QUALITY ASSURANCE & CONTROL
SRIT is the pioneer & leading rubber compounder & tyre retreader in Malaysia. Its quality management system (ISO 9002:1987) was certified by SIRIM in 1990 & to ISO 9002:1994 in 1995. This was further upgraded to ISO 9001:2000 & to ISO 9001:2008 in the year of 2009.
The quality assurance & control activities implemented by SRIT group of companies thus centered on ISO 9001. These activities focus on customer requirements & feedbacks. We emphasized partnership with customers, which has enable us to execute with excellent & deliver technology solutions & values to our customers.
The QA & QC activities have been documented according to ISO 9001 standard requirements & certified by SIRIM.
Our QMS has been further enhanced with the product certification by SIRIM in 2007 & 2014:
- MS 224:2005 (Sun Tyre) - Retreaded Pneumatic Rubber Tyres for Passenger Cars and Commercial Vehicles Tyres
- MS 1208:2010 (Sun Rubber) - Precured Tread for Retreading Tyres
- MS 1348:2010 (Sun Rubber) - Cushion Gum used in Precured Retreading of Tyres
- MS 1097:2010 (Sun Rubber) - Rubber Tread Compound for Hot Retreading for Passenger car and Commercial Vehicles Tyres
We are constantly improving and optimizing our group synergy to provide excellent standards and quality in our products and services. Reasonable and fair pricing, high-yield productivity, on-time delivery and minimal set rejection rates are our top priorities for quality assurance.
The route to our continual success also consists of the following :-
- Maintain and implement an effective management system.
- Continually improve the effectiveness of the management system.
- Establish and monitor measurable objectives / key performance indicators.
- Timely delivery.
- Commitment to comply with applicable statutory and regulatory requirements.
- Operate in accordance with best practice.
- Ensure that all staffs are competent to carry out assigned work.
Our Quality Management System (QMS)
To outline the role & responsibilities of the Research & Development (R&D), our Quality Assurance (QA)/ Quality Control (QC) that will oversee the compliance to check whether a product being developed is meeting specified requirements.
Our quality control is important to ensure that products are able to deliver the performance that customers expect.
In line with our continuous efforts in keeping the highest standards and quality, we embark on training and development for all our staff throughout the year. We also monitor and analyze our systems and continuously improve and innovate upon them.
Our QMS will assist by the following core areas & we are committed to providing quality products, improvement and customer satisfaction.
1.Moisture Analysis – Test Method ASTM C 566-97
This test is used primarily to determine the moisture content in our raw materials as part of our effort to monitor our raw material quality.
Both polymers and carbon black are tested for their moisture content before they are used in production. Evaporable moisture in the sample is determined by drying, thus both surface and pore moisture of the sample can be determined.
2. Flexometer Test
– Test Method ISO 4666
Flexometer test with constant-strain amplitude is used to determine temperature rise and resistance to fatigue in vulcanized rubber. These properties of rubber can suggest possible predictions regarding durability of rubber in finished articles subject to dynamic flexing in service such as tyres, bearings, supports and cable-pulley insert rings.
3. Vertical Rebound Resilience Test
– Test Method ASTM D2632
Impact resilience of solid rubber is determined from measurement of the vertical rebound of a dropped mass in this test. Resilience is a function of both dynamic modulus and internal friction of a rubber.
Test data provides useful prediction for the behavior of rubber compound when it is subjected to impact.
4. Resilience Elasticity Test
-Test Method ISO 4662
A fixed mass on a pendulum is used to deliver impact on to a flat piece of rubber to determine the rebound resilience of the rubber.
The kinetic energy of the impacting mass is measured immediately before and after impact. The result provides an indication for energy loss through hysteresis. The percent rebound measured in the test is inversely proportional to hysteretic loss.
5. IRHD Hardness
– Test Method ISO 48
A method to determine the hardness of vulcanized rubber on flat surfaces (standard-hardness methods). The hardness is expressed in international rubber hardness degrees (IRHD)
6. Compression Set – Test Method ISO 815-1
This test describes the method to determine the compression set characteristics of vulcanized and thermoplastic rubber at ambient or elevated temperatures. This method is intended to measure elastic properties of rubber with hardness within range of 10 IRHD to 95 IRHD
7. Abrasion Resistance Test
– Test Method ISO 4649
This test describes the method to determine the volume loss due to abrasive action of rubbing a test piece over specified grade of abrasive sheet. Runs with a reference compound to express the results as relative volume loss compared to a calibrated abrasive sheet or as an abrasion resistance index compared to a reference compound.
8. Aging Test
– Test Method ISO 188
This test describes the method to determine the accelerated ageing or heat resistance on vulcanized or thermoplastic rubbers with two methods given which are:
Method A: air oven method using a cell-type oven or cabinet oven with low air speed and a ventilation of 3 to 10 changes per hour.
Method B: air oven method using a cabinet oven with forced air circulation by means of a fan and a ventilation of 3 to 10 changes per hour.
9.Flex Cracking & Crack Growth Test
– Test Method ISO 132
This test describes the method to determine the resistance of vulcanized or thermoplastic rubbers to the formation and growth of cracks, when subjected to repeat flexing on the De Mattia type machine.
10. Tensile Test
– Test Method ISO 37
Tensile stress-strain properties of vulcanized and thermoplastic rubbers are useful in the study of the resistance to break of a material under specific tension. Results are defined in term of tensile strength, elongation at break, stress at a given elongation, elongation at a given stress, stress at yield and elongation at yield of a compound
11. Durometer Hardness Test
-Test Method ISO 7619
This test describes the method to determine the indention hardness (Shore hardness) of vulcanized rubber using durometer for the A scale specified for rubber in the normal-hardness range.
12. Mooney Viscosity and Mooney Scorch Test
– Test Method ISO 289-1 & ISO 289-2
This test specifies the method to determine the property called Mooney viscosity of uncompounded or compounded rubbers using a shearing-disc viscometer.
The torque which has to be applied under specified conditions in order to rotate a metal disc in a cylindrical chamber formed from mating dies filled with rubber is measured. The resistance offered by the rubber to this rotation is expressed in arbitrary units as the Mooney viscosity of the test piece. Mooney scorch is a test for determining the pre-vulcanization characteristics of compounded rubber.
The pre-vulcanization characteristics determine by this method provide a means of estimating how long compounded rubber can be maintained at high temperatures and remain processable.
13. Specific Gravity Test
– Test Method ISO 2781
This test describes the method to determine the specific gravity of rubber masterbatch and compound by determining density of rubber masterbatch, compound and a reference substance.
14. Carbon Black Dispersion Test
– Test Method ISO 11345
This test specifies qualitative visual methods for rapid and comparative assessment of the degree of macro dispersion of carbon black and carbon black/silica in rubber.
Ratings are made relative to a set of standard reference photoghraphs, and results are expressed on a numerical scale from 1 to 10.
15. Rheological Test
-Test Method ASTM D 6204-15
This test is use to determine the vulcanization characteristics of rubber compounds. The method covers the use of a rotorless oscillating shear rheometer for the measurement of the flow properties of the rubber and unvulcanized rubber compounds
16.Tear Strength Test
– Test Method ISO 34-1
Tear strength is one of the important mechanical properties of rubber, either vulcanized or thermoplastic. ISO 34-1 is implemented to investigate the overall tearing force required to rupture the rubber specimen
17. Thermogravimetric Analyzer
– Test Method ASTM D6370
TGA is widely used for the purpose of material characterization and weight percentage analysis of organic volatiles, carbon black and filler in a rubber compound, with a function of increasing temperature, or isothermally as a function of time.
18.Oil Resistance Test
–Test Method ASTM D471-06
This test method provides procedures for exposing test specimens to the influence of liquids under definite conditions of temperature and time. The resulting deterioration is determined by measuring the changes in physical properties such as stress/strain properties, hardness and change in volume and dimension, before and after immersion in the test liquid
19. Peel Test
Peel test is used primarily to determine the rubber to rubber surface adhesive strength of vulcanized rubber compound. The force required to separate two pieces of vulcanized rubber bonded by a bonding agent is used to evaluate the adhesive strength between the bonding agent and vulcanized rubber. This in-house testing method is in accordance to ISO 813 (Rubber, vulcanized or thermoplastic – Determination of adhesion to a rigid substrate - 90° peel method)
20. Rubber Swell Test
An in-house test method to determine the relative cross link condition of tested vulcanized rubber piece. The volume fraction of rubber upon mass equilibrium when immersed in solvent is compared to its value of fully cured test piece to evaluate sample’s state of cure.