GB1589014A - High density plastics containers and methods of and apparatus for filling and sealing such containers - Google Patents

Description

(54) HIGH DENSITY PLASTICS CONTAINERS AND METHODS OF AND APPARATUS FOR FILLING AND SEALING SUCH CONTAINERS (71) 1, ALFREDO ANTONIO WHITELOW, a citizen of Argentina, of Etcheverria 568 Martinez, Province of Buenos Aires, Argentina, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is performed, to be particularly described in and by the following statement:- The present invention relates to high density (ultra high molecular) plastics container and to methods of filling and sealing perishable paste-like products into such containers. The invention also relates to apparatus for carrying out the above indicated method.

Edible products such as tomato paste.

pcar pulp, apple pulp, peach pulp, to be referred hereinafter as "products of the forementioned type", are processed in a particular manner so as to prolong their conservation. In this regard, they are generally concentrated and then sterilized by submitting them to a temperature of 105-110"C.

Thereafter the product is cooled to about 25/30"C and filled into an aseptic metal drum.

So far known drums have been made of 18 gauge iron plate coated on the interior by a thin layer of tin plate on which an additional epoxy coating is added. These drums are sealed by means of a cap positioned on the filling opening.

In general, these known drums, when they are to be filled, are fed into a drum filling machine such as that manufactured by.

Franrica of Stockton, California, U.S.A. The edge of the drum surrounding the cap is placed in hermetic relationship with a sterilizing chamber whereafter a magnetic device removes the cap enabling a sterilizing nozzle to be inserted in the drum. Superheated steam is fed into the drum for sterilization of the drum. Once sterilized, the drum is filled through a filling tube, with one of the products of the forementioned type whereafter the above mentioned magnetic device returns the cap to its original position. Thereafter the cap is laterally expanded so as to assure a hermetic seal between the cap and the drum.

There are three outstanding disadvantages in this known system. Metal drums are extremely costly. Additionally, their weight is considerable (approximately 20 Kgs.) and their closure by mechanical expansion of the cap is not always perfect and therefore external contamination of the product cannot be discarded.

To avoid these disadvantages it is therefore necessary to provide a cheap, light and efficiently sealable drum.

To the above effect drums made of Lupolem 5261 manufactured by BASF of Germany or Hostalen GM 7255P (registered trade mark) manufactured by Hoechst Chemie of Germany are used. Both plastics belong to the so called high deilsity polyethylene (ultra high molecular) plastics.

which amongst other characteristics withstand temperatures up to 1800C.

Drums made of the above mentioned plastics cost approximately 1/3 as much as metal drums. Additionally, while the production of metal drums requires costly manufacturing facilities, plastics drums can be produced in relatively inexpensive blow-moulding presses.

Additionally, plastics drums weigh approximately 50 /O less than their equivalents made of metal. This is a feature of enormouse importance where freight is a competitive factor.

So far, plastics drums have not been used because it has been possible to hermetically seal an impermeable plastics cap to them particularly as plastics are only impermeable to external contamination when their thickness is very considerable. known plastics caps for plastics drum are not impermeable.

In accordance with one aspect of the present invention there is provided a sealed high density plastics container. wherein the container has an upstanding spout of plastics material, said spout having an annular ridge of an inverted U-shaped cross section including a base portion, an outer branch and an inner branch, said branches diverging from said base portion, a lip adjacent the end portion of said outer branch which is remote from said base portion, said lip being separated by a recess from said outer branch, said lip having a height less than the length of said outer branch, and a malleable metal foil cap coated on at least one face with a plastics material heat sealable with the plastics material of which said spout is manufactured, said cap having an outer rim and being heat sealed through its plastics layer to substantially the total extension of said annular ridge and its outer rim being press fitted into said recess and said lip overlapping said rim.

The spout is preferably integral with the container.

In accordance with another aspect of the present invention there is provided a method of filling and sealing a sterilized perishable paste-like product into a high density plastics container and thereafter sealing a closure cap to said container, wherein said container has an upstanding spout of plastics material, said spout having an annular ridge of an inverted U-shaped cross section including a base portion, an outer branch and an inner branch, said branches diverging from said base portion, a lip adjacent the end portion of said outer branch which is remote from said base portion, said lip being separated by a recess from said outer branch, said lip having a height less than the length of said outer branch, wherein the inside of said container is sterilised by injecting steam through said spout, then the previously sterilised product is filled through said spout into said container, thereafter a malleable metal foil having an outer endless rim of larger cross section than the remainder of said foil which is coated on at least one face with a plastics material heat sealable with the plastics material of which said spout is manufactured, is pressure applied with said coated face onto said outer branch. base portion and inner branch of said annular ridge and with its rim entering said recess, heat is then applied to said foil and ridge to fuse said ridge with said foil and to adhere said lip at least to said rim, an thereafter cooling the heated portions.

whereby said metal foil defines a sealed closure cap on said spout.

A still further aspect of the present invention provides an apparatus for carrying out the above mentioned method, wherein said closure cap has a central protuberance, said apparatus comprising a hollow upwardly and downwardly movable shaft defining at one end an ejector nozzle, said shaft being connectable to a source of cooling fluid, a resilient clamp mounted on said shaft adjacent said nozzle and capable of resiliently clamping said protuberance, a cup-shaped cylinder open at one end rigidly mounted on said shaft and surrounding it, with its open end directed towards said nozzle, a piston slidably mounted in said cylinder and on said shaft, said piston supporting a downwardly directed pressure fitting, sealing head having a recess complementary with the ridge of said container, means for heating said head. fluid injection means connected to said cylinder for moving said piston, up and down, and said ejector nozzle being adapted to eject a cooling fluid towards said head along said clamp.

In order to facilitate the comprehension of the present invention, a specific embodi men will now be described, by way of example, with reference to the drawing accompanying the provisional specification, wherein: Figure 1 is a vertical section through a spout or neck portion of a drum (only the upper portion of which is shown) and through an apparatus, schematically represented, for filling and sealing the drum, the apparatus and the spout or neck being shown in two different positions, one on the left of a vertical centreline, and the other position on the right of the centreline; Figure 2 is a plan view of a rubber diaphragm which forms part of said apparatus; and Figure 3 is a vertical section through the spout or neck portion of the drum with a cap sealed thereto.

Figures 1 and 3 show a plastics drum or container 10 having an upraised spout or neck 11 which is preferably integral with the container 10 and made of substantially the same material, e.g. polyethylene. The spout 11 has an annular ridge 12 of an inverted U-shaped cross section including a base portion 13, an outer branch 14 and an inner branch 15. Branches 14 and 15 diverge from base portion 13. A lip 16 is provided adjacent the end portion i7 of outer branch 14, which is remote from said base portion.

Lip 16 is separated by a recess 18 from outer branch 14 and has a height h less than the length of outer branch 14.

Spout 11 is externally screw-threaded a.

5 for receiving thereon a lid L to be referred to further on.

Figures I and 3 also show a cap 20 which is made of a malleable preferably 400 micron aluminium foil 21 coated on at least one face with a gasket of a plastics material 22 that can be heat sealed or soldered to the plastics of which spout 11 is manufactured. Obviously, other malleable metals could also be used as long as their malleability allows for quick conformation to any irregularities in the drum neck.

Cap 20 is shaped to also have an inverted U-shaped cross section 23 about its periphery. Externally of annular portion 23 cap 20 is provided with an outer rim 24 preferably of larger cross section than the rest of the cap. Cap 20 has in its center portion a protuberance 25 for the purpose to be explained later on.

It has been found that aluminium foil is the preferred material because of the high heat transmission coefficient of aluminium.

This allows for the quick soldering and/or fusion of the polyethlene gasket 22 and the polyethlene of neck 11.

The 400 micron aluminium foil constitutes an excellent oxygen barrier and protects the product against any external contamination.

Cap 20 has been shaped as described so as to become sealed round neck 11 on three sides 13, 14, 15 and to cause lip 16 to be folded over outer rim 24 when the lid L is screwed onto the spout of the drum as shown on the right hand side of Figure 3.

Reference will now be made again to Figure 1, together with figure 2, for a description of a method and apparatus for filling and sealing the container.

The apparatus comprises a cup shaped cylinder 30 rigidly mounted on a shaft 31 and surrounding it. Cylinder 30 has a bottom open end and houses a piston 32 slidable within the cylinder and on shaft 31.

The necessary sealing means between shaft 31 and piston 32 and between piston 32 and cylinder 30 are provided.

Shaft 31 is hollow and is vertically movable upwardly and downwardly for which it is connected to suitable drive means. Hollow shaft 31 is connectable to an external source of cooling fluid (not shown) to which reference will again be made later on.

Piston 32 supports a downwardly directed pressure fitting, soldering and sealing head 33 having a recess 34 complementary with the ridge 12 of container 10.

Head 33 has heating means 35 associated therewith. Such heating means can be for example, an electrical resistor connected to a power source through outlet cable 36.

Cylinder 30 is connected to fluid injection means (not shown) such as a source of air pressure and vacuum through inlet/out ]et 37 whereby upon fluid under pressure being injected into chamber 38, piston 32 will be caused to descend and upon a vacuum being created in chamber 38 piston 32 will be caused to rise.

The bottom end of hollow shaft 31 is secured to an annular member 39 which has a resilient clamping diaphragm 40 secured thereto. Resilient clamping diaphragm 40 has been more clearly shown in Figure 2 and comprises a disc shaped member which has a cut out center portion.

From the missing center portion there extend radial slots 41.

During operation and in order to sterilize and fill a drum, the latter is positioned as shown in Figure 1. Once this is done, hollow shaft 31 descends and the missing center-portion of diaphragm 40 fits over and becomes clamped to pretuberance 25 of cap 20. During the next step of the operation of the machine hollow shaft 31 lifts cap 20 off container 10 and enables the ingress of steam into container 10 through spout 11.

Thereafter, and once the container is sterilized, the sterilized product is introduced into the container 10 also through spout 11. Once container 10 is adequately full, hollow shaft 31 is caused to descend until cap 20 is positioned substantially as shown on the right hand side of Figure 1, but without head 33 having departed from its relative position, with regard to cylinder 30, shown on the left hand side of Figure 1.

Thereafter, fluid under pressure is supplied into chamber 38 through inlet/outlet 37 whereby piston 32, head 33 and recess 34 are caused to descend, until portion 23 of cap 20 is in pressure contact with annular ridge 12. Thereafter, heat is supplied to cap 20 and to annular ridge 12 to solder or heat seal ridge 12 to plastics material gasket 22 all along base portion 13, outer branch 14 and inner branch 15. Heat is applied to plastics material gasket 22 and ridge 12 by means of heating means 35.

After this sealing process is completed, cool air is blown into shaft 31 cooling cap 20 and releasing annular member 39 and damper (diaphragm) 40 from protuberance 25. In this way, cap 20 is soldered to spout 11 in the position shown on the left hand side of Figure 3. The lid L can be screwed onto spout 11 as shown on the right hand side of Figure 3. Lid L has an inclined walled portion 50 arranged to contact lip 16 and cause it to be forced over outer rim 24 thereby press fitting the latter into recess 18.

Consequently, container 10 is closed by cap 20 along the three sides of annular ridge 12 and within annular recess 18.

WHAT I CLAIM IS: 1. A sealed high density plastics container, wherein the container has an upstanding spout of plastics material, said spout having an annular ridge of an inverted U-shaped cross section including a base portion, an outer branch and an inner branch, said branches diverging from said base portion, a lip adjacent the end portion of said outer branch which is remote from said base portion, said lip being separated by a recess from said outer branch, said lip having a height less than the length of said outer branch, and a malleable metal foil cap coated on at least one face with a plastics material heat sealable with the plastics material of which said spout is manufactured, said cap having an outer rim and being heat sealed through its plastics layer to substantially the total extension of said annular ridge and its outer rim being press

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. protuberance 25 for the purpose to be explained later on. It has been found that aluminium foil is the preferred material because of the high heat transmission coefficient of aluminium. This allows for the quick soldering and/or fusion of the polyethlene gasket 22 and the polyethlene of neck 11. The 400 micron aluminium foil constitutes an excellent oxygen barrier and protects the product against any external contamination. Cap 20 has been shaped as described so as to become sealed round neck 11 on three sides 13, 14, 15 and to cause lip 16 to be folded over outer rim 24 when the lid L is screwed onto the spout of the drum as shown on the right hand side of Figure 3. Reference will now be made again to Figure 1, together with figure 2, for a description of a method and apparatus for filling and sealing the container. The apparatus comprises a cup shaped cylinder 30 rigidly mounted on a shaft 31 and surrounding it. Cylinder 30 has a bottom open end and houses a piston 32 slidable within the cylinder and on shaft 31. The necessary sealing means between shaft 31 and piston 32 and between piston 32 and cylinder 30 are provided. Shaft 31 is hollow and is vertically movable upwardly and downwardly for which it is connected to suitable drive means. Hollow shaft 31 is connectable to an external source of cooling fluid (not shown) to which reference will again be made later on. Piston 32 supports a downwardly directed pressure fitting, soldering and sealing head 33 having a recess 34 complementary with the ridge 12 of container 10. Head 33 has heating means 35 associated therewith. Such heating means can be for example, an electrical resistor connected to a power source through outlet cable 36. Cylinder 30 is connected to fluid injection means (not shown) such as a source of air pressure and vacuum through inlet/out ]et 37 whereby upon fluid under pressure being injected into chamber 38, piston 32 will be caused to descend and upon a vacuum being created in chamber 38 piston 32 will be caused to rise. The bottom end of hollow shaft 31 is secured to an annular member 39 which has a resilient clamping diaphragm 40 secured thereto. Resilient clamping diaphragm 40 has been more clearly shown in Figure 2 and comprises a disc shaped member which has a cut out center portion. From the missing center portion there extend radial slots 41. During operation and in order to sterilize and fill a drum, the latter is positioned as shown in Figure 1. Once this is done, hollow shaft 31 descends and the missing center-portion of diaphragm 40 fits over and becomes clamped to pretuberance 25 of cap 20. During the next step of the operation of the machine hollow shaft 31 lifts cap 20 off container 10 and enables the ingress of steam into container 10 through spout 11. Thereafter, and once the container is sterilized, the sterilized product is introduced into the container 10 also through spout 11. Once container 10 is adequately full, hollow shaft 31 is caused to descend until cap 20 is positioned substantially as shown on the right hand side of Figure 1, but without head 33 having departed from its relative position, with regard to cylinder 30, shown on the left hand side of Figure 1. Thereafter, fluid under pressure is supplied into chamber 38 through inlet/outlet 37 whereby piston 32, head 33 and recess 34 are caused to descend, until portion 23 of cap 20 is in pressure contact with annular ridge 12. Thereafter, heat is supplied to cap 20 and to annular ridge 12 to solder or heat seal ridge 12 to plastics material gasket 22 all along base portion 13, outer branch 14 and inner branch 15. Heat is applied to plastics material gasket 22 and ridge 12 by means of heating means 35. After this sealing process is completed, cool air is blown into shaft 31 cooling cap 20 and releasing annular member 39 and damper (diaphragm) 40 from protuberance 25. In this way, cap 20 is soldered to spout 11 in the position shown on the left hand side of Figure 3. The lid L can be screwed onto spout 11 as shown on the right hand side of Figure 3. Lid L has an inclined walled portion 50 arranged to contact lip 16 and cause it to be forced over outer rim 24 thereby press fitting the latter into recess 18. Consequently, container 10 is closed by cap 20 along the three sides of annular ridge 12 and within annular recess 18. WHAT I CLAIM IS:

1. A sealed high density plastics container, wherein the container has an upstanding spout of plastics material, said spout having an annular ridge of an inverted U-shaped cross section including a base portion, an outer branch and an inner branch, said branches diverging from said base portion, a lip adjacent the end portion of said outer branch which is remote from said base portion, said lip being separated by a recess from said outer branch, said lip having a height less than the length of said outer branch, and a malleable metal foil cap coated on at least one face with a plastics material heat sealable with the plastics material of which said spout is manufactured, said cap having an outer rim and being heat sealed through its plastics layer to substantially the total extension of said annular ridge and its outer rim being press

fitted into said recess and said lip overlapping said rim.

2. A container according to claim 1, wherein said spout is integral with the container.

3. A method of filling and sealing a sterilized perishable paste-like product into a high density plastics container and thereafter sealing a closure cap to said container, wherein said container has an upstanding spout of plastics material, said spout having an annular ridge of an inverted U-shaped cross section including a base portion, an outer branch and an inner branch, said branches diverging from said base portion, a lip adjacent the end portion of said outer branch which is remote from said base portion, said lip being separated by a recess from said outer branch, said lip having a height less than the length of said outer branch, wherein the inside of said container is sterilized by injecting steam through said spout, then the previously sterilized product is filled through said spout into said container, thereafter a malleable metal foil having an outer endless rim of larger cross section than the remainder of said foil which is coated on at least one face with a plastics material heat sealable with the plastics material of which said spout is manufactured, is pressure applied with said coated face onto said outer branch, base portion and inner branch of said annular ridge and with its rim entering said recess, heat is then applied to said foil and ridge to fuse said ridge with said foil and to adhere said lip at least to said rim, and thereafter cooling the heated portions, whereby said metal foil defines a sealed closure cap on said spout.

4. An apparatus for carrying out the method as claimed in claim 3, wherein said closure cap has a central protuberance, said apparatus comprising a hollow upwardly and downwardly movable shaft defining at one end an ejector nozzle, said shaft being connectable to a source of cooling fluid, a resilient clamp mounted on said shaft adjacent said nozzle and capable of resiliently clamping said protuberance, a cup-shaped cylinder open at one end rigidly mounted on said shaft and surrounding it, with its open end directed towards said nozzle, a piston slidably mounted in said cylinder and on said shaft, said piston supporting a downwardly directed pressure fitting, sealing head having a recess complementary with the ridge of said container, means for heating said head, fluid injection means connected to said cylinder for moving said piston, up and down, and said ejector nozzle being adapted to eject a cooling fluid towards said head along said clamp.

5. A sealed high density plastics container substantially as hereinbefore described with reference to the drawing accompanying the provisional specification.

6. A method according to claim 3, substantially as hereinbefore described with reference to the drawing accompanying the provisional specification.

7. Apparatus according to claim 4, substantially as hereinbefore described with reference to the drawing accompanying the provisional specification.