WO2014080044A1

WO2014080044A1 - Method and apparatus for producing filled containers

Info

Publication number: WO2014080044A1
Application number: PCT/EP2014/000078
Authority: WO
Inventors: Christian Rommel; Arne Wiese
Original assignee: Khs Corpoplast Gmbh
Priority date: 2013-03-29
Filing date: 2014-01-15
Publication date: 2014-05-30
Also published as: DE102013007412A1; DE102013007412B4

Abstract

The invention relates to a method and an apparatus for producing containers (2) filled with filling product (45), in which, after thermal conditioning, a preform (1) is stretched within a blow mould (4), for example by a stretching rod (11), and is shaped into the container (2) by the action of blowing pressure, wherein after or during this shaping operation, a filling product (45) is filled into the blow-moulded container (2), and wherein, after this filling operation, the container (2) is closed, and is characterized in that, before the container (2) is closed, it is compressed so as to reduced its internal volume. The apparatus has a corresponding compression device.

Description

Method and device for producing filled containers

Description:

The invention relates to a method for producing filled containers, in which a preform is stretched by a stretching bar and converted into the container by blowing pressure action after a thermal conditioning within a blow molding station, wherein after or during the forming in the blow molded container Filled material is filled, and wherein after filling the container is closed. The invention further relates to a device for producing filled containers, which has at least one blowing station with a blow mold and at least one stretching rod for producing a blow-molded container, which further comprises at least one filling station with a filling member for filling the blow-molded container, and the at least one Closing station having a closing member for closing the filled container.

In a container molding by blowing pressure preforms of a thermoplastic material, such as preforms made of PET (polyethylene terephthalate), supplied to different processing stations within a blow molding machine. Typically, such a blow molding machine has a heating device and a blowing device, in the region of which the previously tempered preform is expanded by biaxial orientation to form a container. The expansion occurs e.g. with the help of compressed air, which in the to be expanded

BESTÄriGONGS * £ M>"£ Preform is initiated. The procedural sequence in such an expansion of the preform is explained in DE-OS 43 40 291. The mentioned introduction of the pressurized gas also includes the introduction of compressed gas into the developing container bubble and the introduction of compressed gas into the preform at the beginning of the blowing process.

As used in this application of blow-molded containers, this term encompasses not only blow-molded containers by pressurized gas introduction but also hydraulically blow-molded containers in which a liquid, e.g. a filling material to be filled, for which blow molding is fed into the thermally conditioned preform. The pressurized fluid used can thus be gaseous or liquid, if below blow-molded containers is mentioned.

The basic structure of a blowing station for container molding by means of compressed gas is described in DE-OS 42 12 583. Possibilities for temperature control of the preforms are described in DE-OS 23 52 926.

Within the blow molding apparatus, the preforms as well as the blown containers can be transported by means of different handling devices. In particular, the use of transport mandrels, onto which the preforms are plugged, has proven to be useful. The preforms can also be handled with other support devices. The use of gripper tongs for handling preforms and the use of expansion mandrels which are insertable into a muzzle region of the preform for mounting are also among the available constructions.

A handling of containers using transfer wheels is described, for example, in DE-OS 199 06 438 in an arrangement of the transfer wheel between a blowing wheel and a discharge path.

The already described handling of the preforms takes place firstly in the so-called two-stage process, in which the preforms are first produced in an injection molding process, then temporarily stored and later conditioned in terms of their temperature and inflated to a container. On the other hand, there is an application in the so-called one-step process, in which the preforms are suitably tempered and then inflated immediately after their injection molding production and sufficient solidification become.

With regard to the blow molding stations used, different embodiments are known. In blow stations, which are arranged on rotating transport wheels, a book-like unfoldability of the mold carrier is frequently encountered. However, it is also possible to use relatively displaceable or otherwise guided mold carriers. In fixed blowing stations, which are particularly suitable for receiving a plurality of cavities for container molding, typically plates arranged parallel to one another are used as mold carriers.

A detailed description of a stretching system of a blowing station with associated stretch rod takes place in DE-OS 101 45 579. The stretch rod is designed here as a solid rod and the blowing air (alternatively also the blowing liquid) is supplied to the blow mold through a connecting piston, which has a larger Inner diameter than the outer diameter of the stretch rod is. In this way, an annular gap is provided between the stretching rod and an inner surface of the connecting piston, through which the pressurized fluid can flow. The use of a hollow stretch rod is known for example from DE-OS 28 14 952. A connection for the pressurized gas takes place here via an end of the tube-shaped stretching rod facing away from a stretching rod tip. A pressurized gas supply via the end of a hollow stretch rod is also described in DE 34 08 740 C2. Again, alternatively, a liquid could be used as a pressurized fluid.

The containers produced with the blow molding machines described in detail above, in particular bottles, are usually designed so that you have a sufficient inherent strength in the axial direction for a stackable transport, that is a force or compressive stress in the direction of the bottle head to the bottom of the bottle or vice versa withstand. It is also known to provide the filled blow-molded containers with an internal pressure which is greater than the ambient atmospheric pressure in order to increase this inherent strength. It is also known to provide stiffening ribs to improve the inherent strength. These requirements on the intrinsic strength require an increased use of materials.

As a rule, blow-molded containers should be able to stand, which is why either already is formed correspondingly in the blow molding of the bottom region, or in a downstream of the blow molding step further action on the bottom area, for example by further impression of contours. Again, the requirement for stability brings an increased use of material in the floor area or an additional process and device complexity with it.

Foil bags, so-called pouches, which are produced from a film material, are also known in the prior art. These pouches need an additional outer packaging to be stackable, because pouches are not very pressure-resistant, as they have sealed seams that easily burst when pressure is applied. Compared with containers produced by blow molding, the manufacturing process is also more complex and less economical. Due to the low compressive strength and the transportability limits are set. The object of the present invention is to provide a method for the production of a lightweight and inexpensive container, which does not have the above-mentioned disadvantages and opens up new possibilities, in particular with regard to the transport and economic production of filled containers.

This object is achieved by a method having the features of claim 1 and by a device according to claim 14. The subclaims specify further advantageous embodiments of the invention. The inventive method is based initially on the known from the prior art conventional blow molding of containers, that is, a preform is stretched after a thermal conditioning within a blow mold, usually by a stretch rod, and formed by blowing pressure into the container. As a blowing fluid is primarily intended to a blowing gas, but it is also a liquid blowing fluid into consideration, as it is already known in the art, see, for example, WO2011 / 076167 A1 and the prior art mentioned therein. After or during this transformation, a product is filled into the blow-molded container. When using a liquid blowing fluid, the use of the filling material as a blowing fluid offers, so that conversion and filling of the container can take place at the same time. However, the use as blowing fluid is not possible with all liquid fillings. When using a gaseous blowing fluid, the filling step will generally take place only after the forming, for example after a transport of the blow-molded container from the blowing station to a filling station, where a filling member is arranged, which carries out the filling. After filling the container is closed, for example, in a closing station, where a closing member is arranged, which performs the closing operation. According to the invention, it is provided that the blow-molded container is compressed in a shrinking manner before it closes its inner volume. This gives the container a flexibility that is comparable to that of a foil pouch, especially when the container is made thin-walled, as defined in claim 2 in more detail. After compression, the container is closed so that it can not return to the state prior to compression.

In the containers produced by the process according to the invention, the requirements of inherent rigidity and inherent stability are deliberately avoided. Both requirements run counter to the compression step. It can thereby be saved significantly in the use of material, since the container bottom and the entire contour of the bottle no stability and / or steadfastness-promoting training or treatments needed more, and the wall thickness of the container can remain below the usual minimum wall thicknesses overall. No further, unevaluable process steps downstream of the blow-molding process have to be carried out for increasing the inherent rigidity or stability of the container, as explained in the description of the prior art (generation of an increased internal pressure in the container interior, subsequent treatment of the container bottom). Overall, the inventive method is material-saving and economical.

Compared to the above-mentioned pouches, the container produced according to the invention has the advantage of higher pressure stability, because the container is formed without sealing seams, because it is produced from a preform by blow molding. The manufacturing method according to the invention proves to be simpler and more economical than the production methods for foil bags.

As further advantages it follows that the containers produced according to the invention can be handled and transported like general cargo. There is also the possibility of being able to fill the same containers with different nominal volumes, for example by adjusting the degree of compression. For the method step of compressing according to claim 3 is proposed according to claim 3 advantageously to use mechanically operating squeezing, which act on the container. The action may be, for example, on the side walls, possibly also as compression in the direction pointing from the bottom to the mouth axial direction of the container. It is considered to be advantageous that the squeezing organs surround the container ring-shaped or partially annular. But it can also linear or selective acting a squeezing force on the side walls. The squeezing members may additionally or alternatively also act on the bottom region of the container, for example in order to compress the container in the axial direction. It is also conceivable that the squeezing organ rotates the bottom opposite the bottle opening and performs a helical compression.

As an alternative to the abovementioned mechanical crushing devices, the desired compression of the container can also be achieved by applying a negative pressure to the container interior.

Basically, the compression can be done at any time prior to closing the container. The only condition is that a reduction of the container volume is still achievable. It is considered advantageous that the compression takes place during or after the filling of the filling material in the container. In particular, with the advantageous features of claim 8 can then be realized in a simple manner, a control of the process step of compressing it, e.g. allows to minimize the headspace free of overfilling without overflow risk, or to fill the container with different nominal volumes and to control the degree of compression of the control in such a way that a constant filling level or a constant head volume free of filling material is achieved. However, the compression can also be done without such control, e.g. by applying a predetermined negative pressure to the container, or e.g. in that the mechanically operating squeezing members execute a predetermined squeezing movement.

The desired flexibility of the container according to the invention is advantageously achieved when the container is produced with an internal volume that is appreciably larger than the filling volume of the filled product (nominal volume). It is considered advantageous that the internal volume is at least 10% greater than the nominal volume. It is in principle so that the filled and sealed container has a higher flexibility (deformability) depending stronger the internal volume exceeds the nominal volume. On the other hand, an increased internal volume also requires an increased use of material in the container material. According to the invention, an optimum which meets both aspects is present when the internal volume is 10% to 50% above the nominal volume. The internal volume referred to here is the internal volume of the blow-molded container before it is compressed.

The method step of compressing the container also determines, among other things, how large the filling material-free head volume will be in the closed container. Here, a large head volume is equivalent to the fact that the nominal volume is considerably smaller than the inner volume of the container, which is in particular synonymous with an increased use of materials. In this respect, it is considered advantageous that the inner volume of the compressed and sealed container is less than 10%, preferably less than 5% greater than the nominal volume.

The degree of compression of the container may e.g. are expressed by the ratio of the inner volume of the container before and after compression. This degree is freely selectable within wide ranges, it being considered advantageous if the inner volume of the container is reduced by at least 5% upon compression, preferably by at least 10%, more preferably by at least 20%. Compression of more than 50%, on the other hand, is considered disadvantageous.

Since in the containers according to the invention no increased demands are placed on the inherent rigidity and the inherent stability of the soil, the container can be blow-molded in the bottom region with a wall thickness substantially equal to the wall thickness of the side walls. In the center of the floor production-related always a thickened area remains, which then has a greater wall thickness than the rest of the floor area and as the side walls. In particular, the bottom region can be formed convexly curved, in particular partially spherical.

The higher compressive strength compared to pouches and the increased flexibility (deformability) compared with the previous blow-molded containers also open up new possibilities for the further transport of the filled and closed containers. In particular, it is now possible and economical to use the usual transport methods for bulk materials. Therefore, it is considered advantageous that sealed containers together with other sealed containers, which are produced by a process according to the invention, to be filled for common transport in a bulk material container, in particular in a flexible bulk material container, in particular in a big bag.

With regard to the devices required for carrying out the method, the following aspects relevant to the invention arise. Conventional blowing devices known from the prior art can be used for the blow molding. Filling devices and closing devices are also generally known in the art, e.g. as separate filling or closing machines. It is also known to sequentially feed these machines, e.g. to arrange in a blocked form to perform the generic method with all the steps on a machine with blowing, filling and closing. According to the invention, this machine or this overall device is to be supplemented by a compression device which acts on the blow-molded container in terms of internal volume.

The compression step of the invention could e.g. be achieved by a vacuum device which is connected to the container opening and the container interior is subjected to a negative pressure.

In a further alternative and with advantage, the compression device can also be designed as a squeezing device with a mechanically operating squeezing member, which is formed mechanically acting on the container. The action can be carried out, for example, on the side walls of the container, the squeezing member can be positioned for example in the radial direction of the container. It is considered advantageous in this case that the squeezing organ is arranged surrounding the container in a ring-shaped or partially ring-shaped manner. Linear or punctiform crushing organs are also conceivable. However, the squeezing member may additionally or alternatively also act on the bottom region of the container, for example in order to compress the container in the axial direction, the axial container direction being the direction from the bottom to the container opening. For this purpose, the squeezing organ is arranged on the bottom side of the container and can be positioned in the axial container direction. It is also conceivable that the squeezing organ rotates the bottom opposite the bottle opening and performs a helical compression. Since the compression can take place at any time, at which a reduction of the container volume can still be achieved, the compression device could be arranged at different positions. For a compression of the container during the filling process, the compression device should be arranged for example in the filling device. It is considered advantageous that the compression takes place after the filling of the filling material into the container, so that an arrangement in the closing device is advantageous. The compression means may comprise a control means which controls the compression. A measuring device supplies the control device with measured values, for example, to the filling level of the filling material in the container or to the filling material-free head space in the container, and the control device controls with the aid of these measured values.

The invention will be further explained below. In the drawings, embodiments of the invention are shown schematically. Show it:

Fig. 1 is a perspective view of a blowing station for the production of

Containers of preforms,

2 shows a longitudinal section through a blow mold, in which a preform is stretched and expanded, Fig. 3 is a sketch to illustrate a basic structure of a

Device for blow-molding containers,

Fig. 4 is a modified heating section with increased heating capacity, Fig. 5 is a schematic representation of the inventive

Manufacturing process undergone manufacturing steps,

6 is a schematic representation of the process step C, namely the step of

Squeezing a container, and

Fig. 7 is a schematic representation of another process step E, namely the

Spend the produced according to the process steps A to D and filled container for onward transport.

The basic structure of a device for forming preforms (1) in container (2) is shown in FIG. 1 and in FIG. 2.

The device for forming the container (2) consists essentially of a blowing station (3), which is provided with a blow mold (4) into which a preform (1) can be inserted. The preform (1) may be an injection-molded part of polyethylene terephthalate. To allow the preform (1) to be inserted into the blow mold (4) and to allow the finished container (2) to be removed, the blow mold (4) consists of mold halves (5, 6) and a bottom part (7), which is a lifting device (8) is positionable. The preform (1) can be held in the region of the blowing station (3) by a transport mandrel (9) which, together with the preform (1), passes through a plurality of treatment stations within the device. But it is also possible to use the preform (1), for example via pliers or other handling means directly into the blow mold (4).

To allow a compressed air supply line below the transport mandrel (9) a connecting piston (10) is arranged, which feeds the preform (1) compressed air and at the same time makes a seal relative to the transport mandrel (9). In a modified construction, it is basically also conceivable to use solid compressed air supply lines.

A stretching of the preform (1) takes place in this embodiment by means of a stretching rod (11), which is positioned by a cylinder (12). According to another embodiment, a mechanical positioning of the stretch rod (1 1) is performed via curve segments which are acted upon by Abgriff rollers. The use of curve segments is particularly useful when a plurality of blowing stations (3) are arranged on a rotating blowing wheel

In the embodiment shown in Fig. 1, the stretching system is designed such that a tandem arrangement of two cylinders (12) is provided. From a primary cylinder (13), the stretch rod (11) is first moved to the area of a bottom (14) of the preform (1) before the beginning of the actual stretching operation. During the actual stretching process, the primary cylinder (13) with extended stretching rod together with a carriage (15) carrying the primary cylinder (13) is driven by a secondary cylinder (16) or via a cam control positioned. In particular, it is envisaged to use the secondary cylinder (16) in such a cam-controlled manner that a current stretching position is predetermined by a guide roller (17) which slides along a curved path during the execution of the stretching operation. The guide roller (17) is pressed by the secondary cylinder (16) against the guideway. The carriage (15) slides along two guide elements (18).

After closing the mold halves (5, 6) arranged in the region of carriers (19, 20), the carriers (19, 20) are locked relative to one another by means of a locking device (20).

To adapt to different shapes of a mouth portion (21) of the preform (1), the use of separate threaded inserts (22) in the region of the blow mold (4) is provided according to FIG.

Fig. 2 shows in addition to the blown container (2) and dashed lines drawn the preform (1) and schematically a developing container bladder (23).

Fig. 3 shows the basic structure of a blow molding machine, which is provided with a heating section (24) and a rotating blowing wheel (25). Starting from a preform input (26), the preforms (1) are transported by transfer wheels (27, 28, 29) into the region of the heating path (24). Heater (30) and fan (31) are arranged along the heating path (24) in order to temper the preforms (1). After a sufficient temperature control of the preforms (1), they are transferred to the blowing wheel (25), in the region of which the blowing stations (3) are arranged. The finished blown containers (2) are fed by further transfer wheels to a delivery line (32).

In order to be able to transform a preform (1) into a container (2) in such a way that the container (2) has material properties which ensure a long usefulness of foodstuffs filled inside the container (2), in particular beverages, special process steps must be taken the heating and orientation of the preforms (1) are maintained. In addition, advantageous effects can be achieved by adhering to special dimensioning regulations.

As a thermoplastic material different plastics can be used. For example, PET, PEN or PP can be used.

The expansion of the preform (1) during the orientation process is carried out by compressed air supply. The compressed air supply is in a Vorblasphase in which gas, for example, compressed air, is supplied at a low pressure level and divided into a subsequent Hauptblasphase in which gas is supplied at a higher pressure level. During the pre-blowing phase, compressed air is typically used at a pressure in the interval of 10 bar to 25 bar and during the main blowing phase compressed air is supplied at a pressure in the interval of 25 bar to 40 bar.

From Fig. 3 it can also be seen that in the illustrated embodiment, the heating section (24) from a plurality of revolving transport elements (33) is formed, which are strung together like a chain and guided by guide wheels (34). In particular, it is thought to open up a substantially rectangular basic contour by the chain-like arrangement. In the illustrated embodiment, in the region of the transfer wheel (29) and an input wheel (35) facing extension of the heating section (24) a single relatively large-sized guide wheel (34) and in the region of adjacent deflections two comparatively smaller dimensioned guide wheels (36) used , In principle, however, any other guides are conceivable.

To enable a possible dense arrangement of the transfer wheel (29) and the input wheel (35) relative to each other, the arrangement shown to be particularly useful, since in the region of the corresponding extent of the heating section (24) three deflecting wheels (34, 36) are positioned, and Although in each case the smaller deflection wheels (36) in the region of the transition to the linear curves of the heating section (24) and the larger deflection wheel (34) in the immediate transfer area to the transfer wheel (29) and the input wheel (35). As an alternative to the use of chain-like transport elements (33), it is also possible, for example, to use a rotating heating wheel.

After a finished blowing of the containers (2) they are led out of the region of the blow stations (3) by a removal wheel (37) and transported via the transfer wheel (28) and a delivery wheel (38) to the delivery line (32).

In the modified heating section (24) illustrated in FIG. 4, a larger number of preforms (1) per unit time can be produced by the larger number of radiant heaters (30) be tempered. The fans (31) introduce cooling air into the region of cooling air ducts (39), which in each case oppose the associated radiant heaters (30) and emit the cooling air via outflow openings. By arranging the outflow directions, a flow direction for the cooling air is realized substantially transversely to a transport direction of the preforms (1). The cooling air ducts (39) can provide reflectors for the heating radiation in the area opposite the radiant heaters (30), and it is likewise possible to realize cooling of the radiant heaters (30) via the discharged cooling air. 5 shows a schematic representation of the production steps A to D taking place in the production method according to the invention. Production step A consists of the blow molding step in which a preform (1) is blow molded into a blow molding station under pressure with a pressurized blown gas (44) Container (2) is transformed. The blow-molded container (2) is characterized by a bottom region (40), which has a convex curvature in the exemplary embodiment shown. The bottom area (40) is adjoined by the side walls (41). The intended for handling neck ring (42) and the external thread (43) are already pronounced in the preform in the final form and remain unchanged during the blow molding step.

In method step B, the filling of the blow-molded container (2) takes place. For this purpose, a filling member (46) is provided which fills the container (2) with a filling material (45), e.g. with a predetermined filling volume, the so-called nominal volume. When this nominal volume is filled, a filling material-free head space (53) remains above the filling level (54).

In method step C, the container (2) is closed with a closure cap (47), see (D). Beforehand, however, the filled container (2) is compressed, whereby the inner volume of the container (2) is reduced, recognizable by the increased filling level (54) and the reduced head space (53).

Fig. 6 shows a schematic representation of the process step C, namely the step of compressing a container. In the middle part of the representation, squeezing members (48) arranged laterally in particular from the container are shown, which can be positioned in the direction of the arrow. Above the still unclosed container mouth (55) a measuring head (50) is arranged, which looks at the surface of the filling material (45) and determines the filling level. The fill level readings become one Control device (51) supplied to the positioning of the Quetschorgane (48) controls, for example based on the measured filling level. The control can look like this, the Quetschorgane (48) are positioned until reaching a certain filling level (54). The control can also be exhausted in an emergency monitoring and intervene only when an overflow of the filling material (45) is to be feared, while otherwise the squeezing or positioning of the squeezing members (48) is predetermined and without control intervention by the control device (51st ) expires. In the right part of the illustration, a squeezing member (49) arranged on the bottom side of the container (2) is shown, which can be positioned in the direction of the arrow, namely in the axial direction of the container (2). With regard to the measuring head (50) and the control device (51) arranged above the still open container mouth (55), reference may be made to the preceding paragraph. The bottom-side pinch member may alternatively be provided and used in addition to or at the same time as the lateral pinching members.

After the squeezing process, the container is closed in a manner not shown. This can be done immediately upon completion of the squeezing operation, e.g. with still acting crushing force. This may be necessary if the compressed container tends to return to its initial state, that is, to the pre-compressed state. If this tendency does not or only to a very small extent, the closure of the container can also be done with a time lag.

FIG. 7 shows a schematic representation of a further process step E, namely the transfer of the containers produced and filled according to the process steps A to D for further transport. A big bag (52) is filled with a plurality of containers (2) produced according to the invention, which can be superimposed due to the increased pressure resistance in many layers over pouches, and because of the previously blow-molded containers (2) increased flexibility (deformability) with a better packing density can be received in the big bag (52). Of course, instead of the big bag, alternative outer packagings for piece goods are conceivable, e.g. any container.

Claims

Method and device for producing filled containers Claims:

1. A process for the production of containers (2) filled with filling material (45), in which a preform (1) after a thermal conditioning within a blow mold (4), e.g. stretched by a stretching rod (11) and transformed by blowing pressure into the container (2), wherein after or during this deformation a filling material (45) is introduced into the blow-molded container (2), and wherein after this filling the container (2) is closed, characterized in that the container (2) is compressed in a shrinking manner before its closing its inner volume.

2. The method according to claim 1, characterized in that the

Side walls (41) of the blow-molded container (2) with a wall thickness of less than 0.3 mm, more preferably of less than 0.2 mm, more preferably of less than 0.1 mm, more preferably in one for pouches (Pouches) usual wall thickness are made.

3. The method according to claim 1 or 2, characterized in that the

Compression by mechanically acting on the container (2) squeezing (48, 49) takes place.

4. The method according to claim 3, characterized in that the

Quetschorgane (48, 49) on the side walls (41) and / or on the bottom portion (40) of the container (2) act, wherein on the side walls (41) acting Quetschorgane (48) preferably the container (2) ring or surrounded part-ring.

5. The method according to claim 3, characterized in that the

Crimping (49) compress the container (2) in the axial direction.

6. The method according to claim 1 or 2, characterized in that the

Compression by applying a negative pressure to the container interior is done.

7. The method according to any one of the preceding claims, characterized in that the compression takes place during or after the filling of the filling material (2) in the container (2).

8. The method according to any one of the preceding claims, characterized in that during the compression of the container (29, the filling level (54) of the filling material (45) in the container (2) or the filling material-free head space (53) of the container (2) is measured , wherein preferably a control device (51) controls the compression based on these measurement results.

9. The method according to any one of the preceding claims, characterized in that the container (2) is produced with an internal volume which is greater by at least 10% than the filling volume of the filled filling material (45) (nominal volume).

10. The method according to claim 9, characterized in that the

Inner volume of the compressed and sealed container (2) is less than 10% greater than the nominal volume, in particular less than 5% larger. Method according to one of the preceding claims, characterized in that the inner volume of the container (2) is reduced by at least 5% upon compression, preferably by at least 10%, more preferably by at least 20%.

Method according to one of the preceding claims, characterized in that the container (2) in the bottom region (40) with a wall thickness substantially equal to the wall thickness of the side walls (41) is blow-molded, wherein the bottom portion (40) in particular convex, in particular partially spherical, is blow-molded.

Method according to one of the preceding claims, characterized in that the sealed container (2) is filled together with other sealed containers (2), which are prepared according to one of the methods specified in the preceding claims, for a common transport in a bulk material container, in particular in a flexible bulk material container, in particular in a big bag (52).

Apparatus for producing filled containers (2), which has at least one blowing station (3) for producing a blow-molded container (2) with a blow mold (4) and preferably with at least one stretching rod (11), which furthermore has at least one filling station with a filling member (46) for filling the blow-molded container (2), and having at least one closing station with a closing member for closing the filled container (2), characterized in that the device comprises a compression means (48, 49) for the reduction of internal volume on the blown container (2) is arranged and formed, wherein the device is further equipped and adapted to carry out one of the specified in claims 1 to 13 method.