The appearance and size detection
1.1 the appearance
Maintain the 300 - 500mm distance, visual bellows into. And feel test of rigid, flexible and elastic corrugated pipe.
1.2 inner, outer diameter
To detect the corresponding corrugated pipe diameter with a special plug each kind of specification, three sample measurement, the sample length is 12-15 times the diameter of the corresponding specifications, requirements for the determination of plug is positive deviation cannot pass, and negative deviation can be weight by.
0.02mm precision vernier caliper to measure the diameter, measuring three samples of 12 points, take the average, should accord with the regulations.
The 1.3 wall thickness
The 0.02mm precision vernier caliper was used to detect the corrugated pipe wall thickness. Measurement of three samples of radial wall thickness, length of the sample is 240mm. Each section of the 4 possible spacing equal position measurement method, the measurement of 12 points, take the average, should accord with the regulations.
Two. Performance test of corrugated pipe
Unless otherwise specified, the test should be in an ambient temperature of 23 ± 2 ℃, each test 6 samples, sample length is 240/480mm, test should be in 7 - 10 days after production.
The 2.1 flexible and elastic
Sample 2.1.1 full length opening. The sample rod bending around the park, where the opening should be located at lateral bending. If a specimen diameter less than 10mm, the garden bar is 4 times the size of specimen diameter, if a specimen diameter greater than 10mm, the garden bar diameter is 2 times the diameter of the specimen.
Requirements: the sample can not be narrowed, opens is not more than 1.5mm.
The 2.1.2 sample is not open, the same way bending specimen, requirements of corrugated pipe is not deformation, not sag.
2.1.3 from the opening in the sample, the sample through the opening corresponds to the diameter size of garden stick out, the opening gradually shrink to its original state.
2.2 compressive properties
The outer diameter of the tested samples corrugated pipe diameter 3/4 wire harness corrugated into 240mm long tube, a sample, a sample placed on a flat plate, and the opening up, uniformly applying a 12.755Kg gravity to sample, time 1min, check the appearance has no deformation or cracks, unloading 15min, determination of specimen diameter change rate of Dt is less than 10%.
2.3 anti impact performance
Samples such as 2.2 projects, a downward opening for placing a flat plate, from the height of sample 100mm distance, the free fall of a 750g object, hit in the sample, check the sample appearance has no deformation or crack.
2.4 bending properties
2.4.1 at room temperature, corrugated tube bending test in bending shelf, requirements in the bend is 100 times (about 50 times) circumstances, may not have fracture phenomenon, and the bent 90 degrees, gauge gravity through.
2.5 flame retardant performance test
The flame retardant properties of 2.5.1 materials
Flame retardant samples should be the same material with bellows. According to the standard of UL94 processed samples. According to the standard of UL94, flame retardant performance test and reach more than V-2.
The flame retardancy of 2.5.2 products
2.5.2.1 routine testing
Samples such as 2.2 project, the blue flame regulating the Bunsen burner height is 30 ± 2mm, will be placed level bellows in the flame, combustion should be self quenching in 30S. Three times in a row.
2.6 electrical performance
2.6.1 insulation strength
Take three long 120mm corrugated tube bent into U shape and fixed. The sample is placed in water, water entry length 1000mm. And then in the sample water filled tube, pipe surface height and external consistency, the water temperature is 23 ± 5 ℃.
2 electrodes were inserted into the corrugated pipe and pipe water, 24h, 2000V is applied between two electrodes, frequency of AC voltage 50HZ, 15S corrugated tube breakdown.
2.6.2 insulation resistance
Measurement using surface resistance, surface resistance is greater than or equal to 10M products
2.7 low temperature and high temperature performance
2.7.1 240mm length open corrugated pipe three, tube into a diameter of the wire pipe diameter 3/4 thickness, into the cold box starts from room temperature, cooling to -25 ± 2 ℃, keeping 2H out, all around the metal tube (4 times the diameter of the sample tube metal tube outer diameter) requirements remove the 2min from the box around the complete involution, samples should be no crack, no deformation of corrugation.
2.7.2 samples such as 2.7.1 projects, in high temperature box starts from room temperature, the temperature is raised to 90 ± 2 ℃ (PE material) or 20 ± 2 ℃ (PP material) to maintain 2h, remove the check sample corrugated without deformation.
2.8 oil resistance test
