Rubber materials testing

Recommended Practice for Scleroscopic Hardness Testing of Metallic Materials Test Method for Rubber Property International Hardness Test Method for Rubber Property Durometer Hardness... 

Withdrawn) 1974 AMD 1 Laboratory methods of test for determination of smoke generation charactenstics of cellular plastics and cellular rubber materials. Part 1 Method for testing a 25 mm cube test specimen of low density material (up to 130 kg/metres cubed) to continuous flaming conditions (AMD 7688) dated 15 July 1993. Withdrawn, superseded by BS ISO 5659-2 1994... 

Withdrawn) 1974 AMD 1 Laboratory methods of test for determination of smoke generation charactenstics of cellular plastics and cellular rubber materials. Superseded by BS ISO 5659-2 1994... 

A migration test was developed to simulate human exposure patterns. 5 g of rubber material was cut into 1-2 mm stripes and then immersed in 20 ml of standard test solution of artificial saliva (4.2 g NaHC03, 0.2 g K2CO3, 0.5 g NaCl, 0.03 g NaNO, ad 1000 ml with aqua dest.j. After 24 h incubation at 40 C volatile nitrosamines were determined in an aliquot and determined after destination with a standard technique (GC-TEA-method). 

Volatile substances in the rubber or compounding ingredients or moisture can cause porosity. Insufficient stock of rubber in the mould and under cure also cause porosity. To prevent this defect from occurring, avoid use of raw materials containing volatile materials, test all raw materials for moisture content, allow the solvents or adhesives to dry up completely, check up the volume and shape of the finished product and increase curing pressure if feasible. 

The aim of this book is to present an up to date account of procedures for testing rubber materials. It intends to be comprehensive in covering the complete range of physical properties and all of the tests in common, and sometimes not so common, use. Inevitably the bulk of methods are the standard ones, often somewhat arbitrary and primarily intended for quality assurance purposes, but in each case the requirements for testing to predict performance and for obtaining meaningful design data are considered. 

The rotary-platform, double-head or Taber abrader, unlike those mentioned above, was not developed by the rubber industry but was intended for very general use. It is of the form (d) in Figure 11.4 but uses a pair of abrasive wheels. Although the degree of slip cannot be varied, the Taber is in other ways a very versatile apparatus. It uses a simple flat disc as the test piece which could, if necessary, be fabricated from more than one piece. The force on the test piece and the nature of the abradant are very readily varied and tests can be carried out in the presence of liquid or powder lubricants. When using the usual type of abrasive wheel, a refacing procedure is carried out before each material tested. 

There is an international method, ISO 295113, for the determination of insulation resistance of rubbers. The test pieces specified are either flat sheets or tube or rod and the electrodes either conductive paint or metal bars. It is apparent by the reference to rigid materials that the wording has been lifted from a general document for insulating materials, presumably IEC 16714. There is no mention of metal backing plates for the paint electrodes and, to obtain consistent results with rubbers, the electrode system would need to be defined more precisely. 

The benefit of such a LAPS sandwich structure consists in a easy manufacturing process, where no patterning and masking as well as encapsulation of conducting tracks are needed (see Fig. 5.1). In the measurement set-up, the LAPS structure itself will be embedded in a measurement chamber. The flat uniform surface of the LAPS assists a proper sealing by, e.g., an O-ring, silicone or rubber material. Finally, only the sensitive membrane will stay directly in contact with the analyte under test. 

Bis(tributyltin)oxide has been implicated in producing irritation of the upper respiratory tract and chest irritation, tightness, and pain in workers using a rubber material containing bis(tributyltin)oxide. Exposure conditions were not described. No changes were observed in pulmonary function tests (NIOSH 1976). 

ASTM D 5132 Standard Test Method for Horizontal Burning Rate of Flexible Cellular and Rubber Materials Used in Occupant Compartments of Motor Vehicles... 

Goodyear material with the same rubber content as the 13% American Cyanamid material exhibited more ductile stress-strain behavior. Possible reasons for this difference will be discussed later in the paper. Figure 6b shows the effect of rate on the behavior of the 13% American Cyanamid material. The yield stress increases with strain rate as was the case in all materials tested. Figure 6c shows the effect of temperature on the behavior of the same material. Again, as was the case in all materials tested, the yield stress decreases as the temperature is increased. 

BS 4735 1974 Laboratory Method of Test for Assessment of the Horizontal Burning Characteristics of Specimens No Larger Than 150 mm X 50 mm (Nominal) of Cellular Plastics and Cellular Rubber Materials when Subjected to a Small Flame, 13 pp... 

BS 5111 Laboratory Methods of Test for Determination of Smoke Generation Characteristics of Cellular Plastics and Cellular Rubber Materials... 

This standard specifies a procedure for determining the dynamic cushioning performance of cellular rubber materials and rigid and flexible plastics by measuring the peak deceleration of a mass when it is dropped on a test piece. The test is intended primarily for quality assurance. However, since this type of test is also used to obtain design data notes are given in Annex A to assist in this objective. The method is applicable solely to packaging materials. 

To determine some of the mechanical properties of the recycled materials from the used vehicle tires, a number of mechanical tests were performed. The mechanical investigation included tensile, compression, three-point bending, and 4-point bending tests. Table (1) summarises the results of the mechanical tests performed on the recycled rubber material. 

Noise abatement tests were performed on a system composed of seven panels. To classify the combustability grade of the material, combustibility tests were performed on small samples of the recycled rubber material these tests were performed according to [3],... 

The standard test method for measuring the durometer hardness of rubbers according to ASTM D2240-05 [6] is based on the penetration of a specified indentor forced into the material under specified conditions. The indentation hardness is inversely related to the penetration and is dependent on the elastic modulus and viscoelastic behaviour of the material. This method is an empirical test intended primarily for control purposes. No simple relationship exists between indentation hardness determined by this method and any fundamental property of the material tested. 

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