Shrinkable film wrapped pack as well as the method for its manufacture
12 claims: 3 independent, 9 dependent
- 1Pakiet owinięty i obkurczony zawierający, co najmniej jeden wyrób, który jest owinięty i obkurczony folią poliestrową z jednostką tereftalanu etylenu z utworzeniem segmentu zamykającego składającego się z sekcji dolnej nieszczelnej i sekcji górnej szczelnej, znamienny tym, że grubość sekcji dolnej nieszczelnej jest mniejsza od 10 pm, przy czym grubość sekcji dolnej nieszczelnej jest wyznaczona, jako odległość pomiędzy punktem początkowym pierwszym A stanowiącym punkt sekcji dolnej nieszczelnej najbardziej odległy od sekcji górnej szczelnej, a punktem początkowym drugim B usytuowanym pomiędzy sekcją dolną nieszczelną, a sekcją górną szczelną rozciągniętymi poprzecznie z prędkością 50 mm/min do osiągnięcia granicy plastyczności.
- 2Pakiet według zastrz. 1, znamienny tym, że grubość sekcji dolnej nieszczelnej jest równa zero.
- 3Pakiet według zastrz. 1 albo 2, znamienny tym, że co najmniej jedna powierzchnia folii poliestrowej ma statyczny współczynnik tarcia od 0,1 do 0,6, a dynamiczny współczynnik tarcia od 0,1 do 0,5.
- 4Pakiet według zastrz. 1 albo 2, znamienny tym, że folia poliestrowa zawiera od 3000 ppm do 200 ppm drobnych cząstek wybranych z grupy zawierającej cząstki nieorganiczne i organiczne o średniej średnicy cząstki od 6 pm do 0,5 pm.
- 5Pakiet według zastrz. 1 albo 2, znamienny tym, że zawiera stos co najmniej dwóch wyrobów.
- 6Pakiet według zastrz. 1 albo 2, znamienny tym, że wyrobem jest sucha bateria.
- 7Pakiet według zastrz. 1 albo 2, znamienny tym, że folia poliestrowa jest perforowana.
- 8Sposób wytwarzania pakietu owiniętego i obkurczonego, w którym folię poliestrową z jednostką tereftalanu etylenu uszczelnia się i przecina się z utworzeniem segmentu zamykającego składającego się z sekcji dolnej nieszczelnej i sekcji górnej szczelnej, i owija się co najmniej jeden wyrób tą folią poliestrową z jednostką tereftalanu etylenu, po czym obkurcza się tę folię poliestrową na wyrobie, znamienny tym, że równocześnie z uszczelnianiem i przecinaniem folii poliestrowej z jednostką tereftalanu etylenu otwiera się sekcję dolną nieszczelną utworzonego na tej folii segmentu zamykającego z uzyskaniem grubości sekcji dolnej nieszczelnej mniejszej od 10 pm, przy czym grubość sekcji dolnej nieszczelnej jest wyznaczona jako odległość pomiędzy punktem początkowym pierwszym A, stanowiącym punkt sekcji dolnej nieszczelnej najbardziej odległy od sekcji górnej szczelnej, a punktem początkowym drugim B, usytuowanym pomiędzy sekcją dolną nieszczelną, a sekcją górną szczelną rozciągniętymi poprzecznie z prędkością 50 mm/min do osiągnięcia granicy plastyczności. PL 196 264B1
- 9Sposób według zastrz. 8, znamienny tym, że otwiera się sekcję dolną nieszczelną segmentu zamykającego poprzez fizyczne rozciąganie segmentu zamykającego w kierunku prostopadłym do linii uszczelniania i przecinania.
- 10Sposób według zastrz. 8, znamienny tym, że otwiera się sekcję dolną nieszczelną segmentu zamykającego poprzez ogrzewanie w wysokiej temperaturze segmentu zamykającego.
- 11Sposób według zastrz. 8 albo 9, albo 10, znamienny tym, że otwiera się sekcję dolną nieszczelną utworzonego na tej folii segmentu zamykającego z uzyskaniem grubości sekcji dolnej nieszczelnej równej zeru.
- 12Sposób wytwarzania pakietu owiniętego i obkurczonego, w którym folię poliestrową z jednostką tereftalanu etylenu uszczelnia się i przecina się z utworzeniem segmentu zamykającego składającego się z sekcji dolnej nieszczelnej i sekcji górnej szczelnej, i owija się co najmniej jeden wyrób tą folią poliestrową z jednostką tereftalanu etylenu, po czym obkurcza się tę folię poliestrową na wyrobie, znamienny tym, że równocześnie z uszczelnianiem i przecinaniem folii poliestrowej z jednostką tereftalanu etylenu prasuje się utworzony na tej folii segment zamykający, uzyskując grubość sekcji dolnej nieszczelnej równą zeru, przy czym grubość sekcji dolnej nieszczelnej jest wyznaczona, jako odległość pomiędzy punktem początkowym pierwszym A, stanowiącym punkt sekcji dolnej nieszczelnej najbardziej odległy od sekcji górnej szczelnej, a punktem początkowym drugim B usytuowanym pomiędzy sekcją dolną nieszczelną, a sekcją górną szczelną rozciągniętymi poprzecznie z prędkością 50 mm/min do osiągnięcia granicy plastyczności.
Independent claims12
100 paragraphs in 2 sections, as filed
Description of the invention
The present invention relates to a wrapped and shrunk packet, a method for producing a wrapped and shrunk packet.
Wrapped and shrunk packages which contain at least one product are known. The product is wrapped and shrunk with a polyester film with an ethylene terephthalate unit to form a closure segment consisting of a leaky bottom section and a sealed top section.
There is also known a method for producing a wrapped and shrunk packet, in which a polyester film with an ethylene terephthalate unit is sealed and cut to form a closure segment consisting of a leaky bottom section and a sealed top section, and in which at least one product is wrapped with this foil. with a unit of ethylene terephthalate, and then the polyester film is shrunk onto the article.
Films for wrapping and shrinking, especially for wrapping and shrinking a stack of products, are required to be free of folds or defects after shrinking, capable of sealing the products tightly and perfectly tear-resistant in the part formed by sealing and cutting constituting the closing segment package. Typically, shrink films made of polyvinyl chloride or polyolefin are used.
Although the shrink films made of polyvinyl chloride have excellent shrink properties and good impact resistance in the part formed by sealing and cutting, i.e. the closing segment of the bundle, these films have hygienic problems due to the such as plasticizers, stabilizers and processing aids, and problems with the effects of heat, because they contain chlorine. In addition, the heat-shrinkable polyolefin films exhibit excellent impact resistance in the sealing and cut portion and do not cause problems with exposure to heat, although they require high-temperature shrinkage to achieve a good end result. Moreover, in the case of polyolefin films, there is a possibility of the film loosening after shrinkage, which makes it difficult to seal the products tightly. These foils are also flaccid and insufficiently transparent.
Shrinkable polyester films are characterized by stiffness, good transparency, excellent shrink properties, the ability to tightly connect products and are insensitive to heat. The only drawback of polyester films is their poor impact resistance in the bundle closing segment, that is, in the portion formed by sealing and cutting.
Japanese Patent Publication No. 29139/1989 discloses a method of improving the impact resistance of a sealed portion. The method uses a polyester heat-shrinkable film as a packaging material, the percentage of which is at least 10% heat shrinkage in both the machine running and transverse directions as measured after immersion in hot water at 100 ° C. A polyester heat-shrinkable film is obtained by orienting a polyester sheet at least 2.5 times in both machine and transverse directions and thermally stress relieving the oriented sheet from 5% to 30% in at least one direction.
The sealed film portions are impact resistant to packaged products of at least 10 kg / cm and then thermally shrink.
However, in this method the sealing method is limited to impulse sealing. Moreover, although the publication states that the film can be welded when a thermal resin bond is applied to the film, the disclosed film, after being sealed and cut, has a low impact resistance in the closing segment of the bundle, i.e. the portion formed by sealing and cutting. and therefore cannot find practical application.
When the stack of articles is packed by wrapping and shrinking, sealing and cutting using ultrasonic waves, high-frequency current or chrome-nickel wire are commonly used. This is because the simultaneous sealing and cutting enables continuous sealing, which increases the speed of the process and results in a closure segment sealed without an overlap so that the resulting packages have the correct appearance and there is no likelihood of the stack of packages collapsing even when wrapped in packages, the products are light.
In contrast, impulse sealing or sealing is performed discontinuously and thus the packaging process is slow. In addition, segments are usually produced
The closure caps are overlapped with a width of 5mm to 20mm so that the resulting bundles have an unsightly appearance and the stack of bundles is prone to tilt and collapse when bundled wrapped products are light.
The object of the present inventions of a wrapped and shrunk bundle and methods of manufacturing the same is to provide a bundle structure and method of manufacturing the same to obtain a wrapped and shrunk bundle with a bundle closing segment with excellent impact resistance.
The wrapped and shrunk package according to the present invention comprises at least one product which is wrapped and shrunk with a polyester film with an ethylene terephthalate unit to form a closure segment consisting of a leaky bottom section and a sealed top section, and is characterized in that the thickness of the section is the lower leakage is less than 10 μm, the thickness of the bottom leaky section is defined as the distance between the first point A, which is the point of the bottom leakage section farthest from the top section, and the second point B situated between the bottom section, and the top section, transversely stretched at a speed of 50 mm / min. until the yield point is reached.
Preferably, the thickness of the leaky bottom section is zero.
Preferably, at least one surface of the polyester film has a static coefficient of friction from 0.1 to 0.6 and a dynamic coefficient of friction from 0.1 to 0.5.
Preferably, the polyester film comprises from 3000 ppm to 200 ppm fine particles selected from the group consisting of inorganic and organic particles with an average particle diameter from 6 µm to 0.5 µm.
Preferably, the package comprises a stack of at least two articles.
Preferably, the article is a dry battery.
Preferably, the polyester film is perforated.
The method of producing a wrapped and shrunk packet, according to an embodiment of the first invention, consists in sealing and intersecting a polyester film with an ethylene terephthalate unit to form a closure segment consisting of a leaky lower section and a sealed upper section, and wrapping at least one the product is made of this polyester film with an ethylene terephthalate unit, and then the polyester film is shrunk on the product, and is characterized by that simultaneously with the sealing and cutting of the polyester film with the ethylene terephthalate unit, the bottom leakage section of the closing segment formed on this film is opened to obtain a bottom leakage thickness of less than 10 μm, the thickness of the leaky bottom section being defined as the distance between the starting point A being the point of the leaky lower section most distant from the upper tight section, and the second starting point B situated between the leaky lower section and the upper sealed section transversely stretched at a speed of 50 mm / min until reaching the yield point.
Preferably, the bottom section of the leaky closure section is opened by physically stretching the closure section in a direction perpendicular to the sealing and cutting line.
Preferably, the leaky bottom section of the closure section is opened by heating the closure section to a high temperature.
Preferably, the bottom leakage section of the closing segment formed on this film is opened to obtain a bottom leakage thickness of zero.
The method of producing a wrapped and shrunk packet, according to a variant of the second invention, consists in sealing and intersecting a polyester film with an ethylene terephthalate unit to form a closing segment consisting of a leaky lower section and a sealed upper section, and at least one product is wrapped around it. this polyester film with an ethylene terephthalate unit, after which the polyester film is shrunk onto the product, and is characterized by that simultaneously with the sealing and cutting of the polyester film with the ethylene terephthalate unit, the closing segment formed on the film is pressed, obtaining a thickness of the lower leakage section equal to zero, the thickness of the lower leakage section being defined as the distance between the first starting point A being the point of the lower leakiest section of the most distant from the sealed top section and the second starting point B situated between the leaky bottom section, and the upper, sealed section transversely stretched at a speed of 50 mm / min until reaching the yield point.
An advantage of the present inventions of a wrapped and shrunk bundle and methods of making the same is that the closing segment of the bundle has excellent impact strength.
The subject of the invention in an exemplary embodiment is shown in the drawing, in which Fig. 1 (a) shows a cross-section of the closing segment of the packet, with the lower section leaky in the area of the part.
PL 196 264B1 formed by sealing and cutting, Fig. 1 (b) shows a cross-section of the foil broken by impact on the closing segment of the bundle, Fig. 1 (c) shows a cross-section of the closing segment of the bundle with the bottom leaky section fully open, Fig. 2 shows cross-section of a differently shaped closing segment, fig. 3 is a perspective view of a wrapped and shrunk packet of dry batteries with a closure segment at the ends of their positive poles, and Fig. 4 is a perspective view of a wrapped and shrunk packet of four AA alkaline batteries with the closure segment at their negative ends.
The present invention will be described in detail below. The polyester film used in the present invention having an ethylene terephthalate unit is a film obtained from a polyester resin having an ethylene terephthalate unit which is formed from terephthalic acid or a derivative thereof as the acid component and ethylene glycol as the glycol component. Examples of terephthalic acid derivatives are dimethyl terephthalate, diethyl terephthalate and other terephthalates.
In accordance with the present invention, polyester resins obtained by copolymerizing terephthalic acid or a derivative thereof and ethylene glycol together with at least one acid component selected from dicarboxylic acids other than terephthalic acid and its derivatives such as phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid and the like aromatic dicarboxylic acids, oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid and the like aliphatic dicarboxylic acids and their derivatives and with at least one diol component selected from diols other than ethylene glycol, such as propylene glycol, butanediol, neopentyl glycol, hexamethylene glycol and the like aliphatic glycols, 1,4-cyclohexanedimethanol and the like alicyclic diols, xylylene glycol, hydroquinone and the like aromatic diols and diethylene glycol and their substitution products. Single polyester resins or combinations thereof can be used.
In the polyester resin as the resin component of the polyester film to be used according to the invention, the content of terephthalic acid or a derivative thereof as the acid component is at least 60 mole%, preferably at least 70 mole%, more preferably at least 80 mole%.
The content of ethylene glycol as a diol component in this polyester resin is at least 50 mole%, preferably at least 60 mole%, more preferably at least 65 mole%.
Preferred polyester resins are those containing terephthalic acid as the dicarboxylic acid component and ethylene glycol as the diol component and cyclohexanedimethanol and / or neopentyl glycol and / or diethylene glycol and polyethylene terephthalate and / or polybutylene terephthalate. .
The intrinsic viscosity of the polyester resin is at least 0.5 g / dL, preferably at least 0.6 g / dL, and more preferably at least 0.7 g / dL. The upper limit of the It.V. is up to 1.5 g / dL, preferably up to 1.4 g / dL, and more preferably up to 1.3 g / dL. When the intrinsic viscosity of the polyester resin is from 0.5 g / dL to
1.5 g / dl, the obtained film has the appropriate strength and the desired impact resistance in the closing segment, i.e. the part formed by sealing and cutting the polyester film.
It is advantageous to add inorganic and / or organic fine particles to the polyester resin in order to improve the lubricity of the film and thus allow the film to be processed automatically at high speeds. There are no restrictions on the fine particles that can be used, and for example, known fines of silica, calcium carbonate, poly (methyl acrylate) (PMA), and poly (methyl methacrylate) (PMMA) can be used.
The average diameter of the fine particles is 6 to 0.5 µm, preferably 5 to 0.5 µm, more preferably 4 to 1 µm. The fine particles with an average diameter ranging from 0.5 µm to 6 µm after their addition make it possible to obtain excellent impact resistance of the closing segment, i.e. the part formed by sealing and cutting the polyester film, and give the polyester film an adequate lubricity.
The fine particles are added to the polyester resin in a proportion from about 3000 ppm to 200 ppm, preferably from about 1500 ppm to 300 ppm, more preferably from about 1000 ppm to 400 ppm. The fine particles in a proportion ranging from 3000 ppm to 20 ppm, when added, provide excellent impact resistance of the closing segment and give the polyester film adequate lubricity.
The static coefficient of friction ^ s) of the polyester film obtained with such fine particles is from about 0.1 to 0.6, and the dynamic coefficient of friction ^ d) of this film is from about 0.1 to 0.5
Such a polyester film is suitable for use in an automatic process in which high speeds are applied.
If desired, stabilizers, processing aids, dyes, antioxidants, UV absorbers, antistatic agents, or other resins can be incorporated into the polyester resin, or these formulations can be applied to the film.
The polyester film for use in the present invention can be obtained by methods known in the art for the production of shrink films. Examples of such methods include a method such as extrusion from a barrel die to form a foil sleeve, while biaxially orienting the foil sleeve from about 1.2 to 8 times machine direction and from about 1.2 to 8 times machine direction. transverse and, if necessary, annealing the stretched film, and such a method which includes extruding the resin from a T-shaped die to form a flat film, with or without biaxially orienting the film sleeve from about 1.2 to 8 times in the machine direction and from about 1.2 to 8 times in the transverse direction and, if necessary, relaxing the stretched polyester film.
The thickness of the polyester film is not limited, but is usually from about 5 µm to 100 µm, preferably from about 10 µm to 30 µm.
The shrinkage of the polyester film, expressed as a percentage, depends on the amount of shrinkage required, i.e. the margin, and is usually at least 5% in each direction, i.e. the machine direction and the transverse direction, as measured after immersion in hot water for 30 seconds. at 70 ° C, and at least 10% in either direction, i.e. the machine running direction and the transverse direction, as measured after immersion for 30 seconds in hot water at 80 ° C.
Now, the offset distance of the starting point of the closure segment, i.e. the portion formed by sealing and cutting, will be described. The starting point of the closing segment in Fig. 1 (a) is indicated by the letter A. The shift distance is measured as follows: a 2mm wide strip perpendicular to the sealing and cutting line is cut from the wrapped and shrunk bundle, and a cross-sectional photomicrograph of the closing segment is taken at 500 times magnification, see Fig. 1. Then, the strip is placed in the tipper, Strograph, with a handle distance of 5 cm, so that the closing segment is centered between the handles of the ripper. The strip is stretched at a speed of 50 mm / min and the stretching stops when the yield point is exceeded. Thereafter, the strip is removed from the stripper. A cross-sectional micrograph of the closure segment, i.e. the portion formed by sealing and cutting, is made in the same manner as above, see Fig. 2. Next, the displacement distance of the starting point of the closure segment according to Fig. 1 and 2, by measuring the distance between the starting point of the closure section and a spot serving as a mark, such as a small ball formed by a sealing, protrusion, depression, fine particle, or foreign matter in the closure section shown in each of Figs. 1 and 2. closure, i.e. the portion formed by sealing and cutting, is as shown in Fig. 2, the starting point travel distance E or F can be measured by the method described above.
When the polyester film is sealed and cut, a closure segment is formed with a leaky bottom section extending from point A to B as shown in Fig. 1 (a). Sealing strength is expressed as tensile strength measured at constant shear rate or constant tensile speed, for example, as per ASTM D 822-64T, JISK 6732 or JIS K 6734. As the transverse deformation or tensile rate is usually low, ranging from 50 mm / min to 500 mm / min, the bottom section of the leak opens during the measurement and finally reaches the state shown in Fig. 1 (c) increasing the tensile strength.
However, when the closing segment is subjected to an instantaneous impact, the lower leakage section of the closing segment does not fully open so that the total impact energy is concentrated on the upper sealed section of the closing segment. Moreover, polyester films have a low tear strength. For this reason, the polyester film breaks as shown in Fig. 1 (b) by the dashed line C or D as a result of low impact strength.
The polyester film used in the present invention, even when subjected to an instantaneous impact, is free from cracks as shown in Fig. 1 (a) and attains the state shown in Fig. 1 (c) for absorbing the impact energy. Since the starting point of the closing segment, i.e. the part formed by sealing and cutting, is characterized by an offset distance of
PL 196 264B1 of about 10 µm or less, according to the present invention, the closure segment, i.e. the portion formed by sealing and cutting, easily attains the state shown in Fig. 1 (c). The starting point shift distance is typically 10 µm or less, preferably 9 µm or less, and more preferably 8 µm or less.
If the displacement distance exceeds 10 µ ^ ι, the portion formed by the sealing and cutting will break completely, as shown in Fig. 1 (b), making it impossible to obtain a wrapped and shrunk packet with a closure segment with excellent impact resistance.
In some cases, the displacement distance of the starting point of the closure segment, i.e. the portion formed by sealing and cutting, falls within the above-defined range, as a natural result of the shrink force of the polyester film that arose during wrapping and shrinking, depending on the relationship between the shape and shape. the wrapped product and the position of the closing segment. For example, the starting point offset distance will be within a certain range when articles having a depression, such as videotapes or hardcover books, are wrapped and shrunk by sealing and cutting at the depression, or the closure segment is at the positive end of a dry battery such as shown in Fig. 3.
Except for such special cases, the shift distance is adjusted to the above-defined range, using suitable methods, without limitation. Preferably, after sealing and cutting, the closure section is physically stretched in a direction perpendicular to the seal and cut line, with a stress suitable for opening the leaky bottom section, usually not less than 500 g / mm.<sup>2</sup> but lower than the seal strength, followed by wrapping and shrinking with a polyester film. Conversely, after sealing and cutting and wrapping and shrinking with a polyester film, the area adjacent to the sealing and cutting segment is heated at high temperature in order to stretch the closing segment by the shrink force of the polyester film produced by heating. Conversely, when sealing and cutting the polyester film, pressure is exerted on the part to be sealed in order to completely seal the part, i.e. no closing segment is formed with the bottom section leaky.
There is no restriction on the products wrapped by wrapping with polyester film in accordance with the present invention, but it is preferable to have a stack of two or more items of heavy weight as the wrapped and shrunk bundle of the present invention has excellent impact resistance in the region of the closing segment. it is a part formed by sealing and cutting, and is capable of joining products tightly together. A preferred embodiment of the present invention is a wrapped and shrunk packet containing dry batteries.
More preferably, the wrapped and shrunken package of the present invention is wrapped with a perforated polyester film to facilitate its opening. The foil can be perforated using a perforator blade, usually during sealing and cutting. In the perforation, the length of the cuts and the length of the intervals between the cuts, hereinafter referred to as "bridges", are not limited, but the ratio of the cut length to the length of the bridge after shrinkage is preferably 1.5 or less, more preferably 0.7 or less. When the ratio is 1.5 or less, the film does not break along the perforation line, even if the wrapped and shrunken package is accidentally dropped.
The present invention will be described in detail below with reference to Examples.
In the examples, the following methods were used to measure and evaluate the properties.
The intrinsic viscosity is measured by dissolving the resin pellets in a 1: 1 weight ratio by weight of the 1: 1 solvent mixture of phenol and 1,1,2,2-tetrachloroethane at a concentration of 0.5 g / 100 ml, measuring the viscosity using automatic capillary viscometer type SS-600-L1, manufactured by Shibayama Scientific Instruments Works, Ltd.
The percentage of film shrinkage was measured as follows: A sample of the film, 100 mm in the machine running direction and 100 mm in the transverse direction, was cut from the film and immersed in hot water at 70 ° C in a water thermostat for 30 seconds. Then the length in the machine running direction L (mm) and the length in the transverse direction L '(mm) were measured to determine the shrinkage percentage (100-L) in the machine running direction (MD) and the shrinkage percentage (100-L') in the transverse direction ( TD).
The impact resistance, impact resistance, of the closing segment, i.e. the portion formed by the sealing and cutting, was measured as follows: A full 3 cm diameter circular hole was made in the center of the PET sheet, approximately 200 µm thick. The polyester film sample was attached to a PET sheet using cellophane adhesive tape so that the closing segment
The foil sample was placed in the center of the opening with the foil sample not being impacted against a surface corresponding to the inner surface of the wrapped and shrunk packet. A polyester film specimen was struck with a 1 inch diameter 2.54 cm impact head to measure the impact toughness of the seal and cut portions using a pendulum impact hammer, Toyo Seiki Co., Ltd.
The sealing strength is measured using a 10 mm wide sample using a HEIDON-17 type foil tear test device, manufactured by Shinto Kagaku KK, at a tensile speed of 200 mm / min.
The displacement distance of the starting point of the closing segment was measured as follows: A 2 mm wide strip perpendicular to the seal and cutting line was cut from the wrapped and shrunk bundle, and a cross-sectional photomicrograph of the closing segment was taken at 500 times magnification, see Fig. 1. Then, the strip was placed in the stripper, Strograph, with a grip distance of 5 cm so that the closing segment is centrally located between the handles of the ripper. The strip was stretched at a speed of 50 mm / min and the stretching was stopped when the yield point was exceeded. Then, the strip was removed from the tipper, and a cross-sectional photomicrograph of the closure segment was taken in the same manner as above, see Fig. 2. Next, the closure segment start point offset distance was determined from Fig. 1 and 2 by measuring the distance between the starting point of the closure section and a spot serving as a mark, such as a small ball formed by a sealing, protrusion or depression, fine particle, or foreign matter in the closure section shown in each of Figs. 1 and 2. closure is as shown in Fig. 2, the travel distance of the starting point E or F can be measured by the method described above.
The drop test was performed as follows: A bundle of wrapped and shrunken stacks of four AA alkaline batteries was gripped by a corner and allowed to fall under its own weight from a height of 60 cm above the floor so that the opposite corner of the bundle hit the floor. The wrapped and shrunk packages were drop tested and evaluated as follows: A - no one package break; B - from 1 to 9 packets broke; C - all packages are broken.
Example 1
A polyester resin was obtained by mixing 15 parts by weight of polybutylene terephthalate, glass transition temperature - 49 ° C; intrinsic viscosity -0.91 dL / g, and 85 parts by weight of an amorphous polyester resin, glass transition temperature-81 ° C; an intrinsic viscosity -0.76 dl / g, containing terephthalic acid as the acid dicarboxylic component and ethylene glycol, 70 mole%, and cyclohexanedimethanol, 30 mole% as the glycol components. The polyester resin was melted and extruded at 280 ° C using a T-shaped die. The extruded film was oriented at 80 ° C on drawing rolls with an elongation of 1.3 times in the machine direction. The film was pre-heated for 5 seconds at 90 ° C, oriented at temperature
85 ° C in the transverse direction using a tenter, with an elongation of 4.0 times and annealed with 4% relaxation, to obtain a film with a thickness of 20 µm. The shrinkage percentage of the thus obtained film is given in Table 1.
Comparative example 1
Four AA alkaline batteries were wrapped in a film obtained by the method of example 1 so as to leave a 5% margin in the major shrinkage direction (TD) and a 4% margin in the direction perpendicular to the major shrinkage direction (MD). Subsequently, the foil was subjected to a sealing and ultrasonic wave cutting operation in the middle part facing the negative pole in order to obtain a pre-shrink package.
The pre-shrunk bundle was passed through a dry-type heat-shrink tunnel
S-200, manufactured by Kyowa Denki KK, to form a wrapped and shrunk bundle, see Fig. 4. The properties of the resulting bundle and the results of its evaluation are shown in Table 1.
Example 2
The wrapped and shrunk bundle was obtained in the same manner as Comparative Example 1. The enclosure of the closing segment of the wrapped and shrunk bundle obtained was heated for 2 seconds with a hot air dryer, exhaust air velocity -4 m / second; the temperature of the exhaust air -300 ° C, in order to obtain the shrink wrapped pack of the present invention. The properties of the obtained package and the results of its evaluation are presented in Table 1.
The sealing strength of the package of Example 2 is similar to that of Comparative Example 1, but significantly different from it in the impact resistance and drop test results.
PL 196 264B1
This is due to the fact that in Comparative Example 1 the offset distance of the starting point of the closing segment, i.e. the portion formed by sealing and cutting, is outside the range specified in the present invention, while in Example 2 the offset distance is within this range.
Example 3
The pre-shrunk package was obtained in the same way as in Comparative Example 1.
The package closing segment was physically shrunk in the direction perpendicular to the sealing line <sub>2</sub> and slitting, at a tension of 600 g / mm<sup>2</sup>. Then, the bundle was shrunk in the same way as in Comparative Example 1. The properties of the resulting bundle and the results of its evaluation are shown in Table 1.
Comparative example 2
The wrapped and shrunk bundle was obtained in the same manner as in Example 3, except that the closure segment was stretched at a tension of 200 g / mm.<sup>2</sup>.
Example 4
A polyester resin was obtained by mixing 15 parts by weight of polybutylene terephthalate, glass transition temperature - 49 ° C; intrinsic viscosity - 0.91 dl / g, and 85 parts by weight of an amorphous polyester resin, glass transition temperature -63 ° C; intrinsic viscosity - 0.78 dl / g, containing terephthalic acid as the acid dicarboxylic component and ethylene glycol, 80 mole%, neopentyl glycol, 15 mole%, and diethylene glycol, 5 mole%, as glycol components. 800 ppm of PMMA fine particles were added to the obtained polyester resin, the average particle diameter was 2 μm. Using the resulting mixture as a film material in the manner described in Examples 1 and 2, a wrapped and shrunk package was obtained, except that the sealing and cutting was performed using a chromium-nickel wire. The percentage of thermal shrinkage of the film, prior to the preparation of the pre-shrunk package, was 10% in the MD direction and 24% in the TD direction, the static coefficient of friction (s) was 0.3 and the dynamic coefficient of friction (d) was 0.4. The properties of the obtained package and the results of its evaluation are presented in Table 1.
Comparative example 3
A polyester resin was obtained by mixing 15 parts by weight of polybutylene terephthalate, glass transition temperature - 49 ° C; intrinsic viscosity 0.91 dl / g, and 85 parts by weight of an amorphous polyester resin, glass transition temperature -63 ° C; an intrinsic viscosity -0.78 dL / g, containing terephthalic acid as the acid dicarboxylic component and ethylene glycol, 80 mole%, neopentyl glycol, 15 mole%, and diethylene glycol, 5 mole%, as the glycol components. To the obtained polyester resin was added 800 ppm of PMMA fine particles, the average particle diameter - 2 μm. Using the resulting mixture as a film material, a wrapped and shrunk package was obtained according to the method described in Example 1 and Comparative Example 1, except that the sealing and cutting was performed using a chromium-nickel wire. The properties of the obtained package and the results of its evaluation are presented in Table 1.
Table 1
<td rowspan="2"></td><td rowspan="2">Strength seals (kg / cm)</td><td rowspan="2">Impact resistance of the closing segment (kg / cm)</td><td colspan="2">Shrink film percentage (%)</td><td rowspan="2">Distance Closing segment starting point shifts (pm)</td><td rowspan="2">Score trials fall- in</td>
<td>MD</td><td>TD</td>
<td>Comparative example 1</td><td> 1,20</td><td> 2,8</td><td rowspan="4"> 10</td><td rowspan="4"> 25</td><td> 18,6</td><td>C.</td>
<td>Example 2</td><td> 1,31</td><td> 17,2</td><td> 5,9</td><td>AND</td>
<td>Example 3</td><td> 1,38</td><td> 19,6</td><td> 3,4</td><td>AND</td>
<td>Example comparative 2</td><td> 1,24</td><td> 5,2</td><td> 13,9</td><td>C.</td>
<td>Example 4</td><td> 1,17</td><td> 13,8</td><td rowspan="2"> 10</td><td rowspan="2"> 24</td><td> 7,7</td><td>AND</td>
<td>Example comparative 3</td><td> 1,10</td><td> 2,9</td><td> 15,2</td><td>C.</td>
PL 196 264 B1
Example 5
The wrapped and shrunk bundle was obtained by the method of Example 4, except that the polyester film was perforated along the machine running direction during sealing and cutting. The ratio of cut length to sternum length was 0.6.
In the drop test, the above package was scored as "A". Moreover, the bundle is easily torn by hand along the perforation line.
The film used in the present invention is a polyester film containing an ethylene terephthalate unit and therefore has stiffness, good transparency and excellent shrink properties and is not heat sensitive.
In addition, when a predetermined amount of fine particles with a defined average particle diameter is added to the polyester resin containing the ethylene terephthalate unit, the resulting film has improved lubricity without reducing its impact resistance in the closing segment and thus has a high applicability in an automatic production process with high efficiency.
Moreover, the wrapped and shrunk bundle according to the invention has the ability to tightly connect products and has excellent impact resistance in the closing segment. Therefore, the package according to the invention may be particularly advantageous for wrapping and shrinking a stack of articles such as dry batteries.
It is very advantageous that the polyester film is perforated which makes it easier to open the package.
Contents2
2 sheets
Sheet 1 Sheet 2
17 members in 11 offices
Priority claims5
| Document | Office | Kind | Date |
|---|---|---|---|
| 15655798 | Japan | A | |
| 9902214 | Japan | W | |
| 1565571998 | – | – | – |
| JP19980156557 | – | – | – |
| WO1999JP02214 | – | – | – |
Members17
| Document | Office | Kind | |
|---|---|---|---|
| WO9955595A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU3536899A | Australia | A | |
| ID23420A | Indonesia | A | |
| PL337666A1 | Poland | A1 | |
| EP1033319A1 | European Patent Office (EPO) | A1 | |
| CN1266408A | China | A | |
| BR9906403A | Brazil | A | |
| HK1027789A1 | Hong Kong, China | A1 | |
| KR20010014249A | Republic of Korea | A | |
| EP1033319A4 | European Patent Office (EPO) | A4 | |
| KR100328582B1 | Republic of Korea | B1 | |
| US2002179479A1 | United States of America | A1 | |
| CN1096393C | China | C | |
| US6513656B2 | United States of America | B2 | |
| JP3577553B2 | Japan | B2 | |
| PL196264B1This record | Poland | B1 | |
| BR9906403B1 | Brazil | B1 |
Numbers
- Publication
- 196264
- Publication, DOCDB
- 196264
- Publication, EPODOC
- PL196264B
- Application
- 337666
- Application, DOCDB
- 33766699
- Application, EPODOC
- PL19990337666
Titles2
- English
- Shrinkable film wrapped pack as well as the method for its manufacture
- Polish
- Pakiet owinięty i obkurczony i sposób wytwarzania pakietu owiniętego i obkurczonego
Classification
- CPC, 2
- B65D71/08
- Y10T156/1054
- IPC, 3
- B65D71 08
- B29C63 40
- B65D71 00
