JPH0130376Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is useful when a consumer, etc. at the final stage of distribution opens an egg pack, which is mainly used to package a plurality of eggs in an array and use it for distribution such as transportation or display sales. It is used as an attachment to the egg carton. Specifically, by vacuum forming polyvinyl chloride or polystyrene film, one side of the body part and one side of the lid part are connected through a connecting part that forms the opening/closing fulcrum. A container for opening containers that is disposed along the inner surface of the connecting portion of a film-like packaging container that is formed in a continuous and integral state, and whose entire length or approximately the entire length is thermally welded to the connecting portion. Regarding the string.

As mentioned above, a container in which one side of the body part and one side of the lid part are vacuum-formed into a single piece through a connecting part that forms an opening/closing fulcrum is susceptible to accidental opening due to rough handling during the distribution process. In order to prevent this from occurring, the free end piece of the body portion and the free end piece of the lid portion are strongly attached in an overlapping state after the article is housed. Particularly in recent years, fixing means by spot welding have been common, and although this has a high closing effect, it is proportionately difficult to open. Looking at the general procedure for opening a container fixed by spot welding, at one longitudinal end of the overlapping free end pieces, grasp one free end piece with your right hand and the other free end piece with your left hand. By applying force with both hands in the direction of separating them, one spot weld at one end in the longitudinal direction is destroyed, and by applying force in the same way with the hands, the spot welds are destroyed one after another. As time goes on, the instructions for opening the package will be adopted. However, when such an opening method is used, the breakage of the spot welds progresses one after another with a time lag, and the concentrated stress for breakage is simultaneously released and a large impact force is applied to the entire container. It is extremely difficult to open the package due to the combination of the following factors: the body and lid are forcibly deformed and destroyed, making an annoying crunching noise, and requiring a large amount of force to overcome the strength of the weld. It was time consuming. In particular, containers containing items such as eggs that are easily breakable and require careful handling are more troublesome to open.

In view of these circumstances, the present applicant has previously filed Japanese Patent Application No. 152937-1982, Utility Application No. 103687-1987,
-130789, Utility Model Application No. 132293/1986, etc., filed applications relating to containers in which an opening cord is provided along the inside of the joint between the body and the lid.

In these earlier applications, by grasping and holding one end of the string with one's hand and pulling it, the folding point of the string is wedged into the connecting portion, and by concentrating force on the wedged portion, the connecting portion is connected. It has now become possible to cut and open the package easily and smoothly with a relatively small operating force, with little impact, and by cutting the parts as if cutting with a sharp cutter knife.

However, in this type of container with an opening cord developed and proposed by someone other than the applicant, as disclosed in the above-mentioned earlier application by the applicant, and furthermore, as disclosed in Japanese Utility Model Application Publication No. 58-12169, etc. No matter who pulls the opening string, the connecting part can be reliably and smoothly cut, and the intended container can be opened reliably, accurately, and easily without any mistakes. Although detailed research has not been conducted to obtain containers with strings in a state suitable for mass production and continuous production, it has not been possible to provide a product that is excellent in both cutting and opening performance and productivity. It wasn't.

To explain this point in more detail,
At the beginning of development, the applicant considered using natural fiber kite string as such an opening string, but such kite string would not be suitable for automatic welding using high-frequency welding machines, ultrasonic welding machines, etc. We have come to know that welding by a machine is not possible, and therefore, containers with strings are unfavorable in terms of productivity.

Next, in consideration of productivity, we considered using a polyamide-based (nylon-based) filament, especially a multifilament, as a string for opening the container, which can be heat-welded to the container.
Heat welding can be used for containers vacuum-formed from polyvinyl chloride or polystyrene film, which is advantageous in terms of productivity, but the tensile strength is insufficient and the string may break midway through cutting and opening. It was found that there is a drawback that it is easy to make a mistake in cutting and opening the package as expected.

Next, we attempted to use multifilament polyester fibers, which have higher tensile strength than polyamide filaments, as strings for opening packages. As a result, the following problems were discovered.

(b) If only roving multifilament is used, there is still a risk of string breakage. Also, if the container is made of polyethylene, the cuts may branch and make it difficult to cut smoothly.

(b) If the yarn is twisted, the cost will increase significantly.

(c) Polyester has a transition point (heat distortion temperature, melting point)
is considerably higher than that of polystyrene and polyvinyl chloride, which are the materials used to construct the container, making it unsuitable for ordinary heat welding. In other words, by the time the polyester softens, the container is greatly deformed and begins to melt.

(d) Polyester itself is extremely difficult to cut. In other words, the part of the string that protrudes from the edge of the container must be cut, but the edge of the cutting blade slips and cannot be held at right angles, resulting in fibers getting caught between the blades. This is because polyester filament is strong and has excellent slipperiness.

Therefore, when using polyester fiber roving multifilament as an opening string,
Although this method has the advantage of reducing string breakage and being easy to cut and open, it has a fatal drawback, particularly in terms of productivity, in that heat welding means cannot be used for the container. In addition, there is a method of fixing the opening string to the inside of the connecting part of the container using adhesive or adhesive tape, or by attaching the string near the end of the string to the longitudinal end of the connecting part of the container without fixing it to the container. There are means for inserting and locking into notches formed in the parts, but all of these require a large number of steps to obtain a container with strings, and are not practical at all in terms of productivity.

The present invention was completed through trial and error as described above, and its purpose is to propose a string for opening film packaging containers that is satisfactory in terms of both cutting and opening performance and productivity.

In order to achieve the above object, the opening string for the film-like packaging container according to the present invention is as described in detail at the beginning, and the string is attached to the container over the entire length and circumference of the polyester fiber roving multifilament. It is characterized by a structure in which a coating layer for heat welding made of the same material as the constituent material is coated with a uniform or substantially uniform thickness by dipping means.

The string for opening a film-like packaging container according to the present invention having such a characteristic configuration has the following effects.

(A) Multifilament polyester fiber is a roving that does not require twisting, and while using the cheapest possible material, the cording layer prevents the roving from coming apart. Therefore, the risk of the string breaking due to unraveling is greatly reduced. Also, no branching occurs at the cut. Coupled with the tensile strength properties inherent to polyester fibers, these act extremely advantageously in terms of cutting and opening.

(B) Good weldability between the container and the string, allowing continuous welding using an automatic welding machine such as a high-frequency welding machine to efficiently produce containers with strings.

The polyester fiber multifilament, which is surrounded by the coating layer, is indirectly bonded to the container in a stable and strong manner.

(C) Coatings (polyvinyl chloride or polystyrene) have significantly lower toughness and lubricity than polyester. When the cutting blade is activated, the edge of the blade is firmly embedded in the coating. If the cutting action continues as it is, even when the blade edge reaches the filament of polyester fiber, the blade edge will not slip and will cut reliably.

Due to the above-mentioned action, when according to the present invention,
It has achieved remarkable practical effects in that it has excellent container cutting and opening performance, and also has good bonding properties to containers, and can greatly contribute to improving the productivity of containers with strings.

Embodiments of the present invention will be described based on illustrative drawings.

In FIGS. 1A and 1B, 1 is a roving multifilament made of polyester fiber, and 2 is a coating layer. This coating layer 2 may be made of polyvinyl chloride or polystyrene, and is coated with a uniform or almost uniform thickness over the entire length and circumference of the roving multifilament 1 by dipping means. And its outer diameter (D)
is generally 0.5 to 2.0 mm.

FIG. 2 shows a cord having the above-mentioned coating layer 2 wound around it.

FIGS. 3 and 4 are usage examples, respectively. 3 is a string that is thermally welded over almost its entire length, and 4 is a vacuum-formed polyvinyl chloride or polystyrene film that connects one side of the body portion 5 and one side of the lid portion 6 via a connecting portion 7 that forms an opening/closing fulcrum. It is a film-like packaging container that is formed into a series of integral parts. 8
is the spot weld. The connecting portion 7 is shown cut approximately in half.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the string, in which A is a longitudinal front view and B is a longitudinal side view. FIG. 2 is a perspective view showing the distribution form of the string. FIG. 3 is a perspective view and a plan view showing the state in which the device is used in a container for eel heads, etc., and FIG. 4 in a chicken egg cage. 1... Roving multifilament of polyester fiber, 2... Bonding coating layer.

Claims (1)

[Scope of utility model registration request] The connecting portion of a film-like packaging container is formed by vacuum forming a polyvinyl chloride or polystyrene film so that one side of the body portion and one side of the lid portion are integrally connected via a connecting portion that constitutes an opening/closing fulcrum. A string for opening a container, which is disposed along the inner surface and whose entire length or approximately its entire length is thermally welded to the connecting portion, and which is a string for opening a container, which is disposed along the inner surface and whose length range over the entire length or almost the entire length is thermally welded to the connecting portion, and which is the entire length and entire circumference of the roving multifilament 1 made of polyester fiber. A string for opening a film-like packaging container, characterized in that a coating layer 2 for heat welding made of the same material as the constituent material of the container is coated with a uniform or substantially uniform thickness by dipping means. .