This standard specifies the method and requirements for determining the linear shrinkage of ceramic green clay by measuring the distance between the marking lines on the sample. This standard is applicable to the determination of the total linear shrinkage of ceramic clay and clay materials during drying, firing and linear shrinkage. QB/T 1548-1992 Test method for linear shrinkage of ceramic green clay QB/T1548-1992 Standard download decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
Determination Method of Line Shrinkage of Ceramic Clay
1 Subject Content and Scope of Application
QB/T 1548--1992
This standard specifies the method and requirements for determining the line shrinkage of ceramic clay by measuring the distance between the marking lines on the sample. This standard is applicable to the determination of the drying, firing and total line shrinkage of ceramic clay and clay. 2 Reference Standards
GB/T5000 Terminology of Daily Ceramics
ZBY 20001
Determination Method of Water Content of Daily Ceramics Clay, Slurry and Glaze Slurry 3 TerminologyWww.bzxZ.net
3.1 Drying Line Shrinkage
The percentage of the difference in the length of the marking line before and after the drying of ceramic clay and clay to the original length of the marking line before drying. 3.2 Firing Line Shrinkage
The percentage of the difference between the length of the marking line of the dried ceramic ring mud before and after firing and the length of the marking line before firing. 3.3 Other terms
According to GB/T5000.
4 Instruments and Equipment
Drying Oven;
Vernier Caliper: Accuracy 0.02mm;
Rust-resistant metal molds and impressions are shown in Figures 1 and 2: Plaster model: inner cavity size 60mm×8mm; rolling rod;
Glass plate: 500mm×500mm.
Figure 1 Mold
Approved by the Ministry of Light Industry of the People's Republic of China on July 6, 1992, and implemented on March 1, 1993
5 Sample preparation
5.1 Preparation of plastic clay samples
QB/T1548--1992
Figure 2 Impression mold
Take a piece of bad material that has been fully kneaded (or vacuum kneaded), place it on a glass plate covered with a wet cloth, and then cover it with a layer of stretch cloth, and use a rolling rod to roll it regularly. When rolling, pay attention to changing the direction so that the force is even on all sides, then gently roll the surface of the clay block flat, remove the wet silk cloth on the surface, and use the mold to make 5 g60mm×8mm samples. After carefully demolding, place them on a glass plate covered with thin paper, and immediately use the impression mold to press two mutually perpendicular markings, recorded as L.
5.2 Preparation of dry powder samples
After crushing according to the process requirements, weigh 1kg and place it in a mud preparation container, add water and mix it to a normal plastic state. After fully kneading, put it into a plastic bag and seal it for aging for more than 24 hours. After fully kneading again, prepare the sample according to the steps in 5.1. 5.3 Preparation of grouting mud samples
According to the production process conditions of grouting molding, use a plaster model to make 5 samples of 60mm×8mm. After demolding, place them on a glass plate covered with thin paper, and use a stamp to press two perpendicular markings, which are recorded as L. . 5.4 The moisture content of the above samples is measured according to the requirements of ZBY20001. 6 Determination steps
6.1 The prepared samples are dried in the shade at room temperature for 24 to 48 hours. During the drying process, they are turned over to prevent deformation. Then they are placed in an oven and dried at 105-110°C (the difference between two weighings 1 hour apart is not more than 1g). Use a vernier caliper to measure the lengths of the two marking lines of the dried samples (accurate to 0.02mm), and take the average value, which is recorded as L1. 6.2 The dried samples with measured marking lengths are fired according to the product firing conditions (clay samples are fired at the required temperature). After the samples are cooled to room temperature, use a vernier caliper to measure the lengths of the two marking lines (accurate to 0.02mm), and take the average value, which is recorded as L2. 7 Expression of results
According to formula (1), formula (2) and formula (3), the drying linear shrinkage, firing linear shrinkage and total linear shrinkage of the five samples are calculated respectively. LcL
Wu Zhong: Y
. Drying line shrinkage, %;
Firing line shrinkage, %;
Total line shrinkage, %;
L.-\Original length of the marking line. mm
L Length of the marking line after drying, mm;
L-Length of the marking line after firing, mm.
Precision
QB/T1548—1992
L_L × 100
Y,—
Lo Le × 100
The average value of the five samples is the measurement result, and the result should be expressed to one decimal place. The relative deviation of the five samples measured line shrinkage shall not be greater than 10%, otherwise it is necessary to re-sample and measure. Additional remarks:
This standard is proposed by the Quality Standards Department of the Ministry of Light Industry. This standard is under the jurisdiction of the National Ceramic Standardization Center. This standard was drafted by Tangshan Ceramics Research Institute. The main drafters of this standard are Wang Zhen, An Heqin, and Cong Zhigang. From the date of implementation of this standard, the former Ministry of Light Industry standard QB920-1983 "Determination Method of Linear Shrinkage of Daily-use Ceramic Clay after Drying and Firing" will be invalidated.
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