JPH036881B2 - - Google Patents
Info
- Publication number
- JPH036881B2 JPH036881B2 JP2169685A JP2169685A JPH036881B2 JP H036881 B2 JPH036881 B2 JP H036881B2 JP 2169685 A JP2169685 A JP 2169685A JP 2169685 A JP2169685 A JP 2169685A JP H036881 B2 JPH036881 B2 JP H036881B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- slip
- water
- slip casting
- binder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 39
- 238000000034 method Methods 0.000 claims description 26
- 238000007569 slipcasting Methods 0.000 claims description 19
- 239000011230 binding agent Substances 0.000 claims description 18
- 238000000465 moulding Methods 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 13
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 5
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 229920002401 polyacrylamide Polymers 0.000 claims description 5
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 5
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 5
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 5
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 5
- 239000003232 water-soluble binding agent Substances 0.000 claims description 5
- 229920001577 copolymer Polymers 0.000 claims description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 3
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 3
- 239000002202 Polyethylene glycol Substances 0.000 claims description 3
- 229920000609 methyl cellulose Polymers 0.000 claims description 3
- 239000001923 methylcellulose Substances 0.000 claims description 3
- 229920001223 polyethylene glycol Polymers 0.000 claims description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 2
- 229920000084 Gum arabic Polymers 0.000 claims description 2
- 241000978776 Senegalia senegal Species 0.000 claims description 2
- 229920002472 Starch Polymers 0.000 claims description 2
- 239000000205 acacia gum Substances 0.000 claims description 2
- 235000010489 acacia gum Nutrition 0.000 claims description 2
- 229920006243 acrylic copolymer Polymers 0.000 claims description 2
- 239000003292 glue Substances 0.000 claims description 2
- 239000008107 starch Substances 0.000 claims description 2
- 235000019698 starch Nutrition 0.000 claims description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 claims 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims 1
- 230000001737 promoting effect Effects 0.000 claims 1
- 239000011505 plaster Substances 0.000 description 10
- 239000000919 ceramic Substances 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000007711 solidification Methods 0.000 description 4
- 230000008023 solidification Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000004576 sand Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 229920002153 Hydroxypropyl cellulose Polymers 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 229910052602 gypsum Inorganic materials 0.000 description 2
- 239000010440 gypsum Substances 0.000 description 2
- 239000001863 hydroxypropyl cellulose Substances 0.000 description 2
- 235000010977 hydroxypropyl cellulose Nutrition 0.000 description 2
- NNPPMTNAJDCUHE-UHFFFAOYSA-N isobutane Chemical compound CC(C)C NNPPMTNAJDCUHE-UHFFFAOYSA-N 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910052845 zircon Inorganic materials 0.000 description 2
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- 229920006328 Styrofoam Polymers 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000004794 expanded polystyrene Substances 0.000 description 1
- 239000001282 iso-butane Substances 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 239000003002 pH adjusting agent Substances 0.000 description 1
- 238000001272 pressureless sintering Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229920002631 room-temperature vulcanizate silicone Polymers 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000008261 styrofoam Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
Landscapes
- Producing Shaped Articles From Materials (AREA)
- Powder Metallurgy (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は例えばセラミツク粒、金属粒などの粒
子のスリツプ（泥しよう）を鋳込んで成形品を造
るスリツプキヤステイング成形方法及び成形用鋳
型に係り、特に複雑形状の成形品を造るに好適な
成形方法及び成形用鋳型に関する。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a slip casting molding method for producing a molded product by casting slips of particles such as ceramic grains and metal grains, and a mold for molding. In particular, the present invention relates to a molding method and mold suitable for producing molded products with complex shapes.
セラミツクスのスリツプキヤステイングに用い
る鋳型は、通常、割り型とし更に抜き勾配をつけ
ることによつて、スリツプ鋳込後の鋳型を固化後
のスリツプ成形体（以下「グリーンボデイ」と称
す）から分離する。そして、得られたグリーンボ
デイを焼結することにより完成セラミツクス品と
する。
The mold used for slip casting of ceramics is usually a split mold and a draft angle is added to separate the mold after slip casting from the solidified slip molded body (hereinafter referred to as "green body"). . The obtained green body is then sintered to produce a finished ceramic product.
外観形状および空洞部の形状が複雑で寸法精度
の高い成形体をスリツプキヤステイングで成形す
る場合、従来は多数個の主型や中子を組合せて所
望の鋳型とする方法が一般的であつた。しかし、
この方法は多数個の主型や中子の製作および組立
に多くの工数が掛ると共に、グリーンボデイの脱
湿過程および鋳型、中子の取外し過程でグリーン
ボデイに割れが発生しやすい。 When molding a molded product with a complex external shape and cavity shape and high dimensional accuracy using slip casting, the conventional method was to combine a large number of main molds and cores to form the desired mold. . but,
This method requires a large number of man-hours to manufacture and assemble a large number of main molds and cores, and the green body is likely to crack during the process of dehumidifying the green body and removing the mold and core.
また、中子が、固化後のスリツプ成形体から引
き抜くことの出来るような形状の場合にしか適用
できない。 Further, this method can only be applied when the core has a shape that allows it to be pulled out from the slip molded product after solidification.
そこで、このような場合にスリツプ鋳込後の鋳
型を除去する方法として、例えば特公昭58−
125658号公報に開示されているように鋳型を組込
んだまま焼結し、その後鋳型を崩壊除去する方法
がある。しかし、この方法は鋳型を組込んだまま
大気中放置等によりグリーンボデイを乾燥するた
め、また鋳型を組込んだまま焼結するため、形状
が複雑なものでは乾燥時および焼結時に生じる鋳
型およびグリーンボデイの収縮・変形により成形
品に割れが生じる。また、この引例はその構成か
ら判断すると、中子の使用を想定していないと考
えられる。 Therefore, as a method for removing the mold after slip casting in such cases, for example,
As disclosed in Japanese Patent Publication No. 125658, there is a method in which sintering is performed with the mold installed, and then the mold is disintegrated and removed. However, with this method, the green body is dried by leaving it in the air with the mold installed, and the green body is sintered with the mold installed. Cracks occur in the molded product due to shrinkage and deformation of the green body. Also, judging from its structure, this reference does not assume the use of cores.
一方、特開昭57−176107号公報に開示されるよ
うに熱水崩壊性石膏鋳型にスリツプを流し込み、
スリツプが固化しグリーンボデイとなつたのち、
（グリーンボデイ＋鋳型）を約85℃以上の熱水に
浸漬して石膏鋳型を除去する方法がある。 On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 57-176107, a slip is poured into a hydrothermally disintegrable gypsum mold,
After the slip hardens and becomes a green body,
There is a method to remove the plaster mold by immersing the (green body + mold) in hot water of approximately 85℃ or higher.
しかし、この方法は浸漬中にグリーンボデイが
吸水により崩壊することを防ぐために比較的多量
（0.5〜５％）の粘結剤をスリツプ中に添加してお
り、これが焼結品の機械的性質に影響を与える。
また鋳型の奥部まで熱水で崩壊させるには長時間
を要する場合があり、条件によつては鋳型の除去
が極めて困難である。 However, in this method, a relatively large amount (0.5-5%) of binder is added to the slip to prevent the green body from disintegrating due to water absorption during soaking, which affects the mechanical properties of the sintered product. influence
In addition, it may take a long time to disintegrate deep parts of the mold with hot water, and depending on the conditions, it may be extremely difficult to remove the mold.
すなわち、細長い中子（すなわち長さ／直径の
値が大きい中子）などを熱水崩壊性鋳型でつくり
周囲にスリツプを鋳込んだ場合、中子全表面積に
占める熱水接触面積の割合が小さければ小さいほ
ど鋳型除去には長時間を要する。 In other words, when a long and slender core (i.e. a core with a large length/diameter value) is made using a hot water disintegrable mold and a slip is cast around it, the proportion of the hot water contact area to the total surface area of the core is small. The smaller the mold, the longer it takes to remove the mold.
本発明は上記に鑑み、スリツプの固化直後に鋳
型の除去を可能とすることにより、成形品の割れ
防止および複雑形状品の成形に好適なスリツプキ
ヤステイング成形方法および成形用鋳型を提供す
ることを目的とする。
In view of the above, it is an object of the present invention to provide a slip casting molding method and a mold that are suitable for preventing cracking of molded products and for molding complex-shaped products by making it possible to remove the mold immediately after solidification of the slip. purpose.
本発明は鋳型内に水もしくは有機溶剤を媒液と
したスリツプを鋳込み、スリツプの固化後に鋳型
を除去する成形方法において、前記鋳型を水溶性
の有機粘結剤で造型することを特徴とするもので
ある。
The present invention is a molding method in which a slip using water or an organic solvent as a medium is cast into a mold and the mold is removed after the slip has solidified, characterized in that the mold is molded with a water-soluble organic binder. It is.
この場合の鋳型骨材にはアルミナ（Al2O3）、
マグネシヤ（MgO）、ジルコンサンド、珪砂など
の耐火性粒子もしくは使用するスリツプの媒液に
不溶性の樹脂粒子などを用いる。 In this case, the mold aggregate is alumina (Al 2 O 3 ),
Use refractory particles such as magnesia (MgO), zircon sand, silica sand, or resin particles that are insoluble in the slip medium used.
また水溶性の合成有機粘結剤としては、ポリビ
ニルアルコール（PVA）、水溶性のイソブタン−
無水マレイン酸共重合体、ポリアクリルアミド
（PAAm）、ポリエチレンオキサイド（PEO）、ポ
リビニルピロリドン（PVP）、水溶性の酢酸ビニ
ル共重合体、アクリル系共重合体、ポリエチレン
グリコール（PEG）、メチルセルロース（MC）、
カルボキシメチルセルロース（CMC）、ヒドロキ
シプロピルセルロース（HPC）、水溶性ワツクス
などのうち１つ若しくは２つ以上の有機物を水に
溶解した形で用いる。あるいは、デンプン、ニカ
ワ、アラビアゴムなどの天然水溶性粘結剤でも良
い。 Water-soluble synthetic organic binders include polyvinyl alcohol (PVA) and water-soluble isobutane.
Maleic anhydride copolymer, polyacrylamide (PAAm), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), water-soluble vinyl acetate copolymer, acrylic copolymer, polyethylene glycol (PEG), methylcellulose (MC) ,
One or more organic substances such as carboxymethyl cellulose (CMC), hydroxypropyl cellulose (HPC), and water-soluble wax are used in the form of a solution in water. Alternatively, natural water-soluble binders such as starch, glue, and gum arabic may be used.
骨機、粘結剤および水の混合割合は鋳型造型時
の作業性、鋳型乾燥強度、スリツプ中の溶媒（水
もしくは有機溶剤、たとえばエタノール、アセト
ン）の吸収性、水分吸収後の、鋳型の崩壊性など
によつてケースバイケースで決定される値であり
画一的にきまるものではない。 The mixing ratio of bone machine, binder, and water depends on the workability during mold making, mold dry strength, absorption of solvent (water or organic solvents such as ethanol, acetone) in the slip, and mold collapse after absorption of water. This value is determined on a case-by-case basis depending on gender, etc., and is not fixed uniformly.
しかし、一応の目やすを云えば骨材粒子；100
重量部に対し、粘結剤；５〜10重量部、水分；20
〜30重量部である。 However, for a rough estimate, aggregate particles: 100
Binder: 5 to 10 parts by weight, water: 20 parts by weight
~30 parts by weight.
上記鋳型に水を媒液としたスリツプを鋳込んだ
場合、薄肉の鋳型ではスリツプ中の水分のみで鋳
型を崩壊させることが出来るが、厚肉のもので崩
壊に十分な水分量をスリツプから得ることができ
ないものでは、(i)鋳型肉厚を薄くすることが好ま
しく、このため厚肉中子では内部に空洞を設ける
(ii)外部より鋳型に水分を添加し鋳型の崩壊性を向
上させる、(iii)、(i)(ii)を併用するなどの方法を採る
と更に有効である。 When a slip using water as a medium is cast into the above-mentioned mold, if the mold is thin, the mold can collapse with only the moisture in the slip, but if the mold is thick, enough moisture can be obtained from the slip to cause the slip to collapse. (i) It is preferable to reduce the mold wall thickness, and for this reason, in the case of thick-walled cores, a cavity is provided inside.
It is even more effective to employ methods such as (ii) adding moisture to the mold from the outside to improve the disintegration of the mold, and using (iii), (i) and (ii) together.
すなわち、鋳型肉厚を出来るだけ薄くしておく
こと、また主型もしくは中子に適宜な空孔を１ケ
もしくは多数個設けておき水分添加を容易ならし
めること、などの施策が鋳型の崩壊除去に有効で
ある。 In other words, measures such as keeping the mold wall thickness as thin as possible, and providing one or more appropriate holes in the main mold or core to facilitate the addition of moisture are effective in eliminating mold collapse. It is effective for
また水分添加の方法として、噴霧状にして添加
することも有効である。さらには高湿度のチヤン
バーの中に（鋳型＋グリーンボデイ）を所定時間
放置し鋳型に吸湿させることも鋳型崩壊除去の一
方法である。 Furthermore, as a method of adding water, it is also effective to add it in the form of a spray. Furthermore, leaving the mold (mold + green body) in a high-humidity chamber for a predetermined period of time to allow the mold to absorb moisture is also a method for removing mold collapse.
本発明において、水溶性の有機粘結剤で骨材粒
子を固めて造型した鋳型に水を媒液としたスリツ
プを鋳込み、鋳型がスリツプ中の水分を吸収して
スリツプが固化し、同時に鋳型が崩壊容易になる
現象は次の通りである。 In the present invention, a slip using water as a medium is cast into a mold made by hardening aggregate particles with a water-soluble organic binder, and the slip is solidified as the mold absorbs water in the slip. The phenomena that make it easier to collapse are as follows.
第１図ａ，ｂ，ｃに示すように、鋳型の骨材粒
子１は未乾燥の状態では水溶性の有機粘結剤２で
被覆されているが（ａ参照）、乾燥され硬化した
鋳型では水分は蒸発して内部に多数の微細な空孔
３が形成され、このような鋳型にスリツプを鋳込
むとスリツプ中の媒液である水は毛管現象で空孔
３内に浸入して水溶性粘結剤２を溶解させるの
で、その粘結力を大幅に弱め、各々の骨材粒子１
を独立させる。（ｃ参照）。 As shown in Figure 1 a, b, and c, the aggregate particles 1 of the mold are coated with a water-soluble organic binder 2 in the undried state (see a), but in the dried and hardened mold, The water evaporates and a large number of fine pores 3 are formed inside, and when a slip is cast into such a mold, water, which is the medium in the slip, enters the pores 3 by capillary action and becomes water-soluble. Since the binder 2 is dissolved, its cohesive force is greatly weakened, and each aggregate particle 1
make independent. (see c).
この現象をマクロ的にみると、鋳型はスリツプ
中の水を吸収するに従い、スリツプとの界面より
徐々に深部まで崩壊可能な状態に移行するが、他
方スリツプは媒液としての水を放出するに従い密
度が上昇するので固化の程度を強め、遂にはグリ
ーンボデイの生成に至る。 Looking at this phenomenon from a macroscopic perspective, as the mold absorbs water from the slip, it gradually transitions to a state where it can collapse deeper than the interface with the slip, but on the other hand, as the slip releases water as a medium, As the density increases, the degree of solidification increases, eventually leading to the formation of a green body.
このグリーンボデイは、その後の脱水過程で、
少しづつ収縮する。反面、鋳型は水分を吸うので
僅かであるが膨潤傾向となる。 During the subsequent dehydration process, this green body
It shrinks little by little. On the other hand, since the mold absorbs moisture, it tends to swell, albeit slightly.
通常の石膏鋳型は、スリツプ中の水分を吸収し
ても強度低下することはないので、グリーンボデ
イの収縮、鋳型の膨潤過程で発生するストレスに
よりグリーンボデイに割れが発生しやすい。 Normal gypsum molds do not lose their strength even if they absorb water in the slip, so the green body tends to crack due to the stress generated during the shrinkage of the green body and the swelling process of the mold.
しかるに本発明においては、鋳型は水分吸収に
伴なつて軟化するのでグリーンボデイの生成過程
で発生する収縮などの微少変形を、鋳型は全く阻
害することがない。換言すればグリーンボデイは
鋳型（主型や中子）から何らの外力を受けること
がないので、グリーンボデイには何らのストレス
も発生せず、したがつて割れは全く発生しない。 However, in the present invention, since the mold softens as it absorbs water, the mold does not impede minute deformations such as shrinkage that occur during the green body production process. In other words, since the green body is not subjected to any external force from the mold (main mold or core), no stress is generated on the green body, and therefore no cracks occur at all.
したがつて成形品が複雑なために鋳型も複雑な
場合や、特に中子を用いる場合でも奥部まで各部
が等しく、スリツプから崩壊除去に必要な水分を
吸収するので鋳型各部は均等に崩壊可能となる。 Therefore, even if the mold is complex because the molded product is complex, or especially when a core is used, each part of the mold is equally disintegrated down to the depths, and each part of the mold can disintegrate evenly because it absorbs the moisture necessary for disintegration removal from the slip. becomes.
なお、鋳型肉厚が大きい場合などで、スリツプ
中の水分量のみでは鋳型除去に不十分の場合は、
外部よりの水分添加が有効であることは前述した
通りである。 In addition, if the moisture content in the slip alone is insufficient to remove the mold, such as when the mold wall thickness is large,
As mentioned above, adding water from the outside is effective.
鋳型の造型は骨材粒子、水溶性粘結剤、および
水の混練物をつき固めて行なわれるが、鋳型材料
に流動性を付与すれば造型時間を短縮できる。 A mold is formed by compacting a mixture of aggregate particles, a water-soluble binder, and water, but the molding time can be shortened by imparting fluidity to the mold material.
流動性を付与するには基本的には水分量を増や
せば良い訳である。しかし多量の水分は蒸発させ
るのに容易ではない。 Basically, to impart fluidity, it is sufficient to increase the water content. However, large amounts of water are not easy to evaporate.
そこで別法として、常温で水和物の形が安定な
水溶性粘結剤のアルコール溶液を作り、これに結
晶水として固定されるに必要な量もしくはそれよ
り若干少量の水を添加することにより鋳型に流動
性を付与すると良い。 Therefore, an alternative method is to prepare an alcoholic solution of a water-soluble binder that is stable in the form of a hydrate at room temperature, and add to this an amount of water necessary for fixation as crystal water, or a slightly smaller amount of water. It is good to give fluidity to the mold.
以上、述べたように、鋳型の軟化はスリツプの
固化と同時に進行するので、複雑形状のセラミツ
クス成形品を割れの全くない状態で、極めて容易
に成形できる。 As mentioned above, since the softening of the mold progresses simultaneously with the solidification of the slip, complex-shaped ceramic molded products can be molded extremely easily without any cracks.
また本発明は有機粘結剤を用いるので、無材の
水溶性粘結剤（たとえばK2CO3）を用いた場合
のように(i)水溶性鋳型と石膏鋳型を組合せて使用
した場合に石膏鋳型が浸食され、石膏鋳型の繰返
し使用回数が極めて少なくなること、(ii)水溶性鋳
型中の粘結剤がグリーンボデイ中に拡散すること
により成形品の品質劣化を起し易い、(iii)スリツプ
と反応したり、スリツプのPHに影響する、などの
問題点を全く有しない。 Furthermore, since the present invention uses an organic binder, as in the case of using a solid water-soluble binder (for example, K 2 CO 3 ), (i) when a water-soluble mold and a plaster mold are used in combination, (ii) The binder in the water-soluble mold diffuses into the green body, causing quality deterioration of the molded product; (iii) ) It does not have any problems such as reacting with the slip or affecting the pH of the slip.
また別の従来法のように焼結前に（鋳型＋グリ
ーンボデイ）を温水中に浸漬する必要もなく、形
状に全く制限なくスリツプキヤステイング成形に
よる焼結品が得られる。 Further, unlike other conventional methods, there is no need to immerse (mold + green body) in hot water before sintering, and a sintered product can be obtained by slip casting molding without any restrictions on shape.
以下に本発明の実施例について述べる。 Examples of the present invention will be described below.
実施例 １
Al2O3（250〜325メツシユ）；100重量部、濃度
５％のポリビニルアルコール（PVA）の水溶
液；20重量部添加して均一に混合し鋳型材とす
る。Example 1 Al 2 O 3 (250-325 meshes); 100 parts by weight, aqueous solution of polyvinyl alcohol (PVA) with a concentration of 5%; 20 parts by weight were added and mixed uniformly to form a mold material.
別途準備した木型により第２図に示す中子４を
上記鋳型材で造型し、また石膏製の主型５，６を
造型した。中子４は100℃で充分乾燥し硬化させ
た。また石膏製の主型５，６は60℃で充分乾燥し
た。その後、これらの主型および中子を組立て所
定の鋳型空洞を形成させた。 The core 4 shown in FIG. 2 was molded from the above molding material using a wooden mold prepared separately, and main molds 5 and 6 made of plaster were also molded. Core 4 was sufficiently dried and hardened at 100°C. Furthermore, main molds 5 and 6 made of plaster were sufficiently dried at 60°C. Thereafter, these main molds and cores were assembled to form a predetermined mold cavity.
次に平均粒径2μｍのAl2O3；100重量部、水；
16重量部に微量の解こう剤、及びPH調整剤を加え
て均一に混合して作成したアルミナスリツプ８を
上記鋳型の空洞部７に鋳込んで１時間放置した。 Next, Al 2 O 3 with an average particle size of 2 μm; 100 parts by weight, water;
An alumina strip 8 prepared by uniformly mixing 16 parts by weight of a peptizer and a pH adjuster was cast into the cavity 7 of the mold and left for one hour.
スリツプ固化後、石膏主型５，６をとり外し
た。中子４はスリツプ中の水分を吸収しているた
め、粘結力は極端に低下しており容易に崩壊し
除々することができた。またグリーンボデイにも
割れの発生は全く認められなかつた。 After the slip hardened, the plaster main molds 5 and 6 were removed. Since the core 4 had absorbed the moisture in the slip, its cohesive strength was extremely low, and it could be easily disintegrated and removed. Furthermore, no cracking was observed in the green body.
実施例 ２
Al2O3（250〜325メツシユ）；100重量部、ポリ
アクリルアミド（PAAm）の５％水溶液20重量
部、を混練して鋳型材を調製し、実施例１に準じ
て、別途準備した木型を用いて造型し、その後
100℃で充分乾燥硬化させて中子を造り、別途造
型した石膏主型５，６と共に組立てた。これにサ
イアロン粉末；100重量部、水；40重量部、解こ
う剤、焼結助剤などを添加して均一に混合したサ
イアロンスリツプ８を鋳型空洞７に鋳込んで１時
間放置した。その結果、実施例１と同様に中子４
は容易に除去でき、グリーンボデイに割れの発生
は認められなかつた。Example 2 A mold material was prepared by kneading 100 parts by weight of Al 2 O 3 (250-325 mesh) and 20 parts by weight of a 5% aqueous solution of polyacrylamide (PAAm), and prepared separately according to Example 1. The mold is made using a wooden mold, and then
A core was made by sufficiently drying and curing at 100°C, and assembled together with separately molded plaster main molds 5 and 6. Sialon slip 8, in which 100 parts by weight of Sialon powder, 40 parts by weight of water, peptizer, sintering aid, etc. were added and mixed uniformly, was cast into mold cavity 7 and left for one hour. As a result, as in Example 1, the core 4
could be easily removed, and no cracks were observed on the green body.
実施例 ３
本発明の方法、鋳型を用いて第４図に示す形状
のケーシングをスリツプキヤステイングで作成す
ることにした。このケーシングはフランジ９、締
結用溝１０、内部は渦巻状の流路１１を有し極め
て複雑な形状をしているので、従来の鋳型を用い
るスリツプキヤステイング法では成形不可能であ
つた。Example 3 A casing having the shape shown in FIG. 4 was created by slip casting using the method and mold of the present invention. Since this casing has an extremely complicated shape including a flange 9, a fastening groove 10, and a spiral flow passage 11 inside, it was impossible to mold it by the slip casting method using a conventional mold.
ジルコンサンド（250〜325粉末）；100重量部、
５％ポリビニルピロリドン（PVP）水溶液；15
重量部を均一に混合して鋳型材を調整し別途準備
した硬質Siゴム製の中子取りに充填し渦巻状中子
を作成し、その後100℃で充分乾燥し、別途造型
した石膏製の半割り方式の主型と共に鋳型を組立
てた。その後、実施例１と同様のアルミナスリツ
プを鋳込んで２時間放置した。 Zircon sand (250-325 powder); 100 parts by weight,
5% polyvinylpyrrolidone (PVP) aqueous solution; 15
Mix the weight parts uniformly to adjust the mold material, fill it into a separately prepared hard Si rubber core holder to create a spiral core, then thoroughly dry it at 100℃, and mold it into a separately molded plaster half. The mold was assembled along with the main mold for the split method. Thereafter, an alumina strip similar to that in Example 1 was cast and left for 2 hours.
その後、石膏製の主型を取り外した。本発明に
よる水崩壊性の渦巻状中子は、スリツプ中の水分
を充分に吸収しているので、鋳型の粘結力は大幅
に低下しており簡単に崩壊除去できた。 Afterwards, the main plaster mold was removed. Since the water-disintegratable spiral core according to the present invention sufficiently absorbs the moisture in the slip, the cohesive force of the mold was significantly reduced and it could be easily disintegrated and removed.
このアルミナ質グリーンボデイを大気乾燥した
のち100℃で乾燥（遊離水分を完全に除去）した
のち常温より徐熱し1700℃×2H加熱することに
より割れのない機械的諸性質の良好なアルミナ焼
結品としてのケーシングが得られた。 This alumina green body is air-dried, then dried at 100℃ (completely removing free moisture), then slowly heated from room temperature and heated to 1700℃ for 2 hours to create an alumina sintered product with no cracks and good mechanical properties. A casing was obtained.
実施例 ４
第４図に示すネジ状ロータの成形に本発明を適
用した。Example 4 The present invention was applied to molding a threaded rotor shown in FIG.
このような形状の場合、石膏鋳型による従来の
スリツプキヤステイング法では鋳型を極めて多数
個に分割する必要が生じ寸法精度の低下、バリの
多発脱鋳型時のグリーンボデイの破損などにより
成形は極めて困難であつた。そこで発泡ポリスチ
ロールにより、第４図と同一のネジ状模型を別
途、金型を用いて発泡成形した。この模型１２の
頂部１５を除く全表面に１液性のRTVシリコン
ゴムを約50μｍの厚さに塗布し硬化させ不溶性皮
覆膜１３を形成させた。 In the case of such a shape, it is extremely difficult to mold the mold using the conventional slip casting method using a plaster mold, which reduces dimensional accuracy due to the need to divide the mold into an extremely large number of pieces, and causes damage to the green body when removing the mold due to a large number of burrs. It was hot. Therefore, a screw-shaped model identical to that shown in FIG. 4 was separately foam-molded from expanded polystyrene using a mold. One-component RTV silicone rubber was applied to the entire surface of the model 12 except for the top 15 to a thickness of about 50 μm and cured to form an insoluble coating film 13.
この模型の頂部を図示せざる定盤上に設置し、
その周囲に木枠を設備する。次にAl2O3粒子；
100重量部、５％の酢酸ビニルエマルジヨン水溶
液；40重量部を添加し均一に混合し鋳型材１４を
作成し、ロータ模型の周囲に充填した。次に模型
１２の頂部１５よりアセトンを噴霧状にして吹付
け発泡スチロール模型の体積を約1/30に収縮さ
せ、そのまま鋳型を100℃で乾燥硬化させたのち、
再度スチロール模型にアセトンを吹付け表面に塗
布したゴム皮膜と共に鋳型外に摘出除去し、その
後100Cで乾燥し硬化せしめた。 Place the top of this model on a surface plate (not shown),
Set up a wooden frame around it. Then Al 2 O 3 particles;
40 parts by weight of 100 parts by weight, 5% vinyl acetate emulsion aqueous solution were added and mixed uniformly to prepare a mold material 14, which was filled around the rotor model. Next, acetone was sprayed from the top 15 of the model 12 to shrink the volume of the sprayed Styrofoam model to about 1/30, and the mold was dried and hardened at 100°C.
Acetone was again sprayed onto the styrene model and removed from the mold together with the rubber film applied to the surface, followed by drying and hardening at 100C.
このようにして出来た鋳型空洞部１６に実施例
２と同様なサイアロンスリツプ１７を鋳込み鋳型
にスリツプ中の水分を吸収させ、固化させた。こ
の時、本発明による鋳型は水分の吸収により鋳型
の粘結力が激減したので崩壊性が極めて良くな
り、ロータのネジ状部を破損することなくグリー
ンボデイを得ることができた。 A Sialon slip 17 similar to that of Example 2 was cast into the mold cavity 16 thus formed, and the moisture in the slip was absorbed into the mold and solidified. At this time, the mold according to the present invention had extremely good disintegration properties because the caking force of the mold was drastically reduced due to absorption of water, and a green body could be obtained without damaging the threaded portion of the rotor.
このサイアロン質グリーンボデイを大気中で
徐々に乾燥したのち100℃の炉中で乾燥し遊離水
分を完全に除去したのち常温より徐熱し1800℃×
2Hで常圧焼結し均質なサイアロン質のロータ焼
結品を得た。 This sialon green body was gradually dried in the air, then dried in a 100℃ oven to completely remove free moisture, and then slowly heated from room temperature to 1800℃
A homogeneous sialon rotor sintered product was obtained by pressureless sintering for 2 hours.
以上説明したように、本発明によれば水溶性の
有機粘結剤を不溶性の骨材粒子、たとえばAl2O3
粉などに混ぜて鋳型を造型し、媒液として水もし
くは水を主体としたセラミツクス等のスリツプを
鋳型むので鋳型はスリツプから水分を吸収して軟
化し崩壊容易となり、同時に水分を吸収されたス
リツプは経時的に密度を上昇させ固化し遂にはグ
リーンボデイとなる。
As explained above, according to the present invention, a water-soluble organic binder is mixed with insoluble aggregate particles, such as Al 2 O 3
The mold is mixed with powder, etc. to make a mold, and a slip of water or water-based ceramics is used as the medium, so the mold absorbs water from the slip and becomes soft and easily disintegrates. increases its density over time and solidifies, eventually becoming a green body.
したがつて本発明によれば、セラミツクス品の
成形に際し次の効果がもたらされる。 Therefore, according to the present invention, the following effects are brought about when molding ceramic products.
(i) スリツプの固化と共に鋳型が軟化するので形
状複雑な主型や中子を使う場合であつてもグリ
ーンボデイには全く割れが発生しない。(i) Since the mold softens as the slip hardens, no cracks will occur in the green body even when using a main mold or core with a complex shape.
(ii) スリツプから水分を吸収して鋳型は軟化する
ので凹凸の大きいこみいつた主型および中子を
必要とする複雑形状の成形品であつても容易に
成形できる。(ii) Since the mold softens by absorbing moisture from the slip, it is possible to easily mold even complex-shaped molded products that require a highly uneven main mold and core.
第１図ａ，ｂ，ｃは本発明の成形に用いる鋳型
の原理を示す説明図、第２図は本発明成形法の実
施例の説明図、第３図、第４図は本発明適用の成
形品の外観図、第５図〜第７図は本発明成形法の
説明図である。
１……鋳型骨材粒子、２……水溶性の有機粘結
剤、３……空孔、４……水崩壊性の中子、１４…
…水崩壊性の主型、５，６……石膏製の主型、
７，１６……鋳型空洞、８，１７……セラミツク
スリツプ、１３……不溶性被覆膜。
Figures 1a, b, and c are explanatory diagrams showing the principle of the mold used for molding of the present invention, Figure 2 is an explanatory diagram of an embodiment of the molding method of the present invention, and Figures 3 and 4 are illustrations of the mold to which the present invention is applied. The external view of the molded product and FIGS. 5 to 7 are explanatory diagrams of the molding method of the present invention. DESCRIPTION OF SYMBOLS 1...Mold aggregate particles, 2...Water-soluble organic binder, 3...Void, 4...Water-disintegratable core, 14...
...Water-disintegratable main mold, 5,6...Main mold made of plaster,
7, 16... Mold cavity, 8, 17... Ceramic strip, 13... Insoluble coating film.
Claims (1)
後に鋳型を除去するスリツプキヤステイング成形
方法において、前記鋳型を有機質の水溶性粘結剤
で造型し、該鋳型がスリツプ中の水分を吸収して
該スリツプを固化させると共に、該鋳型は水分吸
収に伴つて崩壊し易くさせることを特徴とするス
リツプキヤステイング成形方法。 ２ スリツプが固化しグリーンボデイとなつた
後、外部より鋳型に水分を添加することにより鋳
型の崩壊性を助長することを特徴とする特許請求
の範囲第１項記載のスリツプキヤステイング成形
方法。 ３ 鋳型骨材と粘結剤で造型してなるスリツプキ
ヤステイング成形用鋳型において、前記粘結剤は
水溶性の有機粘結剤とすることを特徴とするスリ
ツプキヤステイング成形用鋳型。 ４ 鋳型骨材が耐火性粒子であることを特徴とす
る特許請求の範囲第３項記載のスリツプキヤステ
イング成形用鋳型。 ５ 有機粘結剤は、ポリビニールアルコール、イ
ソブタン−無水マレイン酸共重合体、ポリアクリ
ルアミド、ポリエチレンオキサイド、ポリビニル
ピロリドン、酢酸ビニル共重量体、アクリリ系共
重合体、ポリエチレングリコール、メチルセルロ
ース、カルボキシメチルセルロース、ヒドロキシ
プロピルセルロース、水溶性ワツクスの内１また
は２以上のものを水に溶解して用いることを特徴
とする特許請求の範囲第３項記載のスリツプキヤ
ステイング成形用鋳型。 ６ 有機粘結剤は、デンプン、ニカワ、アラビア
ゴムの内１または２以上のものを水に溶解して用
いることを特徴とする特許請求の範囲第３項記載
のスリツプキヤステイング成形用鋳型。 ７ 有機粘結剤にアルコールを添加して鋳型に流
動性を付与することを特徴とする特許請求の範囲
第５項又は第６項記載のスリツプキヤステイング
成形用鋳型。 ８ 更に崩壊性を助長させるための空洞を設けた
ことを特徴とする特許請求の範囲第３項記載のス
リツプキヤステイング成形用鋳型。[Scope of Claims] 1. In a slip casting molding method in which a slip is cast into a mold and the mold is removed after the slip has solidified, the mold is molded with an organic water-soluble binder, and the mold absorbs moisture in the slip. 1. A slip casting molding method, characterized in that the slip is solidified by absorbing water, and the mold is made to easily collapse due to water absorption. 2. The slip casting molding method according to claim 1, wherein after the slip has solidified to form a green body, moisture is added to the mold from the outside to promote disintegration of the mold. 3. A slip casting mold made of a mold aggregate and a binder, wherein the binder is a water-soluble organic binder. 4. The slip casting mold according to claim 3, wherein the mold aggregate is refractory particles. 5 Organic binders include polyvinyl alcohol, isobutane-maleic anhydride copolymer, polyacrylamide, polyethylene oxide, polyvinylpyrrolidone, vinyl acetate copolymer, acrylic copolymer, polyethylene glycol, methylcellulose, carboxymethylcellulose, hydroxy 4. The slip casting mold according to claim 3, wherein one or more of propylcellulose and water-soluble wax are dissolved in water. 6. The slip casting mold according to claim 3, wherein the organic binder is one or more of starch, glue, and gum arabic dissolved in water. 7. The mold for slip casting molding according to claim 5 or 6, characterized in that alcohol is added to the organic binder to impart fluidity to the mold. 8. The slip casting mold according to claim 3, further comprising a cavity for promoting collapsibility.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60021696A JPS61181611A (en) | 1985-02-08 | 1985-02-08 | Slip casting molding method and mold |
| KR1019860000682A KR890003502B1 (en) | 1985-02-08 | 1986-02-01 | Method for shaping slip-casting and shaping moulds |
| DE8686101459T DE3667627D1 (en) | 1985-02-08 | 1986-02-05 | SLICK ENERGY PROCESS. |
| EP86101459A EP0191409B1 (en) | 1985-02-08 | 1986-02-05 | Slip casting method |
| US06/827,637 US4871497A (en) | 1985-02-08 | 1986-02-10 | Slip casting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60021696A JPS61181611A (en) | 1985-02-08 | 1985-02-08 | Slip casting molding method and mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61181611A JPS61181611A (en) | 1986-08-14 |
| JPH036881B2 true JPH036881B2 (en) | 1991-01-31 |
Family
ID=12062229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60021696A Granted JPS61181611A (en) | 1985-02-08 | 1985-02-08 | Slip casting molding method and mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61181611A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6223705A (en) * | 1985-07-24 | 1987-01-31 | 株式会社日立製作所 | Mold for slip casting |
| JPS63288703A (en) * | 1987-05-22 | 1988-11-25 | Hitachi Ltd | Molds, mold manufacturing methods and equipment, cast molding methods and equipment, cast molded products, and mold materials |
| JP6057598B2 (en) * | 2012-08-09 | 2017-01-11 | 株式会社キャステム | Method for producing sintered metal powder having hollow portion |
-
1985
- 1985-02-08 JP JP60021696A patent/JPS61181611A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61181611A (en) | 1986-08-14 |
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