This standard specifies the brand representation method, technical requirements and inspection rules for self-hardening furan resin for casting. This standard is applicable to self-hardening mold (core) sand binders for casting that are synthesized with sugar alcohol as the main raw material and formaldehyde, phenol or urea, etc. and can be catalyzed by acid. JB/T 7526-1994 Self-hardening furan resin for casting JB/T7526-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Self-hardening furan resin for casting
Subject content and scope of application
This standard specifies the brand representation method, technical requirements and inspection rules of self-hardening furan resin for casting. JB/T 7526-
This standard applies to self-hardening (core sand binders) for casting that are synthesized with furfuryl alcohol as the main raw material and with medium aldehyde, phenol or urea, etc. and can be catalyzed by acid.
2 Reference standard
JB/T7527 Method for determining the properties of self-hardening furan resin for casting 3 Classification, grading and grade indication method
Self-hardening furan resin for casting shall be classified according to the nitrogen content in accordance with the provisions of Table 1. Table 1
Classification code
W (nitrogen-free)
D (low nitrogen)
z (nitrogen)
G (high nitrogen)
Amount, %
>0. 3～2. 0
>2. 0~5. 0
>5.0~13.5
The classification of self-hardening furan resin for casting according to the tensile strength of process samples shall comply with the provisions of Table 2. Table 2
First level)
2 (Second level)
Tensile strength of process samples, MPa
3.3 The classification of self-hardening furan resin for casting according to free formaldehyde shall comply with the provisions of Table 3. Table 3
04 (grade -)
08 (grade 2)
3.4 ​​Grade expression methodbzxz.net
The grade expression method of white hard furan resin for casting is as follows; Approved by the Ministry of Machinery Industry of the People's Republic of China on October 25, 1994 ≥2.2
Formaldehyde, %
70.4~≤0.8
Implemented on October 1, 1995
JB/T 7526
Free formaldehyde grade code in resin
Technology sample tensile strength grade code
-Actual nitrogen content in resin
Chinese phonetic prefix of white hard furan resin for casting For example: The nitrogen content of self-hardening furan resin for casting is 3.5%, the tensile strength is 2.5MPa, and the free formaldehyde is 0.34%, which can be expressed as: ZF-3. 5N-1-04
4 Technical requirements
4.1 Self-hardening furan resin for casting is a light yellow to brown transparent or translucent uniform liquid. 4.2 The performance of various brands of self-hardening furan resin for casting shall comply with the provisions of Table 1, Table 2 and Table 3. 4.3 Other relevant performance indicators of self-hardening furan resin for casting shall comply with the provisions of Table 4. Table 4
Performance indicators
Viscosity.mPa·s.20℃
Density, g/cm2,20°℃
pH+20℃
Quantity classification
4.4 The storage period of self-hardening furan resin for casting shall not be less than 180 days. 7.0±0.5
4.5 If the purchaser has special requirements for the performance of self-hardening furan resin for casting, it can be agreed in the order agreement. 5 Test methods
The determination of nitrogen content, free formaldehyde content, viscosity, density, pH value of furan resin and tensile strength of resin process samples shall be carried out in accordance with the provisions of JB/T7527.
Inspection rules
6.1 Batch division
The resin produced by the same reactor is regarded as a batch number. 6.2 Sampling method
If sampling is taken from an iron barrel, the number of barrels is the unit number. If the number of units is less than 512, the number of sampling units shall be selected according to the provisions of Table 5. When sampling, the sampling tube shall be made of glass products, the length shall be greater than 2/3 of the barrel height, and the diameter shall be determined by the user. After the sample is manually hooked, the sampling volume of each barrel shall not be less than 100g. When the supplier takes samples, it can also take samples directly from the reactor, but the sample must be uniform. 6.3 Supplier inspection
Self-hardening furan resin for casting shall be inspected before leaving the factory, and the inspection results shall comply with the technical requirements specified in this standard or the provisions of the agreement. 6.4 Inspection by the Purchaser
The purchaser may conduct acceptance inspection in accordance with the technical requirements of this standard or the provisions of the agreement. 528
6.5 Re-inspection
Number of units of the overall material
82~101
102~125
126~151
152~181
182216
217~25
255~-296
297-340
341～394
395~~450
451~512
JB/T 7526
Minimum number of units to be taken first
Total units
If one of the test results is unqualified, double sampling should be carried out for re-inspection, and the re-inspection result shall be the final result. If the re-inspection results still do not meet the indicators specified in this standard, this batch of products is unqualified. 6.6 Arbitration Inspection
When the supply and demand parties have disputes over quality, they can negotiate or entrust a third party selected by both parties to conduct arbitration. Marking, packaging, transportation, purchase and storage
7.1 Various brands of self-hardening furan resin for casting should be packaged in galvanized iron drums with lids. The iron drums should be cleaned before packaging. 7.2 The supply should be accompanied by a product quality certificate, which should include: main technical indicators, inspector's signature, etc. The product name, brand, production date, batch number, net weight, manufacturer name, etc. should be marked on the packaging. 7.3 The transportation and storage temperature of self-hardening furan resin for casting should not exceed 40℃, and it should be prevented from direct sunlight. It is strictly forbidden to be close to acidic substances and fire sources. Additional remarks:
This standard is proposed and managed by the National Foundry Professional Standardization Technical Committee. This standard is drafted by the Shenyang Foundry Research Institute of the Ministry of Machinery Industry. The main drafters of this standard are Liu Ye, Jin Guangming and Wang Yan.
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