FR2482564A1 - Biaxially extended moulded bottle - with section from mouth to shoulder of resin having high mechanical strength and chemical resistance before stretching - Google Patents

Abstract

Biaxially extended moulded bottle has a mouth and a neck lined with a mouthpiece (1) which is separately formed in a cylindrical shape. Mouthpiece is prepd. by the injection moulding of a resin having high viscosity (>1.0 IV value) such as satd. polyester resin, or polybutylene terephthalate resin, PVC resin, ABS copolymer resin etd. and having at the same time a height from the neck P1 including the mouth to the shoulder P2 close to the neck where the extention is applied to a lower extent; and a piece proper P prepd. from a low viscosity satd. polyester resin by the injection moulding by inserting (1) as a part of the mould is formed to obtain a bottle P' by a biaxially extending blow moulding by unifying said mouthpiece. Although biaxially extended moulded bottle using satd. polyester resin is widely used, the mechanical strength and the chemical resistance of such bottle are insufficient, since the part of the bottle from the mouth to the neck cannot be extended sufficiently during the injection blow moulding stage. Disadvantage is eliminated by using other resin having high mechanical strength and chemical resistance even when it is not extended biaxially for the material from the mouth to the shoulder.

Description

 The present invention relates to a saturated and biaxially oriented polyester resin bottle, as well as to its molding process.

 Bottles of biaxially oriented synthetic resin, in particular saturated polyester resin such as polyathylene terephthalate, are generally used in large quantities given their excellent physical properties and durability due to the crystallization of the molecules which have when the bottle is subjected to a biaxial orientation during the molding operation.

Despite their excellent characteristics, bottles of saturated and biaxially oriented polyester resin do not necessarily give perfect satisfaction when used as receptacles for alcoholic liquids.

The big disadvantage of resin bottles. Saturate and biaxially oriented is that the neck or the part between the ring and the bulge, which is not oriented or which is only a little, has physical properties and much worse in durability than the body which is molded with sufficient orientation. This drawback is due to the fact that the bottles, and a few rare exceptions taken, are molded by an injection and blow molding process during which closed cylindrical walls are prepared by injection molding and are then formed into bottles by blowing with biaxial orientation.

The disadvantage of the fact that the neck or the part between the ring and the bulge is not oriented is manifested by a whitish appearance or cracking due to the infiltration of alcohol when the bottle is filled with a liquid-containing more than 20% alcohol. In addition, the non-oriented neck is too soft and fragile to be able to be closed by encapsulation, and it can deform under the action of the clamping force applied by a screwed cap.

Accordingly, various devices have been used to enhance the physical and durability properties of the neck or the part between the ring and the bulge.

A device used implements the orientation of the neck and the ring in the radial direction, after the molding of the body with biaxial orientation. The results obtained are satisfactory to a certain extent but they present technical difficulties for the radial orientation, taking into account the apparatus necessary for the orientation and the dimensional precision of the ring.

Another device is intended to make the ring white by crystallization during a treatment at a suitable set temperature. This device has the drawback of not being able to be used in applications in which the neck or the ring must be transparent like the body, although the ring is made chemically stable and mechanically robust by crystallization, up to a certain point. The increase in mechanical strength obtained by crystallization is limited in the. case of saturated polyester resin which has a low clean cosiness screw.

According to the invention, the physical properties and durability can be improved without the
disadvantages presented by the aforementioned conventional methods.

Thus, the invention relates to a method for improving the chemical and mechanical properties
the neck, the ring and the bulge of a bottle of a saturated polyester resin with biaxial orientation, by using a weak or zero orientation.

The invention also relates to a method for
make integral a tip forming the neck of the bottle, and the body thereof.

 The essential characteristic of the invention is the coating of the neck or of the part between the ring and the bulge, which is in direct contact with the liquid contained, by a layer which resists alcohol and other chemicals even without biaxial orientation, so that the problems posed by the properties of the saturated polyester resin itself are resolved.

Other characteristics and advantages of the invention will be better understood on reading the description which follows - of embodiments and with reference to the appended drawings in which
- Figure 1 is a perspective. with parts cut away from an example of a nozzle used according to the invention
- Figure 2 is a longitudinal section of the tip placed on the core, when the molds are closed
- Figure 3 is a longitudinal section of a parison injection molded into the cavity
- Figure 4 is a longitudinal section of the bottle having the nozzle shown in Figure 1 placed in its neck
- Figure 5 is a longitudinal section of the bottle having a nozzle of a different type placed in its neck
- Figure 6 is a longitudinal section of a tip cooperating with the parison before the biaxial orientation
- Figure 7 is a longitudinal section of the nozzle and the bulge of the bottle after the biaxial orientation of the parison shown in Figure 6
- Figure # re 8 is a perspective with parts torn from another example of a nozzle; and
- Figures 9 to 11 are sections representing an example using the tip of Figure 8, Figure 9 being a longitudinal section of a tip molded by injection # ion, mounted on the core, Figure 10 being a longitudinal section of the parison injection molded into the cavity, with the end piece in place, and FIG. 11 being a longitudinal section showing the structure of the bottle obtained by implementing the method of the invention.

The bottle according to the invention is formed by a body P 'of the bottle and a nozzle 1 molded separately. The cylindrical tip 1 is held tightly inside a ring P2 of the body P 'and it practically plays the role of the neck of the bottle. As shown in Figures 4 and 5, the tip 1 fixed inside the ring P2 of the neck P 'shape.

the neck of the bottle with biaxial orientation. The end piece 1 which in practice forms a neck for the bottle, has a cylindrical configuration and is fixed tightly inside the ring P2 of the body P ′ or of the parison P. The end piece 1 preferably has a flange 3 wide enough to cover the upper end of the P2 ring so that the entire part of the neck that comes into contact with the liquid contained, during actual use of the bottle, is formed by the end piece 1. The flange 3 is formed on the upper part of the body 2 as shown in FIG. 1.

 The nozzle 1 is molded separately and independently of the blow molding of the body P 'of the bottle. The end piece 1 can be formed from various materials but it is preferably formed by a polyethylene terephthalate resin, by molding with biaxial orientation taking into account the resistance obtained during mounting on the body P ′ of the bottle.

 Other resins which can be used are a polyester resin with an intrinsic viscosity of more than 1.0, a polybutylene terephthalate resin, a polyvinyl chloride resin and an acrylonitril # -butadiene-styrene resin.

The tip can also be molded from a metallic material, for example aluminum.

The following description relates to the molding of the bottle according to the invention. The end piece 1 is molded with dimensions such that it adjusts without play on the base of the core C on which the parison
P is molded, before its orientation blow molding which forms the body P '. The end piece 1 thus prepared is slid onto the base of the core C and the molds K are then closed as shown in FIG. 1. The parison P- is formed by injection of polyethylene terephthalate melted into the cavity which is delimited by the core C, molds K and em-.

tip 1. In other words, the parison P is formed by molding around an insert, the end piece 1 being incorporated into the molds. Consequently, end 1 and parison P are closely combined.

The injection molded parison P, combined with the nozzle 1, is then placed in the blow mold used for orientation.

 The robust connection of the parison P and the end piece 1 is obtained by molding on the insert, as indicated above, but the connection resistance can be further increased when the body 2 of the end piece 1 has a part 4 of locking in the form of a projection or a cavity at its periphery. The locking part 4 is not necessarily continuous at the periphery of the body 2 but it can be discontinuous.

The locking part 4 is not particularly important when the end piece 1 is formed from polyethylene terephthalate with biaxial orientation, firmly attached to the parison P when the latter is molded. However, the locking part 4 has an important role for robust fixing when the end piece 1 is made of aluminum which does not adhere well to the parison P.

 When the end piece 1 extends beyond the flange 3 as shown in FIG. 5, the projecting part prevents contact of the liquid contained with the ring P2 of the body P ′, when a liquid is poured, and therefore protects this P2 ring against any deterioration. In addition, the protruding part facilitates the preservation of the seal for a long period when cooperating with a capsule or a gasket.

When the end piece 1 is formed from a synthetic resin, it preferably has a length greater than that of the ring of the body P ', as indicated in FIG. 6, so that the lower part of the end piece 1 covers the inside of the bulge near the neck, in a relatively poorly oriented place, as shown in Figure 7, when the parison P is molded with biaxial orientation, forming the body
P '.

The lower part forming the extension of the end piece 1 can cover the inside of the neck and of the swollen part which have not undergone sufficient orientation, although the end piece 1 is formed from a synthetic resin of viscosity high, since this organ only undergoes a weak orientation.

 FIG. 8 represents another example of end piece 1 which covers the interior of the bulge.

In FIG. 8, the end piece 1 is formed of a cylindrical body 12 having a smooth internal wall, an orifice 15 formed in the upper part of the body 12, a flange 13 placed just below the orifice 15, and a locking part 14 formed just below the flange 13.

This part 14 provides the connection between the end piece 1, and the parison P when the latter is formed by molding on the end piece 11 which is mounted on the core.

This locking part 14 may be in the form of a projection or a cavity. It is not necessarily continuous, as shown, but can be discontinuous.

 The locking part 14 is formed at a location corresponding to the ring or the neck P2 of the parison P, and the lower part of the body 12 is extended so that it covers the part of the parison P which forms the bulge P3 when the parison P is molded in the form of body P 'devbou teille, with biaxial orientation. In other words, the end piece 11 is long enough to cover the entire area between the orifice 15, at the upper part of the body P 'of the bottle, and the bulge P3, close to the ring P2 and who does not undergo sufficient orientation.

 The flange 13 is arranged so that it completely covers the upper face of the parison P and prevents contact of the liquid contained, during its pouring, with the outside of the ring Pa, as far as possible v it can however be deleted. it is advantageously used because it allows stable cooperation between the tip II and the parison-P and the increase in the mechanical resistance of the orifice 15.

The end piece 11 can be injection molded in saturated polyester resin or polybutylene terephthalate, having an intrinsic viscosity greater than 1.0, in polyvinyl chloride resin, in acrylonitrile-butadiene-styrene resin, etc., having a resistance mechanical and chemical properties such as resistance to alcohols and various chemicals which are better, even without orientation.

The end piece 11 is slid onto the base of the core C as shown in FIG. 9, and the molds
K are firm, when the nucleus C is placed between them.

A saturated polyester resin of low viscosity is injected through the pouring funnel G, into the cavity limited by the molds K, the core C and the end piece 11, so that the parison P shown in FIG. 10 is closed. At the end of the injection molding, the end piece 11 is secured to the parison P.

The parison P thus prepared is then removed from the mold and transported in a blowing mold with biaxial orientation so that the parison P is blown in the form of a body P ′ of bottle as shown in FIG. 11. During the operation ~ blow molding, the lower part 16 of the end piece 11, joining the bulge P3 near the ring P of the body P 'as indicated above
2 months, undergoes orientation with the parison P.

 The end piece 11 formed of a high cosity screw resin has poorer molding properties than those of the parison P which is formed of a low viscosity polyester resin, but the lower part 16 of the end piece 11 can take the configuration of the bulge P3 near the ring P2 because the orientation is weak in this region.

 The parison P formed from a saturated polyester resin of low viscosity can take the form of a body P ′ of bottle having relatively sharp angles as indicated in FIG. 11, given its good molding properties.

The bottle according to the invention is suitable as a container for cosmetic products which, in many cases, have a rectangular shape with sharp corners. In addition, the bottle according to the invention is suitable for liquid cosmetic products containing relatively concentrated alcohol and for perfumes.

The advantages obtained according to the invention can be summarized in the following manner. The chemical life and mechanical strength of the tip and neck, between the ring and the bulge of the bottle, at a location that experiences little or no orientation, can be increased. The bottle may have relatively sharp corners since the body is formed from a low viscpsity polyester resin having good molding properties. The tip is secured to the body of the bottle due to the molding on the insert, the tip ~ constituting a part of the mold. The mouthpiece and the parison can be handled as a whole, in a conventional manner and without any modification.

 Of course, various modifications can be made by those skilled in the art to the devices and methods which have just been described solely by way of nonlimiting examples without departing from the scope of the invention.

Claims (7)

1. Blow molded bottle formed from saturated polyester resin and biaxially oriented, said bottle being characterized in that it comprises a body (P ') and a cylindrical mouthpiece (1) held tightly inside the body ring . 2. Bottle according to claim 1, characterized in that the cylindrical end piece (1) which is fixed tightly to the ring of the body has a flange (3) which covers the outer end of the ring. 3. Bottle according to claim 1, charac terized in that the cylindrical tip (I) has a locking part (4), projecting or recessed, & the outer periphery of the body of the tip. 4. Bottle according to claim 1, characterized in that the nozzle - (1) is formed by biaxial orientation of a saturated polyester resin. 5. Bottle according to claim 1, characterized in that the tip -! 1) is formed of a metal. 6. Method for producing a blow molded bottle, form biaxially oriented saturated polyester resin: said method being characterized in that it comprises the arrangement without play of a cylindrical end piece on the base of a core, closing the molds between which the core is placed, injecting a saturated polyester resin into the cavity delimited by the core, the molds and the end piece so that a parison is formed, and placing the parison in the form of a bottle by blow molding with biaxial orientation. 7. Blow molded bottle, formed from a saturated polyester resin and biaxially oriented, the bottle dibe being characterized in that it comprises a body (P ') and a cylindrical nozzle (1) molded separately and forming the interior the neck and the ring of the bottle, this nozzle being injection molded with a synthetic resin such as a saturated polyester resin or a polybutylene terephthalate resin having an intrinsic viscosity greater than 1.0, a chloride resin of polyvinyl or an acrylonitríle-butadidne-styrene resin, the nozzle (1) being long enough to cover the part of the bottle which is between the ring and the bulge and which normally undergoes a weak orientation, the bottle being formed by blow molding with biaxial orientation of a parison of which the endpiece is integral, this parison being formed by injection of a saturated polyester resin with low viscosity in a cavity of which a part is eliminated by the nozzle.