The Benefits of Rubber Testing for Manufacturers and Consumers

Rubber testing is a crucial process for manufacturers to ensure that their products meet safety and quality standards. From automotive parts to medical devices, rubber is used in a wide range of products, making it important to test for durability, strength, and other factors. In this article, we'll explore the benefits of rubber testing for both manufacturers and consumers.

For more information on the key areas of rubber testing, including specific test methods and instruments, view our comprehensive guide to rubber testing methods.

Ensuring Product Safety And Quality

One of the primary benefits of rubber testing is ensuring the safety and quality of products. By testing for factors such as processability, strength, and resistance to environmental factors, manufacturers can ensure that their products are produced as intended and do not pose a later risk to consumers. This is because variations in the raw materials and processing methods can have a knock-on effect on the performance of the final rubber product. If the material properties fall outside of specified ranges, the likelihood of underperformance and failure increases, potentially creating hazardous conditions for consumers.

To maintain product safety, quality control processes are typically employed at every stage of the rubber manufacturing process. Starting with raw rubber, polymer or natural rubber, compounders mix rubber into technically specified blends that match the requirements of the application. Using statistical quality control methods, batches are continually monitored and measured against pre-determined limits and gates. Hardness, Mooney viscosity and natural rubber testing are commonly used together to build up a picture of the material properties of a rubber compound before vulcanisation.

Additional considerations include the material effects of the environmental conditions. Temperature, humidity and time in storage can all alter the base material properties of polymer compounds, including synthetic rubber. To account for this, a rubber sample can be artificially aged using an environmental chamber to simulate changes in temperature and humidity. Together, rubber testing for quality control can help prevent product recalls and legal issues, as well as build trust and loyalty among consumers who know they can rely on the quality and safety of the products they purchase.

Two example products that have benefitted greatly from rubber testing are passenger tyres and medical gloves. Consumers rely on these products to be high-quality and meet high safety standards. In these cases, the risk to consumers due to poor product safety could result in injury or loss of life.

Meeting Industry Standards And Regulations

Another benefit of rubber testing is ensuring that products meet industry standards and regulations. Different industries have specific requirements for the quality and performance of rubber products, and polymer testing helps manufacturers ensure that their products meet these standards. This can help them avoid fines and legal issues, as well as build a reputation for producing high-quality products that meet industry standards. Additionally, consumers can have peace of mind knowing that the products they purchase meet these standards and are safe to use.

Using the example of medical gloves, it is important for consumers that medical products meet the appropriate regulatory standards. Without testing to international standards accredited to a regulatory body, consumers lack confidence in the manufacturer and the product, resulting in a negative impression and less brand favourability.

For rubber and polymers, ASTM and ISO standards are used internationally to easily convey and transfer information. Standards are used to either specify a test method, the rubber test equipment used, the acceptable range of results, or a mixture of the three.

In the rubber industry, there are a wide variety of standards used that are end-product dependent. Three examples of common standards used throughout the rubber industry are:

1. Cure testing: A Moving Die Rheometer is used to determine the cure properties of a rubber sample during the vulcanisation process by measuring the flow of the material under shear stress conditions. This test can also act as a quality control process. [ISO 6502, ASTM D 5289]
2. Physical testing: A Tensile Tester, or Tensometer, is used to measure the tensile strength and elongation at break of a rubber test piece. Like all elastomers, rubber has high elasticity, so a tensile test is particularly useful for high-strain applications. [ASTM D412]
3. Chemical testing: rubber compounds can contain chemicals that are harmful to humans and the environment. Chemical analysis is used to measure the chemical makeup of rubber materials and identify any potential sources of harm. Gas Chromatography-Mass Spectrometry (GC-MS) is a combined analytical technique that is currently regarded as the 'gold standard' for substance identification within a test sample.

Many other rubber testing standards cover areas such as natural rubber testing, cure/rheological testing, chemical analysis, environmental testing, thermodynamic testing, physical testing and mechanical testing. See our comprehensive guide to rubber testing methods for full details.

Identifying Potential Defects And Weaknesses

Another benefit of rubber testing is the ability to identify potential defects and weaknesses in products before they reach consumers. Testing can reveal issues such as poor adhesion, low tear strength, or inadequate resistance to environmental factors like heat or chemicals. By identifying these issues early on, manufacturers can make necessary improvements to their products and prevent safety hazards or product failures. This not only protects consumers but also saves manufacturers from costly recalls and damage to their reputations.

Usually, this type of testing involves testing a large number of rubber products or samples against more than one variable factor using an experimental design technique, such as the Taguchi method. Statistical analysis techniques can then be used to determine which factors are having the greatest impact on product performance. For example, this could involve testing the adhesive strength of a rubber-to-metal bonded product across a range of environmental conditions (temperature, humidity, time) to determine which combination resulted in the worst outcome.

Alternatively, any rubber product that needs to be flexible can be tested within and outside of its expected range to identify any areas of weakness. This can include cracks, tears and areas of stress concentration. Tensile testers and Dynamic Mechanical Analysers (DMA) can be used to apply stress in more than one direction of deformation (tension, compression, flexure, shear) across a wide range of frequencies and strains. This can be combined with an environmental chamber to include temperature and humidity variations. It is also possible to test rubber components whilst submerged in a liquid, such as water or oil, or in the presence of other gases.

By casting a wide net across many experimental factors, it is possible to determine which circumstances will result in a poor test result and whether defects are one-off or widespread. This information can be used to define safe working ranges or to amend manufacturing processes such as rubber compound formulation, mixing and moulding techniques.

Improving Product Performance And Durability

Rubber testing can also help manufacturers improve the performance and durability of their products. By testing different materials and formulations in terms of processability and performance, manufacturers can identify the best options for their specific product needs. This can lead to products that last longer, perform better, and are more resistant to wear and tear. Consumers benefit from this as well, as they can trust that the products they purchase will meet their expectations and provide long-lasting value.

Depending on the end purpose, rubber products are expected to perform in a wide range of environments, subjected to varying stresses and strains over short and long timescales. Test methods designed to optimise performance are often centred on improving a single physical property that plays a key role in the performance of the product. For instance, while grip and rolling resistance are key to the tyre industry, the rubber glove industry will focus on flexibility, comfort and biocompatibility.

Meanwhile, test methods for improving durability will focus often on performing repetitive motions until a rubber sample breaks or fails. In this case, dumbbell test pieces are securely fastened into Fatigue Tester, Universal Test Machine or sometimes a Dynamic Mechanical Analyser (DMA). The test machine is set to run for a set number of cycles, often into the millions, or indefinitely until the sample begins to, or completely, fails. Using high frequencies and elevated temperatures, it is possible to accelerate long-term effects into the short term. By recording the number of cycles to failure against the test variables, the expected lifecycle of a rubber part or product can be determined across a range of input conditions.

Generally speaking, every rubber application has specific hardness, elasticity, strength and durability requirements that are reflective of the intended environmental conditions during use. In each case, manufacturers need to use rubber testing data to ensure their products are capable of meeting consumer expectations.

Building Consumer Trust and Loyalty

One of the biggest benefits of rubber testing for manufacturers is the ability to build consumer trust and loyalty. When customers purchase a product, they expect it to be safe and reliable. By conducting rigorous testing and ensuring the quality of their products, manufacturers can establish a reputation for producing high-quality goods. This can lead to increased customer satisfaction, repeat business, and positive word-of-mouth recommendations. In today's competitive market, building consumer trust and loyalty is essential for long-term success.

In addition, rubber testing gives manufacturers tangible evidence that their products will perform as expected, providing both proof of compliance and fulfilment of customer expectations. In many cases, demonstrating a performance improvement in a key area can also give a manufacturer a clear advantage over its competitors.

While some manufacturers may feel quite removed from the end-user, with their products forming part of a long supply chain, it remains important to apply the principles of quality control, compliance and performance optimisation. Failure or underperformance of small or even mundane rubber parts can cause outsized annoyance and frustration. For example, a windscreen wiper blade is one of the thousands of parts that make up a car, but if poorly performing can cause a disproportionate amount of irritation for the driver, with this negative sentiment reflecting badly on the car manufacturer and its suppliers.

Conclusion

This article has outlined a few key reasons why rubber testing is crucial to both manufacturers and consumers. Without investing in laboratory testing, manufacturers risk poorly performing products that may also be non-compliant with international standards. Consumers lose out too, with inconsistent and disappointing products often the result of a poorly executed production process.  

To find out more information on the key areas of rubber testing and how manufacturers implement these test methods, use our comprehensive guide to rubber testing methods.