Standard Test Method for Adhesion of Tire Cords and Other Reinforcing Cords to Rubber Compounds by H-Test Procedure

Importancia y uso:

5.1 Test Method D4776/D4776M for the determination of the H-test adhesion of reinforcing cords to rubber compounds can be used for the acceptance testing of commercial shipments of reinforcing cords but caution is advised since information about between-laboratory precision is incomplete. Comparative tests as directed in 5.1.1 shall be advisable.

5.1.1 In cases of dispute arising from the differences in reported test results when using Test Method D4776/D4776M for acceptance testing of commercial shipments, the purchaser and the supplier shall conduct comparative tests to determine if there is statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties shall take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens shall then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories shall be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before testing begins. If a bias is found, either its cause must be found and corrected or the purchaser and the supplier must agree to interpret future test results in light of the known bias.

5.2 This test method is used to measure the force required to extract the cord from a rubber compound test block.

5.3 This test method is designed to test the adhesion of textiles that are bonded to rubber compounds. Variables that could contribute to differences in results of this test method include adhesive type, adhesive application procedure, adhesive vulcanization, fiber type, construction of cords, rubber type, rubber vulcanization, and rubber thickness.

5.3.1 The deleterious effect of ozone in combination with atmospheric moisture on the ability of adhesives to bond with rubber requires assiduous protection of cords prior to embedment.

5.4 The expected range of values which characterize acceptable adhesion can be determined in any cord-rubber combination with experience. For this reason, the purchaser normally establishes a minimum level of adhesion to be obtained by the supplier in either the supplier's laboratory or the purchaser's laboratory using either the supplier's standard rubber compound or the purchaser's rubber compound.

Subcomité:

D13.19

Referida por:

D6477-23

Volúmen:

07.02

Número ICS:

83.160.01 (Tyres in general)

Palabras clave:

adhesion; reinforcements (textiles); rubber; tire cord;