CZ293296A3 - Plastic container blown into a mould and process for producing thereof - Google Patents

Abstract

A blow moulded plastic container (40) comprises: (i) a neck portion (41) defining an opening (42); (ii) a bottom portion (43); and (iii) a body portion (44) interconnecting the neck and bottom portions; where: (a) the neck, body and bottom portions define a hollow space closed at the bottom and open at the neck, and have an inside and an outside wall face and a support (50) in the hollow space extending completely across and integral with the inside wall face of the body at two points to support the inside wall face; (b) the body portion defines regions comprising two adjoining lobes (60) which have two spaced depressions and a wall portion extending from one depression to the other to form a handgrip; (c) a support in the hollow space extends from one of the depressions to the other to support them; (d) the depressions have a base portion and the support extends in the hollow space from the depression base of one depression to the depression base of the other; and (e) the wall portion of the lobe(s) is blown in a mould to include segments releasable from the mould and deformed under internal pressure into the configuration of the handgrip. Also claimed are: (i) a method (I) of blow moulding a plastic container; and (ii) a method (II) for providing a blow moulded plastic container with lobes sepd. by depressions.

Description

Plastic container blown into a mold and process for its manufacture

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container designed especially for storing pressurized liquids such as carbonated beverages and the like. It relates to a blow molded plastic container made of a blow molded plastic preform consisting of a throat that defines an inlet, a bottom and a body connecting the throat and the bottom, the throat, body and bottom having an inner side of the wall and an outer the side of the wall, and the neck of the body and the bottom create a hollow space, closed at the bottom and open at the side of the neck. In the hollow space there is provided at least one that extends over the entire hollow space and which passes into the inner side of the body wall at two spaced apart positions for supporting this inner side of the wall, the body forming regions comprising at least two adjacent lobes. two spaced apart recesses and a wall that extends from one recess to the other to form a handle-shaped wall. The invention further relates to a method of manufacturing such a plastic container.

BACKGROUND OF THE INVENTION

These containers are usually made of preforms, which can be either injection molded or extruded. Further, the preform is blow molded into a suitably shaped container in a blow mold of the desired shape. Typical thermoplastic materials are polyethylene terephthalate (PET), polyolefins, and the like, although others may be used.

The container typically consists of a neck with a stopper attachment device, a neck extending from the transition portion, a wall or main portion that extends from the transition portion and the bottom connected to and extending from the main portion.

For the convenience and economy they represent, the public is calling for large-volume containers, such as two-liter PET bottles, widely used for carbonated drinks and gallon milk bottles. In fact, even larger containers would be desirable. Unfortunately, the handling of such containers, if not fitted with a convenient gripping device, is particularly difficult for small children.

Thus, different handles or handles are used, the method of manufacture of which mainly depends on the material of the bottle and the most suitable process of its transformation into the desired shape. As is well known, in blow molded polyethylene (PE) bottles, the hollow handle may be formed in the same operation in which the extruded parison in the mold takes the shape of the bottle itself. The prerequisites for this technology are extruded preforms and plastic, such as PE, which is easily pressure weldable. Bottles made of PET with injection molded preforms do not have a hollow integral handle, since welding the PET into a closed handle is nearly impossible with the above technology.

There are known ways to make a handle for PET bottles, but none of them is integral with the bottle body, i. that the handle is not made of preforms from which the bottle itself is deflated. Instead, separately formed handles are mechanically attached to the finished bottle body or molded in a separate molding step, for example as shown in U.S. Pat. No. 4,727,997 to Y. Nakamura. This procedure is expensive, often unreliable and commercially unsuccessful.

Handles may be used in place of the handle, the difference being that when grasping the handle, at least one finger of the user's hand passes through an opening that forms the ear attached to the bottle or is an integral part thereof, while the handle forms a recess in the bottle wall designed to handle it could be grasped between the thumb and the other fingers.

Such a handle can easily be formed as an integral part of the bottle from an otherwise normal preform in a mold having in addition to the cavities for the remaining walls of the bottle also a corresponding corresponding cavity for the handle. PET bottles with such a handle are commercially used in larger sizes, usually about two liters, for example for packaging spirits, wine and other liquids.

The same design cannot be applied to cylinders subjected to internal pressure, such as the case of carbohydrate containers, since any shape, including recesses, on a thin-walled, flexible, cylindrical, hollow body exposed to internal pressure will attempt to occupy a spherical or cylindrical surface, that said recesses or other deviations from the more or less circular cross-section will bulge and disappear.

It is an object of the present invention to provide an economical and aesthetic bottle made of PET or other plastic of comparable forming properties, such as polycarbonate, polystyrene and the like, having a handle that is part of a wall and which is deformed in a predetermined manner by internal pressure.

Attempts have been made in the past to achieve this goal by increasing the wall strength at the recesses, by strengthening the ribs. As an example, U.S. Pat. U.S. Patent 4,890,752 to A. Ota et al. The disadvantages of this solution, if it is to prevent collapsing into hands that are difficult to grasp, in particular the pressures typical of lemonade and carburized water, arise in particular from the excessive wall thickness and associated material costs.

The main object of the invention is to provide a plastic container blown into a mold for carbonated beverages having an improved configuration and method for producing it.

Another object of the invention is to provide a container as described above with a reinforced gripping portion.

Another object of the invention is to provide a container as described above in which the reinforced gripping portion retains its effectiveness in filling the container with carbonated beverage.

Other objects and advantages of the invention will be described below.

SUMMARY OF THE INVENTION

These objects are achieved by a blow molded plastic container made of a blow molded plastic preform consisting of a neck defining an inlet, a bottom and a body connecting the neck and the bottom, the neck, body and bottom having an inner side the walls and the outside of the wall, and the throat, body and bottom form a hollow space closed at the bottom side and open at the side of the throat, there is at least one reinforcement in the hollow space extending over the entire hollow space and two spaced apart locations for supporting this inner side of the wall, the body forming regions that comprise at least two adjacent lobes, between the lobes there are two spaced apart recesses and a wall that extends from one recess to the other and forms a handle-shaped wall according to the invention , the nature of which is that at least one reinforcement in the hollow The space in the hollow space extends from the base of one of the recesses to the base of the other of the recesses and the wall of at least one of the lobes comprises sections deformable by the action of overpressure into the shape of the handle.

In a preferred embodiment, the body forms two adjacent lobes of unequal size. Also, the stiffener and handle are preferably limited to the body region. Further, in this embodiment, the body comprises an axially inwardly concave portion having an inner side of the wall, wherein the stiffener also passes into the inner wall of the axial concave portion, thereby supporting it. If desired, a plurality of such stiffeners may be formed in the cavity.

The container according to the invention brings a number of advantages. First, the plastic container blown into the mold is provided with a reinforcement inside it to support it. The receptacle is provided with handles that gain efficiency by filling the receptacle with carbonated beverage. The container according to the invention with reinforced handles is easily manufactured by commercial methods.

The aforementioned objects are also achieved by a method of manufacturing a blow molded plastic container by injecting a preform with a body having a hollow space and an inner side of the wall and having an inner wall within the body that extends across the entire hollow space and extends the inner side of the wall at two distant locations and supporting the inner side of the wall, then the preform is blow molded in a blow mold into a blank comprising at least two adjacent lobes separated by two mutually spaced depressions between which a stiffener is arranged according to the invention characterized in that upon removal of the workpiece from the blow mold, the workpiece is subjected to internal overpressure until at least one of the workpiece lobes is formed into a rounded handle.

According to a preferred embodiment, the internal pressure is applied to the blank by filling it with a carbonated beverage.

Overview of the drawings

The invention will now be described with reference to the drawings.

Figure 1 is a longitudinal section of a preform for making a container according to the invention. Figure 1A is a cross-sectional view of Figure 1A-1A of Figure 1. Figure 2A is a partial perspective view of the preform forming core of Figure 1. Figure 2B is a cross-sectional view of the core-injection molding assembly of the preform of Figure 1. a partial section of a blow mold for forming a container according to the invention from a preform similar to that of Figure 1. Figure 4 is a front elevation of a container according to the invention. Figure 5 is a cross-sectional view of the container 5-5 of Figure 4 showing the container blank in an unfilled state as well as a container filled with a carbonated beverage.

DETAILED DESCRIPTION OF THE INVENTION

According to the invention, the external configuration of the container according to the invention is such that it has depressions and lobes between depressions which serve to facilitate the grip of the bottle when said bottle is under internal pressure. This is particularly desirable for large-circumference bottles or containers and facilitates handling of full or partially filled pressurized containers. The inner stiffener or stiffeners adjoin the depressions which support against internal overpressure and prevent their bulging while said overpressure shapes at least one of said lobes into a fixed handle.

The preform for forming these containers can be injection molded and comprises at least one inner wall that extends over the entire interior of the preform at a location that corresponds to the position of the finished internal reinforcement to the blown and pressurized container.

According to Figure 1, the plastic preform 10 is injection molded with a synthetic resin, preferably biaxially oriented, such as polyethylene terephthalate. The preform 10 has a neck 11 which forms an inlet opening 12, and on which there may be an external thread 13, which serves to attach the plug or closure element to the finished plastic container blown into the mold. The preform 10 has a body 14 extending from the neck 11 and an integral bottom 15 extending from the body. The body is generally tubular in Figure 1, although another embodiment may, of course, deviate from the tubular structure. The neck 11 has an inner side of the wall 11A and an outer side of the wall 11B, the tubular body 14 has an inner side of the wall 14A and an outer side of the wall 14B, and the bottom 15 has an inner side of the wall 15A and an outer side of the wall 15B. The body 14 forms a cavity 16 within the preform 10 which is closed by the bottom 15 and opened by the inlet opening 12 of the neck. Depending on the desired treatment and the nature of the final container, the bottom 15 may have any desired or convenient shape, for example rounded-rounded as in Figure 1, or for example flat or even slightly concave.

The preform 10 comprises at least one or two, or even more, inner walls 17. In Figure 1, these walls are shown as two. The inner walls 17 extend across the entire hollow space 16, and from the bottom 15 to the tubular body 14, ending in the tubular body 14. As shown in Figure 1A, the inner walls 17 form four separate chambers 17A, 17B, 17C and 17D, these the chambers are of course connected above the wall 17. As will be discussed below, alternatively, the inner walls 17 may be limited to that area of the preform 10 which subsequently forms the handle. As can be clearly seen from Figures 1 and 1A, the inner walls 17 adjoin the inner side of the wall 14A. The preform 10 can be made of transparent PET so that the inner walls are easily visible.

An injection molding method of the preform 10 is shown in Figures 2A and 2B. The injection mold core 20 consists of an outer wall 21 of generally cylindrical shape including slots 22 which correspond to the desired internal baffles in the preform 10. The core 20 is conventionally placed in the injection mold 23 in a position where the injection nozzle 24 seated in the injection mold 23 faces the bottom. 25 of the injection mold core 20. The core 20 is seated in the injection mold 23 such that a space 26 is formed between the core 20 and the injection mold 23. The molten plastic 27 is injected into the space 26 to be filled by the injection nozzle 24. The molten plastic 27 also flows into the slots 22 in the core 20, thereby forming the inner walls 17. The injection mold and core assembly is then opened and the preform 10 is removed in the conventional manner.

Heated to a temperature suitable for blow molding, the preform 10 is inserted into the blow mold 30 as shown in Figure 3, and by conventional blow molding or stretch blow molding, a hollow product is formed into a container blank according to the invention.

The warm preform 10 is placed in a blow mold having the shape of a blank of the desired container, such as blow mold 30 in Figure 3, and compressed air is injected into the mold. The preform 10 is inflated into a shape 31 that corresponds to said blank as shown by the dashed line in Figure 3, extending both axially and circumferentially. This process can be carried out either with or without a stretching rod or mandrel to assist axial extension. If such a bar is used, it should have the same spikes as the chambers on the preform, with each spike resting on the bottom of the preform in a different chamber. The walls 17 also expand to the size that the blow mold 30 allows. The particular blow mold shown in Figure 3 has an internal configuration that allows the formation of a hollow plastic product that is a blank of the container 40 shown in Figure 4, the lobe section of said blank being shown in dotted line in Figure 5. The mold 30 comprises at least two adjacent lobes joined together by depressions, which are not shown in section in Figure 3 but in Figure 5 are clearly visible. If an inwardly concave bottom is desired, the blow mold will have this configuration. The preform is blown into a shape that the blow mold allows, and the inner walls also extend accordingly.

In accordance with a conventional procedure, the mold 30 is split as indicated by the arrow 32 in Figure 3 to release the container blank.

As can be seen from Figure 5, the circumference of the blank is larger than the circumference of the circle described by it. Thus, the body 14 of the preform 10 of Figure 1 is excessively stretched in the regions in which the recesses of the handle are formed. In a preferred embodiment, the walls of the preform 10 are provided with reinforcements 19 shown in Figure 1A which, during blow molding, abut the said depressions and thus prevent excessive thinning of the walls of the depression. It is particularly preferred that the thickened regions abut those portions of the blow mold in which the recesses are formed, thereby preventing excessive thinning thereof and providing a container whose wall thickness in the recesses is more or less the same as the thickness of the other walls.

Thus, the plastic container 40 blown into the mold is complete. It has a throat 41 that forms an inlet 42, a bottom 43 and a body 44 that connects the throat 41 and the bottom 43. The throat 41 is provided with an external thread 45 for receiving a closure that corresponds to the thread 13 on the parison 10. and typically a conical recess 46. The vessel 40 also includes a transition portion 47 that connects the neck 41 and the tubular body 44.

The container 40 is provided with at least one inner reinforcement 50 which corresponds to the inner wall 17 of the preform 10 and which extends across the entire hollow space 51 of the container 40 and from the bottom 43 to the body 44, ending in the body.

As illustrated in Figures 3 and 5, the inner walls are an integral part of the container. The inner wall or walls may extend to the bottom of the container as shown in Figure 3, or may begin and end in the body as shown in Figure 4.

Referring to Figure 5, the body 44 comprises adjacent rounded lobes 60 together with recessed areas or recesses S1 which are particularly suitable for gripping on a large-sized container. Naturally, alternative shapes can be made. The stiffeners 50 in the cavity 51 connect the recesses, maintain their spacing and support them. The reinforced handle does not bulge when pressurizing the container. Since the reinforcing walls are integral with the inner side of the body wall and adjoin the recesses, they reinforce them firmly, thus preventing, for example, the walls from bulging. This will keep the handle firm and stable whether the container is full or half filled. As seen in Figure 4, the inner wall preferably terminates in the body near the end of the handle. Thus, the lobes and depressions that form the handle also preferably end in the body. As shown in Figure 4, the lobes and depressions preferably begin and end in the body to form a separate and closed handle. This is shown in the embodiment of Figure 4, wherein the container 40 has separate handles formed by depressions 61 and lobes 60. The stiffener 50 contacts and supports the depressions as described above. Of course, if desired, the handles may extend to the bottom or extend into the transition portion.

Figures 4 and 5 show a preferred embodiment of a container 40 according to the invention. Figure 5 shows a blank of a blank forming a section 52 deformable by an internal overpressure to the shape of a handle as formed in the mold. In Figure 5 the outline of this section 52 is indicated by a dashed line with an internal stiffener 50 connecting two adjacent recesses or recesses 61 in their. peaks and thus prevent the lobe from widening at the junction between the stiffener 50 and the recess 61. On the container blank 40, the segment 52 comprises substantially parallel segments 53, indicated by a dashed line, with a slight inclination of 1 ° or more in When the container blank is pressurized, i.e. when filled with a carbonated beverage, the segments 53 deform into the shape of the rounded sections 55 that form the boundary of the small lobe 60. Thus, the molded section 52 has more or less parallel sides. This is necessary for the blow mold to be relatively inexpensive and easy to operate because the lobe is not undercut in the mold opening direction indicated by the arrow 56. Obviously, the section 52 (the outline of which is indicated by the dashed segments 53) is not suitable for gripping hands or fingers as handles. Conversely, the lobe 60 (whose contour is formed by rounded sections 55) is particularly suitable for use as a handle, not only has the apexes of the depressions 61 supported by the stiffener 50, but also the sides of the deflated section 52 transform into rounded sections that easily allow fingers or hands to embrace the handle to achieve a secure grip between the thumb and the other fingers.

Another advantage of the containers of Figures 4 and 5 is that there are two different handle sizes per bottle. A smaller lobe is considered to be one handle, and the remainder of the bottle is considered a second, larger, handle suitable for gripping a larger hand. Appropriate placement of the reinforcement in or out of the container allows the sizing of both lobes, for example one to fit the size of the adult's hand and the other to fit the child's hand. Furthermore, the two surfaces represented by these lobes provide suitable locations for placing two different labels, one of which is the principal that identifies the brand and the quality of the content, and the other contains the information required by law to appear on beverage containers. This offers the opportunity to emphasize the sales slogan on a bottle displayed on a shelf in a store.

A preferred embodiment of the handle of the invention, as shown clearly in Figure 5, assumes that the handle is adapted to a size that approximately corresponds to the width of the hand. Thus, the handle is preferably located longitudinally in the central portion of the bottle, as clearly shown in Figure 4. Since a strut or stiffener is only needed in the region of the handle, its size may be limited to that area only. Naturally, it can be extended down to the bottom of the container as shown in Figure 3, which represents a suitable manufacturing process.

The invention is not limited to the examples described and illustrated herein, which are considered to be only exemplary embodiments of the invention, in which the shape, size, arrangement of parts and details of use can of course be varied. The invention includes all such modifications that fall within the scope defined by the claims.

Claims (9)

PATENT CLAIMS A blow molded plastic container (40) made of a blow molded plastic preform (10), comprising a neck (41) defining an inlet (42), a bottom (43) and a body (44), which connects the neck (41) and the bottom (43), the neck (41), the body (44) and the bottom (43) having an inner side of the wall and an outer side of the wall, and the neck (41), body (44) and bottom (43). forming a hollow space (51) closed on the side of the bottom (43) and open on the side of the neck (41), in the hollow space (51) at least one stiffener (50) extending over the entire hollow space (51) and passes into the inner side of the body wall (44) at two mutually spaced locations for supporting the inner side of the wall, the body (44) forming regions that include at least two adjacent lobes (60), two lobes (60) spaced apart from each other (61) and a wall that extends from one depression (61) to the other and forms a wall at t a handle boiling, characterized in that at least one stiffener (50) in the cavity (51) is arranged from one of the recesses (61) to the other recess (61) to support these recesses (61) and each recess (61) has a base wherein the stiffener (50) extends in the hollow space (51) from the base of one of the depressions (61) to the base of the other of the depressions (61), and the wall of at least one of the lobes (60) comprises sections (52) handle shape. Plastic container according to claim 1, characterized in that one of the lobes (60) is smaller than the other. Plastic container according to claim 2, characterized in that the smaller lobe (60) comprises walls which extend from said depressions and are more or less straightforward to bulge outwards and form round portions (55) after filling the plastic container (40) with a carbonated beverage carbon dioxide. Plastic container according to claim 3, characterized in that the smaller lobe (60) together with the two depressions (61) and the wall extending from one depression (61) to the other form a handle. Plastic container according to claim 4, characterized in that the handle extends only in the region of the body (44). Plastic container according to claim 5, characterized in that the stiffener (50) extending from one depression (61) to the other extends only in the region of the body (44) and the handle. Plastic container according to claim 1, characterized in that the handle has a rounded shape. A method of manufacturing a blow molded plastic container, wherein the molded body is molded with a body having a hollow space and an interior wall side and having an interior wall inside the body that extends across the entire hollow space and extends to the interior wall side in a mold. two distal locations and support the inside of the wall, then the preform is blow molded in a blow mold into a blank comprising at least two contiguous lobes separated by two mutually spaced recesses with a stiffener, characterized in that after removal of the blank from the blow mold is applied to the workpiece by internal overpressure until at least one of the workpiece lobes is formed into a rounded handle. Method according to claim 8, characterized in that the internal pressure is applied to the blank by filling it with a carbonated beverage.