LID FOR FOOD CONTAINER

Abstract: A lid member (1) having substantially the same external form as the opening in the container body of a food container and adapted to be stuck thereto, the lid member (1) comprising a first tab (2) for stripping the lid member (1) from the container body, a second tab (3) for stripping the surface sheet of the lid member to open a hot-water discharge port, a first slit (4) for forming the hot-water discharge port, a second slit (5) for defining an easy-to-strip region (A) and a non-strip region (B), and a third slit (6) extending from the attachment end (d) of the second tab (3) spaced from the second slit (5) to the crossing position (e) at which it crosses the second slit (5).

Description: The present invention relates to a lid member for a food container, and is particular to an improved lid member to be used for containers for quick cook foods. Conventionally, quick cook foods like chow mein, spaghetti, polished rice and sekihan (steamed rice with red beans) or the like have been distributed in a manner allowing them to be cooked by pouring hot water into a container, leaving it for predetermined time and thereafter removing the hot water. Containers for quick cook foods to be cooked by with hot water, typically have structure comprising a cup-shaped container body and plastic lid member mounted thereon. Container bodies for such container are usually produced by thermoforming expanded resin particles (expandable resin beads) made of polystyrene resins and blowing agent like butane, pentane or the like. Typical plastic lid members are in sheet-form and have discharge apertures at their outer circumference. The plastic lid member is simply to cover the container body. Generally, the lid member is engaged with the container body by projections engaging with grooves provided on the flange at the outer circumference of the lid member. With reference to Figure 7 of the accompanying drawings a conventional plastic lid member (100) has a pair of apertures in mutually opposite positions at its circumference edge. These apertures are to discharge the poured hot water from the container body and comprise split blade portions (a). When these split blade portions (a) are raised, apertures to discharge the hot water from the container are formed. However, the number of such apertures which can be formed at a restricted area in the flange is limited, therefore, discharging rate of the hot water is accordingly limited and it usually takes a long time to remove hot water. Furthermore, when apertures are blocked by the food in the container, it takes additional time to remove the hot water. Further, when a blade (a) is broken, the fragment may enter into the container. Further, sealability of the container is not good, thereby, allowing moisture to penetrate into the container through space formed by an upstanding blade portion (a) and the space formed between the lid and the container. In addition, since most conventional lid members (100) are sheet-form products having a circumferential flange, when the container body is covered by the lid member, the configuration of the container and lid is undesirable due to the bulk, and further space is necessary in transportation or storage thereof. Furthermore, consumers have recently expressed increased concern on environmental issues, and it is undesirable to dump these plastic lid members. In addition, when such containers are mishandled when discarding of the hot water, the lid member may become detached from the container body, and food together with hot water may be spilt. Accordingly, there is a potential danger of suffering from burns, and it is essential to securely hold both of the container and the lid member during the discharging step. Japanese Utility Model Publication No.JP60009171 discloses a container for quick cook foods utilizing a lid member according to the preamble of claim 1 of the present invention. This utilizes paper as base layer and is to stick to the opening of the container. With reference to Figure 8 of the accompanying drawings, lid member (200) has substantially the same circumferential shape as the opening in the container body. The discharge apertures (204) on the surface of the lid are exposed by pulling up the tab (203) integrally formed on the lid member (200). The lid member (200) is formed by laminating polyethylene, aluminum foil or the like onto the base paper. The lid member (200) is adhered to the container body and the discharge apertures (204) are formed by pulling up the tab (203) integrally formed on the lid member (200), whereby, the easily-peelable area (D) is separated from the slit linking both foot-ends (b, b) across the base of the tab (203). The lid member (200) according to the prior art is better than the conventional lid member 100 (Figure 7), since it reduces the bulk of the container and is easily manufactured and discarded. However, the tab (203) may be broken at the slit linking both ends b, b when the tab (203) is pulled. The tab (203), is positioned opposite to the tab (202), at about the centre of the circumference edge of the easily-peelable area (D). In use, it is necessary to pull up the tab (203) to open the apertures, such that the pulling force is applied radially and uniformly directly towards the tab (203. Considerable force and technique are required to separate the easily-peelable area (D), otherwise, the tab (203) itself may be broken during the peeling step. In view of disadvantages of the prior art an object of the present invention is to provide a lid member for a container of quick cook which has excellent sealability with a container body, which allows hot water to be discharged safely and rapidly, its discharging apertures are easily formed, and it can be readily disposed of as waste. According to the invention there is provided a lid member for a food container having substantially the same circumferential configuration as that of an opening in the container body of the food container, the lid member having a layered structure comprising a base layer (20) and a surface sheet (40) laminated together by an adhesive layer (30), the lid member being divided into a non-peelable area (B) and adjacent thereto an easily-peelable area (A) in which is positioned a non-peelable opening area (C) comprising apertures (C) which are formed upon peeling of the surface sheet (40), a first tab (2) to peel off the lid member from the container body extending from a circumferential portion of the non-peelable area (B), and a second tab (3) extending from a circumferential portion of the easily-peelable area (A) to open the apertures of the opening area, in which the easily-peelable area (A) has a first slit (4) which cut from the base layer (20) to the adhesive layer (30) and defines the circumferential edge of the apertures (C), in the opening area and the easily-peelable area (A) has a lubricant (11) between the surface sheet (40) and the base layer (20) characterised in that: the second tab (3) is positioned along the boundary of the non-peelable area (B) and the easily-peelable area (A), the lid member further comprises a second slit (5) which cuts from the surface sheet (40) to the adhesive layer (30), along the boundary line between the non-peelable area (B) and the easily-peelable area (A), and a third slit (6) which cuts from the base layer (20) to the adhesive layer (30)is positioned in the vicinity of where the second tab (3), extending from the base of the second tab (3) spaced from the second slit (5) to a point of intersection with the second slit (5). The lid member of the present invention has the advantage that any desired number of apertures can be formed, thereby, blockage of all the apertures by the food in the container may be prevented, and the hot water can rapidly be removed. Since the fragments of the lid member removed when the forming of the apertures are adhered and peeled with the back surface of the surface sheet no fragments will enter into the container. The lid member according to the present invention may be formed by layered products consisting mainly of paper. Thus a compact and aesthetic lid member and container can be provided and the bulk of container at transportation or storage are reduced. Further, sealability of the container may be improved by heat-sealing the lid member to the container body, thereby, spilling of contents is effectively prevented when the hot water is discarded from the container. The lid member according to the present invention may be disposed of as combustibles and as garbage. The lid member according to the present invention will eliminate breaks of the tab to open apertures for discharging hot water, which are problems in the conventional paper lid member, and provide a container for quick cook foods in which the surface sheet can be smoothly peeled. Furthermore, the lid member of the present invention allows the surface sheet to be peeled correctly and easily by providing the notch on the circumference edge of the lid member and using it as an origin for peeling the surface sheet. Referring to the drawings: Figure 1 (A) and (B) respectively show a plan view and a back view of the lid member according to an embodiment of the present invention. Figure 2 (A) and (B) respectively show a cross sectional view taken along the lines X-X and Y-Y in Figure 1. Figure 3 is a schematic view showing the areas (A, (B)) and (C)on the surface of the lid member according to one embodiment of the present invention. Figure 4 (A) and (B) respectively show a plan view and a partially enlarged view of the lid member according to a further embodiment of the present invention. Figure 5 shows a back view of the lid member according to a further embodiment of the present invention. Figure 6 is a perspective view showing as to how to use a food container employing the lid member according to an embodiment of the present invention. Figure 7 shows a plan view of the conventional plastic lid member. Figure 8 shows a plan view of the conventional paper lid member. With reference to Figures 1 to 3, a lid member for food container (hereinafter simply referred to as "lid member") according to the present invention which can discharge hot water is a lid member (1) which has substantially the same circumferential configuration with that of an opening (15) and is adhered to the opening (15) of a container body (14). The lid has a layered structure comprising a base layer (20) and a surface sheet (40) which are laminated together via an adhesive layer (30). The lid member (1) has an easily-peelable area (A) of the layered structure having lubricant (11) additionally positioned between the base layer (20)and the surface sheet (40), a non-peelable opening area (C) of the aforenoted layered structure placed within the easily-peelable area (A), a non-peelable area (B) of the aforenoted layered structure placed adjacent to the easily-peelable area (A). The lid member further has a first tab (2) to peel off the lid member (1) from the container body (14), and a second tab (3) formed at the side on the easily-peelable area (A)along the boundary line between the non-peelable area (B) and the easily-peelable area (A) to open the discharge apertures of the opening area (C) by peeling off from the lid member (1) a surface sheet in the easily-peelable area (A). The lid member (1) comprises a series of slits (4 to 6), wherein: a first slit (4) which cuts from the base layer (20) to the adhesive layer (30) and defines discharge apertures in the opening area (C), a second slit (5), which cuts from the surface sheet (40) to the adhesive layer (30), along the boundary line between the easily-peelable area (A) and non-peelable area (B), and a third slit (6), which cuts from the base layer (20) to the adhesive layer (30) and is placed where the second tab (3) is mounted, of from the base (d) of the second tab (3) spaced from the second slit (5) to point of intersection (e) with the second slit (5). According to the lid member of the present invention, the surface sheet in the easily-peelable area (A) can be easily and securely peeled along with the second slit (5) by pulling up the second tab (3), thereby the desired number of discharge aperture(s) can be formed. According to the other embodiment of the present invention, with reference to the Figure 1 (B), a lid member is arranged so that at least a part of the third slit (6) in the lid member (1) is placed over the adhesion region portion (17) substantially corresponding to the circumference edge of the opening (15). In this case, preferably, the point of intersection (e) by the second slit (5) and the third slit (6) is in the adhesion region (17). By arranging the third slit (6) in this manner since the surface sheet (40) can be peeled smoothly from the base layer (20) along the third slit (6) while the second tab (3) can also be peeled completely and the second tab (3) can easily be pulled. According to the another embodiment of the present invention, with reference to the Figure 4(A), a lid member is configured so that the second slit comprises at least one slit zone (50) wherein a pair of discontinuous slits oriented mutually outwardly make a row along the boundary line and between the easily-peelable area (A) and the non-peelable area (B). Thus, when the second slit is the slit zone (50), as the second tab (3) is pulled it tears the slit zone (50) going through the adjacent slits successively, and the surface sheet (40) in the easily-peelable area (A) can easily be separated, and the discharge apertures can also be opened smoothly. According to the another embodiment of the present invention, with reference to the Figure 5, a notch (18) is formed around the second tab (3) from the circumferential edge of the lid member to the second slit (5) (or the slit zone (5)) thereby, by pulling up the second tab (3), after the notch (18), the third slit (6) and the second slit (5) (or the slit zone 50) are broken sequentially and the surface sheet (40) in the easily-peelable area (A) is peeled from the base layer (20). In particular, when the notch (18) is formed from the circumference edge of the lid member to the point of intersection (e) (See Figure 3) of the second slit (5) and the third slit (6), peeling of the easily-peelable area (A) by the second tab (3) is particularly easy. With reference to Figures 1 to 3, a lid member (1) of the present invention has a layered structure in which the baselayer (20) and the surface sheet (40) are laminated by an adhesive layer (30). The lid member (1) is stuck over the opening (15) of the container body of food container and have substantially the same circumferential configuration as the opening (15). The lid member (1) is divided into the easily-peelable area (A) having the layered structure in which the lubricant (11) is present between the base layer (20) and the surface sheet (40) to facilitate to peel the base layer (20) from the surface sheet (40); a non-peelable opening area (C) within the easily-peelable area (A) having apertures to discharge the hot water and the non-peelable area (B) positioned adjacent to the easily-peelable area (A). Both the opening area (C) and the non-peelable area (B) have the layered structure in which the base layer (20) and the surface sheet (40) are adhered so that they can not be peeled from each other. A first slit (4) is formed in the opening area (C) which cuts from the base layer (20) to the adhesive layer (30). It is preferably that transverse cross-section to be made by the first slit (4) should be a little larger than that of the opening region (C). The circumferential edge of the lid member has at least two tabs; a first tab (2) to peel the lid member (1) from the container body (14) and a second tab (3) to form the apertures to discharge the hot water in the opening area (C) by peeling the surface sheet (40) in the easily-peelable area (A) of the lid member (1). The first tab (2) is preferably provided on the non-peelable area (B), while the second tab (3) is usually provided at the side of the easily-peelable area (A) and adjacent to the boundary line between the non-peelable area (B) and the easily-peelable area (A). Lid member (1) can have one or more first tab(s) (2). Lid member (1) can have one or two tabs (3)when the lid member (1) has single second slit (5). The second slit (5), which cuts the surface sheet (40) to the base layer (20), is formed linearly substantially along the boundary line between the easily-peelable area (A) and the non-peelable area (B) which is adjacent to the area (A) and may be on such boundary line or in the easily-peelable area (A). The third slit (6), which cuts the base layer (20) to the adhesive layer (30), is formed around the second tab (3) and from the circumferential edge (d) of the lid member (one of foot-ends of the second tab (3)) spaced from the second slit (5) and intersect the second slit (5) at point of intersection (e). Referring to Figure 1 (B), an adhesive region (17) of the lid member(1) is provided at a position to be contacted with the opening of the container body, the width of an adhesive region is usually 1 to 10mm. Preferably, a part of the third slit (6) overlies the adhesive region (17). Specifically, the point of intersection (e) by the second slit (5) and the third slit (6) is preferably over the adhesion region (17). The slits(4), (5) and (6) may either be continuous linear slits or discontinuous slits such as perforated slits. The second slit (5) may be in the form of a slit zone (50) as illustrated in Figure 4. The slits (5a) are arranged in rows as discontinuous pairs of slits which are mutually oriented outwardly and have inclination of approximately 20 degree on the peeling direction (pull direction). Slits (5a) may be arranged as two or more rows. Then, when the slits (5a) are formed as discontinuous pairs of slits which are mutually looking outwardly and are arranged symmetrically, slits can be broken easily, and fragments of the base layer at the broken sites can also be prevented. Although the slits (5a) may be arranged in two or more rows, for optimum peeling, it is preferable to arrange the slits (5a) in 3 to 5 rows. Preferably, the slit zone (50) is formed on the boundary line between the easily-peelable area (A) and the non-peelable area (B). As illustrated in Figure 5, a notch (18) may be provided on the second slit (5) (the slit zone (50)) or in adjacent thereto within the circumferential edge of the lid member. The notch (18), which cuts from the surface sheet (40) to the base layer (20), is in the form of a slit of several mm length from the circumferential edge of the lid member and extends from the circumference edge of the lid member (1) to the second slit (5). Preferably, the notch (18) is arranged to extend from the circumference edge of the lid member to the third slit (6) (the point of intersection (e) in Figure 3) on or along the second slit (5). If the notch (18) is simultaneously prepared with a knife to make the second slit (5) or the third slit (6), the mutual position can be assured. The base layer (20), may comprise any layered structure prepared by extruding sealant (10) onto the aluminum foil (9). The sealant (10) may be any sealant which is easily peeled from the container body (14) including resins such as expanded styrol, styrol and polypropylene, and those having cold adhesion such as olefin resin e.g. ethylene covinyl acetate (EVA), polyolefin resin e.g. ethylene vinyl alcohol acetate (EVOH) or a heat seal varnish. The surface sheet (40) may comprise paper having a weight of 60 g/m2 or more, in particular, paper of 60 to 150 g/m2 is preferred. Both sides of the paper (7) may be processed by a gravure printing method, so that printing layer (12) with ink is coated on the front side, and lubricant (11) (thickness of 0.2 to 20µm) containing a mixture of an edible surfactant agent, such as lecithin, digestive cotton adhesive, wax or silicon or the like is coated on the area corresponding to the easily-peelable area (A)on the back side. The adhesive layer (30), comprises an adhesive (8) which is excellent in heat bonding at the surface coated by the lubricant (11), in particular, polyethylene, ethylene methacrylic acid (EMA) or the like is applicable. Laminated products having layered structure [of base layer (20), adhesive layer (30) and surface sheet (40)] can be produced by laminating, with an extruder, the base layer (20), the surface sheet (40) and the adhesive layer (30) sandwiched therebetween. Each of slits and notch may be provided before or after cutting the laminated products into leaf-like form. The lid member (1) may be produced by a stamping process before or after cutting slits. Each of slits and notch are simultaneously formed a single cutting step or each slit can be formed respectively in separate cutting processes. For example, the second slit (5) (the slit zone (50)) can be made on the surface sheet (40) prior to the lamination. Likewise, the slits (4) and (6) can also be made prior to the lamination. In this case, however, the slits (4), (5) and (6) have to be cut in the form of the perforated line (not in the continuous line). The lid member (1) so produced is stuck to the opening (15) of food container (14) by means of heat seal or the like. The food container (14), may be made from various kinds of materials including expanded styrol, styrol, polypropylene and paper. The container employing the lid member of the present invention may be used as described below: Firstly, the first tab (2) is pulled up, then one third of the lid member (1) is peeled toward opposite direction from the opening (15), and hot water is poured into the container body (14). Next, the first tab (2) is bent over circumferential edge of the container body (14) to reseal the container, and it is left for the determined time. Thereafter the easily-peelable area (A) is peeled (the fragment (16) is removed) by pulling up the second tab (3), to open the apertures (13), and unnecessary hot water is discarded as illustrated in Figure 6. Example 1 The base layer (20) was produced by applying sealant (10) (25µm thickness) made from cold adhesive EVA (olefin resin) to aluminum foil 9 (15µm thickness). Callendered paper (7) (coated paper: 84.9g/m2) was processed by the gravure printing, whereby a printing layer (12) with ink was coated on the front side, and lubricant (11) prepared by mixing an edible surfactant agent with silicon was coated on the back side, thereby, the surface sheet (40) was produced. Laminated products having layered structure (of base layer (20), adhesive layer (30) and surface sheet (40) were produced by laminating, the base layer (20), the surface sheet (40) and the heat adhesive polyethylene (8) (adhesive layer (30) with thickness of 15µm thickness) sandwiched therebetween using an extruder. Slits and notch were provided by cutting the laminated products into leaf-like form, then the lid member (1) was produced by a cutting and drawing process. The third slit (6) was arranged such that at least a part of the slit (6) overlies the adhesion region (17), and the third slit (6) is laid from the circumferential edge (d) (one of foot-end (d) of the second tab (3) in adjacent to the second tab (3) spaced from the second slit (5) to the point of intersection (e) (about 3mm inside from the outer circumference) by the second slit (5) (See Figure 3). The lid member was stuck via the adhesion region, 4mm width, to the cup-shaped container body made of polystyrene paper. Thus, a container for quick cook foods (the container for quick cook noodle) according to the present example was produced. As illustrated in Figures 2 and 3, slits according to this Example included circularly perforated line employed as the first slit (4) and straight line slits employed as the second and the third slits (5) and (6). Example 2 Laminated products were produced according to the same procedures as those in Example 1 except that EVOH was used as the sealant (10), then slits were provided by cutting them into leaf-like form, and the lid member 1 was produced through a cutting and drawing process. This lid member was stuck with heat-fusing to the cup-shaped container body made of polystyrene paper. Continuous curve slits were employed as the first slits (4) and (6), and the slit zone (50) consisting of slits (5a) oriented mutually outwardly were employed as the second slit (5) as illustrated in Figures 4 (A) and (B). Thus, a container for quick cook foods (the container for quick cook noodle) according to the present Example was produced.

Claims: A lid member for a food container having substantially the same circumferential configuration as that of an opening in the container body of the food container, the lid member having a layered structure comprising a base layer (20) and a surface sheet (40) laminated together by an adhesive layer (30), the lid member being divided into a non-peelable area (B) and adjacent thereto an easily-peelable area (A) in which is positioned a non-peelable opening area (C) comprising apertures (C) which are formed upon peeling of the surface sheet (40), a first tab (2) to peel off the lid member from the container body extending from a circumferential portion of the non-peelable area (B), and a second tab (3) extending from a circumferential portion of the easily-peelable area (A) to open the apertures of the opening area, in which the easily-peelable area (A) has a first slit (4) which cut from the base layer (20) to the adhesive layer (30) and defines the circumferential edge of the apertures (C), in the opening area and the easily-peelable area (A) has a lubricant (11) between the surface sheet (40) and the base layer (20) characterised in that : the second tab (3) is positioned along the boundary of the non-peelable area (B) and the easily-peelable area (A), the lid member further comprises a second slit (5) which cuts from the surface sheet (40) to the adhesive layer (30), along the boundary line between the non-peelable area (B) and the easily-peelable area (A), and a third slit (6) which cuts from the base layer (20) to the adhesive layer (30)is positioned in the vicinity of where the second tab (3), extending from the base of the second tab (3) spaced from the second slit (5) to a point of intersection with the second slit (5). A lid member as claimed in Claim 1 in which the second slit (5) is in the form of a slit zone comprising a pair of discontinuous slits oriented mutually outwardly forming two or more rows. A lid member as claimed in Claim 1 or Claim 2 which comprises a notch (18) which cuts from the surface sheet to the base layer on said second slit or in adjacent thereto within the circumferential edge of the lid member. A lid member as claimed in Claim 3 in which the notch extends along said second slit, from the circumferential edge of the lid member to the point of intersection by the third slit. A food container which comprises a container body having an opening and a lid member adhered thereto, the lid member having substantially the same circumferential configuration as the opening of the container body, positioned over the opening and adhered to the container body, in which the lid member is as defined in any preceding Claim. A food container as claimed in Claim 5 in which at least a part of said third slit extends over the adhesion region between the lid and container body at the circumferential edge of the opening. A food container as claimed in Claim 5 or Claim 6 in which the point of intersection of the second slit and third slit is positioned over the adhesion region between the lid and container body.

Inventors: IKEDA KYUTARO, KAWAI HIROFUMI, SAWADA KIYOSHI, YOSHIMURA MITSUO, IKEDA, KYUTARO, KAWAI, HIROFUMI, SAWADA, KIYOSHI, YOSHIMURA, MITSUO, KAWAI, Hirofumi, Toppan Insatsu Kabushiki Kaisha, SAWADA, Kiyoshi, Toppan Insatsu Kabushiki Kaisha, YOSHIMURA, Mitsuo, Toppan Insatsu Kabushiki Kaisha
Applicants: NISSIN FOOD PRODUCTS LTD, NISSIN SHOKUHIN KABUSHIKI KAISHA
Application year: 1999
Main classification: B65D81
IPC codes: B65D77, B65D17, B65D81, B65D85