Testing

SRKP uses the latest equipment and technology for testing of raw materials, compounds and the finished products. We have a laboratory that is very well equipped and our chemists and engineers have extensive academic and practical knowledge and experience in the rubber industry. The following are the key areas under testing

  • Quality of Incoming Materials
  • Quality of compound & In-process Materials
  • Quality of finished products
  • Compounding Development
  • Product performance testing
  • HIPOT Testing/Di-Electric Testing

Testing in SRKP

Raw Material Testing Internal & External

Mooney viscosity test-Internal

  • Type of samples
    Raw polymer , Un-vulcanized Compound
  • ASTM Standards
    D1646, D3346
  • Significance
    This test gives an idea about the processing characteristics and correlation between viscosity value and molecular mass. This test also gives an idea about the processing safety of the compound

Melting point test-Internal

  • Type of samples
    Chemicals
  • ASTM Standards
    D1519
  • Significance
    This test helps to check the purity of the chemicals and also the processing characteristics of the chemicals

DBP Absorption test-Internal

  • Type of samples
    Carbon Black
  • ASTM Standards
    D2414
  • Significance
    This test indicates the structure of the black, this test gives an idea about the processing and vulcanizing characteristics of blacks

Aniline point test-Internal

  • Type of samples
    Processing Oils
  • ASTM Standards
    D611
  • Significance
    This test indicates the Aromaticity of the processing oils. This is an important properties of oils for selecting in compound development

Solubility test-Internal

  • Type of samples
    Chemicals, Fillers
  • ASTM Standards
    D4578, D4315, D4934
  • Significance
    This test indicates about the percent impurities

Ash content test-Internal

  • Type of samples
    Raw polymer, Chemicals, Fillers, Finished Product
  • ASTM Standards
    D297, D1506, D4574
  • Significance
    This test indicates the percent inorganic impurities in the sample. This may vary with respect to color of compound & Polymer

Sieve residue test-External

  • Type of samples
    Chemicals, Fillers
  • ASTM Standards
    D1512, D4572, D5461, D4315
  • Significance
    This test indicates the aggregate size of powdery materials. This test also indicates the distribution of powdery materials in the compound

Miscellaneous Test for Raw materials-External

Chemical PropertiesType of samples ASTM Standards Significance
Heat lossCarbon black, antioxidants, zinc oxideD1509, D4571This test indicates the low boiling organic materials
PH valueCarbon black, silica, clay, latexD1512, D1417This test indicates the acidity/alkalinity of the materials
Surface areaCarbon black, silica, zinc oxideD4820This test indicates the available surface area of the materials for interaction with the rubber molecule

Compound testing Internal & External

Vulcanizing characteristics test-Internal

  • Type of samples
    Un-vulcanized Compound
  • ASTM Standards
    D2084, D5289
  • Significance
    This test gives an idea about the rate of cure, maximum torque of the compound with a particular curing system.

Shore A Hardness test-Internal

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D2240, D1415
  • Significance
    This test gives an idea about the degree of curing.

Tensile strength & elongation at break test-Internal

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D412, D624
  • Significance
    This test gives an idea about the state of cure, This test also gives information regarding the uniformity of the product

Compression set test-Internal

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D395
  • Significance
    It measures the retention of elastic properties of vulcanized rubber compound

Specific gravity test-Internal

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D297
  • Significance
    This is a quick method of checking the weighing error during mixing. This test also gives an idea about the consistency of batches

Ageing properties test-Internal

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D856
  • Significance
    This test indicates the degradation of the vulcanized rubber under accelerated condition. This test also helps the Compound to predict the compound properties suitability in a particular application

Resilience test-External

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D2632
  • Significance
    Resilience is a function of both dynamic modulus and internal friction of a rubber, percent resilience of a rubber compound is an indication of hysterisis energy loss

Abrasion test-External

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D5936, D1630, D2228
  • Significance
    This test gives an indication of wear properties of the vulcanized rubber, for tyre it gives direct idea about mileage

Ozone resistance test-External

  • Type of samples
    Vulcanized Rubber
  • ASTM Standards
    D1149, D3395
  • Significance
    This is another degradation test to find out the characteristic of the vulcanized rubber compound in ozone atmosphere.

Miscellaneous test for compound-External

Physical Properties Type of Samples ASTM Standards Significance
Low temperature resistance Rubber Compound D832With standing temperature of compound
Fuel resistanceRubber Compound D471Swelling percentage of rubber
Flex crackingRubber Compound D813Crack resistance of compound
Water resistanceRubber Compound D6284Swelling of compound with eater

Finished product testing Internal & External

Di-Electric resistance test-Internal

  • Type of samples
    Rubber Product
  • ASTM Standards
    D4496
  • Significance
    Conductivity of the product

Bonding strength test-Internal

  • Type of samples
    Rubber to Metal Bonded Product
  • ASTM Standards
    D905
  • Significance
    Bonding strength of the product

Polymer identification test-External

Pyrolysis test

  • Type of samples
    Rubber Product
  • ASTM Standards
    D7579
  • Significance
    To identify the NR ,SBR & CR polymer

FTIR Test

  • Type of samples
    Rubber Product
  • ASTM Standards
    D6348
  • Significance
    To identify the polymers

Leakage test-External

  • Type of samples
    Oil Seals
  • ASTM Standards
    F2786
  • Significance
    To ensure the leakage of oil seals

Flammability test-External

  • Type of samples
    Rubber Product
  • ASTM Standards
    E2058
  • Significance
    To verify the extent of flame resistance of the product

Shelf Life of Rubber Products

Storage conditions are important for product usage after longer storing. Ageing effect continues even at room temperature even though very slow.

Hence it is advised to store the rubber product away from heat, Sunlight & moisture, preferably covered with black poly. Contact with grease, solvent, oil etc. should be strictly avoided.

Also FIFO system and storage stack height / rotation should be followed if stored for longer time to avoid any de-shaping.

Shelf Life of Rubber Products

S.No Rubber Type ASTM Designation Shelf life (Years)
1Nitrile Butadiene Rubber NBR

Up to 5

2Polyisoprene NR/IR

Up to 2

3Styrene SBR

Up to 3

4Ethylene propylene EPDM/EPM

Up to 7

5Chloroprene CR

Up to 10

6Polyurethane EU

Up to 10

7Fluorocarbon FKM Up to 20
8Silicone Q Up to 20
9Fluorosilicone FVMQ Up to 20
10Polyacrylic ACM/ANM Up to 20