JPS61106430A - Ceramic die for blow-molding glass article - Google Patents

Abstract

PURPOSE:To provide the titled die for obtd. a glass article having excellent grace as well as a long life and enabling easy maintenance by prepd. the die from a sintered ceramic body having a specified water absorbing characteristic. CONSTITUTION:A sintered ceramic material having 8-41wt% water absorption (JIS-R-2205), ca. 4-20wt% momentary water absorption, and <=ca. 70mg abrasion is obtd. by calcining powdery ceramic material after molding the material. The sintered ceramic is used as a material for die and a molding die is obtd. Suitable compsn. of the sintered ceramic body is one consisting of, for example, 5-99wt% X (one - three kinds among Al2O3, SiC, Si3N4, AlN, ZrO2), 0-37wt% RO (wherein R is at least one among Mg, Ca, Ba, Zn), 0-90wt% SiO2, 0-10wt% R2'O (wherein R' is at least one among K, Na, and Li), and 0-30wt% Y (at least one among P2O5, B2O3, and Y2O3).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a mold for blow molding glassware, and more specifically, the present invention relates to a mold for blow molding glassware, and more specifically, by using a ceramic sintered body as a mold material and imparting good water absorption performance and wear resistance to the mold. , relates to a ceramic mold for blow molding glassware that improves the quality of glassware products, simplifies maintenance of the mold, and extends the life of the mold.

Here, glassware refers to glass products such as table glassware, glass tubes, bottle glasses, glass ornaments, etc. whose form itself has a certain 1iIillii, and is usually blow molding, press molding, centrifugal molding, etc. Refers to products used in molding processes such as cast molding.

(Background of the Invention) Conventionally, glassware forming molds used for so-called glass blow molding such as blow molding or rotary blow molding are made by applying paste oil to the inner surface of a cast iron mold.
Next, it is known that cork powder is deposited to a thickness of about 0.5 to 1.0 m, and then heated to form a carbonized layer in the form of a sponge cake. When molding glassware using this mold, make sure that the glass does not touch the inside of the mold.
In order to smooth the surface of the resulting product, each time the glass is blown, water is added to the carbonized layer to form a film of water vapor between the inner surface of the mold and the glass.

However, in such a mold, the carbonized layer is thin, and repeated glass molding causes the carbonized layer to wear out and become thin. Therefore, the amount of water contained in the carbonized layer also gradually decreases. As a result, the water vapor film is insufficient during molding, causing record-like patterns, undulations, etc. on the skin of the glass molded product, degrading the quality of the product. In addition, in order to prevent deterioration of quality, it is necessary to periodically re-form the carbonized layer, but this operation is extremely troublesome.

Furthermore, Japanese Patent Publication No. 53-29163 describes a glass molding mold in which the inner surface of the mold is lined with a heat insulating layer made of asbestos, porous alumina, diatomaceous earth, etc., and a porous layer made of alumina powder, ceramic powder, etc. is disclosed. However, such a mold has the drawbacks that sufficient water absorption cannot be obtained because the water-absorbing layer is thin, and the manufacturing cost is high due to the complicated structure.

(Object of the Invention) The present invention was made in view of the above-mentioned problems, and aims to maintain stable formation of a water vapor film between the mold surface and glass during molding, and to improve the quality of glass products. The purpose of this invention is to provide a glassware blow molding mold that simplifies mold maintenance and extends the life of the mold, and is used for rotary blow molding or blow molding.

(Background of the Invention) In order to achieve the above object, the present inventors developed a mold that can absorb water in a short period of time without any special treatment on the inner surface of the mold, and has excellent wear resistance. As a result of research on molds, it was discovered that by using a ceramic sintered body as the mold material and molding and firing the raw material powder, a glass molding mold with sufficient water absorption performance and wear resistance can be obtained. Reached.

(Structure of the Invention) That is, the present invention provides a ceramic raw material powder having a water absorption rate of 8 to 41% by weight according to JISR2205, which is obtained by molding and then firing ceramic raw material powder, or by simultaneously performing molding and firing. This is a mold for glass molding.

In the present invention, a ceramic sintered body is used as a mold material for a glass molding mold. The composition of the ceramic sintered body is not particularly limited, but preferably includes the following five groups.

(■Group) A J 20370-999% by weight and ZrO20~
and S! 020-30 heavy pot%, R'
200 to 20% by weight (however, R' is K, Na.

Ceramic sintered body whose main components are 0 to 30% by weight of ~80% by weight, preferably 25-8
0% heavy water, R00-25% by weight, preferably 10-25
% by weight (where R is 1 of Mg, Ca, Ba, Zn)
5i0225 to 80% by weight, preferably 25 to 55% by weight, more preferably 30 to 55% by weight, R' 200 to 53114% (however, R' is K,
Na.

1-i), and Y0 to 30% by weight
(However, Y represents P2O5 and/or B2O3) as a main component, and a ceramic sintered body containing 2 to 30% by weight of RO+R'20 as a main component (Group ■) A420310 to 10% by weight, preferably 15 ~70% by weight, more preferably 20-45% by weight, RO0-31
% by weight, preferably 10-25% by weight (where R is Mg
, Ca, Ba, Zn), 5iO
z4G to 90% by weight, preferably 20 to 80% by weight, more preferably 55 to 15% by weight, R' 200 to 10% by weight, preferably 1 to 8% by weight, more preferably 3 to 6
RO+
R'20 is 5-47% by weight! 02 +Y is 30
~90% by weight ceramic sintered body, (IV group) AJ2035~30% by weight, RO0~10% by weight (however, R represents one or more of Mg, Ca, 8a, 7n), 5iOz70~ Ceramic sintered whose main components are 95% by weight, R' 200 to 2% by weight (where R' represents one or more of K, Na, and Li), and RO+R' 20 is 2 to 10% by weight. (Group V) 70 to 99% by weight of one or three of SiC, Si3Na, AJN, 7r02, 800
~31% by weight (where R is fvlo, Ca, B
a, representing Zn), 5i020 to 30% by weight,
R'2O0-2% by weight (wherein R' represents one or more of K, Na, and Lt) and Y0-301! ! In addition to these main components, a ceramic sintered body containing Pb 0.3n as a main component (where Y represents one or more of P2O3, B203, and Y203) as a main component, and ceramics used in the present invention 02.

Gd2C)3. Ce 02, 3ro, 3e
3 N2.

Optional components such as 5C203 or Tl 02 , Fe
A small amount of unavoidable impurity components such as 203 may be contained.

In order to obtain a ceramic sintered body having such a composition, it is necessary to appropriately select rock-forming minerals and soil minerals, such as minerals such as feldspar, silica, talc, dolomite, clay, and minerals such as chamotte. A calcined product is selected as appropriate.

Further, in the glassware blow molding mold of the present invention,
In addition to these ceramic raw materials, K, walnut powder, sawdust, coal powder, sponge with continuous holes, etc. can be mixed in order to provide high water absorption performance.

The mold material blended in this manner is molded by any method such as potter's wheel molding, casting molding, press molding, etc., and then fired. The firing temperature and firing time vary depending on the ceramic composition and blending ratio, but for example, in the ■ group, 1300 to 1400 °C, held for 1 to 2 hours, in the ■ group, 1100 to 1400 °C, held for 1 to 2 hours, in the ■ group, 950 °C ~1200℃, held for 1-2 hours, IV
Crew 7 r G, t 1250~1400℃, 1~
Hold for 2 hours, 1400-1900℃ for ■group, 0
．． The preferable range is 5 to 2 hours.

A preferred method for molding and firing the glassware blow molding mold of the present invention includes the following method.

That is, a sponge 3 of arbitrary density as shown in FIG. 2 is sandwiched between a gap 2K of a casting mold made up of plaster molds 1 and 1' as shown in FIG. Next, add water as a medium to the ceramic raw powder to form a slurry with a viscosity of 500 to 1000 cps (
The mold material raw material) 4 is poured under pressure from above the injection pipe 5 as shown in FIG. 3, and the slurry 4 is filled into the air holes 6 of the sponge 3 by applying pressure. After a certain period of time has elapsed, the slurry 4 is dehydrated by the plaster molds 1 and 1' and becomes a solid body, and when removed from the mold, it becomes a mold having a sponge 3 inside as shown in FIG. The thus formed unfired mold is dried and fired at a predetermined temperature to burn out the sponge 3.

As shown in FIG. 5, the mold 7 thus obtained is made of a porous material with communicating holes 8 formed therein by the burnout of the sponge 3. This mold 7 is made of a porous material that allows water to quickly penetrate into the interior, and since the interior is composed of communicating holes 8, it is also possible for water to pass through from the outside of the mold 7, reducing the water absorption rate. Any water feature, regardless of size, can be easily supplied into the mold 7.

The glass molding mold of the present invention has a water absorption rate of 8 to 41 according to JISR2205! ! ! 19%, instantaneous water absorption rate 4-2
It is necessary that the amount of wear is 0% by weight and the amount of wear is 70 o+g or less. In addition, wear [100mg is JIS A145
This approximately corresponds to a wear amount of 80 to 90 mg in the wear resistance test specified in 2. Further, the water absorption rate and the instantaneous water absorption rate are almost proportional to each other. The instantaneous water absorption rate and the amount of wear mentioned here are measured by the following test method.

First, the instantaneous water absorption rate was calculated by immersing a plate-shaped sample of 140 x 100 x 7 mm+ in water for 3 seconds at room temperature (25° C.) and under normal pressure, measuring the weight of water absorbed, and calculating it using the following formula.

Instantaneous water absorption rate (i1m%) - 100 (, 3 Weight after soaking in water - Weight) (Dry weight) Also, the amount of wear is 100X 70X 7 A plate-shaped sample of II was fixed at an angle of 45°. 1. Directly above the sample 100
From the 0 ■ position, add synthetic mullite grains (2 to 3
mm) was dropped onto the sample through the guide tube, and the decrease in m1tffi of the sample was measured and expressed in units of 10.

In the present invention, if the instantaneous water absorption rate of the glass molding mold is less than 4% by weight, or if the water absorption rate is less than 8% by weight, the amount of water retained will be small, and the skin of the resulting glass product will have record-like patterns, undulations, etc. Also, if the instantaneous water absorption rate exceeds 20% by weight or the water absorption rate exceeds 41% by weight, there are too many pores formed in the mold, or the pore diameter is too large, resulting in poor wear resistance. Deteriorate.

Furthermore, if the amount of wear exceeds 70 mg, the inner surface of the mold is abraded to a large degree, resulting in poor durability, and the worn mold material adheres to the glass surface, causing scratches.

The glass molding mold of the present invention, which is obtained by molding and firing ceramics and has the properties described above, has a cleaner skin than a metal mold, even if the mold generally has cracks that allow water vapor to escape. Glass products are obtained. Furthermore, by providing a vertical crack in the mold, it is possible to prevent the mold itself from cracking or splitting, further extending the life of the mold.

Hereinafter, the present invention will be explained in detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

(Examples 1 and 2) Raw material powders for mold materials such as ceramics (ceramic sintered body composition of Nigeloop) were mixed in a predetermined ratio so as to have the chemical composition shown in Table 1, and the particle size was 8 μm or less using a ball mill. It was wet-pulverized to a weight of 60-700-70%. Thereafter, the mixture was dehydrated using a filter press, and then vacuum mixed using a screw mixer to obtain a molding clay, which was then molded into an unfired mold by potter's wheel molding in a conventional manner. Further, firing was performed at the temperatures shown in Table 1 to produce a glass molding mold. The water absorption rate of the mold obtained,
The amount of wear (measured value of wear resistance), instantaneous water absorption rate, and apparent porosity were measured, and the results are shown in Table 1.

Here, the amount of wear and instantaneous water absorption were measured according to the method described above, and the apparent porosity was measured according to JIS R2205.

Further, the mold thus obtained was used for rotary blow molding to produce glassware products, and the skin condition and mold life of the resulting glassware are shown in Table 1. In addition, these evaluations were evaluated in the four stages shown below.

Evaluation of the skin condition of the obtained glass product: A: Very good, with no record line patterns or waving.

B...Record line pattern, no waving, good condition.

C: Record line pattern and some waving occur, which is defective.

D...Very poor record with line patterns and a lot of waving.

Evaluation of mold life A: It has a very long lifespan.

B...Long lifespan.

C...Short lifespan.

D: Very short lifespan.

As shown in Table 1, the molds obtained in Examples 1 and 2 all had water absorption rates and abrasion levels within the range of properties required by the present invention, and the skin condition of the obtained glass products. The mold life and mold life were also fully satisfactory.

(Comparative Example 1 and Reference Example 1) Molds were manufactured in the same manner as in Examples 1 and 2, except that the firing temperature was changed. The water absorption rate and other properties of these molds were measured in the same manner as in Examples 1 and 2 and are shown in Table 1. The skin condition and mold life of the glass products were measured in the same manner as in Examples 1 and 2, and the results are shown in Table 1.

The molds obtained in Comparative Example 1 and Reference Example 1 had water absorption and/or abrasion that were outside the range of properties required by the present invention, and the skin condition and mold life of the resulting glass products were also poor. It wasn't satisfying.

As is clear from this result, for ceramic compositions in the above-mentioned Niger loop range, the firing temperature is 1300~1300~
It has been found that a range of 1400°C is preferable.

(Examples 3 to 8) Raw material powders for mold materials such as ceramics (ceramic sintered body composition of group ■) were mixed in a predetermined ratio so as to have the chemical composition shown in Table 1, and a particle size of 8μ was obtained using a ball mill. (2) The following materials were wet-pulverized to a concentration of 60 to 10% by weight. Thereafter, the mixture was dehydrated using a filter press, and then vacuum mixed using a screw mixer to obtain a molding clay, which was then molded into an unfired mold by potter's wheel molding in a conventional manner. Furthermore, a mold for glass molding was produced by firing at the temperature shown in Table 1, and the water absorption rate and wear m of the mold obtained were determined.
, instantaneous water absorption and apparent porosity were measured in the same manner as in Example 1, and the results are shown in Table 1.

Further, the obtained mold was used for rotary blow molding to produce glassware products, and the skin condition and mold life of the obtained glassware are shown in Table 1 as in Example 1.

As shown in Table 1, the molds obtained in Examples 3 to 8 all had water absorption rates and wear amounts within the range of properties required by the present invention, and the skin condition of the obtained glass products. The mold life and mold life were also fully satisfactory.

(Reference Example 2 and Comparative Example 2) Glass molding molds were manufactured in the same manner as Examples 3 to 8 except that the firing temperature was changed. The water absorption rate and other properties of these molds were measured in the same manner as in Example 1 and are shown in Table 1.The molds obtained were used for rotary blow molding to produce glass products,
The skin condition and mold life of the obtained glass products were measured in the same manner as in Example 1, and the results are shown in Table 1.

The molds obtained in Reference Example 2 and Comparative Example 2 had either or both of the water absorption rate and the amount of abrasion outside the range of properties required by the present invention, and the skin condition and mold of the obtained glass products The lifespan was also not satisfactory.

As is clear from this result, for ceramic compositions in the range of K and the above-mentioned group (2), the firing temperature is 1iooo to 14
It has been found that a range of 00°C is preferable.

(Examples 9 to 13) Raw material powders for mold materials such as ceramics (ceramic sintered body composition of group ■) were mixed in a predetermined ratio to have the chemical composition shown in Table 1, and a particle size of 8μIl was prepared using a ball mill.
Wet pulverization was carried out so that the content of 1 or less particles was 80-70 m%. Thereafter, the mixture was dehydrated using a filter press, then vacuum mixed using a screw mixer to obtain a molding clay, which was then molded into an intermediate product by potter's wheel molding in a conventional manner.

Furthermore, a mold for glass molding was produced by firing at the concentrations shown in Table 1, and the water absorption rate, abrasion m, instantaneous water absorption rate, and apparent porosity of the obtained mold were measured in the same manner as in Example 1. The results are shown in Table 1.

In addition, the obtained mold was used for rotary blow molding to produce glass products, and the skin condition and mold life of the obtained glass products were measured in the same manner as in Example 1. The results are shown in Table 1. Ta.

As shown in Table 7, the molds obtained in Examples 7 to 9 all had water absorption rates and abrasion amounts within the range of properties required by the present invention, and the skin condition of the obtained glass products. The mold life and mold life were also fully satisfactory.

(Comparative IN3 and Reference Examples 3 to 5) Molds were manufactured in the same manner as Examples 9 to 13, except that the firing temperature was changed. The properties such as water absorption rate of these molds are shown in Example 1.
and JBJl! The obtained mold was used for rotary blow molding to produce glassware products, and the skin condition and mold life of the obtained glass products were measured as in Example 1. Measurements were made in the same manner, and the results are shown in Table 1.

The molds of Comparative Example 3 and Reference Examples 3 to 5 had either or both of the water absorption rate and the amount of wear outside the range of properties required by the present invention, and the skin condition and mold life of the obtained glass products were also satisfactory. It wasn't possible.

From this result, it is clear that for ceramic compositions in the range of K, the above-mentioned group 1, the firing temperature is 950 to 12
It has been found that a range of 00°C is preferable.

(Examples 14 to 15) Raw material powders for mold materials such as ceramics (ceramic sintered body composition of group ■) were mixed in a predetermined ratio to have the chemical composition shown in Table 1, and Lancaster (trade name) powder was prepared. Mixer (Muller type mixer ribbon or paddle rotates horizontally,
5 to 7% by weight of water was added in a container (which also rotates horizontally) and mixed in a semi-wet manner to obtain a press-molding clay, which was then press-molded into an intermediate product. Furthermore, a glassware blow molding mold was manufactured by firing at the temperature shown in Table 1, and the water absorption rate, wear amount, instantaneous water absorption rate, and apparent porosity of the mold obtained were measured in the same manner as in Example 1. The results are shown in Table 1.

In addition, the obtained mold was used for rotary blow molding to produce glass products, and the skin condition and mold life of the obtained glass products were measured in the same manner as in Example 1, and the results are shown in Table 1. .

As shown in Table 1, the water absorption rate and amount of abrasion of the molds obtained in Examples 14 and 15 are within the range of properties required by the present invention, and the skin condition of the obtained glassware products is The mold life was also fully satisfactory.

(Reference Example 6 and Comparative Example 4) A mold was manufactured in the same manner as in Example 15 except that the firing temperature was changed. The water absorption rate and other properties of these molds were measured in the same manner as in Example 1 and are shown in Table 1, and the molds obtained were used in rotary blow molding to manufacture glass products, and the resulting glassware products were The skin condition and mold life were measured in the same manner as in Example 1, and the results are shown in Table 1.

As is clear from this result, the firing temperature is 1250 to 1400 for ceramic compositions in the range of group 1 mentioned above.
It has been found that a range of .degree. C. is preferred.

(Examples 16 to 18) Using mold material raw material powder with the same composition and blending ratio as in Examples 2, 6, and 12, casting was performed using plaster molds 1 and 1' as shown in Fig. 1. A sponge 3 of arbitrary density is sandwiched between the molds with a gap of 2K as shown in FIG.
As shown in FIG. 3, this slurry 4 was poured into the vibrator 5 from above under pressure, and pressure was applied to fill the air transport hole 6 of the sponge 3 with the slurry 4. After 40 to 90 minutes, the slurry 4 was dehydrated by the plaster molds 1 and 1' and turned into a solid body. When the mold was removed, a mold 7A having a sponge 3 inside was formed as shown in FIG. After drying the mold thus formed, it was fired at the temperature shown in Table 1 to burn out the sponge 3 and produce a ceramic mold 7 for glassware blow molding.

The water absorption rate, wear amount, instantaneous water absorption rate, and apparent porosity of the mold obtained were measured in the same manner as in Example 1, and the results are shown in Table 1.

Further, the obtained mold was used for rotary blow molding to produce a glass product, and the skin condition and mold life of the obtained glass product were measured in the same manner as in Example 1, and are shown in Table 1.

As shown in Table 1, the molds obtained in Examples 16 to 18 all had water absorption rates and abrasion amounts within the range of properties required by the present invention, and the skin condition of the obtained glass products. The mold life and mold life were also fully satisfactory.

In addition, as shown in FIG. 5, these molds have additional communication holes 8 formed inside the porous material by burning out the sponge, allowing water to penetrate into the inside more quickly. Moreover, since these molds have internal ventilation holes 8, it is possible to pass water from the outside of the mold, and any amount of water can be easily supplied into the mold regardless of the water absorption rate. It was possible to do so.

(Effects of the Invention) As explained above, the ceramic mold for glassware blow molding of the present invention, which is obtained by molding and firing the K ceramic raw material powder and has the above-mentioned properties, has a wall thickness that can be selected arbitrarily. Because sufficient water absorption performance is obtained, sufficient water vapor can be supplied between the mold and the glass during blow molding of glassware, resulting in record-like linear patterns on the skin of glassware. The quality of the product can be greatly improved without causing waving or the like. Note that if there is excess or excess water vapor, even if the mold is provided with cracks to allow the water vapor to escape, a glass product with a cleaner surface than a metal mold can be obtained.

Furthermore, since the treatment of the inner surface of the mold, which was conventionally required, is no longer necessary, maintenance of the mold can be easily performed, and since the mold has excellent wear resistance, the life of the mold can be significantly extended.

Zara K. In the ceramic mold for glassware blow molding of the present invention, by providing a vertical crack in the mold, it is possible to prevent the mold itself from cracking or cracking, and furthermore, the life of the mold can be extended. can.

[Brief explanation of the drawing]

FIGS. 1 to 5 are process diagrams showing a preferable molding method for manufacturing the glassware blow molding mold of the present invention, and a sectional view of the ceramic mold after firing. 1.1'...Gypsum mold, 2...1IJi of the casting mold,
3...Sponge, 4...Sludge, 5...Pipe, 6
...Lucky hole, 7A...Unfired ceramic type, 7...
・Ceramic type, 8: Continuous ventilation holes.

Claims (1)

[Claims] 1. Obtained by molding and firing ceramic raw material powder,
Water absorption rate according to JIS R2205 is 8-41% by weight
A ceramic mold for glassware blow molding made of a ceramic sintered body. 2. The composition of the ceramic sintered body is X5 to 99% by weight (
However, X is Al_2O_3, SiC, Si_3N_4,
(represents any one to three of AlN, ZrO_2), RO0 to 37% by weight (however, R represents Mg, Ca, Ba
, Zn), SiO_20-90% by weight, R'_2O0-10% by weight (however, R' is K, Na
, represents one or more types of Li), and Y0 to 30% by weight
(However, Y is P_2O_5, B_2O_3, Y_2O_
3. The ceramic mold for blow molding glassware according to claim 1, which comprises as a main component one or more of the following. 3. The composition of the ceramic sintered body is Al_2O_310
~99 wt% and ZrO_20-30 wt%, RO0
~20% by weight (where R is 1 of Mg, Ca, Ba, Zn)
species), SiO_20-30% by weight, R'_
The main components are 0 to 2% by weight of 2O (however, R' represents one or more of K, Na, and Li) and 0 to 30% by weight of Y (however, Y represents one or more of P_2O_5, B_2O_3, and Y_2O_3). A ceramic mold for blow molding glassware according to claim 2. 4. The composition of the ceramic sintered body is Al_2O_310
~80% by weight, RO0~25% by weight (where R is Mg,
represents one or more of Ca, Ba, Zn), SiO_2
25 to 80% by weight and R'_2O0 to 5% by weight (wherein R' represents one or more of K, Na, and Li) and Y
The main component is 0 to 30% by weight (however, Y represents P_2O_5 and/or B_2O_3), and RO+R'_
A ceramic mold for blow molding a glassware according to claim 2, wherein the 2O content is 2 to 30% by weight. 5. The composition of the ceramic sintered body is Al_2O_310
~70% by weight, RO0~37% by weight (However, R is Mg,
represents one or more of Ca, Ba, and Zn), SiO_22
0 to 90% by weight, R'_2O0 to 10% by weight (however, R
'represents one or more of K, Na, and Li) and Y0~
30% by weight (however, Y is P_2O_5 and/or B
_2O_3) is the main component, and RO+R'_2O
The ceramic mold for blow molding glassware according to claim 2, wherein the amount of SiO_2+Y is 5 to 47% by weight and 30 to 90% by weight. 6. The composition of the ceramic sintered body is Al_2O_35~
30% by weight, RO0-10% by weight (where R is Mg, C
a, Ba, and Zn), SiO_270
~95% by weight and R'_2O0~2% by weight (however, R
The ceramic mold for blow molding glassware according to claim 2, wherein RO+R'_2O is 2 to 10% by weight.