Method and apparatus for producing foamed molded body
阅读说明:本技术 发泡成型体的制造方法及装置 (Method and apparatus for producing foamed molded body ) 是由 小野寺正明 大野庆词 五十岚优 于 2016-09-28 设计创作,主要内容包括:提供一种能够以简单的工序抑制折弯壁的产生的发泡成型体的制造方法。根据本发明,提供一种发泡成型体的制造方法,具备:型坯形成工序,从环状缝隙将包含发泡剂的熔融混炼树脂朝夹在一对分割模具之间的成型区域的挤出方向挤出,从而形成发泡型坯;以及成型工序,对位于所述成型区域的所述发泡型坯进行所述分割模具的闭模而进行发泡成型体的成型,在所述型坯形成工序中,以相对于所述挤出方向为45度以上135度以下的方向,向所述发泡型坯的内表面喷射空气而进行预吹塑。(Provided is a method for producing a foamed molded body, wherein the occurrence of a folded wall can be suppressed by a simple process. According to the present invention, there is provided a method for producing a foamed molded article, comprising: a parison forming step of forming a foamed parison by extruding a molten kneaded resin containing a foaming agent from an annular gap in an extrusion direction in a molding region sandwiched between a pair of divided molds; and a molding step of molding a foamed molded body by closing the split mold with respect to the foamed parison positioned in the molding region, wherein in the parison forming step, air is injected into an inner surface of the foamed parison in a direction of 45 degrees to 135 degrees with respect to the extrusion direction to perform preliminary blowing.)
1. A method for producing a foamed molded body, comprising:
a parison forming step of forming a foamed parison by extruding a molten kneaded resin containing a foaming agent from an annular gap in an extrusion direction in a molding region sandwiched between a pair of divided molds; and
a molding step of molding a foam molded body by closing the split mold with respect to the foam parison positioned in the molding region,
in the parison forming step, pre-blowing is performed by injecting air into the inner surface of the foamed parison in a direction of 45 degrees to 135 degrees with respect to the extrusion direction.
2. The method for producing a foam molding according to claim 1,
the pre-blow molding is carried out using a pre-blow nozzle located above or below the molding zone.
3. The method for producing a foam molding according to claim 1 or 2, wherein,
in the parison forming step, the foamed parison is first positioned over substantially the entire molding region, and then the foamed parison is clamped and sealed by clamping, and then the pre-blow molding is performed.
4. The method for producing a foam molding according to claim 1,
in the parison forming step, the pre-blow is started before the lower end of the foamed parison reaches the lower end of the molding region.
5. The method for producing a foam molding according to claim 1,
in the parison forming step, the foamed parison is clamped and sealed by a clamp portion before a lower end of the foamed parison reaches a lower end of the molding region, and the preliminary blow molding is performed while the clamp portion is lowered as the lower end of the foamed parison is lowered.
6. The method for producing a foam molding according to claim 4 or 5, wherein,
in the parison forming step, the foamed parison formed so as to be positioned at a part of or above the upper side of the molding region is clamped and sealed by upper clamping.
7. An apparatus for producing a foam molded body, comprising:
a foaming extruder for extruding a molten and kneaded resin containing a foaming agent in an extrusion direction through an annular gap to form a foamed parison in at least a part of a molding region;
a pre-blowing nozzle that performs pre-blowing by injecting air into an inner surface of the foamed parison in a direction of 45 degrees to 135 degrees with respect to the extrusion direction; and
and a pair of split molds that mold the foamed parison into a foamed molded body by closing the molds.
8. The apparatus for producing a foam molding according to claim 7,
the pre-blowing nozzle is arranged above or below the molding area.
9. The apparatus for producing a foam molding according to claim 7 or 8, wherein,
the apparatus for producing a foamed molded article further includes a clamping portion that clamps and seals the foamed parison.
10. The apparatus for producing a foam molding according to claim 9,
the clamp portion performs a lower clamp for clamping and sealing the foamed parison formed to be located substantially over the entire molding region.
11. The apparatus for producing a foam molding according to claim 9,
the clamp portion performs an upper clamp for clamping and sealing the foamed parison formed to be positioned at or above a part of an upper side of the molding region.
[ technical field ] A method for producing a semiconductor device
The present invention relates to a method and an apparatus for producing a foamed molded article.
[ background of the invention ]
In an air conditioning apparatus such as an automobile, a tubular air conditioning duct for ventilation is used.
As an air conditioning pipe, a foamed molded article using a foamed resin obtained by foaming a thermoplastic resin with a foaming agent is known. In the case of foam molding, high heat insulation and weight reduction are widely required.
As a method for producing such a foamed molded article, a foam blow molding method is widely known in which a foamed resin in a molten state is closed by a split mold and air is blown into the inside to expand the resin.
In recent years, there is a tendency that the expansion ratio of the foamed molded article is increased from the demand for weight reduction, but when the expansion ratio is increased, the outer surfaces of the foamed parison are fused to form stripes on the outer surface of the foamed molded article, and a phenomenon called "wall bending" is likely to occur. In patent document 1, in order to suppress the occurrence of the folded wall, a lower portion of a cylindrical foamed parison is closed, the foamed parison is sandwiched before or/and between molds, and a gas is blown into the parison to expand the parison.
[ Prior art documents ]
[ patent document ]
[ patent document 1 ] Japanese laid-open publication No. 2002-192601
[ summary of the invention ]
[ problem to be solved by the invention ]
However, in the method of patent document 1, since it is necessary to blow gas into the parison before the mold is closed, the manufacturing process becomes complicated.
The present invention has been made in view of such circumstances, and provides a method for producing a foamed molded article, which can suppress the occurrence of a folded wall in a simple process.
[ means for solving problems ]
According to the present invention, there is provided a method for producing a foamed molded article, comprising: an extrusion step of extruding a molten kneaded resin containing a foaming agent from an annular gap between a core and a mold shell surrounding the core to form a cylindrical foamed parison, and extruding the parison between a pair of divided molds; a lower clamping step of clamping the foamed parison at a lower clamping portion disposed below the split mold; and a molding step of molding the foamed parison by closing the split mold after the lower clamping step, wherein the diameter of the core is D, the distance between the lower surface of the core and the upper surface of the split mold is H, the distance between the lower surface of the split mold and the upper surface of the lower clamping portion is L, H/D is 1.33 to 3.33, and L/D is 0.33 to 2.00.
According to the experiments of the inventors, it was found that when the diameter of the core is D, the distance between the lower surface of the core and the upper surface of the split mold is H, and the distance between the lower surface of the split mold and the upper surface of the lower clamp is L, the core, the split mold, and the lower clamp are arranged such that H/D is 1.33 to 3.33 and L/D is 0.33 to 2.00, and the occurrence of a folded wall can be suppressed, and the present invention was completed.
Various embodiments of the present invention are exemplified below. The embodiments shown below can be combined with each other.
The expansion ratio of the foamed molded article is preferably 2.5 or more.
Preferably, the foamed molded article is a tubular body having a main passage and a sub-passage connected to the main passage, and an angle between the main passage and the sub-passage is 45 to 90 degrees.
Preferably, the blow-up ratio of the foamed molded article is 0.5 to 0.8 in a cross section at an angle of 0 to 45 degrees with respect to the extrusion direction of the foamed parison.
Preferably, the molding step includes a step of depressurizing each of the split molds to cause the foamed parison to adhere to each of the split molds, and the depressurization start timing of one of the split molds is delayed by 1 second or more from the depressurization start timing of the other of the split molds.
In the extrusion step, the thickness of the foamed parison is preferably controlled so that the thickness of the foamed parison at a portion where a folded wall is likely to be formed is smaller than the thickness of the foamed parison at another portion.
Preferably, in the extrusion step, the preliminary blow molding is performed by injecting air into the inner surface of the foamed parison in a direction of 45 degrees to 135 degrees with respect to the direction in which the melt-kneaded resin is extruded.
The pre-blowing is preferably performed using a pre-blowing nozzle located above or below between the split molds.
Preferably, the foamed parison is positioned substantially entirely between the divided molds, and then the foamed parison is clamped and sealed by a lower clamp, and then the pre-blow molding is performed.
[ description of the drawings ]
Fig. 1 shows a configuration of an apparatus for producing a foamed molded article according to embodiment 1 of the present invention.
Fig. 2 is a cross-sectional view of die 12 of fig. 1.
Fig. 3 is a sectional view of the
Fig. 4 is a cross-sectional view showing a state in which the
Fig. 5 is a cross-sectional view showing a state in which the
Fig. 6A is a plan view showing the structure of a foamed molded
Fig. 6B shows a section a-a or a section B-B in fig. 6A.
Fig. 7A is a diagram showing the collapse of the parison shape.
Fig. 7B is a view showing a bent wall failure (curtain phenomenon) in the cross section C-C in fig. 7A.
Fig. 8 is a diagram showing a state in which a
Fig. 9 is a view showing a state in which the
Fig. 10 is a diagram showing a state in which pre-blowing is performed in the outer circumferential direction of the parison from the state of fig. 9.
Fig. 11 is a diagram showing a state in which the
Fig. 12 is a
Fig. 13 is a view showing a state in which the
Fig. 14 shows embodiment 4 of the present invention.
Fig. 15 is a view showing a state in which the
Fig. 16 shows a modification of embodiment 4 of the present invention.
[ detailed description ] embodiments
The following describes embodiments of the present invention. Various features shown in the following embodiments may be combined with each other. The invention is established independently for each feature item.
In addition, according to the 1 st aspect of the present invention, there is provided a method for producing a foamed molded article, comprising: an extrusion step of extruding a molten kneaded resin containing a foaming agent from an annular gap between a core and a mold shell surrounding the core to form a cylindrical foamed parison, and extruding the parison between a pair of divided molds; a lower clamping step of clamping the foamed parison at a lower clamping portion disposed below the split mold; and a molding step of closing the split mold after the lower clamping step to perform the foamed parison. And if the diameter of the mold core is D, the distance between the lower surface of the mold core and the upper surface of the cutting mold is H, and the distance between the lower surface of the cutting mold and the upper surface of the lower clamping part is L, H/D is 1.33-3.33, and L/D is 0.33-2.00.
Further, according to the 2 nd aspect of the present invention, there is provided a method for producing a foamed molded article, comprising: a parison forming step of forming a foamed parison by extruding a molten kneaded resin containing a foaming agent through an annular gap in an extrusion direction in a molding region sandwiched between a pair of divided molds; and a molding step of molding a foamed molded body by closing the split mold with respect to the foamed parison located in the molding region, wherein in the parison forming step, air is injected into an inner surface of the foamed parison in a direction of 45 degrees to 135 degrees with respect to the extrusion direction to perform preliminary blowing.
1. Embodiment 1
First, an apparatus for producing a foamed molded article suitable for carrying out the method for producing a foamed molded article according to embodiment 1 of the present invention will be described, and then, the method for producing a foamed molded article according to embodiment 1 will be described.
1.1 apparatus for producing foamed molded article
As shown in fig. 1 to 5, the apparatus for producing a foamed molded article according to embodiment 1 of the present invention includes a foaming extruder 1, a split die 14, and a
The respective constituent elements are described in detail below.
<
The
<
The
< blowing agent injection port P >
The
The blowing agent injected from the blowing agent injection port P includes a physical blowing agent, a chemical blowing agent, and a mixture thereof, but the physical blowing agent is preferable. As the physical foaming agent, an inorganic physical foaming agent such as air, carbon dioxide gas, nitrogen gas, or water, an organic physical foaming agent such as butane, pentane, hexane, dichloromethane, or dichloroethane, or a supercritical fluid thereof can be used. The supercritical fluid is preferably prepared using carbon dioxide, nitrogen or the like, and in the case of nitrogen, the supercritical fluid is obtained by adjusting the critical temperature to-149.1 ℃, the critical pressure to 3.4MPa or more, and the critical temperature to 31 ℃, and the critical pressure to 7.4MPa or more. The chemical foaming agent may be a chemical foaming agent that generates carbon dioxide gas by a chemical reaction between an acid (e.g., citric acid or a salt thereof) and a base (e.g., sodium bicarbonate). The chemical foaming agent may be injected from the resin inlet instead of being injected from the foaming agent injection port P.
< temperature control part 9 >
The temperature control unit 9 is configured to control the temperature of each part of the
< resin extrusion opening 11. die 12 >
A molten kneaded resin obtained by melting and kneading a raw material resin and a blowing agent is extruded from a resin extrusion port 11 and injected into a die 12 through a connecting
< cutting
The pair of
The method of molding the
As shown in fig. 2 to 3, the
2. Method for producing foamed molded article
The method for producing a foamed molded article according to embodiment 1 of the present invention includes an extrusion step, a lower clamping step, and a molding step.
As shown in fig. 3, in the extrusion step, a molten kneaded resin containing a foaming agent is extruded from an
As shown in fig. 3 to 4, in the lower clamping step, the foamed
As shown in fig. 4 to 5, in the molding step, after the lower clamping step, the
In view of this, when the step of sucking the foamed
In the extrusion step, the thickness of the foamed
3. Foamed molded article
The method for producing an expanded molded article according to embodiment 1 can be suitably used for producing an expanded molded article having an arbitrary shape and expansion ratio, but is a method for effectively suppressing the occurrence of a bent wall, and is therefore particularly suitable for producing an expanded molded article in which the shape of a bent wall and the expansion ratio are likely to occur.
From such a viewpoint, the expansion ratio of the foamed molded article is preferably 2.5 times or more. This is because the higher the expansion ratio, the lower the strength of the foamed
As shown in fig. 6A, in one example, the foamed molded
Preferably, the blow-up ratio of the cross section S at an angle beta of 0 to 45 degrees with respect to the extrusion direction of the foamed
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