfaces of the conditioning molding tool 32. After that part of the blank to be formed within the conditioning molding tool 32 has been extruded and closed, the conditioned molding tool 32 is moved away from surface arrangements so that another corresponding conditioning molding tool may enclose the next molding molding tool to be extruded according to the method shown in FIG. First

The hollow needle 50 is then moved through the wall of the closed strip portion into the free area 51 thereof, after which liquid is pressurized introduced through the passage 54, through the interior of the needle 50 and then into the closed strip portion, whereby it is expanded outwardly. to contact the cooled surfaces of the cavity 38. Hereby 35

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12, a self-supporting, preformed workpiece of varying wall thickness is formed with an outer layer at a reduced temperature thanks to the layer's contact with the cooled surface of the cavity 38. The size of the outward expansion of the blanket portion with the varying wall thickness within the conditioning molding tool 32 is minimal. and rather critical, and must be maintained at a value between 150 and 300% of the smallest internal diameter of the blanket portion formed by extrusion. As can be seen, for example, in FIG. 2, the portion 81 of the preformed blank 80 after expansion is not greatly reduced in thickness relative to the thickness of the blank as it emerges from the surface arrangement 10 of FIG. 1 (for example, from 6.3 to 4.5 mm). This is important because if the expansion that takes place in the conditioning molding jet 32 is too large, the stresses that must necessarily be developed in the thermoplastic material to form the desired molecular orientation cannot be sufficiently developed during the following blow-up operation if the pre-expansion at the elevated extrusion temperature (whereby such stresses cannot be developed) is too high. On the other hand, some expansion is required and is preferably made by the one required to form the molded neck end 45 on the preform blank 80, while the thermoplastic material is within the temperature range of 204-260 ° C, It is also desired to be performed at this elevated thermoplastic temperature to accurately form the rather critical closing support surfaces of the bottle 114.

Such an expansion is also desirable as it causes a relatively rapid formation of an outer surface with reduced temperature on the preform so that the surface is able to support itself without the use of auxiliary arrangements during the following steps of 35.

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13 process.

After a relatively short period of time (i.e., the order of magnitude 5-15 seconds after expansion of the blanket part 5 of the conditioning molding tool 32), sections 34 and 36 are separated and the preformed blanket 80 having an inflated and precisely defined neck finish 45, is removed from the molding tool 32, which is then immediately able to receive a second strip part for the next 10 cycle. Opposite jaws 76 and 78 are then closed about the holding section 42 of the preformed blank (80), after which the belt portion (either manually or automatically) is placed in holders 60 of the temperature-conditioning arrangement 56. However, the holding section and the neckline may be removed, if desired, between the conditioning form 38 and temperature conditioning arrangement 56. Similarly, the rear section 47 (Fig. 2) may be broken in the usual manner, either at this stage of the process, i. after the preform blank has assumed its shape and before the final Equal Inflammation, or after the final inflation that the bottle 114 has occurred.

Since the thermoplastic material is still quite yielding at this stage of the process compared to its later. condition, a removal of the waste portion in this step will be facilitated.

The preformed blank 80 is maintained in the temperature conditioning arrangement 56 for a period of time sufficient to reduce the temperature of the thermoplastic material so much that the temperature is within the range in which a substantially molecular orientation occurs upon stretching. For the nitrile group-containing polymer in the example shown, this is temperate

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14 temperature range located at 121 ° C and 177 ° C, and this temperature range will also vary somewhat from said temperature range for other thermoplastic materials. As will be appreciated, the temperature of the outer layer of the preform formed by the cooling shock contact with the cooled surfaces of the cavity 38 in the conditioning mold 32 will tend to increase as a result of the heat conductive contact with the material. warmer inner surface of the wall of the preform. Also, a thicker portion 81 of the preformed blanket 80 will have a slightly larger temperature than that of the smaller thicker portions, for a given period of time a heat flow will flow from the thicker portions which will be smaller than the thinner portions. however, it is still important that the total wall of the preformed blank is within a temperature range in which a substantially molecular orientation may occur in the temperature conditioning arrangement 56. The time within which the preformed blank will be exposed to a temperature-conditioning medium, is dependent on the temperature and nature of the latter, on the nature of the thermoplastic material, and on the thickness and temperature of the preform. In general, the time for developing such a medium for most orientable thermoplastic substances is between 5 and 200 seconds.

After the thermoplastic wall of the preformed workpiece 80 has been brought within the molecular temperature-oriented range, the workpiece is removed from the holder 30 64, either automatically or manually, and transferred to a position between the open sections of the final molding tool 82, which is then closed to enclose the workpiece within sections 84 and 86. As will be seen from FIG. 4, the thus-formed preform 35 is supported

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15 is a workpiece 80 of an annular flange 122 formed in each of sections 86 and 88. In the embodiment shown in FIG. 4, the piece 49 and the waste section 51 above the neck end 45 must be removed in this step of the 5 process in order for the shaft 96 to enter the supported blank. However, the preformed workpiece 80 can be formed in the conditioning molding tool 32 without closing its one end, whereby such an open preformed workpiece can be placed in the final molding tool 82 without removing the burr at the neck end. In each case, the length of the temperature-conditioning preformed blank 80 before the final blow-up, and before the blank is closed inside the mold 32, is increased by placing an end piece 98 on the shaft 96 against the inner surface 15 of the closed end of the blank. whereby the preform is extended longitudinally toward the surface 124 of the cavity 84 of the final mold tool 82. Such a longitudinal stretch within the molecular oriented temperature range serves to form a multi-axis molecular orientation in the thermoplastic material. scythe. Since the thickened portion 81 of the preformed blanket 80 is at a greater temperature than the adjacent thinner portions of the blanket, such an extension will cause the thicker parts to stretch more than the colder thinner portions of the result. the thermoplastic material flows from the thicker portions 81 into the thinner portions which optionally form the bottom area 117 of the bottle 114.

Contrary to what one would expect, in order to obtain material at the bottom of the bottle, the material must be added to this portion of the preform. Thus, after the preformed member has been stretched in the axial direction, and preferably after the closed end is pressed against the bottom portion 124 of the cavity, a liquid is passed under pressure through the channel 100 of the shaft 96 to expand it.

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16, the blank or the preform blank extends radially outwardly against the walls of cavity 84, thereby forming a radial orientation in the temperature-conditioning thermoplastic material during the formation of the body of the container. Upon contact with the cooled surfaces of the cavity 84, the temperature of the thermoplastic material will be reduced sufficiently to further unlock the stresses formed by the longitudinal and radially extending stretch of the thermoplastic material. As will be seen, the thinner and heavier portions of the preformed blank 80 will extend at the final expansion to a lesser extent than the thicker and warmer portions thereof (i.e., the portions designated 81), thereby forming a relatively uniform wall thickness distribution in both the axial and radial directions in the finished container, although the degree of stretching at the final inflation must necessarily vary to form the container 114 which is made up of material of different diameters. Any type of orientable thermoplastic material can be used in the process of the invention, the preferred thermoplastic material being one in which a major component thereof has been polymerized from a monomer containing at least one one nitrile group (-CN) 25 in its molecular structure. This nitrile group-containing polymerized monomer must be present in an amount of at least 60% by weight in the thermoplastic material, and preferably in an amount of between 85 and 95% by weight in order for the article to have the combination of chemical and physical properties. which is necessary for it to be effective for its preferred use. When such polymers are to be formed by the process of the invention, the temperature of the thermoplastic material in the various stages of the process must be kept within the following 35

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17 areas of fox to achieve the desired molecular orientation and material distribution in the finished product. Extrusion at 204-260 ° C; after conditioning and during the longitudinal and radial stretch: 121-177 ° C. The temperature will vary within the limits of the aforementioned ranges, depending on the content of the nitrile group-containing component of the polymer. In general, as the content of the nitrile group-containing component of the polymer increases, the temperature of the thermoplastic material during the various steps of the process must be increased, whereas the reverse should be the case when the content of the nitrile group-containing component is increased. -to about 60% by weight.

Typical examples of nitrile group-containing monomers suitable for use in the invention are: acrylonitrile, methacrylonitrile, ethacrylonitrile, propacylonitrile, α-chloroacrylonitrile, α-bromoacrylonitrile, α-fluoro-acrylonitrile, α-cyanlonitrile, α-cyano α-cyanoacrylic acids, α-cyanoacrylates, such as α-cyanomethylacrylates, α-cyanoethylactylates and the like, 2,3-dicyanobutene-2, 1,2-dicyanopropene-1, α-methylene glutaronitrile and the like. The preferred monomers are acrylonitrile and especially methacrylonitrile.

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Any monomer or mixture of monomers which can be copolymerized with the nitrile group-containing component of the polymer can be used in the process of the invention. Such a comonomer is present with the aim of improving the melting process (blank formation) of the thermoplastic material, since if there is an excess of CN groups in the polymer, the material becomes polar, which tends to reduce the processability properties in the molten state. The comonomer for -35

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18 diminishes this tendency, but not sufficiently, to destroy the barrier properties caused by the nitrile group-containing component. This comonomer may be present in amounts of up to 40 weight percent, but 5 to 15 weight percent is preferred. Examples of such monomers are ethylenically saturated aromatic compounds such as styrene, α-methylstyrene, o-, m- and p-substituted alkyl styrenes, for example o-methylstyrene / o-ethylstyrene / p-methyltyrene, p-ethylstyrene, m - or p-10 isopropylstyrene, o-, m- and p-butyl styrene ph-, m- and p-sec. -butylstyrene, o-, m- and p-tert. -butyl styrene and the like / o-halogenated styrene, for example ot-chloro-styrene, α-bromostyrene, ring-substituted halogenated styrenes, for example o-chlorostyrene, β-chlorostyrene and the like, esters of ethylenically saturated carboxylic acids, for example methyl acrylate, methyl methacrylate , ethyl methacrylate, ethyl acrylate, bytyl acrylate, propyl acrylate, butyl methacrylate, glycidol acrylate, glycidol methacrylate and the like, ethylenically saturated acids and carboxylic acids, such as acrylic acid, methacrylic acid, propacrylic acid and the like Also mentioned are vinyl esters, for example, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate ect., Vinyl and vinylidene halides, for example vinyl chloride, vinyl bromide, vinylidene chloride, vinylidene bromide, vinyl fluoride etc., vinyl ether, e.g. α-alkenes, for example, ethylene, propylene, bytes, pentene, hexene, heptene, octene, isobutene, and other isomers thereof.

When it is desired to provide improved physical properties to the finished article, up to 40% by weight impact-strengthening materials compatible with the nitrile group-containing polymer can be used. The amount of such materials relative to the amount of the non-nitrile group 19

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However, the polymer-containing material should not be allowed to exceed 40 percent / if changes in the properties of the finished product are to be avoided. Typical impact strength modifiers which can be blended with the polymer of the invention are synthetic or natural rubber components such as polybutylene, butadiene-styrene copolymers, isoprene, neoprene, nitrile rubber, acrylate rubber, natural rubber, interpolymers of butadiene with acrylonitrile, methacrylonitrile, tert.-butyl styrene, styrene and mixtures thereof, such as acrylonitrile-butadiene copolymers, methacrylonitrile-butadiene copolymers, acrylonitrile-styrene-butadiene terpolymers, methacrylonitrile lymers, methacrylonitrile tert.-butylstyrene-butadiene terpolymers, acrylonitrile tert, -butylstyrene-butadiene terpolymers, ethylene-propylene copolymers, chlorinated or fluorinated rubbers and the like. Other hard polymers not considered or known as rubber-based materials can be used as impact modifiers. These include polycarbonate, polyethylene, polyethylene vinyl acetate, polyethylene vinyl alcohol, polyamides, polyketones, phenorides, polyacetals and silicones.

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Claims (4)

Method according to claim 1, characterized in that a finished part of the blank is formed in the first molding tool, while the thermoplastic material 15 has a temperature above the region in which a significant molecular orientation takes place by stretching. Method according to claim 2, characterized in that the finished part of the blank is formed by expanding part of it against a corresponding part of the mold surface of the first molding tool and the manufactured container is a bottle with a thin lift. . A process according to claim 1, characterized in that the thermoplastic material is a polymer having a high content of nitrile groups, which polymer is extruded at a temperature of 204-260 ° C. Apparatus for carrying out the method according to any of the preceding claims for the manufacture of molecularly oriented containers having a lift with a terminating portion at the open end, from an extruded frame, comprising apparatus for temperature conditioning means. for bringing the temperature of the thermoplastic material within the range in which molecular orientation takes place by stretching, and a blow molding tool arranged after these means for final forming of the container, characterized in that the temperature conditioning means there is a mold tool having mold parts which can be moved away from each other and in the closed state confines an inner cavity which is similar but has less surface area than the blow mold tool and which has one mold surface at one end which determines the final shape of the end portion of the container neck, and which molding tool has means for cooling the walls of the inner cavity at which temperature The r-conditioning means has a housing having an internal temperature controlled atmosphere, which housing is arranged for simultaneously accommodating a plurality of preformed items. 20 25 30 35