Europaisches Patentamt 19 European Patent Office Office europeen des brevets © Publication number : 0 538 1 76 A1 EUROPEAN PATENT APPLICATION © Application number: 92610070.2 6i) int. ci.5 : B65D 23/08 © Date of filing : 12.10.92 © Priority : 15.10.91 US 775846 © Inventor : Farrell, Robert Anthony 14609 Jaystone Drive Silver Spring, Maryland 20905 (US) @ Date of publication of application Inventor : Huffman, Tood Hunter 21.04.93 Bulletin 93/16 503 Baldwin Road Richmond, Virginia 23229 (US) Inventor : Forbes, Hampton Edward States @ Designated Contracting : 1911 Kirkwood Highway DE DK FR GB NL SE Newark, Delaware 19711 (US) Inventor : Rigby, William Roger © Applicant : WESTVACO CORPORATION 348 Delaware Circle 299 Park Avenue Newark, Delaware 19711 (US) New York New York 10171 (US) © Representative : Vingtoft, Knud Erik et al Plougmann & Vingtoft Sankt Annae Plads 11 P.O. Box 3007 DK-1021 Copenhagen K (DK) © Paperboard bottle. © A bottle type container is fabricated by blow molding a continuous wall liner of thermoplas- tic polymer integrally to the interior wall surface of an oppositely matched pair of paperboard cladding jackets. Paperboard cladding jackets respective to each pair are joined substantially edge-to-edge along the meeting seam exclu- sively by the continuous liner wall lap. For container stability when resting on a flat sur- face, at least one folded ridge is formed in the bottom edge panel of both jackets. CO 00 CO If) UJ Jouve, 18, rue Saint-Denis, 75001 PARIS 1 EP 0 538 176 A1 2 BACKGROUND OF THE INVENTION Another object of the present invention is to pro- vide a composite material liquid container having a Field of the Invention: paperboard exterior structural jacket having preprint- ed graphics and an blow molded interior liquid seal. The present invention relates to composite mate- 5 Another object of the present invention is to pro- rial containers suitable for transport and storage of liq- vide a high production rate composite material bottle uid food products, household cleaners and other flu- that relies upon a minimal quantity of polymer as an ent materials. interior liquid seal liner. Another object of the present invention is the pro- Description of the Prior Art: 10 vision of a blow molded liquid container having im- proved rigidity and stiffness. Utility for the present invention is focused upon recloseable liquid containers in consumer sizes of SUMMARY OF THE INVENTION one to five liters such as is used for milk, fruit juice, bleach, automotive antifreeze and household clean- 15 These and other objects of the invention to be ing chemicals. A considerable portion of the present hereafter described or made apparent from the de- market demand for such containers is provided by scription, are served bya recloseable container of the blow molded plastic containers as are represented by bottle type comprising a pair of exterior paperboard those described by U. S. Patent 4,070,429 to A. R. cladding jacket halves, butt joined along meeting Uhling. 20 edges by the bridging lap of a blow molded polymer Blow molding is a term of art used to describe the lining. Such lining is integrally bonded to the entire in- process by which a hollow, tubular parison of hot, vis- terior surface of the paperboard cladding jacket cous thermoplastic polymer is extruded into a re- halves and continuously converges into a bottle-neck closeable mold cavity. When sufficient parison mate- opening. In the bottle-neck region, the polymer wall rial is in place within the closed mold cavity and both 25 thickness is increased to achieve free-standing rigid- ends of the parison tube are closed as by pinching, an ity without reliance upon an exterior paperboard rein- inflation needle is inserted into the closed parison forcement. volume and pressurized gas released therethrough. The sides and bottom of the bottle are structur- Expansion of the pressurized gas within the closed ally rigidif ied by the cladding jacket halves which are parison expands the hot thermoplastic walls of the 30 fold-formed from sheet stock paperboard: a suitable closed parison against the closed mold walls thereby surface for high quality print graphics. After printing forming the desired final article shape. So formed, and cutting, the flat paperboard cladding jacket the mold confined thermoplastic article is chilled blanks are magazine fed to a transition mechanism within the mold to solidification. Thereafter, the mold which breaks the paperboard blanks along the desig- cavity is opened to release the article so formed. 35 nated fold lines and inserts the erected blank into the Generally, this process is practiced with a mono- exposed cavities of an open pair of blow mold half layer thermoplastic parison but multiple layer lamin- sections carried by a multiple mold, blow molding ations are known to the art. wheel machine. The two mold half sections are Product or contents identification and informa- passed on opposite sides of a continuously extruded tion is applied after the vessel is formed. This may be 40 polymer parison aligned to fall tangentially against the by masked exterior spray application or a printed pa- blow molding wheel machine arc. With the parison per label secured adhesively to the exterior article aligned between the open mold halves and the erect- walls. In either case, the graphics field is somewhat ed blanks positioned within each mold half cavity, the limited. mold halves are closed upon the parison to pinch it Along a separate line of development, reclose- 45 closed. Thereafter, the parison is inflated with a pres- able liquid containers are also made from wax or plas- surized blowing gas such as air to line the blanks and tic coated paperboard. These containers are usually lap the two blank formed cladding jackets together. flat sided, square sectioned rectangles folded from When parison expansion is complete, the hot polymer flat sheet stock. An attractive marketing feature of is chilled to solidification. Ejection from a mold is fol- such containers is the capability of complex graphic 50 lowed by final trimming and content filling. presentations printed directly upon the exterior con- To provide a flat-bottom resting surface for the tainer surfaces before folding. On the negative side, bottle, both cladding jackets halves are given a the liquid seal integrity of paperboard containers is straight line crease along the bottom edge panel. The less than satisfactory. finish mold configuration of this arrangement is two It is, therefore, an object of the present invention 55 parallel-planar fold edges in the nature of rails offer- to combine the superior features of blow molded and ing stable support upon a flat surface. paperboard containers without the corresponding negative consequences. 2 3 EP 0 538 176 A1 4 BRIEF DESCRIPTION OF THE DRAWINGS perboard may be formed from bleached pulp stock with a clay coated and calendered surface or from re- Relative to the drawings wherein like reference cycled paperboard. characters designate like or similar elements through- As a first step toward finished bottle fabrication, out the several figures of the drawings: 5 paperboard blanks as represented by Figures 3 and FIGURE 1 is a side elevational view of the finish- 4 are graphically decorated by register controlled ed bottle article of the invention. printing and cutting presses. Mirror opposite right and FIGURE 2 is a rear end elevational view of the left hand blanks R and L are crease scored along the finished bottle article of the invention. dashed lines between major facet panels to bias fold FIGURE 3 is a plan view of the left hand paper- 10 breaking of the blank along such lines. Acrow-footcut board blank profile. line pattern in the handgrip area 15 permits a con- FIGURE 4 is a plan view of the right hand paper- verging facet surface depression in that area from the board blank profile. facet plane of broadsides 1 0R and 10L Rail crease 18 FIGURE 5 is a partial section of a blow mold shell divides the two bottom edge panels 14Rand 14L into pair having a corresponding pair of paperboard 15 two additional facet planes, respectively. blanks positioned therewith. External perimeter edges of both blanks in the FIGURE 6 is a sectional view of the invention bot- mirror opposite pair are dimensioned and cut for a tle article as taken along the cutting plane VI-VI edge-to-edge match in the finished article except for of Figure 1 . edges 19, 20 and 21 which are set back from a meet- FIGURE 7 is a side elevational view of the inven- 20 ing edge line. These set-back edges close upon an tion bottle article as removed from the blow mold uninflated parison to be subsequently described and and prior to flash trimming. require a gap distance therebetween to accommo- FIGURE 8 is an end elevational view of the inven- date the collapsed, double wall thickness of polymer tion bottle article as removed from the blow mold squeezed between the opposing edges when the and prior to flash trimming. 25 mold halves close as illustrated by the trim flash 40 of Figures 7 and 8. DESCRIPTION OF THE PREFERRED Of particular note to the blank design is a char- EMBODIMENT acteristic absence of any tabs or other lapping devic- es to structurally lock the blank pair together. Material Acompleted article representative of the present 30 properties of the blow molded polymer liner including invention is seen by Figures 1 and 2 to include a bottle tensile strength and adhesive tenacity to adjacent pa- having flat, faceted surfaces for the broad sides 10, perboard faces preclude the necessity for any addi- the leading edge 11, the trailing edge 12, the top edge tional joint strengthening across the blank perimeter 13 and the bottom edge 14.