JPS6179638A - Method of molding cover material of pressure-resistant vessel made of paper and mold - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The disclosed technology belongs to the technical field of manufacturing lid materials for pressure-resistant containers for carbonated beverages such as beer and cider.

According to the invention of this application, a paper body material with a circular cross section is prepared in advance, and then, when forming a lid material to be welded and joined to the end portion of the body material, a three-dimensional molding mold for the lid material is formed. The mold consists of a lower mold, an upper mold, and a side mold set on the outside of both of them, and a non-woven mat lidding material of a predetermined size and bulk density is sandwiched between these three molds, and hot molding is performed. This invention relates to a method of molding in a press state and a mold directly used in the method.In particular, the invention relates to a method of molding in a press state and a mold used directly in the method. A molding method in which a skirt part is formed by an upper mold and a side mold while a spherical shell part and a shoulder part are held between molds, and the mold directly used in the method consists of an upper mold, a side mold, and a lower mold, The side mold has a right cylindrical inner surface, the lower mold and the upper mold mounted on the right cylindrical inner surface have sliding surfaces relative to the right cylindrical inner surface, and the upper mold has a spherical shell molding surface corresponding to the spherical shell molding surface of the lower mold, and a shoulder molding surface corresponding to the shoulder molding surface, and a shoulder molding surface corresponding to the right cylindrical inner surface of the side mold. This invention relates to a mold for forming a lid material for a paper pressure-resistant container, which has a skirt molding surface, and further has a lower mold that is temperature-controlled by being lower than the upper mold by a set temperature during molding. be.

<Prior Art> As is well known, storage containers for carbonated drinks such as beer and cider are affected by the internal pressure of the carbon dioxide gas filled in them, so in order to basically prevent the permeation of carbon dioxide gas and make it practical. Glass bottles must have pressure resistance and gas barrier properties, and for this reason, glass bottles that meet these requirements and are also reasonably priced have been widely used.

Although glass bottles have economical and resource-saving advantages because used empty bottles can be collected and used repeatedly, on the other hand, they are heavy and require extra transportation costs. In addition, if it is exposed to high temperatures in the summer and stored, there is a risk of accidents such as glass breaking if handled improperly. Complex secondary processes such as cleaning and inspection of empty bottles and treatment of washing wastewater are required each time they are recycled, making the work extremely cumbersome and requiring large-scale facilities, making it economically difficult. It was not necessarily an advantageous container.

Therefore, recently, in the distribution field that handles carbonated drinks, a technology has been developed to replace the container with a glass bottle and wrap a plastic shrink label around a lightweight glass bottle to reduce the risk of bursting and make it a disposable container. These types of disposable lightweight glass bottles are being used with the aim of pulverizing them after use and effectively recycling them into glass products again, making it economically viable, but there are many difficulties in establishing a new collection system. Due to the disadvantages of recycling, used lightweight bottles that cannot be recycled are scattered on roads, parks, and recreational areas, which is an undesirable situation. It's getting close up.

Furthermore, metal-bottomed cans, represented by so-called aluminum cans, which have appeared as an alternative to these cans, are relatively easy to manufacture, and
It is lightweight, has excellent physical properties such as pressure resistance, and gas barrier properties, and has a stable demand outlook due to its low cost due to mass production and ease of use, and has the potential for mass distribution.
Recently, they have become widely sold mainly in vending machines, but like the glass bottles mentioned above, the problem of so-called empty can pollution can no longer be ignored, and some industries have introduced deposit systems under guidance from local governments. Although there has been a shift towards recovery and recycling, the current situation is that the overall problem remains unresolved.

In addition, for aluminum cans, which are the mainstream metal cans, there are no domestic resources for the raw material aluminum, so there is a constraint that they have to rely entirely on imports from overseas. The cost is high due to the large amount of electricity required for scouring, and in Japan it is unacceptable to use such expensive materials in a disposable manner, and sooner or later it will become the subject of criticism.

Here, polyester containers represented by the commonly known PET bottles that have recently appeared are lightweight and safe when used, flammability when disposed of, freedom of container design in the distribution department, good design, etc. However, like the metal cans mentioned above, they may cause environmental pollution due to mass disposal after use, or they are difficult to crush in general incinerators, are bulky, etc. However, it has the disadvantage that it is not immediately adaptable to incineration work due to poor handling, etc., and in reality, there are problems that prevent large m1 from being adopted over a wide area.

In fact, under the guidance of administrative authorities and self-regulation by related industries, there is a condition that prohibits the sale of containers with sizes under 11, except for certain uses, which does not seem to be effective.

By the way, paper as a membrane material is an abundant resource, lightweight and inexpensive, the potential of related technology is historically high, and it is also extremely easy to incinerate once used and disposed of. It requires almost no exhaust gas treatment, has excellent crushability, is easy to handle, and depending on the treatment, can be reused as waste paper, and a recycling system has been established for a long time.

In addition, paper processing technology has been highly developed, supported by the expansion of excellent educational policies and the rapid growth of industries such as information, printing, and office businesses, and furthermore, there is a great deal of potential development and research. It has the favorable condition that the accumulation m is extremely large.

Therefore, in the field of static pressure containers such as milk containers, attention was paid from an early stage as an alternative container to glass, wood, and metal containers, and basic conditions such as waterproofness and sealability were technically resolved at the early stage of development. As is well known, it has been put into practical use and widely used.

Therefore, there is a strong demand for a switch to paper containers in the field of pressure-resistant containers for carbonated drinks such as beer and cider.
Moreover, the momentum is increasing.

Regarding paper containers for storing beverages at near normal pressure, practical developments have recently been published and become publicly known technology in some areas related to printing, which are excellent in paper material processing technology.

However, the development of pressure-resistant containers for carbonated beverages made of paper has been delayed, and the reason for this is not only economic issues, but especially the three-dimensionally curved structure of the pressure-resistant containers, which has to be overcome in many ways. For example, the design requirements for pressure-resistant containers for carbonated beverages such as beer and cider are quite high, and it is difficult to explain them in detail. For example, a beer container has a temperature of 2 to 2.5 K at room temperature (1/ci2 gauge pressure, 4 to 5 K at 50°C).
K(+/cm2 gauge pressure), and the internal pressure of Saigu type containers is 3 to 3.5 Kg/cm2 gauge pressure at room temperature and 6 to 7 Kg/cm2 gauge pressure at 50°C; In order to have pressure resistance, it is necessary to make the shape have a circular curved part to cope with the internal pressure, but compared to container materials such as glass, aluminum, or plastic, paper is Since it is generally in the form of a flat plate, there are extremely disadvantageous conditions in processing such a three-dimensional three-dimensional container from a flat plate-like material.

In addition, flat paper materials have poor workability such as bending, and the joint between the body material and the lid material, which forms the basic simple structure of a three-dimensional container, is sealed by rolling it like a gold flask can. It is extremely difficult to do so, and the fourth reason is that the paper itself has poor pressure resistance and gas barrier properties, and to meet this requirement, a film that has excellent barrier properties against oxygen, carbon dioxide, etc. is used, such as by laminating it. Furthermore, as mentioned above, it is also required to ensure both bonding weldability and sufficient bonding strength when bonding the lid material and the body material, which have a three-dimensionally curved shape. There are significant restrictions on material selection.

In addition, as mentioned above, compared to products such as beer cans that have already established marketability and are therefore stable in price, they do not have the ability to compete sufficiently in terms of initial market price. , potentially having adverse economic conditions.

Therefore, when developing paper containers that have pressure resistance and gas barrier properties that can be used as containers for carbonated drinks such as beer and cider, it is necessary to develop paper containers that have potentially favorable material conditions as described above. Despite this, extremely difficult technical and economic bottlenecks still exist, and the brakes are being put on putting the technology into practical use.

By the way, as shown in FIG. 7, the shape of the paper pressure container 1 is basically a simple structure, for example, a cylindrical body material 2 manufactured in advance has upper and lower inner peripheral surfaces at both ends. Lid material 3.
3', and an inner spherical shell part 5 and an outer skirt part 6.6' formed through the shoulder part 4 of the circumference of the lid member.
These are attached to the upper lid material 3 (depending on the design, a drinking lower part is formed on the upper lid material 3), and then the lower lid material 3' is fitted and fixed by adhesive. structure can be adopted.

The above-mentioned body material 2 is basically technically possible in that a flat material can be wound into a cylindrical shape and the edges can be joined.

However, as mentioned above, it is extremely difficult to form the lid material 3.3' into a three-dimensional shape from a flat paper material due to its poor workability. Although it is possible to form a curve to a certain extent by moistening and softening a paper material, this curve forming method does not improve pressure resistance or strength by forcibly separating the bonds between the fibers that make up the paper. There is a potential defect that causes deterioration.

There is also the so-called wet slurry method, in which pulp fibers suspended in water are poured into a mold, shaped, and then dried to create a shape.
The power cost is high and it is not a good idea.

It is necessary to remove wrinkles generated during bending and forming the skirt portion 6.6', but this technique is generally not possible, and therefore, the skirt portion 6.6' must be removed.
When the wrinkles 6' are bonded to the body material 2, a minute gap is created at the joint, making it difficult to maintain airtightness.

Therefore, due to the many potential benefits that paper lids and paper containers still have, we changed the original idea of molding lids from paperboard and molded them from pulp, which is the material of paper. With the goal of developing a technology to mold the above-mentioned lid material from a non-woven mat obtained by a dry method, we are exploring the possibility of making the entire container substantially entirely made of paper, and we are exploring the possibility of making the entire container substantially entirely made of paper. As a result of intensive research aimed at perfecting containers for carbonated beverages such as beer, etc., we have developed a container for pressurized beverages such as beer that can be stored as disclosed in the applicant's earlier patent application No. 180004/1983. For example, pulp fiber 7 can be used as a lid material that has a spherical curved surface in contact with the shell material and is fitted onto the shell material and fixed with a joint seal.
0% by weight and 30% as a binder, a thermoplastic synthetic resin such as low-density polyethylene is made into a fiber or powder form and mixed in a hot air stream to bond the pulp fibers to a thickness of 10 to 50 mm. , for pressure-resistant containers, in which at least the spherical shell surface that comes into contact with the pressurized beverage is laminated with a thermoplastic synthetic resin film, of a molded product obtained by hot-press molding a dry nonwoven fabric mat of so-called synthetic pulp loaded with a bulk specific gravity of about 0.05. We have developed a lid material with a fairly complex three-dimensional shape that can be obtained relatively easily, and currently there are only 5 to 10 pieces! By making it possible to have sufficient pressure resistance and gas barrier properties against internal pressures of +/cm2 gauge pressure, we paved the way for practical application.

However, although the foundation for practical application has been laid, various problems have arisen as the prospects for practical application become clearer.

That is, when the above-mentioned non-woven mat lid material is hot-press molded using a mold, the bulk specific gravity, that is, the density of the shoulder portion interposed from the spherical shell portion to the skirt portion of the lid material, is as shown in FIG. Based on the experimental data, if we take the radial distance S moving from the center C of the spherical shell part to the skirt part on the horizontal axis and the density ρ on the vertical axis, it becomes extremely small at the shoulder part. It was done.

The cause of this is that in the conventional molding of instruments, the nonwoven fabric mat formed as described above is preheated to 130 to 150°C, and a pressure of 20 to 30K (J/Cl + 2 is applied to the nonwoven fabric mat to reduce the bulk specific gravity to 0.6 to 0. After being compressed to about 90%, it is press-molded into a lid material using a predetermined mold, and this process involves first molding the shoulder part, then the skirt part, and then the spherical shell part. This is due to the compositional flow of the tissue occurring in the shoulder region, the pulp mN shifts, thinning occurs, and the composition m fibers become empty.

<Problems to be Solved by the Invention> It has gradually become clear that the problem lies in the molding process and the structure of the mold used therein that cause such compositional degassing.

That is, as shown in Fig. 8.9, in the molding molds that have been used up until now, the upper mold 1, which is fixedly connected to the upper plate of the hot press, mainly integrally fixes the side mold 8 for forming the skirt. The lower die 9 connected to the lower plate of the hot press is pressed from above, and the pre-pressed circular flat disk-shaped plate of a predetermined size is pressed onto the upper part of the side die 8. When the upper die 7 is lowered to form the cover material 3.3' having a predetermined three-dimensional curved surface, the top end of the upper die 1 is first placed and set, as shown in FIG. The lid material material 10 is sandwiched between the right cylindrical inner surface of the side mold 8 and the lid material material 10' is bent by the force of the couple, and the lid material material 10' is inserted into the lower mold 9 along the right cylindrical inner surface of the side mold 8. The skirt portion 6' is formed by lowering the skirt portion 6'.

Therefore, in the process of transition from FIG. 8.9 to FIG. ' is molded, and finally, as shown in FIG. 11, the spherical shell portion 5 is formed by the upper mold 7 and the lower mold 9.

Therefore, in the process of first making contact with the lid material 10 in the shape of a circular flat disk as shown in FIG. Then, when the shoulder portion 4 shown in FIG. 10 is formed, the peripheral portion of the lid material 10 is bent and becomes thicker, and a predetermined upper portion is formed. Considerable sliding resistance occurs due to the clearance between the side portion of mold 1 and the right cylindrical inner surface of side mold 8, and the skirt portion 6 overcomes the sliding resistance.
．． 6', tensile stress is generated in the skirt part 6.6', so composition flow is assisted in the shoulder part 4, the composition fibers are evacuated, and the lid material material 10 is further evacuated. On the other hand, as mentioned above, by applying residual heat of 130 to 150° C. to the nonwoven fabric mat of the lid material, the voiding of the above-mentioned composition fibers is further promoted.

In addition, in the final step shown in FIG. 11, when the spherical shell portion 5 is formed, the molded surface is curved in an uneven manner, so tensile stress is applied to the shoulder portion 4 in this process as well. This further assists the voiding of the composition fibers, and these actions compete to form the shoulder portion 4 of the lid material.
It is designed to work to reduce the density in the.

The shoulder portion 4 of the lid material is a part that supports the entire load that the lid material receives due to the internal pressure after the completed pressure-resistant container is filled with beer, etc., and therefore, the above-mentioned evaporation of the composition is prevented. The shoulder portion lacks strength against the internal pressure and is also unable to exhibit sufficient gas barrier properties.

In order to prevent such voiding of the composition i fibers, it is possible to reduce the residual heat temperature of the nonwoven fabric mat or to lower the temperature of the mold itself, but the basics governing such problems The conditions are due to the above-mentioned molding process and mold structure, so even if the cooling and solidification of the set lid material 10 is promoted and the deviation of the valve fibers is somewhat reduced, fluidity is lost. As a result, the lid material cannot sufficiently overcome the above-mentioned sliding resistance, and therefore,
The fibers in the shoulder portion 4 are cut or broken, resulting in defects such as the formation of pinholes.

In addition, when removing the lid material 3.3' of the molded product, since the side mold 8 is integrally constructed with the lower mold 9, the side mold 8 must be removed each time, making the work cumbersome and reducing efficiency. There was also the drawback that it could not be made higher.

As a result, there was a disadvantage that the efficiency of mass production decreased, resulting in higher costs.

The purpose of the invention of this application is to solve the problems that lead to a decrease in the density of the shoulder portion of the lid, which is one of the scale problems that hinder the practical use of paper pressure-resistant containers, which have recently been gaining momentum based on the above-mentioned prior art. This is a technical issue to be solved, and we aim to prevent variations in the thickness of the non-woven mat material for the lid material, that is, to prevent the density from becoming low in the shoulder area, and to ensure an average density in all parts of the lid material. Furthermore, it is an object of the present invention to provide an excellent method for forming lids for paper pressure-resistant containers and molds for direct use therein, which enable highly efficient mass production and benefit the field of container utilization in the beverage industry. It is.

In order to solve the above-mentioned problems, the structure of the invention of this application, which is based on the above-mentioned claims, is to solve the above-mentioned problems. When molding a lid material to be joined to the end of the material separately from the material, a side mold, a lower mold set inside the right cylindrical inner surface of the side mold, and a lower mold installed on the upper part of the lower mold so that it can be raised and lowered. The upper mold is arranged and set in a predetermined manner, and the temperature of the three parts is adjusted to a predetermined temperature. At this time, the temperature of the lower mold is adjusted to a predetermined temperature lower than that of the upper mold. Preheat the mat in advance, pre-press it, and place it on the top of the side mold, so that the upper end of the side surface of the lower mold is set slightly above the upper end of the straight cylindrical part of the side mold, and then When the upper mold is lowered relative to the mold, the upper mold comes into contact with the lower mold,
Contrary to the conventional molding process, first the spherical shell part and shoulder part of the lid material are press-molded, and finally the skirt part is formed, so that the shoulder part is not subjected to tensile stress. No tensile force due to friction or sliding resistance acts,
Therefore, compositional flow does not occur, and when the spherical shell is molded by contacting the spherical shell from the mold to the lower mold, the lid material has a lower temperature adjustment temperature than the upper mold, so that the spherical shell immediately changes. A cooling solidification state occurs before and after molding, and this also prevents the composition from flowing! The voiding of the IN is prevented, and the density is averaged in all parts of the lid material as much as possible.Furthermore, in the process of disassociating all the molds, the molded lid material is removed from the upper mold. After molding is completed, the lid material can be removed smoothly and efficiently without having to lift up and remove the side mold.
This allows the entire process of setting, press molding, and removal to be carried out efficiently, thereby ensuring high precision and mass production of the lid material.

<Embodiment> Next, one embodiment of the invention of this application will be described below based on the drawings of FIGS. 1 to 6.

Note that the same parts as in FIGS. 7 to 11 will be described using the same reference numerals.

Reference numeral 11' denotes a molding mold which constitutes one of the gist of the invention of this application, and is used for molding a lid material for a pressure-resistant paper container for carbonated beverages such as beer and cider. A side mold 8' is fixedly installed through the lateral mold 8', and from the upper end of the right cylindrical inner surface 14 with a set diameter, a short right cylindrical cylinder for a nonwoven fabric mat set, which will be described later, is connected through a rounded part 15 that gently connects and opens outward. A ring-shaped short cylindrical portion 16 forming a right cylindrical inner surface is integrally formed, and a ring-shaped stopper 11 is integrally formed at a mid-set height portion of the right cylindrical inner surface 14.

In addition, the surfaces of the short cylinder's right cylindrical inner surface 16, rounded portion 15, and right cylindrical inner surface 14 that are in contact with the circular flat nonwoven fabric mat of the lid material are areas where sliding resistance occurs, and are hard chrome plated. The mat is finished with a puff finish to make it slippery.

Note that Teflon coating may be applied depending on the design, but in that case, the coating should be done taking into account the life expectancy due to circumferential kinetic friction.

A heater coil 18 as a temperature control device is provided inside the side mold 8'' and electrically connected to a predetermined temperature control device (not shown) outside the device via a lead wire 19.

Therefore, inside the side mold 8', there is a right cylindrical inner surface 14.
A lower die 9' is provided via a sliding surface 20 so as to be able to slide up and down, and is fixed to the upper end of a piston 23 that is loosely inserted into the guide hole 21 of the bed 13 via an elastic spring 22. On the upper surface thereof, a substantially W-shaped spherical shell molding surface 24 and a shoulder molding surface 25 are formed concentrically with the curved portion being gently continuous.

Note that the outer end of the shoulder molding surface 25 is connected to the side surface mold 8.
The so-called parting line is formed extremely sharply and accurately so that when the lower mold 9' is lowered with a predetermined stroke with respect to the rounded portion 15 of the part 9', a so-called parting line is formed in the product lid material and does not remain.

A stopper 26 is provided at a predetermined position of the piston 23.
are integrally formed, and the stopper 17 of the side mold 8'
The shoulder molding surface 25 of the lower mold 9' engages with the lower mold 9' to regulate the upper limit position of the lower mold 9', and in that state, that is, in the state in which the lid nonwoven fabric mat in the free state is installed and set, the shoulder molding surface 25 of the lower mold 9' The outer end is the upper part of the rounded part 15 and is at a predetermined height, for example, 1 to 20 mm above the right cylindrical inner surface 14.
0111. Preferably, it is arranged to protrude upward by 6 to 12++ m.

The lower mold 9' also has a built-in heater coil 27 as a temperature control device, and is electrically connected to a temperature control device (not shown) via a lead wire 28 having a flexible portion in the middle.

Further, the upper molding surfaces 24 and 25 of the lower mold 9' are also plated with chrome to improve the sliding of the nonwoven fabric mat that is the material of the lid material to be molded, and are further finished with a puff finish.

On the other hand, stands 29 and 29 erected on the base 12
A frame 30 is integrally fixed to the upper end, and a predetermined hydraulic cylinder 31 that operates at a set stroke is mounted on the lower stage of the frame 32, and a piston 32 that is movable up and down within the set stroke is connected to the hydraulic cylinder 31. Upper mold 7'
is provided.

A similarly cylindrical skirt molding surface 35 is formed at a predetermined portion of the cylindrical side surface 33 of the upper mold 1' with a predetermined width through an edge 34 to the nonwoven fabric mat of the lid material (not shown). , Subsequently, a non-woven fabric mat of the lid material is sandwiched between the molding surfaces 24 and 25 on the upper surface of the lower mold 9' to form the molding surfaces 36 and 36 for the spherical shell portion and shoulder portion.
37 are formed so that the bent portions are gently connected.

These molding surfaces 35, 36, 37 and the sliding surface 33 against the right cylindrical inner surface 14 of the side mold 8' are finished with chrome plating as described above in order to smooth the friction against the nonwoven mat of the lid material material. It is then processed into a puff.

Of course, the molding surfaces 35, 36, and 37 may be coated with Teflon instead, but the coating should be done with due consideration given to the wear caused by the friction.

Furthermore, a heater coil 38 as a temperature control device is built into the upper mold 7', and electricity is connected to a temperature control device (not shown) provided outside the device as described above via a lead wire 39 having a flexible portion. connected.

The temperature control device allows the upper mold 1' and the side mold 8' to be heated to a temperature of 170°C in advance.
While the mold is preheated to about 100°C, the lower mold 9' is adjusted and set to a lower temperature of about 80 to 90°C.

The reason why the lower mold 9' can be used at a lower temperature than the upper mold and the side mold because it only takes part in molding the spherical shell and shoulder parts of the nonwoven mat that is the lid material material and does not participate in molding the skirt part. As mentioned above, this is to prevent the specific gravity and density of the shoulder portion 4 of the lid member 3, 3' from becoming small.

As mentioned above, this mold structure is designed to cope with the problem of lowering the density of the shoulder part of the lid material of the prior art.
Completely opposite to the conventional molding process of forming the skirt part and spherical shell part, the shoulder part is first formed, then the spherical shell part, and the lid is formed using the upper mold 7' and the lower mold 9'. The mold structure is such that it is possible to follow the process of firmly clamping the nonwoven fabric mat as a raw material to prevent the flow of the fiber composition of the nonwoven fabric mat, and finally forming the skirt portion.

As a design change, the upper mold 1' is slid relative to the lower mold 9' and the side mold 8' by raising and lowering, but instead of this, the upper mold 7' is fixed and the lower mold 9' , and by forming the side mold 8' and using the lower plate of a predetermined hot press,
Alternatively, various modifications may be made such as raising and lowering may be performed using a hydraulic actuator, or stroke regulation of the lower mold 9' may be performed using a hydraulic cylinder instead of using the elastic spring 22 as in the above embodiment. are possible, all of which are equivalent to the embodiments described above.

Further, the heater coil of each mold may be of a heater jacket type, and the stroke motion of the mold moving up and down may be used for forced circulation. These are also equivalent means.

Further, the molding curved surface or size of each mold has sufficient flexibility to be deformed according to the design.

When manufacturing paper pressure-resistant containers for carbonated beverages such as beer and cider using the above-mentioned mold, the body material is separately formed in a predetermined manner, and 60 to 80% by weight of valve fibers and low-density polyethylene as a binder are used. A lidding material in which 40 to 20% by weight of flakes or powder is added, mixed in a hot air stream using the air-lay method as in the past, and the valve fibers are connected to each other by the binder to form a matte sheet. The material has a bulk specific gravity of about 00OS and a thickness of 10 to 50o+i.
For example, 130 to 150°C
The raw material is preheated to , compressed to a bulk specific gravity of 0.6 to 0.9 by applying a pressure of 20 to 30 kg/Cl12, and is punched and formed into a disc-shaped sheet with a diameter of 90 to 100 φ. is further preheated to a uniform temperature of 140 to 150°C by high-frequency dielectric heating, and a gas barrier film is laminated and welded thereto.The material is used as the lid material 10, and as shown in FIG. ′
It is inserted into the inside of the ring-shaped short cylindrical part 16 and set horizontally on the upper part of the lower mold 9'.

It goes without saying that the lid material 10 may be provided with a circular hole of approximately 20φ for attaching a drinking spout according to the design, if necessary.

In this case, the drinking spout hole is centered on the protrusion of the lower mold 9', and the set state is stabilized.

Therefore, as a process of the molding method, the hydraulic cylinder 31 is operated via a predetermined control device, and the upper mold 7' is lowered from the state shown in FIG. 2 to the state shown in FIG. 4 via the piston 32, and the lower mold 9' is lowered. The lid material material 1 is lowered into contact with the lid material material 10 set in the upper part, and the lid material material 1
0' is drawn and curved, and the shoulder molding surfaces 31 and 25 of the upper mold 7' and lower mold 9' match, and the lid material 10 is drawn as shown in FIG. Shape it.

At this time, as mentioned earlier, the shoulder part of the lid material material 10 is immediately cooled and solidified because the temperature of the lower mold 9' is lower than that of the upper mold 1' by a predetermined temperature. Fluidization of the composition fibers is prevented and density reduction is prevented.

When the upper mold 7' is further lowered, the state shown in FIG. 4 is reached, and the spherical shell part 5 and shoulder part 4 of the lid material 10' are formed. The spherical shell part 5 is formed first from the shoulder part 4 to the spherical shell part 5, and since it is lowered in temperature and solidified, fluidization of the composition fibers is prevented, and the spherical shell part 5 is formed from the shoulder part 4 to the spherical shell part 5. Although an attempt is made to apply a slight tensile stress, the tensile stress is significantly relaxed, and the composition fibers of the shoulder portion 4 are prevented from becoming airy.

Further, from this state, when the upper mold 7' and the lower mold 9' are integrally lowered against the elastic spring 22,
The surrounding part of the lid material wood 10' is the rounded part 15 of the side mold 8'.
The shoulder portion 4 is completely formed by bending upward, but the diameter of the lid material 10' is set large in anticipation of a certain amount of misalignment, and also due to errors in preforming, etc. However, during the drawing process, the excess length of the peripheral portion is cut off by the right cylindrical inner surface 14 of the side mold 8' and the edge 34 of the upper mold 7', and a residue is left on the rounded portion 15. It will be left as such.

When the outer sliding surface 33 of the upper mold 7' slides on the right cylindrical inner surface 14 of the side mold 8' and descends, the skirt portion finally moves against the upper mold due to the sliding resistance. The spherical shell part and the shoulder part are sandwiched and formed by the lower mold, and in the process, tensile stress is applied upward, but the shoulder part 4 is formed before the skirt part 6, and the upper mold 7' and the lower part are formed. The lid material 1
01 is cooled and solidified to prevent the fluidization of the composition fibers, the composition fibers in the shoulder portion 4 are prevented from becoming airy, and therefore, the lid material 3.3' reliably has an average density over the entire area. Molded to have strength and rigidity.

Then, the upper mold 7' and the lower mold 9' are integrally lowered by a full stroke, and the lower end of the lower mold 9' reaches the stopper 17 of the side mold 8'.
, the control mechanism (not shown) operates, the hydraulic cylinder 31 double-acts, the upper mold 7' rises, and the lower mold 9' springs back by the elastic spring 22 and moves upward, causing both of them to move upward. The lid member 5' sandwiched therebetween rises integrally.

Then, the lower mold 9' stops when the stopper 26 of the binton 23 comes into contact with the stopper 17 of the side mold 8', and only the upper mold 7' rises due to the double-acting action of the hydraulic cylinder 31, and the lid material After 3.3' is curved press-formed, the spring back action is converted into an adhesion force to the upper mold 7', and the lid material 3.3' rises together with the upper mold 7'.
is extracted from the rounded portion 15 of the side mold 8' and rises integrally to the top dead center.

In this state, the lid material 3.3' is located above the side mold 8' and exposed, so the lid material 3.3', which has been formed by hand, can be easily moved into the upper mold. It can be removed from 7'.

Therefore, the remaining residue after cutting into a ring shape is removed and the preformed and preheated nonwoven fabric mat lid material 10 is again placed on the rounded portion 15, and the next molding is restarted.

As mentioned above, the shoulder molding surface 25 of the lower die 9'
Since the end of the lower mold 9' is sharply formed so that the connection between the curved part 15 of the side mold 8' and the rounded part 15 of the side mold 8' is smooth, the parting line etc. ′
It will not remain large.

According to experiments, the time required for the above-mentioned entire molding process is about 10 seconds per step, including the 1 to 3 seconds of the main molding process.
It can be completed in a short time of seconds, and if the instruction work of setting, resetting and removing is continuously automated, one machine can produce approximately 2 million pieces of high-speed mass-produced lid material 3.3' by operating 250 days a year. Ta.

Furthermore, the fruit of the invention of this application is 7jl! Of course, the mode is not limited to the above-mentioned embodiment. For example, all the devices can be automatically controlled, a vacuum pad or the like that can be easily inserted and removed under the upper mold can be provided, and the upper mold can be fitted from below. It is possible to remove the molded lid material by suction.

Therefore, in any case, the lid material can be taken out at will without the need for the complicated steps of removing the side mold from the lower mold every time the lid material is taken out, as in the conventional aspect.

<Effects of the Invention> As described above, the invention of this application provides the best paper pressure-resistant container with internal pressure for carbonated beverages such as beer and cider, which is excellent in all problems such as manufacturing and disposal after use. In the press-forming method from the non-woven mat material of the lid material, which is the bottleneck, we now follow the process of molding the spherical shell and shoulder part of the lid material, and finally the skirt part, in the reverse of the conventional molding process. This prevents the composition fibers in the shoulder part, which is the most important part of the lid material manufactured, from becoming void, and in the entire process from forming the spherical shell part of the lid material to forming the shoulder part and forming the skirt part. By averaging the density of all the parts of the cup, shoulder, and skirt, as well as the strength and rigidity, the lid material is the one that can most easily bear the load due to the total pressure when storing the beverage. Excellent basics that will allow us to create a paper pressure-resistant container that can be mass-produced with high product precision without damaging the shoulder part or forming pinholes that would make it unusable for practical use. The desired effect is produced.

Therefore, in the conventional molding process, as mentioned above, the mold structure that controls the molding process is such that stress is most likely to be concentrated in the shoulder part of the lid material, causing voiding of the composition fibers. In contrast, in the invention of this application, the spherical shell part is molded most quickly, and then the shoulder part is molded, and finally the skirt part is molded. By using a mold 1i1ff structure, the low density of the shoulder part can be reduced. This has the excellent effect of preventing deterioration.

In other words, because the upper mold has a molding surface corresponding to the spherical shell molding surface and the shoulder molding surface of the lower mold, when the upper mold and the lower mold sandwich the nonwoven fabric mat that is the lid material material, First, the shoulder part begins to be formed, and when the shoulder part of the nonwoven mat material is held and then the first spherical shell part molding process is started, even if tensile stress is applied between the spherical shell part and the skirt part, the shoulder part An excellent effect is achieved in that the fluidization of the composition fibers is prevented and voiding does not occur.

In addition, since the upper mold has a molding surface that corresponds to the right cylindrical inner surface of the side mold, even if an extra size is formed in the nonwoven fabric mat in consideration of an allowance, there will be no difference in level on the molding surface of the skirt part. Since the excess portion is automatically cut off and removed by the edges formed in the section, an excellent effect is achieved in that a lid material of an accurate size can be molded.

In addition, since the upper and lower molds have sliding surfaces against the right cylindrical inner surface of the side mold, the nonwoven fabric mat that is sandwiched and molded can be reliably drawn and press-formed as designed. The effect of being carried out is also produced.

The temperature of the lower mold is adjusted to be lower than that of the upper mold and the side mold by a set temperature, so that the nonwoven fabric mat that is held between the lower molds by the low temperature of the lower mold, which is not related to the molding of the skirt part. When molding the spherical shell part and the shoulder part, the shoulder part is immediately cooled and solidified due to the low temperature difference, and from this point of view, the fluidization of the composition fibers is prevented during the initial shoulder part molding by the upper and lower molds. An excellent effect is added.

Furthermore, since the upper mold and the lower mold have sliding surfaces on the right cylindrical inner surface of the side mold and can be operated separately, the lid material can be easily removed after press molding is completed. This means that the lid can be automatically pushed up and separated from the side mold, and the lid that adheres to the upper mold and rises can be manually or automatically removed from the upper mold. When removing the material, the troublesome work of dismantling the side mold from the lower mold each time is eliminated, and the excellent effect is that it improves molding efficiency, shortens the molding cycle, and facilitates mass production. It is played.

Therefore, the entire molding apparatus including the mold can be automated, and from this point of view as well, the molding process can be sped up, and a zero-production system with good product accuracy can be established, which is an excellent effect.

[Brief explanation of drawings]

1 to 5 are explanatory diagrams of one embodiment of the invention of this application, in which FIG. 1 is a partially sectional side view of a molding device, FIG. 2 is a side sectional view of an upper mold, and FIG. 3 is a lower mold and A side sectional view of the side mold, FIG. 4 is a partial sectional view of the initial molding process, FIG. 5 is a partial sectional view of the final stage of molding, FIG. 6 and the following are explanatory diagrams of the prior art, and FIG. Figure 7 is a cross-sectional view of a paper pressure container, Figure 8 is a cross-sectional view of an upper die based on the conventional technology, and Figure 9 is a graph showing the relationship between the radial distance and density between the shoulder part and the spherical shell part. 10 is a corresponding sectional view of the mold at the initial stage of molding based on the prior art, and FIG. 11 is a sectional view of the mold at the final stage of molding.

Claims (3)

[Claims] (1) In the method for forming a lid of a paper pressure-resistant container consisting of a cylindrical paper body and a spherical shell-shaped non-woven mat lid joined to its end, the lid is first molded by an upper mold and a lower mold. A paper characterized in that a spherical shell part and a shoulder part are formed, and then a skirt part is formed by an upper die and a side die while the spherical shell part and shoulder part are held between an upper die and a lower die. A method for forming lid materials for manufactured pressure containers. (2) A mold for forming a lid material for a paper pressure container consisting of a cylindrical paper body material and a spherical shell-shaped nonwoven mat lid material joined to the end thereof, which includes a lower mold and an upper mold. In a mold consisting of a side mold set on the outside of both, the side mold has a right cylindrical inner surface, and the lower mold and the upper mold have a sliding surface with respect to the right cylindrical inner surface. The upper mold is relatively movable up and down, and further has a spherical shell molding surface and a shoulder molding surface corresponding to the spherical shell molding surface and shoulder molding surface of the lower mold, and a skirt portion corresponding to the right cylindrical inner surface. A mold for forming a lid material for a paper pressure-resistant container, characterized by being formed with a molding surface. (3) A mold for forming a lid material for a paper pressure container consisting of a cylindrical paper body material and a spherical shell-shaped nonwoven mat lid material joined to the end of the body material, which includes a lower mold and an upper mold. In a mold consisting of a side mold set on the outside of both, the side mold has a right cylindrical inner surface, and the lower mold and the upper mold have a sliding surface with respect to the right cylindrical inner surface. The upper mold is relatively movable up and down, and further has a spherical shell molding surface and a shoulder molding surface corresponding to the spherical shell molding surface and shoulder molding surface of the lower mold, and a skirt portion corresponding to the right cylindrical inner surface. A lid material molding tool for a paper pressure-resistant container, characterized in that a molding surface is formed, the upper mold and the lower mold are temperature-adjusted, and the lower mold is further temperature-adjusted to be lower than the upper mold by a predetermined temperature. Type.