KR20150142446A - Pressure-proof plastic bottles for liquid fertilizer and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a pressure resistant plastic bottle for a liquid fertilizer and a manufacturing method thereof and, more specifically, to a pressure resistant plastic bottle for a liquid fertilizer and a manufacturing method thereof, wherein a bottom part (30) having a pressure-resistant end (31) formed to endure expansion pressure resulting from gas generated in a liquid fertilizer is arranged to prevent deformation of an outer shape and plastic particles forming a bottle are mixed with 65-70% of a polyethylene (PE) resin and 30-35% of a hydroxide flame retardant (R) to prevent combustion gases toxic to a human body from being emitted in the case of fire due to external factors. Accordingly, the plastic bottle of the present invention is safer in light of spread of fire and environmental pollution and a blow pin is controlled to make a discharge of a bottle having a completed outer shape out of a mold easy in blow molding, thereby being easily manufactured.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-resistant plastic bottle for liquid fertilizer,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-resistant plastic bottle for liquid fertilizer and a method of manufacturing the same, and a bottom surface of the plastic bottle is provided with a pressure- It is safe to add flame retardant to the plastic particles forming the bottle so as to prevent combustion gas harmful to the human body in the event of occurrence, and it is easy to manufacture by controlling the blowpin so as to facilitate the discharge of the finished bottle from the mold during the blow molding Pressure type plastic bottle for a liquid fertilizer and a method of manufacturing the same.

In general, in order to add a function such as gas barrier property to a biaxial oriented blow-molded container, a functional resin is used. In which a gas barrier resin such as an ethylene vinyl alcohol copolymer, an intermediate layer made of a resin composition comprising an oxidizing organic component and an oxidizing organic component in a polyamide resin are combined in the inner and outer layers made of a polyester resin such as polyethylene terephthalate Containers and the like have been proposed.

On the other hand, in the case of a container made of a polyester resin, it is preferable that the entire container is made of a polyester resin and that a resin or a resin composition other than a polyester resin is not used from the viewpoint that containers are recycled recently Also in such multi-layer containers, it is required that the functional resin or resin composition to be the intermediate layer is a polyester resin.

However, since the biaxially stretched blow-molded container needs to be formed in a multi-layered structure, the manufacturing process is complicated and the manufacturing time is relatively long.

European Patent Application Publication No. 1650260 discloses a conventional technique proposed to solve such a problem.

The above-mentioned prior art is also known as a functional polyester resin excellent in heat resistance, gas barrier property, and particularly carbon dioxide gas barrier property, and also known as polytrimethylene naphthalate, and includes a polyethylene terephthalate (PET) resin layer and a polytrimethylene naphthalate resin layer Layered bottle made of a polyester multi-layered sheet having a polyolefin-based polyester resin, a blend of ethylene terephthalate-based polyester resin, polybutylene naphthalate and polytrimethylene naphthalate has been proposed

That is, since the polytrimethylene naphthalate-based polyester resin is a polyester resin having heat characteristics close to that of polyethylene terephthalate (PET) and has excellent gas barrier properties, it is preferable to use a polytrimethylene terephthalate Layered container with polyethylene terephthalate has excellent recyclability because it is a polyester resin which is superior in heat build-up and is the same as polyethylene terephthalate as compared with the case of using a gas barrier resin or the like.

On the other hand, as shown in Fig. 1, a polyester resin and a thermostable plastic bottle have been disclosed in Korean Patent No. 10-1313349 (2013.09.24, Japan Priority Claim, JP-P-2005-00273614) .

Here, the polyester resin and the heat-resistant pressure-resistant plastic bottle are biaxially drawn blow-molded polyester resin-made thermostable plastic bottles having a cylindrical body portion and a pressure-resistant bottom portion, wherein the polyester resin is a titanium- Polymerized; Wherein the polyester resin comprises at least one copolymerizable component selected from isophthalic acid, cyclohexanedimethanol, and diethylene glycol as main components, wherein the polyester resin comprises an ethylene terephthalate unit, wherein the copolymerizable component Is less than 3 mol%; The bottom portion is formed in a petal shape and a portion in a range of 30 mm in diameter centering on the central axis position of the bottom surface of the bottom portion is configured to have a degree of crystallization of 20% or less and a thickness of 1.5 mm or more .

However, the above-mentioned prior art attempts to improve the heat resistance of the PET bottle from the material side, and it provides a plastic bottle suitable for a thermostable plastic bottle and provides a plastic bottle having pressure resistance and heat resistance at a high temperature, There is a problem that it can not cope with flame retardancy.

In addition, the above-mentioned prior arts have a problem in that the production cost is increased due to the production using an expensive polyester polymerizable resin, and the production of a plastic bottle is expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and it is an object of the present invention to provide a liquid fertilizer, It is safe to fire by adding flame retardant to the plastic particles forming the bottle so as to prevent combustion gas harmful to the human body in case of fire in accordance with external factors. In order to facilitate the discharge of the finished bottle from the die during the blow molding, Pressure type plastic bottle for a liquid fertilizer which is easy to manufacture by controlling a fin, and a method of manufacturing the same.

In order to accomplish the above object, the present invention provides a method for producing a pressure-resistant plastic bottle for liquid fertilizer, comprising the steps of: preparing a plastic bottle having a pressure-resistant bottom portion to withstand the expansion pressure of gas generated from liquid fertilizer, A tube supplying step of supplying the plastic particles to a tube in a mold having an open head assembly to which molten plastic particles are supplied at a temperature of < RTI ID = 0.0 > A mold transferring step in which the molds are brought into close contact with each other so that the lower end of the tube supplied in the tube supplying step is sealed, and the metal molds are transferred to a place where the blowing pins are disposed; A blow molding step of supplying the air to the tube whose bottom end is closed in the mold transfer step to form air into the bottle; A cooling step of cooling the mold so that the shape of the bottle formed in the blow molding step is maintained; A rising step of raising the bottle so that the bottom of the bottle and the mold are separated so that the mold is opened to a size of 5 to 10 mm so that the bottle cooled down in the cooling step can be taken out; And a discharging step of discharging the bottle downward after the mold finely opened in the lifting step is fully opened.

Wherein the plastic particles supplied in the tube supply step are mixed with 65 to 70% by weight of a polyethylene resin and 30 to 35% by weight of a flame retardant material, wherein the flame retardant material is one of aluminum hydroxide and magnesium hydroxide .

A pressure-resistant plastic bottle for liquid fertilizer according to the present invention is a plastic bottle whose bottom portion is formed in a pressure-resistant type so as to withstand the expansion pressure of gas generated from a liquid fertilizer. The plastic bottle includes a bottle- And a bottom portion provided with a pressure-resistant end in the shape of an oval so as to withstand the expansion pressure caused by the gas generated from the contents contained in the body portion while supporting the body portion, wherein the pressure- And are arranged at intervals of 60 degrees so as to be symmetrical to each other.

Wherein the plastic particles composed of 65 to 70% by weight of the polyethylene resin and 30 to 35% by weight of the flame retardant are cooled after the blow molding, and the hydroxide flame retardant is aluminum hydroxide Or magnesium hydroxide.

Thus, the pressure-resistant plastic bottle for liquid fertilizer of the present invention and its manufacturing method have the following effects.

First, a pressure-resistant end is provided at the bottom portion to withstand the expansion pressure of the gas generated from the liquid fertilizer, so that the outer shape of the bottle is prevented from being deformed by the expansion pressure of the gas,

Second, since the plastic particles added to the pressure-resistant bottle include a flame retardant, flame retardancy improves as hydroxyl groups (OH ^- ) discharge water particles (H ₂ O)

Thirdly, since the pressure-resistant pressure-resistant step in which the bottom of the bottle is formed is formed, the opening of the bottle and the mold is controlled so as to improve the problem that the pressure-resistant end is interfered with the mold and the discharge is difficult, Efficiency is improved,

Fourth, since the manufacturing process is simplified by not following the two-layer or multi-layer stretch manufacturing process, the manufacturing cost is lowered and the container for storing the liquid fertilizer is highly usable, thereby increasing the economic efficiency.

Fig. 1 is an embodiment of a polyester resin and a thermostable plastic bottle according to the prior art,
2 is a flowchart showing a method of manufacturing a pressure-resistant plastic bottle for liquid fertilizer according to the present invention,
3 is a perspective view of a pressure-resistant plastic bottle for liquid fertilizer according to the present invention,
4 is an exploded view showing the development of a bottom portion of a pressure-resistant plastic bottle for liquid fertilizer according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A method for producing a pressure-resistant plastic bottle for liquid fertilizer according to the present invention is a method for producing a plastic bottle whose bottom portion is formed in a pressure-resistant type so as to withstand the expansion pressure of gas generated from liquid fertilizer, (S10) for supplying the plastic particles to the tube (4) with the mold (3) having the head assembly (2) fed thereto; The metal mold 3 is brought into close contact with each other so that the lower end of the tube 4 supplied in the tube supply step S10 is closed and the metal mold 3 in close contact is transported to the place where the bropin 5 is disposed A mold transfer step S20; A blow molding step (S30) of forming the bottle (B) by supplying air to the tube (4) whose lower end is sealed in the mold transferring step (S20); A cooling step (S40) of cooling the mold so that the shape of the bottle (B) formed in the blow molding step (S30) is maintained; The mold 3 is finely opened by 5 to 10 mm so that the bottle 3 cooled in the cooling step S40 can be taken out so that the bottom of the bottle B and the mold 3 are separated from each other. An ascending step (S50) in which the broth (5) raises the bottle (B); And a discharging step (S60) of discharging the bottle (B) downward after the mold (3) finely opened in the lifting step (S50) is fully opened.

Here, the fact that the plastic particles are melted at a temperature of 140 to 180 DEG C is related to a critical temperature at which oxidation of the flame retardant (R) is prevented.

The plastic particles supplied to the head assembly 2 are supplied by rotation of a screw (not shown), the screw is connected to a mixing device in which the plastic particles are mixed, and the plastic particles are melted at a constant temperature In order to maintain the state, it is general that a hot wire is provided inside.

On the other hand, in order to cut the tube 4 to a predetermined size, a hot wire knife (not shown) is additionally provided on the outer side so that the tube supply step S10 is performed.

The plastic particles form the tube 4 in a jelly state having viscoelasticity.

The plastic particles supplied in the tube supplying step S10 may further include a mixing step S10a in which 65 to 70% by weight of a polyethylene resin (PE) and 30 to 35% by weight of a flame retardant (R) are mixed , The thermoplastic flame retardant (R) is made of any one of aluminum hydroxide (A) and magnesium hydroxide (M).

Among the inorganic flame retardants that increase the flame retardancy of plastics, there are aluminum hydroxide (A), antimony oxide, magnesium hydroxide (M) and boron-containing compounds. Unlike organic flame retardants, inorganic flame retardants are not volatilized by heat and decompose to release gases such as water, carbon dioxide, dioxide, and hydrochloric acid, and are mostly endothermic. In the gas phase, the combustible gas is diluted and the plastic surface is applied to prevent access to oxygen. At the same time, there is an effect of reducing the generation of plastic cooling and pyrolysis products through the endothermic reaction at the surface of the solid phase.

Aluminum hydroxide (A) is the most expensive inorganic flame retardant because it is inexpensive and can be easily injected into plastics, but it can be used only in plastics having a decomposition temperature of about 200 ° C and a low processing temperature. Magnesium hydroxide (M), on the other hand, is decomposed at temperatures above 300 ℃ and can be used for plastics with high processing temperatures.

A pressure-resistant plastic bottle for liquid fertilizer according to the present invention is a plastic bottle (B) having a bottom portion formed in a pressure-resistant form so as to withstand the expansion pressure of gas generated from a liquid fertilizer, A cylindrical body 20 extending from the bottle mouth 10 to receive the contents and a cylindrical body 20 for supporting the body 20 to withstand the inflation pressure caused by the gas generated from the contents contained therein, And a bottom portion 30 having a pressure-proof end 31. The pressure-proof end 31 is provided at an interval of 60 degrees so as to be symmetrical with respect to the center of the bottom portion 30. [

In this case, symmetrical spacings are provided at intervals of 60 degrees, so that a total of six pressure-resistant ends 31 are formed on the bottom portion 30.

The bottle inlet portion 10, the body portion 20 and the bottom portion 30 are made of a mixture of 65 to 70% by weight of polyethylene resin (PE) and 30 to 35% by weight of a hydroxy flame retardant (R) Wherein the thermoplastic flame retardant (R) is composed of either aluminum hydroxide (A) or magnesium hydroxide (M).

Therefore, the pressure-resistant plastic bottle (B) for liquid fertilizer according to the present invention is produced by adding a flame-retardant material (R), which is an inorganic flame retardant, as an additive and decomposing in a combustion process to release a non-combustible gas such as water, nitrogen, ammonia or carbon dioxide And the flame retardancy is increased.

That is, aluminum hydroxide and magnesium hydroxide are typical flame retardants, and their chemical action is decomposed into an endothermic reaction to produce water.

The pressure-resistant plastic bottle for liquid fertilizer having the above-described structure and the manufacturing method thereof will have the following functions.

As shown in FIG. 2, the method of manufacturing the pressure-resistant plastic bottle (B) for liquid fertilizer according to the present invention improves the conventional taking-out method of the pressure-resistant plastic bottle, The mold 3 and the brounfin 5 are controlled to minimize damage or deformation of the produced bottle B. [

More specifically, the molten plastic particles forming the bottle B are discharged into the mold 3 through the head assembly 2, and the mold 3 is closed and then the bloop 5 is disposed (S10) and a metal mold transferring step (S20).

Thereafter, air is supplied to the tube 4 by using the bropin 5 in the blow molding step S30 to shape the shape of the bottle B, and in the cooling step S40, (B) is cooled and solidified. Here, in the cooling step (S40), a water-cooling type in which cooling water is supplied to the mold 3 and cooled is mainly used.

In the ascending step S50, the mold 3 is finely opened by 5 to 10 mm so that the bottle B cooled in the cooling step S40 can be taken out so that the bottle B ).

At this time, the end of the blown 5 is interlocked with the bottle inlet 10 of the bottle B.

Meanwhile, in the ascending step S50, the gap between the bottom part 30 and the mold 3 makes the mold 3 more free to open, and the productivity of the bottle B is improved. That is, by separating the pressure-resistant end 31 from the mold 3, the interference between the pressure-resistant end 31 and the mold 3 is minimized and the frictional force between the pressure-resistant end 31 and the mold 3 is also reduced, So that the bottle B is accurately discharged.

Finally, in the discharging step (S60), the bottle (3) which has been finely opened in the ascending step (S50) is fully opened, and the bottle (B) is descended down to be accurately discharged.

Therefore, when the pressure-resistant end 31 having the bottom surface is provided, the opening of the mold 3 is prevented from being unreasonable, and the bottle B is damaged by the mold 3 Is prevented.

Meanwhile, the pressure-resistant plastic bottle for liquid fertilizer of the present invention manufactured by the above-described method comprises a bottom portion 30 having a pressure-proof end 31 formed to withstand the expansion pressure caused by the gas generated from the contents. do.

The plastic particles constituting the bottle B are composed of a mixture of 65 to 70% by weight of a polyethylene resin (PE) and 30 to 35% by weight of a flame retardant (R) B) is increased.

Here, the flame retardant (R) includes aluminum hydroxide (A) or magnesium hydroxide (M), which is a typical inorganic flame retardant.

On the other hand, when the pressure-proof ends 31 are disposed at an interval of 60 degrees so as to be symmetrical with respect to the center of the bottom portion 30, the bottom portion 30 functions to withstand the expansion pressure transmitted in any direction of 360 degrees .

That is, the gas generated from the inside of the bottle B corresponds to the inflation pressure applied in one direction rather than the inflation pressure applied to the bottle B, so that the inflation pressure is adhered to.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. Of course, such modifications are within the scope of the claims.

2: head assembly 3: mold
4: tube 5: bromine
10: feed-in bore 20:
30: bottom 31: pressure-resistant end
S10: Tube supply step S10a: Mixing step
S20: mold transfer step S30: blow molding step
S40: cooling step S50: rising step
S60: Emission stage
A: aluminum hydroxide B: bottle
M: magnesium hydroxide R: hydroxide flame retardant
PE: Polyethylene resin

Claims (4)

A manufacturing method of a plastic bottle in which a bottom part is formed in a pressure-resistant type so as to withstand an expansion pressure of a gas generated in a liquid fertilizer,
A tube supplying step (S10) of supplying the plastic particles to the tube (4) in a mold (3) in which a head assembly (2) supplied with melted plastic particles at a temperature of 140 to 180 占 폚 is opened;
The metal mold 3 is brought into close contact with each other so that the lower end of the tube 4 supplied in the tube supply step S10 is closed and the metal mold 3 in close contact is transported to the place where the bropin 5 is disposed A mold transfer step S20;
A blow molding step (S30) of forming the bottle (B) by supplying air to the tube (4) whose lower end is sealed in the mold transferring step (S20);
A cooling step (S40) of cooling the mold so that the shape of the bottle (B) formed in the blow molding step (S30) is maintained;
The mold 3 is finely opened by 5 to 10 mm so that the bottle 3 cooled in the cooling step S40 can be taken out so that the bottom of the bottle B and the mold 3 are separated from each other. An ascending step (S50) in which the broth (5) raises the bottle (B);
And a discharging step (S60) of discharging the bottle (B) downwardly after the mold (3) finely opened in the lifting step (S50) is fully opened. ≪ / RTI > The method according to claim 1,
The plastic particles supplied in the tube supplying step S10 may further include a mixing step S10a in which 65 to 70% by weight of a polyethylene resin (PE) and 30 to 35% by weight of a flame retardant (R) are mixed,
Wherein the flame retardant material (R) is made of any one of aluminum hydroxide (A) and magnesium hydroxide (M). A plastic bottle (B) having a bottom portion with a pressure-resistant shape so as to withstand an expansion pressure of a gas generated from a liquid fertilizer,
A cylindrical body 20 extending from the bottle inlet 10 to receive the contents, and a gas outlet 20 for supporting the body 20, And a bottom portion (30) provided with a pressure-resistant end (31) having a concave shape so as to withstand the expansion pressure caused by the pressure-
Wherein the pressure-resistant end (31) is provided at an interval of 60 degrees so as to be symmetrical with respect to the center of the bottom part (30). The method of claim 3,
The bottle inlet 10, the body 20 and the bottom 30 are made of a plastic material composed of a mixture of 65 to 70% by weight of polyethylene resin (PE) and 30 to 35% by weight of a hydroxy flame retardant (R) The particles are cooled after the blow molding,
Wherein the flame retardant material (R) is made of any one of aluminum hydroxide (A) and magnesium hydroxide (M).

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