Plastic containers
13 claims: 1 independent, 12 dependent
- 1Zastrzeżenia patentowe 1. Sposób formowania pojemnika z tworzywa sztucznego o zmniejszonej gazoprzepuszczalności, znamienny tym, że wytwarza się z warstwowego kęsa mającego zewnętrzną obwodową część z żywicy termoplastycznej oraz środkową część rdzeniową z żywicy termoplastycznej modyfikowanej * innym materiałem nadającym żywicy korzystne właściwości fizyczne, korpus zamknięty z jednego końca, oraz zakończony z drugiego końca obwodowym kołnierzem wystającym na zewnątrz i stanowiącym z korpusem całość, przy czym kołnierz tworzy się z termoplastycznej zewnętrznej, obwodowe j części kęsa, zaś korpus z termoplastycznej modyfikowanej, rdzeniowej części kęsa.
- 2Sposób według zastrz. 1, znamienny tym, że zewnętrzną obwodową część formuje się z polietylenu jako materiału wyjściowego.
- 3Sposób według zastrz. 1, znamienny tym, że obwodową zewnętrzną część kęsa formuje się z polipropylenu.
- 4Sposób według zastrz.. 1, znamienny tym, że zewnątrzną, obwodową część formuje się z polistyrenu.
- 5Sposób według zastrz. 1, znamienny tym, żę rdzeń kęsa formuje się z mieszanki żywicy termoplastycznej o dużej gazoprzepuszczalności i drugiej żywicy o małej gazoprzepuszczalności wybranej z grupy żywic zawierającej polimery chlorowinilide101 201 nowe, nylon i kopolimery akrylonitrylu zawierające akrylonitryl w ilości co najmniej 60 procent wagowo.
- 6Sposób według zastrz. 1, znamienny tym, że rdzeń kęsa formuje się z laminatu złożonego z arkusza pierwszej żywicy termoplastycznej o dużej gazoprzepuszczalności i arkusza drugiej żywicy o małej gazoprzepuszczalności wybranej z grupy żywic zawierającej polimery chlor owinilidenowe, nylon i kopolimery akrylonitrylu zawierające akry- 10 lonitryl w ilości co najmniej 60 procent wagowo.
- 7Sposób według zastrz. 1, znamienny tym, że rdzeń kęsa formuje się z mieszanki żywicy termoplastycznej i wypełniacza.
- 8Sposób według zastrz. 7, znamienny tym, że jako wypełniacz stosuje się mączkę drzewną.
- 9Sposób według zastrz. 1, znamienny tym, że rdzeń kęsa formuje się z mieszanki żywicy termoplastycznej i wypełniacza mineralnego.
- 10Sposób według zastrz. 9, znamienny tym, że jako wypełniacz stosuje się mikę. .
- 11Sposób według zastrz. 9, znamienny tym, że jako wypełniacz stosuje się włókno azbestowe.
- 12Sposób według zastrz. 9, znamienny tym, że jako wypełniacz stosuje się CaCO 3 .
- 13Sposób według zastrz. 9, znamienny tym, że jako wypełniacz stosuje się TiO 2 .
Independent claims13
43 paragraphs in 4 sections, as filed
POLSKA PATENT DESCRIPTION RZECZPOSPOLITA
FOLK -<sub>-</sub>101201
Additional patent to patent no -
<img file="PL101201B1_D0001.tif" />
OFFICE
PATENT
PRL
Reported: 2/17/75 (P. 178094)
Priority: 5/13/74 United States of America
The application was announced on: 1/31/76
Patent description was published: 03/31/1979
Int. Cl.<sup>2</sup> B29C 17/03
CIt IfcLNIA
Un «du Fe * ··» * »· * '
Inventor: Donald Jay Roth
Proprietor of the patent; Continental Can Company, Inc., Chicago (United States of America)
The method of forming a plastic container i
The present invention relates to a method of forming a plastic container, especially for food products.
In the manufacture of canned preservation products such as meat products ham, beef stew, beef stew with paprika, containers, usually metal cans, are filled with the food product, covered with a metal lid and sealed.
The disadvantage of enclosing meat products in metal containers is that the presence of these products will cause corrosion of the inside of the can, as a result of which the product becomes contaminated or spoiled.
Attempts to replace the metal with some inert synthetic resins, preferably polyethylene, polypropylene in applications for food containers have failed due to the high gas permeability of these resins to gases such as oxygen. As a result of oxygen permeation through the walls of the containers, unfavorable discoloration and deterioration of the taste as well as the quality of the food product occur.
The gas permeability of synthetic resins, such as polyethylene, makes it impossible to use containers made of them for packaging oxygen-sensitive products, although the chemical inertness of these resins is their great advantage.
In the field of other applications such as the packaging of motor oils, the sidewalls of containers made of thermoplastic resins such as polyethylene and polypropylene do not have sufficient stiffness to prevent them from buckling under the loads generated during storage.
There are methods known to reduce gas permeability and increase the stiffness of polyethylene and other thermoplastic resins. One is a method of making a container from a laminate formed of multiple layers of thermoplastic material, one of the layers acting as an effective gas barrier and being made of a thermoplastic resin such as polyvinylidene halogens and acrylonitrile polymers, e.g. America no
453 173, 3 464 350 and 3 615 306.
Other methods consist in adding fillers to the thermoplastic resin, preferably wood flour, mineral inorganic fillers, preferably clay or mica, as is known from US Pat. Nos. 3,463,350 and 3,668,038, or another resin, preferably nylon, which is a hindrance to the gas permeation, as is also known from U.S. Patent Nos. 3,093,255 and 3,373,224.
Known methods are effective in reducing gas permeability, increasing stiffness and advantageously improving other physical properties of thermo-resins.
101 201 plastic. However, there are difficulties in trying to close containers formed from the above-mentioned modified plastics.
When closing and sealing the containers with a metal lid made of steel, galvanized sheet or aluminum, the lid is fixed to the upper end of the container body with a double fold. In the double-folding operation, a lid with a perimeter flange is placed over the open end of the container body, on which there is a flange uniformly joined to the body, located on the outer perimeter of the opening: The flange of the container is so formed ί dimensioned. so that it can be folded over with the lid flange to form a double closure to accommodate the container body. The flanges of the container body and lid are rolled together to form an overlapping double closure. Metal lids are double-attached to containers made of unmodified thermoplastic resins. However, when the same resins are modified by lamination, with admixtures of other synthetic resins or the addition of fillers, the containers made of them are inelastic and inelastic, unable to withstand the high stresses occurring during double closure, which causes tearing and cracking of the upper parts of the container during fastening the cover.
The object of the invention is to provide a method for forming a plastic container with reduced gas permeability.
The object has been achieved by providing a method of forming a plastic container with reduced gas permeability, which consists in forming a layered billet having an outer peripheral portion of thermoplastic resin and a central core portion of a thermoplastic resin modified with another material imparting favorable physical properties to the resin, wherein the body closes at one end, and the other open end terminates in a peripheral flange extending outwardly with the body integral with the body, the flange being formed by the thermoplastic outer circumferential portion of the billet and the body being formed by the thermoplastic modified core portion of the billet.
The method is explained in more detail on the basis of the drawing in which Fig. 1 shows a layered thermoplastic resin billet, the central part of which has an addition of a material favorably influencing the physical properties of the resin, Fig. 2 - the billet along the line 2 and 2 of Fig. 1, Fig. 3 - a thin-walled container formed from the billet shown in fig. 1 and 2 in section, fig. 4 - a container with a metal lid visible in a partial section, fig. 5 the container shown in fig. 4 with double closing of the lid, fig. 6 - billet placed between two dies in the forming chamber before molding begins, fig. 7 - folded die completely inserted into the forming chamber to form the billet container, fig. 8 - separation of the collapsible die after the container has been made immediately before the container is pushed out of the forming chamber.
One method of making containers from layered billets is to grasp the billet by its outer periphery and gradually deform the center of the non-gripped portion in a heat-softened state by forcing the die downward to compress the modified core material of the billet and form the sidewalls of the container as it descends. matrix.
The shaped laminar billet (Figs. 6, 7, 8) is composed of a peripheral outer portion 31 made of a flexible thermoplastic resin with high gas permeability or low stiffness, and an inner, central core 32 made of a modified thermoplastic resin with reduced gas permeability or greater. stiffness. The ply billet is sandwiched between the opposing lower die 35 and the upper die 36. Both dies slide in the forming chamber 37 ~ The lower die 35 is reciprocating telescopically with respect to the inner walls 38 of the forming chamber 37 by means of mechanisms not shown. The upper die 36 includes a support plate 38 with a sleeve 39 attached thereto, and an insert 41 attached to the lower end of the sleeve 39.
The interior of the molding chamber 37 has a predetermined transverse dimension greater than the upper die 36 so as to provide the space needed for the extrusion process between the sleeve 39 and the interior walls 38 of the molding chamber. In order to obtain this free space, the chamber for-. The mowania is equipped with a ferrule 43 mounted on the upper rim 44 of the molding chamber 37. The ferrule 43 has an opening dimensioned to provide sliding sliding with the outer surface 45 'of the sleeve walls 39. The annular gap between the sleeve wall surface 45 and the mold chamber inner wall surface 38 defines a space 4 having the shape and dimensions necessary to form the walls. sides of the container to be formed.
The forming chamber 38 includes a groove or recess 47 formed in the inner portion of its periphery. The groove 47 accommodates plastic material displaced during the molding process from the unmodified thermoplastic resin outer portion 31 of the billet 30 to form the closure flange of the molded container.
The ply billet 30 (FIG. 6) is placed on the lower face of the die 35 raised to its first position at the upper rim 44 of the forming chamber. If preferred, the billet 30 is uniformly heated to the forming temperature by suitable devices, not shown, before being placed on the die 35.
The billet is then compressed (FIG. 7) between the dies 35 and 36 to cause it to flow out
101 201 of its outer portion 31 radially outward from between the dies and forcing it into the groove 47 to form the receptacle flange. After the outer portion 31 of the billet is pressed into the groove 47, the dies 35 and 36 are advanced through the forming chamber 37 and cause a continuous layer of the modified material, the thermoplastic core, to be forced into the space 46 and consequently to form the side walls of the container.
After the extrusion of the material * of the billet core (Fig. 8) is completed, by moving the dies 35 and 36 in the forming chamber 37, a container 50 with a collar 51 is formed of an unmodified thermoplastic material, and the side walls 52 and the bottom 53 are made of a thermoplastic resin modified to obtaining favorable physical properties.
After the container 50 is formed, the top die 36 is pulled out of the forming chamber 37 to the fully open position. The lower die 35 moves sir upward in the forming chamber 37 to eject container 50 from the forming chamber 37. After container 50 is pushed out, the lower die is in a position to receive a second layered billet and repeat the forming operation immediately. Pushed out of the forming chamber 57, the containers are ready for the packing and double closure operation and require no edge alignment or any processing after formation.
The layered billets, which are used to form plastic containers, are made of any thermoplastic material that has so far not been suitable for the production of containers used for packaging purposes, in which high stiffness or low permeability of gases such as oxygen, carbon dioxide is required. and steam. Examples of such materials are polyvinyl chloride, copolymers of styrene butadiene acronitrile (ABS), polystyrene and olefin polymers such as polyethylene, polypropylene, poly-1-butane, poly-4-methyl-pentene-1 and other homopolymers and copolymers of similar mono-1 -olefins with up to eight carbon atoms per molecule.
Completely unmodified thermoplastic resins are intended to form the outer peripheral portion of a layered billet from which a flange is formed to seal the container. The inner part, the core of the sandwich billet consists of the same materials modified in order to obtain low gas permeability or higher stiffness.
Among the methods of modifying the thermoplastic resin to make it stiff or to reduce its gas permeability, there is a method of adding filler materials such as chopped natural organic fibers to the resin, especially particles such as sawdust and wood flour, mineral fillers such as TiO.<sub>2</sub>, CaCO<sub>3</sub>, asbestos fiber, clay-like materials with a lamellar structure such as mica, vermicellite, talc, and also silicon materials such as silica and aluminosilicate. Fillers are used in amounts ranging from percent to 90 percent by weight, which favorably improves the physical properties of the resin while allowing it to be extrusion or impact molding.
Alternatively, or in conjunction with the fillers, another resin with a low gas permeability is added to the thermoplastic resin. Such resins are nylon, acronitrile, alkyl acrylic (Barex) or copolymers of acrylonitrile and styrene with an acrylonitrile content greater than 60 percent by weight, and chlorovinylidene polymers (Saran), preferably polyvinylidene chloride, vinylidene chloride, vinyl chloride and vinylidene and acrylonitrile copolymers.
Alternatively, or in conjunction with the low gas permeability fillers or resins added to the thermoplastic resin, a laminate made of one or more layers of a thermoplastic resin and a low gas permeability resin is used as the material for the core portion of the ply billet. The core of the billet consists of a laminate containing two or more layers of a thermoplastic resin such as polyethylene or polypropylene having an inner layer of sarah or barax therebetween.
The ply billet used has any shape, preferably round, square, polygonal, and is prepared by pressing unmodified and modified thermoplastic resins together in the form of a bar, and then cutting / bar or other mixed resin form into billets of the required dimensions. The proper size of the layered billet is experimentally determined for a specific forming chamber and the formation of the dies, and the total volume of the billet must be such as to provide the specified container dimensions.
Contents4
1 sheet
Sheet 1
29 members in 23 offices
Priority claims3
| Document | Office | Kind | Date |
|---|---|---|---|
| 46948674 | United States of America | A | |
| 1974469486 | – | – | – |
| US19740469486 | – | – | – |
Members29
| Document | Office | Kind | |
|---|---|---|---|
| BE828981A | Belgium | A | |
| DK678574A | Denmark | A | |
| SE7502436L | Sweden | L | |
| NL7505421A | Netherlands (Kingdom of the) | A | |
| JPS50144579A | Japan | A | |
| DE2505492A1 | Germany | A1 | |
| US3923190A | United States of America | A | |
| FR2271021A1 | France | A1 | |
| DD117399A5 | German Democratic Republic (until 1990) | A5 | |
| BR7502871A | Brazil | A | |
| AU7675274A | Australia | A | |
| GB1442958A | United Kingdom | A | |
| ZA751843B | South Africa | B | |
| ES434663A1 | Spain | A1 | |
| CH593175A5 | Switzerland | A5 | |
| US4120932A | United States of America | A | |
| FR2271021B1 | France | B1 | |
| CS185677B2 | Czechoslovakia (until 1993) | B2 | |
| CA1045064A | Canada | A | |
| PL101201B1This record | Poland | B1 | |
| TR19385A | Türkiye | A | |
| SE406730B | Sweden | B | |
| IT1031165B | Italy | B | |
| HU175586B | Hungary | B | |
| JPS5722818B2 | Japan | B2 | |
| YU287680A | Yugoslavia, later Serbia and Montenegro (until 2006) | A | |
| RO82089B | Romania | B | |
| RO82089A | Romania | A | |
| DE2505492C2 | Germany | C2 |
Numbers
- Publication, DOCDB
- 101201
- Publication, EPODOC
- PL101201B
- Application
- 178094
- Application, DOCDB
- 17809475
- Application, EPODOC
- PL19750178094
Titles2
- English
- METHOD OF FORMING A PLASTIC CONTAINER
- Polish
- SPOSOB FORMOWANIA POJEMNIKA Z TWORZYWA SZTUCZNEGO
Classification
- CPC, 17
- B65D1/165
- B29C43/16
- B29C51/002
- B29C51/02
- B29C51/082
- B29C70/603
- B29K2023/06
- B29K2023/12
- B29K2025/00
- B29K2105/16
- B29K2105/253
- Y02A40/90
- Y10T428/24942
- Y10T428/31732
- Y10T428/31743
- Y10T428/3192
- Y10T428/31928
- IPC, 16
- B65D1 10
- B29C33 00
- B29C43 00
- B29C43 16
- B29C43 18
- B29C43 20
- B29C43 32
- B29C51 00
- B29C51 02
- B29C51 08
- B29C70 60
- B65D1 16
- B65D1 48
- B65D8 04
- B65D8 20
- B65D77 20
