NL1034717C2 - Blown plastic bottle with standing foot and method for the manufacture thereof. - Google Patents

Description

P83162NL00

Title: Blown plastic bottle with standing foot and method for its manufacture.

The invention relates to a blown plastic bottle. The invention relates in particular to a blown plastic container with a standing foot.

Blown plastic bottles are known from practice. A bottle is blown into a blow mold from a pre-form that is being injection-molded, by heating air under high pressure into the pre-form, whereby the pre-form is inflated and pressed against the wall of a mold cavity of the blow mold is pressed. The bottle then cools in that form.

In a first embodiment, a bottle is known which is provided with a standing foot which is fixed against the underside by use of a hot melt. The bottle is blown from PET or a PET blend, the standing foot being formed from, for example, PC or PE. Such a bottle, or at least the material thereof, is difficult and can only be recycled at relatively high costs.

In a second embodiment, a bottle is known that has no standing foot. Such a bottle is provided with a specially shaped bottom on which the bottle can stand. Such a shape is, for example, a pentaloid bottom, which means that the bottom has five dents with intermediate bulges on which the bottle can stand. Similarly, soils are known with more or less such dents and bulges. Such a bottle can be made of one material, for example PET, and is therefore more recyclable than the bottle with standing foot. However, such a bottle has, inter alia, the disadvantage that it is poorly resistant to, for example, relatively high pressures, while moreover the bottom requires a relatively large amount of material, which is disadvantageous because then either wall thickness 3 to 7 to 7 2 must be applied differently, or a relatively large wall thickness of the entire bottle must be used.

It is an object of the invention to provide a blown plastic bottle that overcomes or at least reduces one of the disadvantages of the known bottles.

In a first aspect, a bottle according to this description is characterized in that the bottle is formed from a plastic, as well as a standing foot connected thereto, wherein the plastic of the bottle and of the standing foot are collectively recyclable.

In particular, the bottle and the standing foot are made of the same plastic, more particularly a monomaterial bottle being obtained.

In a second aspect, a bottle according to this description is characterized in that the bottle is formed from a plastic, as well as a standing foot connected thereto, the bottle being connected to the standing foot by means of welding technology or by means of another technique in which no material is made. added or in no material other than the material of the bottle and / or the standing foot or at least that can be recycled for reuse.

In a third aspect, a bottle according to this description is characterized in that the bottle is connected to the standing foot by a clamp connection, a form closure or the like. Preferably, the bottle is thereby at least partially blown into the standing foot.

In a fourth aspect, a bottle according to the description is characterized in that the bottle and the standing foot are made of PET or a PET blend.

To clarify the invention, embodiments of a bottle and method for its manufacture will be further described with reference to the drawing. Therein: FIG. 1 a sectioned side view of a bottle with standing foot; 3

FIG. 2 is a sectional side elevation of a step in a method for connecting a standing foot to a bottle;

FIG. 3 is a sectional side elevation of an alternative device and method for connecting a standing foot to a bottle; and FIG. 4 a bottle in partially sectioned side view with a standing foot.

In this description, the same or corresponding parts have the same or corresponding reference numerals. The embodiments shown are shown for illustrative purposes only and should not be construed as being limitative in any way.

In this description, material should be understood to mean both a mono material and a blend, unless explicitly stated otherwise. In this description, "the same material" for the bottle and the standing foot is to be understood, at least but not exclusively, to use materials that are collectively recyclable, for reuse, or similar materials, for example materials with the same chemical components or composition . Reuse here should at least be understood to mean that the recycled material is suitable for use in production processes that are the same or comparable to those with which the bottle and / or the standing foot are manufactured. Preferably, the material is recyclable such that it can be used in the same material category as the original materials. Preferably the bottle and the standing foot are collectively, without prior separation, recyclable, preferably as material from which the bottle is made, such as, for example, as PET if the bottle 1 is made therefrom.

In this description, essentially, approximately, or similar relative terms should be understood to mean at least but not exclusively that deviations of at least plus or minus ten percent, in particular at least plus or minus five percent more in particular 4 at least plus or min 2% of a given given value or condition are possible within the invention.

A bottle according to this description is preferably made from a plastic pre-form as is customarily used, which pre-form is, for example, injection molded. The preform is then placed in a blow mold and heated and inflated therein until it has its final shape. The bottle is then cooled so that it retains its shape. It is taken out of the blow mold and used further, for example filled with a drink and sealed by a cap.

The bottle is provided on a bottom side with a separately formed standing foot which is fixedly connected to the bottle, in a manner to be described hereinafter. In one embodiment, this can be done in the blow mold. In an alternative embodiment, this can be done outside the blow mold.

A bottle according to the description is preferably made from PET, a PET blend or laminated PET. The material from which the bottle is made can comprise more than 50% by weight (% by weight) of PET, for example more than 60% by weight. In one embodiment the material comprises more than 70% by weight, more in particular more than 80% by weight, for example more than 90% by weight. The bottle may, for example, comprise 95% by weight or more of PET, based on the entire bottle, including any films and additives used therein and / or thereon, such as, for example, barrier layers against gas entry and / or exit into or out of the bottle, protection against radiation, aging, discoloration and the like, scavengers for, for example, O2 or CO2 and / or decorative layers and the like. The bottle can also consist of almost 100% PET. The bottle is preferably made from food grade PET and / or from "virgin" PET, which can sometimes be referred to as PET-1 in a recycle symbol.

A standing foot according to the description, usually also referred to in the art as bottom cap, is preferably made from PET, a PET blend or laminated PET. The material from which the standing foot is made can comprise more than 50% by weight (% by weight) of PET, for example more than 60% by weight. In one embodiment the material comprises more than 70% by weight, more in particular more than 80% by weight, for example more than 90% by weight. The standing foot may, for example, comprise 95% by weight or more of PET, based on the entire standing foot, including any films and additives used therein and / or thereon. The standing foot can also consist of almost 100% PET. In an advantageous embodiment, the standing foot can be at least partially, preferably substantially, and more particularly wholly made from recycled PET.

As indicated, the bottle and the standing foot are preferably made of the same material, PET being particularly advantageous because of the high recyclability.

The bottle and / or the standing foot can alternatively be manufactured from other plastic materials, as long as they are collectively recyclable in the same production process and yield a material with a purity of above 60% by weight, in particular above 70% by weight, more in in particular more than 80% by weight, such as for example more than 90% by weight and preferably more than 95% by weight. Preferably, the recycled material 20 falls into a purity category that is maximum for the plastic in question.

Figs. 1 and 2 show a bottle 1 with standing foot 2 according to the description in a first embodiment, with a section on the left-hand side and a view on the right-hand side. This bottle 1 comprises a thin wall 3 of plastic, in particular PET, wherein the wall can be a monolayer 25 (as shown) or a multilayer wall (not shown), for example provided with one or more barrier layers, while for example additives on or may be provided in the plastic, such as O2 and / or CO2 scavengers and the like, the material of the bottle being regarded as mono material. The bottle 1 is provided in the usual manner with a neck 4 on which, for example, external thread 5 can be provided for placement 6 of a cap (not shown). The neck 4 can be provided with a collar 6 with which a preform 22 (as shown in Fig. 3) can be held in a usual manner in a blow mold during blowing of the bottle 1 and which moreover can simplify handling of the bottle 1. Incidentally, it is noted that the bottle can have any desired shape, also for instance without neck 4 and / or screw thread 5 and / or without collar 6.

On the side remote from the neck 4, a bottom 7 is provided, integrally formed with the wall 3, which bottom 7 is formed essentially as a sphere segment, in particular as a hemisphere in this embodiment (dome shaped). Incidentally, it could also have a different shape, as long as it fits completely or partially in the standing foot 2. The spherical shape has the advantage that it gives an ideal pressure distribution, as a result of which the wall 8 of the bottom 7 can be relatively thin, for example approximately the same thickness as the wall 3. Tension in the bottom 15 can hereby also be minimized, removed and / or optimized.

The bottom 7 offers an additional advantage that a bottle 1 designed therewith can withstand relatively high pressures, for example above atmospheric, without undesired deformations, also with relatively large volumes, for example bottles with a capacity of 1.5 or 2 liters or more and / or with relatively small wall thicknesses, for example smaller than the currently usual wall thicknesses for bottles suitable for carbonated drinks such as soft drinks and carbonized water.

The bottom 7 as such has the drawback that the bottle 1 cannot stand upright thereon. Moreover, the appearance of the convex bottom 7 can be seen as annoying or unpleasant. The standing foot 2 covers the bottom 7 at least partially, at least in side view of the bottle 1, and moreover can offer a standing surface 9 on which the bottle 1 can stand. As indicated, the standing foot 2 is preferably made of the same material as the bottle 1. The standing foot 2 can be manufactured by injection molding. In this case, use can advantageously be made of a method and / or device in which a mold is provided with at least one mold cavity which has a movable wall part, such that, preferably with substantially or completely closed mold, the plastic in the mold cavity can be brought while the volume thereof is larger than that of the product to be formed, such as preform or standing foot, and can be moved during or preferably after introduction of the plastic, so that the final product is essentially formed by forming the mold cavity in a mold and bring volume corresponding to the product to be formed. Preferably, the movement of the movable wall part is thereby controlled such that in the mold the temperature of the plastic, in particular near a flow front thereof, only minimally or even not decreases or even increases slightly, so that the fluidity is maintained or even increased. improved until the mold cavity is at least largely filled. With this, particularly thin-walled products can be manufactured, with low closing forces and short cycle times. Optionally, the temperature of the plastic, in particular of the flow front, can be kept as close as possible to the injection temperature, preferably between about plus and minus 5 degrees Celsius thereof, at least until all plastic has been introduced and more particularly until the entire mold cavity is filled. Thus, for example, crystal formation in the plastic, in particular in the case of PET, can be prevented or at least minimized. Such devices and methods are known, for example, from WO03 / 039838 or WO00 / 024416. These applications are incorporated herein by reference 25, at least as regards the molds, injection molding devices and methods described therein.

In the embodiment shown, the standing foot 2 has a bottom part 10 and a wall part 11, connected to the bottom part 10 by a curved edge part 12. The edge part 12 essentially defines the standing surface 9. In the example shown, the bottom part 10 is hollow in the direction of the bottle 1, 8 such that a middle part 13 thereof touches the apex 14 of the bottom 7 of the bottle 1. The wall part 11 has a longitudinal edge 15 on the side remote from the edge part 12, which, in assembled condition, abuts the wall 3 of the bottle 1, for example near the transition of the wall 3 and the bottom 7. The longitudinal edge 15 can be connected to the wall 3 of the bottle. In addition or alternatively, the bottom part 10 can be connected to the bottom 7.

In a bottle 1 with standing foot 2 according to this embodiment, any connection between the standing foot 2 and the bottle 1 is preferably obtained by a method in which no material is added, such as glue or hot melt, because they make it difficult to recycle the bottle and standing foot or even impossible, without contaminated recycling material being obtained. For this purpose use can for instance be made of a welding method, such as ultrasonic welding, such as schematically shown in Fig. 2, spinwelding, pressure welding, or other welding techniques without material addition. In an alternative embodiment, the or each compound can be obtained by adding material that can be recycled together with the bottle and the standing foot, such as, for example, welding with the aid of a plastic welding rod, of the same plastic as the bottle and the standing foot.

Fig. 2 schematically shows that a bottle 1 can be arranged in a standing foot 2, for example on a turntable 16, after which the bottle 1 and the standing foot 2 are rotated about the longitudinal axis 17 of the bottle, in the direction of arrow Pi . Subsequently, for example, an ultrasonic welding head 18 is held near or against the longitudinal edge 15 and the wall 3, as a result of which the plastic of the longitudinal edge 15 and / or the wall 3 is slightly heated and fused together, wherein they are connected to each other at least after cooling. Other welding techniques can be applied in a similar way.

It will be clear that also for instance biodegradable glue can be used for connecting the standing foot to the bottle, or an glue which on heating above the use temperature or near or above 9 the melting temperature of the plastic burns or evaporates or otherwise disappears. disappears from the material to be recycled or in a conventional washing process of PET to be recycled.

Fig. 3 schematically shows a blow mold 20, in cross-section, 5 for forming a bottle 1. In the example shown, the mold 20 comprises two mold parts 20A, 20B, which from a closed state (as shown in Fig. 3) can be moved apart in the direction of the arrows P2 and P3, whereby the mold is opened and the mold cavity 21 is released for taking out a bottle 1 and / or placing a standing foot 2. In Fig. 3 there is a top pre-form 22 suspended from the collar 6, so that a body 23 protrudes into the mold cavity 21. In this state, hot air (or other propellant fluid such as a gas or liquid) can be introduced into the body 23 of the pre-form 22, in the direction B, applying such pressure that the pre-form 22 becomes bottle 1 blown. For this purpose use is made in a usual manner of a blowing head (not shown) which can connect to the neck 4. The mold cavity 21 can be heated, for example before and / or during blowing, for example by heating the mold cavity, walls thereof or such measures known per se.

In the embodiment shown in Fig. 3, a standing foot 2 is placed on the bottom 24 of the mold cavity 21. In this embodiment the standing foot 2 has a cup part 25 and a wall 26, mutually connected by an edge part 27. In the exemplary embodiment shown, partitions 28 are provided under the cup part 25, for example four (two in the plane of the drawing and two at right angles thereto) which are preferably connected centrally below the cup part 25 and support the cup part 25. Incidentally, the partitions 28 can also be omitted or a different number of partitions 28 can be provided or they can be placed differently. For example, a grid can be provided with bulkheads. The purpose of the partitions can be to support the bowl part, in particular during the blowing of the bottle 1, to absorb pressure in the bottle and / or to provide improved stiffness of the standing foot, in particular with small wall thicknesses of the wall 26 and / or or the bowl part 25. The standing foot 2 is preferably made in one piece from plastic, in particular the same plastic as the bottle, for example by injection molding.

In this embodiment, the edge part 27 is designed in such a way that it partially extends somewhat inwards and thus forms an undercut 29. The shape can herein be chosen such that the edge part 27 comprises a curved edge 30 with an inner wall part 31 lying below it on the inside, which is slightly recessed.

When the pre-form 22 is inflated, the wall 32 thereof will dilute and be pressed against the wall 33 of the mold cavity 21. Moreover, the wall 32, and in particular the part of the preform forming the bottom 7, will be blown into the standing foot 2, against the cup part 25 thereof and against the undercut. As shown in Fig. 4, a curved wall part 34 is thereby formed which encloses the edge part 27 and provides a form closure. The wall part 31 is herein preferably displaced outwards, under the edge 30, whereby additional compressive stress is released and an even better confinement. By an appropriate choice of the temperature of the preform and the mold cavity, in an embodiment 20 a partial fusion of the material of the standing foot 2 and the bottle 1 can be obtained, whereby a fixed connection is obtained, also when a standing foot according to for example, FIG. 1 is used.

Fig. 4 shows a bottle 1 with standing foot 2, for example formed in a mold 20 according to Fig. 3, with a partial section on the left-hand side and a view on the right-hand side.

With a standing foot 2 according to Figs. 3 and 4, in which a bowl part 25 is used, the advantage is achieved that the bottom 7 of the bottle 1 can be formed in a simple manner, such as spherical, while the pressure exerted during blowing can be exerted collected by the bowl part 25 and optionally the partitions 28. Even when the pressure in the bottle 11 increases during use, for example due to temperature rise and by CO2 or other gas development or discharge, the pressure can be at least partially absorbed by the bowl part 25.

In a variant not shown, one or more openings can be provided in a central part of the bowl part 25, through which the bottle 1 can be blown, so that it can comprise a widening under the bowl part, so that an additional or alternative adhesion can be obtained. To that end, for example, a part of the bottom 7 can be blown through such an opening, whereafter the part extending through the opening can be pressed slightly upwards, forming a widening under the bowl part.

In one embodiment, the standing foot 2 in the mold cavity 21 can be cooled at least partially or at least protected against heating to or above the melting point. The bottom 24 of the mold cavity 21 can be shaped such that it supports the bowl part 25 wholly or partially, for example by raising it on or off the bottom 24, so that this bowl part 25 and / or the bottom 7 can for instance be made particularly thin, optionally without baffles, and yet can withstand the blowing pressure when blowing the bottle. In such an embodiment 20 it is also possible to completely or partially dispense with the bowl part 25.

With a bottle 1 according to this description, a wall 3 and a bottom part 7 can be formed with approximately the same wall thickness everywhere. That is technically and economically advantageous. A minimum of material and weight is necessary for the formation of a pressure-resistant bottle, also at 25 volumes above, for example, 1.5 or 2 liters, such as, for example, about 3 or 5 liters or more, while moreover the shape of the bottle is retained to relatively high pressures , for example more than about 1.3 bar, more in particular more than about 1.6 bar such as, for example, more than 2 bar or more than 4 bar, or at least at comparable pressures which can occur at room temperature or above with carbonized drinks in closed bottles.

In general, a bottle 1 according to this description can be formed from a material that is the same as the material from which a standing foot connected to the bottle is formed, the connection between the standing foot and the bottle being formed without the application of a hot melt or other adhesive that is not recyclable with said material, in particular in an economical and technical sense. Preferably, the bottle and standing foot are at least substantially made from PET or PET blends.

The invention is in no way limited to the embodiments shown and described in the description and drawings. Many variations thereof are possible within the scope of the invention as set forth in the claims.

The bottle and / or the standing foot can thus have other shapes and be blown into a differently constructed mold. The neck may have a different design, while moreover the bottle may, for example, have integrally formed parts such as a handle, surface profiles such as ridges, edges, surfaces and the like. Labels and sleeves can be provided, whether or not they are arranged in the mold cavity. The standing foot can also be used with bottles that can be placed on the wall 3, wherein the standing foot (bottom cap) is only provided for covering and / or pressure relief and can for instance be designed such that the bottle cannot stand on it independently. Combinations and permutations of parts of the embodiments shown are understood to fall within the invention. Combinations and permutations of described connection methods can also be used within the invention. These and comparable variations are understood to fall within the scope of the invention.

1034717

Claims (20)

1. Bottle, blown from plastic material, provided with a standing foot made from the same plastic material, which standing foot is connected to the bottle. 2. Bottle as claimed in claim 1, wherein the bottle and the standing foot are mutually connected such that they are collectively recyclable. A bottle according to claim 1 or 2, wherein the standing foot is connected to the bottle without the use of a hot melt. A bottle according to any one of the preceding claims, wherein the standing foot is connected to the bottle at least by welding. A bottle according to claim 4, wherein the bottle is connected to the standing foot at least by ultrasonic welding, spin welding or pressure welding. A bottle according to any one of the preceding claims, wherein the standing foot is connected to the bottle at least by clamping and / or form closure. 7. Bottle as claimed in any of the foregoing claims, wherein the bottle and the standing foot are made from PET or a PET blend. A bottle according to any one of the preceding claims, wherein the bottle and the standing foot are collectively recyclable as PET. 9. Bottle as claimed in any of the foregoing claims, wherein it is adapted for pressure-containing liquid such as carbonized (CO2-containing) beverage. 10. Bottle as claimed in any of the foregoing claims, wherein the volume of the bottle is at least 1.5 liters, more in particular at least 2 liters. 11. Bottle as claimed in any of the foregoing claims, wherein in the blown state the bottle has a wall and a bottom part with a substantially equal wall thickness. 1034717 12. A bottle according to any one of the preceding claims, wherein the bottle has a bottom part then substantially forms a sphere segment, such as about a half sphere. 13. Method for forming a bottle, wherein the bottle is blown out of a pre-form and connected to a standing foot, without the use of a hot melt or the like that cannot be recycled with the material of the bottle. 14. Method for forming a bottle with a standing foot, in particular according to claim 13, wherein the bottle and the standing foot are manufactured from the same material. The method of claim 13 or 14, wherein the standing foot is at least connected to the bottle by welding. A method according to claim 13 or 14, wherein the standing foot is at least connected to the bottle by form closure and / or clamping. 17. Method as claimed in any of the claims 13-16, wherein the standing foot is manufactured by injection molding in a mold provided with a mold cavity with a movable wall part, wherein the plastic is introduced into the mold cavity with the movable wall part in a position such that the mold cavity has a mold cavity. has a relatively large volume and is moved in the mold cavity by moving the wall part to a position in which the volume of the mold cavity substantially corresponds to the volume of the standing foot. A method for forming a bottle with a standing foot, wherein the bottle is blown at least partially into the standing foot. The method of claim 18, wherein the standing foot is placed in a mold cavity of a blow mold and the bottle is blown into the blow mold. The method of claim 19, wherein the bottle in the blow mold is connected to the standing foot. 1034717