Durability and resistance testing

Do you need to check whether your products are resistant to different climatic agents?How do you test the durability of plastic? Do you want to know how your products, or the materials chosen to manufacture them, will perform when subjected to different factors that could affect their final properties? Do your products comply with the durability, fire resistance and chemical resistance regulations required by market quality standards?

Plastic materials and the products manufactured with them will suffer the continuous attack of external agents during their life cycle. Accordingly, it is essential to be aware of how they are going to perform during these attacks, either to foresee problems and prevent them or to ensure they comply with quality specifications that will help position the products on the market.

Plastic resistance to external agents

Climate testing
(temperature and humidity)

After cycles combining temperature and humidity, either for compliance with standards or personalized to each client, different product and/or material properties are evaluated, such as deformations, changes in appearance and loss of mechanical properties to determine how these change after ageing and whether these changes affect the product’s life cycle.

Accelerated artificial ageing (chambers with Xenon-arc lamps and chambers with UV fluorescent lamps)

This consists of solar simulation tests in which the aim is to simulate accelerated exposure to solar radiation. There are a wide range of applicable standards, such as UNE-EN ISO, and ASTM as well as in-house automobile manufacturer standards. The properties that can be measured after this type of ageing are diverse and will depend on the use and application of the tested product.

Fire behaviour

UL94 classification

One of the typical characteristics of all plastics is their low fire resistance. The demand for self-extinguishing materials is increasing due to the need to offer higher safety levels. There are two types of flammability tests according to UL 94: horizontal and vertical, which consist of measuring the burning time of a plastic sample fixed horizontally or vertically, after it has touched the flame of a burner during the time specified in the corresponding standard.

Horizontal Flammability

A specific flammability test is carried out for the automotive sector under international regulations and specifically adapted by the main vehicle manufacturers: Ford, Volvo, Opel, Nissan, VW, etc. This Horizontal Flammability test evaluates the fire resistance of materials inside a car and affects all non-metallic materials that are used in the manufacture of parts located in car interiors. The maximum speed of flame propagation in these materials is standardised and established by most vehicle manufacturers at a maximum of 100 mm/min.

Cone calorimeter:

This device is used to determine the heat release rate, ignition time, smoke production rate, mass loss rate and the release rate of toxic gases (e.g. CO, CO₂). This makes it possible to evaluate materials used in industries such as the maritime sector (IMO 2010 FTP Code Part 2, IMO-Resolution MSC.307 (88)), the railway industry (EN 45545-2), the furniture industry (ASTM E1474), the electrical device sector (ASTM D6113) and the construction industry (ASTM E1740), not to mention the field of research and development of plastic materials for the construction industry. Applicable standard: ISO 5660-1.

Limiting oxygen index (LOI):

This method is used to determine the minimum fraction of oxygen in a mixture with nitrogen that will support the combustion of small specimens arranged vertically under specific test conditions. The result is the limiting oxygen index. Applicable standard: UNE-EN ISO 4589-2.

Conductive properties

Thermal conductivity:

The material’s ability to conduct temperature from one of its surfaces to another is evaluated. Applicable standard: UNE-EN 12667.

Comparative tracking index (CTI) of solid insulating materials (resistance to forming conductive paths):

The tracking test equipment takes measurements to determine the degree of protection against the formation of conductive paths on solid insulating materials. Tracking phenomenon, i.e. the formation of conductive paths, may be due to electrolytic contamination of the surface or moisture on the surface of these materials. The tests for measuring the formation of conductive paths in accordance with standard IEC 60112 involve applying voltages of 100 V to 600 V. However, with AIMPLAS equipment, voltages of more than 1000 V can be applied.

Glow wire tests (GWIT, GWFI):

These tests are used to determine the temperature (between 550°C and 960°C) at which a glow wire in contact with a specimen ignites. If the specimen ignites, it should self-extinguish any flames in less than 30 seconds after the ignition source is removed. Applicable standards: UNE-EN 60695-2-10, UNE-EN 60695-2-11, UNE-EN 60695-2-12 and UNE-EN 60695-2-13.

Resistance to stress cracking or verification of chemical compatibility

This analysis is used to verify the feasibility of contact between the packaging material and the packaged product, especially in chemical product packaging. Exposure conditions are defined considering factors such as temperature, shelf life, container shape, thickness distribution, filling volume, head space and composition of the packaging material and the packaged product.

Resistance to chemical agents and petroleum products

These tests are closely linked to thermoset plastics, reinforced with fibreglass, etc., though they are also used to test the capabilities of some thermoplastics. In these tests, the sample is subjected to the action of a liquid (fuel) in its liquid and vapour phases and, after the treatment, the mechanical properties (tensile and flexural) of the original sample are compared with the one tested, as well as the variation in mass and appearance of the samples. The evaluation will depend on the corresponding standard or on the agreement between the parties as to how much the mechanical properties should diminish or the absence of changes in the appearance of the material. The typical liquids used are solvents, gas oils, and liquids used in the automotive sector (oils, cleaning liquids, etc.).

Resistance to staining

The test products are exposed to different chemical agents and substances commonly used in different sectors (construction, automotive, furniture) under varying weather and environmental conditions, to verify the surface effect they have when they come into contact with plastic products.

AIMPLAS has the know-how and the appropriate equipment to be able to offer solutions for all needs when evaluating the performance of plastic materials exposed to external agents..