JP2899696B1 - Molding method of particle-dispersed composite material - Google Patents

Abstract

An object of the present invention is to provide a method capable of predicting a molding pressure at the time of extrusion molding in advance by using a new parameter of an effective thickness specified for each die opening shape and performing smooth molding. SOLUTION: In extrusion molding a particle-dispersed composite material, there is provided a molding method using an extrusion molding pressure obtained by an arbitrary material composition and an arbitrary extruder according to the following formula. (Equation 1) However, P: extrusion pressure (MPa) t _e: effective thickness of the die opening (cm) P _max: extrusion pressure (MP when closing the die opening
a) t _e0 : the effective thickness of the die opening at the end of the barrel (c)
m)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for forming a particle-dispersed composite material, in which cement or plastic is used as a binder and particles such as sand and wood chips are used, in particular. It provides a method of molding.

[0002]

2. Description of the Related Art A cement-based extruded member used in a building is preferably made of a particle-dispersed composite material mixed with an aggregate having a low drying shrinkage in order to reduce a dry, wet, hot and cold movement during use. Desired. However, since the pressure generated when extruding the mixture in a fresh state before the reaction hardening of the member, that is, the mechanism of generating the extrusion pressure is complicated and unclear, extrusion molding of the cement-based particle-dispersed composite material was performed. If you do
The reality is that members are manufactured through trial and error.

[0003]

SUMMARY OF THE INVENTION According to the present invention, a molding pressure at the time of extrusion molding is predicted in advance by using a new parameter of an effective thickness specified for each die opening shape, and smooth molding is performed. The purpose of the present invention is to provide a new method.

[0004]

SUMMARY OF THE INVENTION The present inventors have found that, for example, in the extrusion molding of a cement-based particle-dispersed composite material, when the shape of the die opening is changed, the composition of the material used and the extruder used are Finding that a certain relational expression is established, finding that a smooth extrusion is performed by setting a material composition and an extruder to be used to obtain a desired extrusion molding pressure based on this relational expression,
The present invention has been accomplished based on this finding.

That is, the present invention is characterized in that, when extruding a particle-dispersed composite material, an extrusion molding pressure determined according to the following equation is used in an arbitrary material composition and an arbitrary extruder. It provides a method.

(Equation 2) However, P: extrusion pressure (MPa) t _e: effective thickness of the die opening (cm) P _max: extrusion pressure (MP when closing the die opening
a) t _e0 : the effective thickness of the die opening at the end of the barrel (c)
m)

[0006] Here, the effective thickness of the die opening and the (t _e), is defined as the twice the ratio of the die opening area to the entire perimeter of the die opening to be used, which is the same ratio This corresponds to the converted thickness when assuming an infinite width plate to be obtained. The effective thickness of the die opening is such that in the barrel, that is, in the passage of the raw material, a fresh material passing through a circular or toroidal cross-section is converted into an infinitely large plate-shaped cross-section that can be identified only by the thickness. And a parameter indicating the degree of plastic deformation to be deformed. For example, when the die opening is formed in a rectangular shape having a width W and a height t, t _e = W · t / (W
+ T), and when the rectangular cross section has a shape in which n cavities having a width W ′ and a height t ′ are provided, t _e = [W · t −n ・
W ′ · t ′] / [W + t + n (W ′ + t ′)]. In the above formula 2, _Pmax shows a constant value for each composition of the sample when the same extruder is used. That is, it is a material constant that can be determined for each material composition. t _e0 is the effective thickness of the cross section near the end of the barrel at which the material is compacted, that is, the boundary with the tapered barrel, and is a mechanical constant determined by the extruder body.

[0007]

According to the method of the present invention, the optimum extrusion pressure can be determined according to the following procedure. (1) First, there raw material composition of the material (material I), extruded effective thickness by one extruder is a die with a t _e1, the molding pressure P ₁ at that time, the horizontal axis effective thickness ( t _e), is plotted on the vertical axis in FIG. 1 which is a molding pressure (P). (2) The effective thickness ( _te0 ) at the end of the barrel of the extruder is placed on the horizontal axis of FIG. (3) point (t _e1, P ₁₎ and the point (t _e0, 0) and a line connecting a straight line. The vertical axis intercept of this straight line is the extrusion molding pressure (P _max1 ) when the die opening of the material I is closed. (4) Next, using the same extruder, a different material composition material (material II) the effective thickness of extruded using a die t _e1, obtaining a molding pressure P ₂ at that time. (5) point (t _e1, P ₂₎ and (t _e0, 0) and connected by a straight line. The vertical axis intercept of this straight line is the extrusion molding pressure (P _max2 ) when closing the die opening in the material II. (6) Another effective thickness (t _e ') extrusion pressure when using a die of the point (0, t _e' a) horizontal axis, and the straight line parallel to the longitudinal axis passing through the point ( The intersection between the two straight lines corresponding to the materials I and II determined in 3) and (5) is determined. The vertical axis coordinate values P ₁ ′ and P ₂ ′ at the intersection are the optimum extrusion molding pressures when the material I and the material II are used, respectively. In this way, the optimum extrusion pressure in a certain extruder is obtained, but when the extruder is changed, it is obtained from the effective thickness ( _te0 ) of the opening shape of the barrel end with respect to the extruder. Point (0, t _e )
And a point (0, _Pmax ) on the vertical axis (actually, _Pmax1 or _Pmax1 ).
_max2 ) with a straight line. Next, when the above procedure (6) is performed in the same manner, an optimum extrusion molding pressure is obtained.

[0008] The relationship between the normal stress and the shear stress generated in a fresh material in the state of being subjected to plastic working in a tapered barrel when the shape of an extruder and a die opening is fixed is defined as a component used and a content ratio. It has been clarified that even if the material conditions change, the relationship is unambiguous, and from this finding and the relationship between the extrusion molding pressure and the effective thickness, as a result, a member having a sectional shape required for member performance is obtained. Can be predicted from the material conditions of shearing properties of the material and the mechanical conditions of effective thickness. In other words, when manufacturing extrusion molded members of various cross-sectional shapes, the extrusion molding pressure, which is the most basic manufacturing characteristic that determines the feasibility or difficulty of manufacturing, can be obtained under a combination of the following three conditions. Become.

(1) Material condition of raw material composition (2) Shape of barrel end of extruder used (3) Die opening shape The above is how the extruder and the die opening shape change. Therefore, this is an essential basic condition for smoothly and efficiently producing members having various cross-sectional shapes by extrusion molding using materials composed of components and content ratios of various materials.

[0010]

According to the present invention, by introducing a new parameter called effective thickness, any extruder can be used for extruding a particle-dispersed composite material such as a cement-based material or a waste plastics mixed material. The optimal extrusion molding pressure when using a die and an arbitrary die can be easily set.

[0011]

Next, the present invention will be described in more detail by way of examples.

Example 1 100 parts by weight of ordinary Portland cement and Toyoura standard sand 1
A cement raw material was prepared by mixing 00 parts by weight, 1 part by weight of methylcellulose (thickener), and 5 parts by weight of chrysotile (fiber additive). Next, as an extrusion molding machine, Honda "DE-50" [motor 0.75 kW, transport capacity 12 ~
25 liter / h, vacuum pump capacity 60 liter / mi
n, using a barrel inner diameter _{5.0cm (t e0 = 2.5cm)]} , the water volume ratio was extruded about what has changed in the range of 0.13 to 0.25. The opening shape of the die used at this time was 6.0 cm in width, 1.2 to 2.5 cm in height, and 1 in width.
5. a rectangle of 0.0 cm and height of 1.2 cm, and a width of 6.
It had a square cavity in a rectangle of 0 cm and a height of 2.5 cm, and the porosity was 33.85% and 45.0%. For water ratios of 0.15 and 0.20, the effective thickness t _e (cm) of the die opening and the extrusion pressure P (M
Pa) is shown in FIG. 2 as a graph. In this figure, the solid line indicates the case where the water amount ratio is 0.15.
The broken line shows the case where the water amount ratio is 0.20. From this figure, it can be seen that when using the same extruder and using dies of various opening shapes, the optimum extrusion pressure for each material composition can be set based on the effective thickness of the die opening. .

EXAMPLE 2 A molding material for high-strength non-fired ceramics, in which 1 part by weight of fine silica and 1 part by weight of a special admixture were blended with 100 parts by weight of slag, was used as an extruder for Honda "HDE-3".
[Motor 2.2kW, transport capacity 20-50 liters /
h, using a vacuum pump capacity 150 l / min, a barrel inner diameter _{7.5cm (t e0 = 1.63cm)]} , was extruded at a water volume ratio 0.12 and 0.14. FIG. 3 is a graph showing the result of obtaining the extrusion molding pressure P (MPa) with respect to the effective thickness t _e (cm) in this case. In this figure, the solid line shows the case of the water ratio of 0.12, and the broken line shows the case of the water ratio of 0.14.
Is the case. From this figure, using the same extruder,
It can be seen that when dies having various opening shapes are used, the optimum extrusion pressure for each material composition can be set based on the effective thickness of the die opening.

Example 3 A cement mortar material was prepared by mixing an equal amount of Toyoura standard sand with a gel obtained by hydrothermally reacting fly ash and quicklime. First, Miyazaki "M
V-FM "with [motor 5.5kw, carrying capacity 120 l / h, the vacuum pump capacity 50 l / min, a barrel diameter _{10.0cm (t e0 = 5.0cm)]} , the water volume ratio 0.30 and 0 Extrusion molding was performed for the material having a diameter of 0.35. At this time, the effective thickness t _e of the die and the extrusion pressure P
Is shown in FIG. In this figure, the solid line shows a case where the water ratio is 0.35, and the broken line shows a case where the water ratio is 0.30.
From this figure, it can be seen that when the same extruder is used and dies having various opening shapes are used, the optimum extrusion molding pressure for each material composition can be set based on the effective thickness of the die opening. Next, the same molding machine ( _te0 = 2.5 cm) as that used in Example 1 was used as the extrusion molding machine, and the water ratio was set to 0.3.
Extrusion molding was carried out using the ratios of 5 and 0.30. Relationship of the effective thickness of the die opening and the (t _e) and extrusion pressure (P) at this time, now indicated by the solid line in FIG. 4, respectively and the broken line. As can be seen from this figure, the point (0,
P _max ), (0, P _max1 ) or (0, P _max
and _max2), a point on the horizontal axis of the effective thickness of the extruder (t _e0) used, i.e. (t _e0, 0), in FIG. 4 (t
Since there is an optimum extrusion molding pressure when using dies having various opening shapes on a line connecting ( _e01 , 0) or ( _te02 , 0), another type of extruder ( _te0 ') is used by using a certain material. )), The point (0, P ′ _max ) and ( _te 0 ′) can be obtained as long as the extrusion pressure (P ′ _max ) when the die opening of the material is closed is obtained. , 0) the effective thickness of and the straight line connecting the used die opening (t _e)
Can be obtained as an intersection with a straight line parallel to the vertical axis on the horizontal axis.

[Brief description of the drawings]

FIG. 1 is a graph for explaining a relational expression in the method of the present invention.

FIG. 2 is a graph showing a relationship between an effective thickness of a die opening and an extrusion molding pressure in Example 1.

FIG. 3 is a graph showing a relationship between an effective thickness of a die opening and an extrusion pressure in Example 2.

FIG. 4 is a graph showing the relationship between the effective thickness of the die opening and the extrusion pressure in Example 3.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ identification code FI C04B 24:38 20:00) (58) Field surveyed (Int.Cl. ⁶ , DB name) B28B 3/20 B28B 3/26

Claims (1)

(57) [Claims] 1. A molding method wherein an extrusion molding pressure determined according to the following formula is used in an arbitrary material composition and an arbitrary extruder when extruding a particle-dispersed composite material. (Equation 1) However, P: extrusion pressure (MPa) t _e: effective thickness of the die opening (cm) P _max: extrusion pressure (MP when closing the die opening
a) t _e0 : the effective thickness of the die opening at the end of the barrel (c)
m)