JP4028110B2 - Tube container forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for integrally forming a tube container in which a closure member with a snap-type hinge cap is attached to one end of a cylindrical body.
[0002]
[Prior art]
In forming a tube container 50 in which a conventional closure member with a snap-type hinge cap is attached to one end of a cylindrical body portion, as shown in FIG. 5, a head portion previously formed by an injection molding method is used. The mouth-and-neck portion of the tube container body comprising a cylindrical body portion 41 formed by a direct blow molding method or the like, a shoulder portion 42, and a cylindrical mouth-and-neck portion 43 formed from a closing member having a hinge cap connected via a hinge. A molding method for joining to 43 has been generally adopted.
On the other hand, as a method of forming a laminated tube container (not shown) with a screw cap, a kind of compression molding is adopted, a certain amount of molten resin is retained in the cavity, and the tip is One end of the cylindrical body part inserted around the mandrel that is the core is pushed into the cavity together with the core to push the molten resin into the closed space formed by the cavity and the core, and the shoulder part and the mouth. A method has been employed in which the outer peripheral end of the shoulder and the end of the cylindrical body are heat-sealed at the same time as the neck is formed.
[0003]
[Problems to be solved by the invention]
However, in the formation of a tube container to which a closure member with a snap-type hinge cap is attached so far, in addition to the process of separately forming the closure member and the tube container body, separate processes for joining both of them As a result, there is a problem that the whole process becomes long. Further, according to such a method, there is a problem that a dead space is formed in the head of the molded tube container, the storage volume of the contents is reduced correspondingly, and an extra resin amount is required in the head. Derived.
Further, according to the compression molding method in the case of a laminated tube container, it is possible to easily form a tube container body in which a cylindrical body part, a shoulder part, and a mouth and neck part are integrated. In addition, there is a problem that even a complicated closing member cannot be molded.
The present invention has been made in view of the above-mentioned problems. The present invention forms a closing member having a complicated structure with a hinge cap, and at the same time, joins it to one end of a cylindrical body, and integrates it. It aims at providing the shaping | molding method which shape | molds a tube container specifically.
[0004]
[Means for Solving the Problems]
The method for forming a tube container according to the present invention includes:
Hinge consisting of a lid plate having a plug portion projecting substantially in the center and a side plate surrounding the lid plate periphery with respect to a head portion comprising a top plate having a spout at the center and a shoulder portion surrounding the top plate. A closure member formed by connecting a cap to a predetermined position of the shoulder via a hinge is joined to one end of a cylindrical body made of a single layer or a laminated material at an outer peripheral end of the shoulder. A tube container forming method comprising:
Inserting the cylindrical body portion into a mandrel having a head core having an inner surface shape of the head portion at an end; and
The head portion and the hinge cap have a cavity having an open surface shape of the closing member in a state where the head portion and the hinge cap are horizontally opened through the hinge, an outer surface shape, and the head portion and the hinge cap A step of clamping a mold composed of a plurality of blocks consisting of a side core that can be divided into left and right with a passing center line as a boundary, and the head core;
Injecting resin from the cavity side into a closed space formed by mold clamping;
Dividing the mold of the integrally formed tube container, and pulling out the mandrel and taking it out;
It is characterized by comprising.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in more detail with reference to the drawings.
FIG. 1 is an explanatory view of a tube container formed by the tube container forming method according to the present invention. Fig.1 (a) is a top view, FIG.1 (b) is a center longitudinal cross-sectional view.
As shown in FIGS. 1 (a) and 1 (b), the closing member 30 is provided for the head portion 10 including the upper plate 2 having the spout 4 at the substantially center and the shoulder 3 surrounding the periphery of the upper plate 2. A hinge cap 20 composed of a lid plate 11 having a plug portion 14 projecting substantially in the center and a side plate 12 surrounding the periphery of the lid plate 11 includes a pair of connecting bodies 21 having a hinge 23 at the center and a belt-like body 22 having hinges 23 at both ends. The hinge cap 20 is pivoted about the hinge 23 of the coupling body 21 and is folded on the head portion 10 so that the open surfaces of the closing member 30, that is, FIG. The upper surface of the head portion 10 and the upper surface of the hinge cap 20 in FIG. 6B are closed opposite to each other. At this time, the closure member 30 is sealed by fitting the plug portion 14 into the spout 4.
As shown in FIG. 1B, the outer peripheral end portion of the shoulder portion 3 of the head portion 10 forms a joint portion 8 together with the end portion of the cylindrical body portion 1. Further, as shown in FIG. 1A, the cross-shaped vertical rib 6 and the horizontal rib 7 are provided on the lower surface of the head portion 10 so as to intersect with each other outside the pouring hole 4. Due to this rib structure, the entire head portion 10 has a flat shape, and despite the fact that each portion is thin, rigidity is imparted to the head portion 10, reducing stress deformation of the upper plate 2, and applying force when closed. Even if it is not inserted, it can be easily and securely sealed by fitting the stopper portion 14 to the fitting portion 5 of the spout 4 and can be easily lifted by placing a finger on the protruding portion 13 of the hinge cap 20. Can be opened.
[0006]
FIG. 2 is an external view of a tube container 40 formed by the tube container forming method according to the present invention.
2A is a side view of the closing member 30 in a closed state, and FIG. 2B is a plan view of an empty tube container 40 that is not sealed at the bottom before filling, and FIG. ) Is a side view of the state in which the closing member 30 is opened.
The outer shape of the tube container formed by the method for forming a tube container according to the present invention is such that a closing member 30 that is flatter than the conventional closing member is attached to the tip of the cylindrical body 1, and FIG. As shown to a) and (b), it is designed so that there may be no part which protrudes outside the outer diameter of the cylindrical trunk | drum 1. FIG. The shape of the closing member 30 at the time of molding is such that the head portion 10 and the hinge cap 20 are horizontally opened by 180 ° as shown in FIG. However, once the closing member 30 taken out from the molding die is bent inward, the hinge cap 20 is bent to a position opened approximately 135 ° with respect to the head portion 10 as shown in FIG. This state is also a state when the closing member 30 is opened in use. This posture is achieved by the spring function of the strip 22.
[0007]
FIG. 3 is a block diagram of a mold used in the method for forming a tube container according to the present invention.
In the method for forming a tube container according to the present invention, one end of the cylindrical body 1 is inserted in advance into the injection mold 60, and the closing member 30 and the body 1 that are injection-molded inside the mold 60 are heated. A so-called in-mold injection molding method is adopted in which fusion is performed.
As shown in FIG. 3, the mold 60 for that purpose is composed of a head core HC, a cavity K, and a side core SC.
As shown in FIG. 3, the head core HC has an inner surface shape of the head portion 10 and is processed at the tip of the mandrel M. Further, a cylindrical body 1 slightly longer than the cylinder portion of the mandrel M is inserted into the mandrel M.
As shown in FIG. 3, the cavity K has an open surface (surface on which the head portion 10 and the hinge cap 20 face each other when closed) when the head portion 10 and the hinge cap 20 are horizontally opened via the hinge 4. have.
The side core SC is a split type that can be divided by sliding left and right with a center line passing through the head portion 10 and the hinge cap 20 as a boundary, and has an outer surface shape in a state in which the closing member 30 is closed.
Further, the cavity K and the side core SC also have the shapes of the connecting body 21, the band-like body 22, and the hinge 23.
Furthermore, a gate G connected to the hot runner L is provided on the cavity K side, but the position is not limited to the upper plate 2 part of the head part 10 shown in FIG. Good.
[0008]
FIG. 4 is a process explanatory diagram of the tube container forming method according to the present invention.
The method for forming a tube container according to the present invention includes:
(1) A step of inserting the cylindrical body 1 into a mandrel having a head core HC at one end;
(2) A step of clamping the head core HC, the cavity K, and the left and right side cores SC,
(3) An injection process for injecting resin into a closed space formed by mold clamping;
(4) The step of removing the integrally formed tube container;
It consists of
First, the insertion process of the cylindrical body 1 of (1) is a process of inserting the cylindrical body 1 from the head core HC side of the mandrel M provided with the head core HC having the inner surface shape of the head at the end. Then, as shown in the lowermost part of FIG. 4, the end of the cylindrical body 1 is inserted with the end slightly protruding from the cylinder portion of the mandrel M. This is because the projecting portion joins the outer peripheral end portion of the shoulder portion 3 shown in FIG.
In the method for forming a tube container according to the present invention, a plurality of tube containers are simultaneously formed, so that a plurality of cylindrical body portions 1 are simultaneously inserted into a plurality of mandrels M on an injection molding machine. Any means may be used for the insertion.
The mold clamping step (2) is a process of clamping a mold block composed of the head core HC, the cavity K, and the left and right side cores SC. An example of the clamping order is shown in FIG. 4 shows the aa ′ cross section of the hinge cap 20 in FIG. 3 and the lower part of FIG. 4 shows the bb ′ cross section of the head unit 10 in FIG. 3, and shows the behavior of each mold block at each stage. ing. First, in the first stage, as shown in (1), the cavity K and the side core SC are in an open state. Next, as shown in (2), the left and right side cores SC are clamped with respect to the cavity K, and then the head core HC is clamped together with the cylindrical body 1 to a predetermined position (position indicated by a dotted line). . This order of clamping may be reversed to the order described above, the head core HC may be moved to a predetermined position with respect to the cavity K, and then the side core SC may be clamped. The side core SC and the head core HC may be clamped simultaneously.
The injection step (3) is a step of injecting resin from a gate G (see FIG. 3) provided on the cavity side into a closed space formed by clamping as shown in (3).
The removal step (4) is a step of opening the die block that has been clamped after cooling and taking out the tube container integrally formed by injection molding, and the order in which the die blocks are opened may be appropriately determined.
According to the method for forming a tube container according to the present invention, the tube container 40 in which the body portion 1 and the closing member 30 are integrated in the mold is efficiently formed by repeating the above steps (1) to (4). can do.
In the case of production production, the mold 60 shown in FIG. 3 can be sufficiently increased by an arbitrary number to perform multi-cavity.
The above molding can be performed simply by attaching to the normal injection molding machine the above-described mold designed according to the model and the automatic insertion device for the cylindrical body 1 and the tube container removal device integrally formed. It becomes.
[0009]
As the resin used in the method for forming a tube container according to the present invention, since the closing member 30 has a hinge function as described above, a polyolefin-based resin that gives the hinge 23 appropriate elasticity and bending resistance, especially polypropylene resin is used. Is desirable. Also, the molten resin in the mold needs to pass through the extremely narrow hinge 23 and spread in a closed space in the mold 60 in a short time, and it is desirable to use a resin having excellent flow characteristics.
A laminated material having various single layers or laminated structures is applied to the body 1, and at least on the joint surface side with the outer peripheral end of the shoulder 3 of the head 10, a polyolefin used for the closing member 30. It is preferable to use a resin that exhibits good wetting, compatibility, and thermal adhesiveness with respect to a resin, especially adhesives represented by Modic (Mitsubishi Chemical Corporation), Admer (Mitsui Chemicals Co., Ltd.), etc. It is preferable that a polyolefin resin is used.
[0010]
The tube container forming method according to the present invention is not limited to the above description or drawings, and various modifications can be made without departing from the scope of the present invention.
For example, the mold clamping order is not limited by FIG. 4, and the position of the gate in the injection molding is not limited by FIG.
Moreover, the shape of the cylindrical trunk | drum 1 in the planar view before the filling of the tube container 40 made into object may be not only circular but elliptical.
The connection mechanism between the head unit 10 and the hinge cap 20 is not limited to the so-called three-point hinge provided by the pair of connection pieces 21 and the single band-like body 22, and any other kind of film hinge or the like can be used. It may be a hinge.
The reinforcing ribs formed on the inner surface of the head portion 10 do not have to be in the shape of a cross made up of two vertical ribs 6 and two horizontal ribs 7 as shown in FIG. 3 may extend radially, and its configuration is free.
Further, any fitting means may be used for sealing the closing member 30 with the plug portion 14 on the hinge cap 20 side of the spout 4.
[0011]
【The invention's effect】
According to the method for forming a tube container according to the present invention, the cylindrical body 1 is formed in the mold 10 at the same time as the closing member 30 in which the head 10 and the hinge cap 20 are connected via the hinge 23 is injection-molded. Therefore, the process can be shortened and the tube container can be produced efficiently.
Compared to conventional tube containers by joining the closure member and the mouth and neck of the tube container body, the amount of resin used can be reduced, and the internal capacity can be increased by reducing the dead space. A hinge cap 20 having a simple closure member 30 and a flat lid 11 can be provided.
Moreover, from the viewpoint of equipment, it is only necessary to newly provide a mold 60, the insertion of the cylindrical body 1, and a device for taking out the integrally formed tube container, and the conventional injection molding machine is used as it is. Yes, with little initial investment.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a tube container formed by the method for forming a tube container according to the present invention. FIG. 2 is an external view of the tube container formed by the method for forming a tube container according to the present invention. FIG. 4 is a process diagram of a tube container molding method according to the present invention. FIG. 5 shows a conventional closure member with a hinge cap attached to one end of a cylindrical body. Illustration of the tube container attached [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical trunk | drum 2 Upper board 3 Shoulder part 4 Outlet 5 Fitting part 6 Vertical rib 7 Horizontal rib 8 Joint part 10 Head part 11 Cover plate 12 Side plate 13 Projection part 14 Plug part 20 Hinge cap 30 Closing member 40 This invention The tube container 50 formed by the tube container forming method by the conventional tube container 60 formed by attaching a closing member with a hinge cap to one end of the cylindrical body part HC head core G gate L runner used in the present invention M Mandrel K Cavity SC Side core

Claims (1)

Hinge consisting of a lid plate having a plug portion projecting substantially in the center and a side plate surrounding the lid plate periphery with respect to a head portion comprising a top plate having a spout at the center and a shoulder portion surrounding the top plate. A closure member formed by connecting a cap rotatably at a predetermined position of the shoulder through a hinge is joined to one end of a cylindrical body made of a single layer or a laminated material at the outer peripheral end of the shoulder. A tube container forming method comprising:
Inserting the cylindrical body portion into a mandrel having a head core having an inner surface shape of the head portion at an end; and
The head portion and the hinge cap have a cavity having an open surface shape of the closing member in a state where the head portion and the hinge cap are horizontally opened through the hinge, an outer surface shape, and the head portion and the hinge cap A step of clamping a mold composed of a plurality of blocks consisting of a side core that can be divided into left and right with a passing center line as a boundary, and the head core;
Injecting resin from the cavity side into a closed space formed by mold clamping;
Dividing the mold of the integrally formed tube container, and pulling out the mandrel and taking it out;
A method for forming a tube container, comprising:

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