This part of GB/T 10357 specifies test methods for determining the strength and durability of various chairs and stools.
This part is applicable to various chairs and stools used in household, hotel and restaurant.
This part is not applicable to revolving chair, Children's chair as well as chairs and stools made of ceramic, vine and osier.
2 General Test Conditions
2.1 Specimen
If the specimen is made by gluing timber or similar materials, after manufacture, it shall be stored continuously in general indoor environment for at least 7d before the test.
Specimen shall be finished product. If the specimen is knock-down, the product shall be assembled in accordance with assembly instruction; if the specimen may be assembled or combined according to different modes, during the test, it shall be assembled or combined according to the most adverse combination for the strength test and durability test. Before the test, the connection piece of knock-down product shall be fastened; the assembling components shall be firmly installed and cannot be reinforced additionally without special requirements of manufacturer.
2.2 Loading requirements
The forces in strength tests shall be applied sufficiently slowly to ensure that negligible dynamic load is applied. The forces in durability tests shall be applied sufficiently slowly to ensure that kinetic heating does not occur. Unless otherwise specified, the load shall be maintained for (10±2)s in strength test and shall be maintained for (2±1)s in durability test.
2.3 Load
The test is divided into five levels according to the normal use frequency and potential misusage degree of product under intended application conditions and based on the magnitude and times of loading; the determination of test level is detailed in Appendix A.
2.4 Test conditions
In addition to the specified test equipment, any suitable equipment is applicable to this part. During running, the loading equipment for seat shall neither restrict the free tipping of specimen, nor obstruct the horizontal movement of chair during back test. All load pads shall rotate towards the direction of applied force and the rotation center shall be close to the bearing surface as possible.
Each test shall be carried out on the same specimen according to the test procedures specified in this part; in case that the specimen does not conform to the specified test procedures due to its particular structures, the differences associated shall be recorded in the test report.
Except for seat impact test, foam plastic pad may be positioned between the loading pad and test equipment.
2.5 Precision requirements
