Sampling Method of Resin-coated Ceramic Sand
When sampling the coated sand in each batch (divided by tonnage, each continuous production of 10t is a batch), the average sample can be selected from the same batch of coated sand with intact packaging. The average sample of bagged coated sand is selected from 1% of the same batch, but at least not less than 3 bags, with a mass of not less than 5 kg. The samples required for inspection shall be selected from the total samples by "quartering method" or sampler. If there is any doubt about the quality of a certain part of coated sand, it should be sampled separately for inspection.
Melting point of Resin-coated Ceramic Sand
(1) Definition
Under the action of heat, the phenolic resin coated on the outer surface of coated sand starts to melt, and the temperature at which the sand particles are bonded together is called its melting point.
(2) Device melting point tester.
(3) Test method
The temperature on the metal plate surface of the melting point tester increases from 60℃ to 130℃ along the axial direction, and is divided into many different temperature intervals, and the temperature in each interval should be kept constant.
During the test, use a special funnel to evenly sprinkle a layer of 1.5 mm thick and 20 mm wide strip coated sand belt on the surface of the above metal test plate, keep it warm for 1 min to start melting, and then use a brush to move along the metal plate of the instrument at a uniform speed to brush off the uncured coated sand. Test the point temperature of cured coated sand and set it as the melting point temperature of coated sand. Each sample shall be measured three times, and the arithmetic mean value shall be taken as the test result.
Bending strength of Resin-coated Ceramic Sand at room temperature
(1) Device
SWY hydraulic strength testing machine, ZS-6 sample preparation device and supporting device (the distance between two fulcrums is 60 mm). (2) sample preparation
The bending strength sample size at room temperature is 22.36 × 11.18 × 70 mm.
First heat the sample mold and the upper and lower heating plates to 232 ℃ ± 5 ℃, then remove the upper heating plate and quickly pour the coated sand into the mold cavity from the sand bucket; The blade edge of the scraper is perpendicular to the mold (parallel to the length direction of the mold), scrape the excess grandson from the middle of the sample to both sides in two times, add a holding plate on the missing, start timing, keep the temperature for 2 minutes, take out the sample, place it in a dry place, cool it naturally to room temperature, and measure it within 1 hour.
(3) Test method
Place the tensile specimen on the guzhan of the testing machine so that the smooth surface of the specimen falls on the two supporting edges, and the loaded single edge falls on the flat surface of the specimen, and gradually load until the specimen is broken.
(4) Expression of results
The bending strength of the sample at room temperature shall be determined according to the provisions of GB/T 2684.2009, and its bending strength value is 16 times of the tensile strength value in the pressure gauge.