ASTM D4393/D4393M-10

Single Test Cord— Adhesive treating of cords singly or adhesive treating individual ends simultaneously (referred to as “multi-cord treating” as opposed to “fabric treating”) and winding the cords as single ends is the most common laboratory method of preparing reinforcement materials for evaluation in reinforced rubber articles such as tires, belts, and hoses. This system of adhesive treating facilitates the study of a large number of adhesion variables at minimum cost. This test method provides a good comparison of variables on adhesion because it produces both an average numerical value of peel force over several linear centimetres of cord and provides convenient specimens for assessing appearance (see 11.3) of the peeled area as well. It may be used for purchase specification requirements for adhesive treated cords, steel tire cord, adhesives, rubber compounds, or manufacturing control of such products.

Preparation of weftless fabric from single cord is not recommended for acceptance testing of commercial shipments of tire cord fabric because single cords of long length cannot be conveniently obtained from fabric for drumwinding. See 5.2.2.

This test method is usually not preferred for acceptance testing of commercial shipments of adhesive treated cord, such as single end cord for hose. The more usual and convenient method for acceptance testing of such single cords is to prepare from a shipment a test piece or article in the same manner as the commercial article to be produced and to test cord-adhesion characteristics in this piece in a manner that compares its adhesion characteristics against a previously established, acceptable control. “H” and“ U” tests (Test Methods ) provide convenient and rapid adhesion results for acceptance testing of textile cords if needed. For steel cord, Test Method D2229 provides convenient and rapid adhesion results.

Using Woven Fabric—The woven fabric method of 4.2-4.4 is often chosen for rapid adhesion testing of textile woven fabric being adhesive treated in large volume. Fabric is tested “as is” and, through experience, constitutes a valuable process control tool. The same basic test can be conveniently executed by the receiving customer for process control purposes by sampling rubberized fabric from that to be processed into finished rubber articles.

This test method may be used for acceptance testing of commercial shipments of adhesive treated fabric, but duplicate numerical values for peel force and appearance are not to be expected between two testing locations. Rubber compound differences are only one of many parameters affecting peel force and appearance. Nevertheless, the expected range of values which characterize acceptable adhesion can be determined in any cord-rubber combination with experience. For this reason, the buyer normally establishes a minimum level of adhesion to be obtained by the seller in the seller's laboratory using either the seller's standard rubber compound or the buyer's rubber compound on the fabric made to the buyer's specification.

In case of a dispute arising from differences in reported test results when using Test Method D4393 for acceptance testing of commercial shipments, the purchaser and the supplier should conduct comparative tests to determine if there is statistical bias between their laboratories. Competent statistical help is recommended for the investigation of bias. As a minimum, the two parties should 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 should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before testing began. 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 the light of the known bias.

1.1 This test method covers the determination of peel adhesion of reinforcing fabrics that are bonded to rubber compounds. It is applicable to either woven or parallel cord textile structures from both natural and manmade fibers and to parallel steel cord structures.

1.2 This test method is primarily used to evaluate tire cords and tire cord fabrics, including steel tire cords, using a suitable tire cord adhesive and a suitable rubber compound. This test method may be used to evaluate tire cord adhesives (fabric dip), metallic (usually brass) coatings on steel cord, and the process of adhesive reaction on the cord using one consistent form of tire cord or fabric and one consistent rubber compound. This test method may be used to evaluate cords and fabrics in industrial hose and belting products and other cord or fabric reinforced rubber products.

1.3 Variables that may contribute to differences in results of this test method include adhesive type, adhesive application procedure, adhesive cure, fiber type, construction of cords or reinforcing fabrics, rubber type, rubber cure, rubber thickness, and cord spacing.

1.3.1 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 rubber embedment.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard..

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.