What Causes Plastic Aging

When plastic is processed or formed, its quality will gradually decrease. This phenomenon is called aging or degradation. Although the term aging or aging has long existed in the rubber field, it often refers to changes over time and is not suitable for indicating a wide range of performance changes.

The main factors of aging are: the effects of heat, ultraviolet rays, radiation, ozone, electrical, machinery, chemistry, microorganisms, etc., while oxygen, moisture, strain and so on accelerate the aging with these factors. Therefore, the changes in properties caused by this are various, and the specific situation is also complicated in terms of aging alone.

The stability of plastics is generally considered to be the stability to a certain specific property required and the stability to maintain general properties. Generally, the physical, mechanical, and electrical performance requirements are relatively high. However, it is important to recognize that changes in the chemical structure caused by the aging of plastics have an impact on these properties-a fundamental problem.

The chemical aging process of plastics is: molecular chain breaks, cross-linking, changes in the chemical structure of polymer chains, changes in side chain groups, etc. The combination and degree of these reactions vary with the environment.

When plastic is heated, it will soften or melt. Especially when exposed to high temperature, it will be slowly oxidized by oxygen in the air. When exposed to high temperatures above the melting point, thermal decomposition can occur not only in air but also in vacuum. It is well known that plastics deteriorate rapidly when exposed to direct sunlight outdoors, and ultraviolet rays from the sunlight and oxygen from the air are the largest for the stomach. However, it would be weaker if acting alone.

UV Lamp

Plastics are oxidized by heat and ultraviolet rays, and physical properties change significantly as soon as the reaction begins. As mentioned before, this is because the molecular chain in the polymer is broken and new bonds are generated, namely regenerative bonds, branching, crosslinking, and cyclization.

Polymer chemistry has developed rapidly with the advancement of modern instrumental analysis technology. The chemical structure research method uses infrared absorption spectrum, ultraviolet absorption spectrum, gas chromatography, mass analysis, electron spin resonance, radioisotope and other powerful methods to identify structural changes. The degree of chain breakage and cross-linking reaction accompanying the aging, and the changes in the molecular weight of the polymer resulting therefrom, were studied by the solution method, osmotic pressure method, light scattering method, sedimentation method and the like.Thermal effects of polymer melting and glass transition are reversible changes. But heat can cause irreversible or permanent chemical changes to the polymer. If there are no other active substances and effects, the thermal stability of the polymer is related to the bond dissociation energy of the various chemical structures that make up the polymer.

In addition, the photochemical reaction occurs according to the selective chemical structure of the polymer to absorb light radiation energy. Generally sunlight is radiant energy. The wavelength of sunlight that causes polymer aging is in the ultraviolet range of 300 to 400 nanometers.

Outdoor exposure and aging are the result of the main factors such as ultraviolet radiation energy and moisture, ozone, oxygen, heat, and other actual conditions of use. Considering the complex aging mechanism, it is necessary to conduct a general evaluation after obtaining a basic understanding of how various major factors work on polymers. Therefore, in order to explain the complexity of polymer stability under the influence of various parameters, more basic information must be accumulated, and efforts are made to establish a practical accelerated aging test method.

Advantages of the LIB Xenon Arc Test Chamber

The LIB Xenon Arc Test Chamber provides high-precision, standards-aligned weathering simulation designed for R&D laboratories, quality assurance teams, and material scientists who require consistent, traceable, and repeatable test results. Its advantages include:

Full-Spectrum Sunlight Simulation

Using a water-cooled xenon arc lamp with quartz inner glass and borosilicate outer filters, the chamber reproduces the complete solar spectrum (UV → visible → IR). This ensures accurate correlation to natural outdoor exposure.

High Irradiance Stability

Closed-loop irradiance control maintains light intensity within ±5% throughout long test cycles. This guarantees repeatability across different batches and laboratories, meeting ISO 11341, ASTM G155, and IEC 60068 requirements.

Precise Environmental Control

The chamber tightly regulates:

Black Panel Temperature (BPT) 35–85°C ±2°C

Chamber temperature up to 100°C

Humidity 50–98% RH

Programmable spray cycles (1–9999 H 59 M)

Such multi-factor control allows realistic and accelerated aging under complex environmental stress.

Interchangeable Optical Filters

Three optical filters simulate different real-world conditions:

• Daylight Filter - outdoor sunlight
• Window Glass Filter - indoor behind-glass UV
• UV-Extended Filter - intensified UV for extreme accelerated testing

Users can match test conditions to application-specific environments.

xenon lamp and filters

Large Capacity and Uniform Exposure

The rotating specimen rack ensures uniform illumination and can hold up to 42 samples. This is ideal for comparative testing of coatings, plastics, rubber, adhesives, and automotive components.

Intelligent Touchscreen Controller

The PID-controlled touchscreen system offers:

Multi-program scheduling

USB/PC/Ethernet data export

Real-time monitoring of irradiance, BPT, humidity, and spray

Automatic DI water supply

These features provide traceability and simplify long-duration test management.

Long Lamp Life and Efficient Cooling

Water-cooled xenon lamps (4500W / 6500W) offer ~1600 hours of stable output. Cooling efficiency minimizes thermal drift and improves spectral consistency.

Safer, More Reliable Operation

Safety features include:

Over-temperature protection

Water-flow protection

Electrical leakage protection

Door interlock design

All of these ensure safe and stable long-term operation.

LIB UV Test Chamber For Plastic Testing

Plastics undergo degradation from UV light, heat, humidity, and oxygen. LIB's UV (UVA340 / UVB313) test chambers provide a controlled environment to simulate this degradation and evaluate the durability of plastic materials under accelerated conditions.

Realistic UV Spectrum Simulation

LIB UV testers use UVA340 or UVB313 fluorescent lamps that comply with ASTM G154-ideal for evaluating:

Outdoor durability

Color stability

Gloss retention

Mechanical property changes

Surface cracking, chalking, or brittleness

UVA340 closely matches sunlight UV (295–365 nm), while UVB313 accelerates degradation with stronger short-wave UV (280–315 nm).

High Irradiance Accuracy & Stability

The chamber provides an irradiance range of 0.3–20 W/m², controlled through closed-loop feedback for stable intensity across the entire test duration. This ensures repeatable results for plastics sensitive to small UV variations.

Comprehensive Environmental Simulation

LIB UV chambers integrate:

Large Sample Capacity for Comparative Testing

The standard rack holds 52 specimens, with thickness up to 3.5 cm. Optional 3D fixtures allow testing of formed plastic components, molded parts, packaging materials, or irregular shapes.

Intelligent Touchscreen Control System

The PID-controlled touchscreen (USB / PC Link / Ethernet) supports:

120 programmable groups

100 steps per program

Real-time data monitoring

Automatic water supply + water purification system

This allows users to create precise test cycles for different plastics, such as PP, ABS, PVC, PET, nylon, polycarbonate, and HDPE.

Reliable, Repeatable Plastic Aging Evaluation

The chamber provides accelerated data on:

Color change (ΔE)

Gloss retention

Mechanical properties

Surface hardening/embrittlement

Cracking or chalking

Tensile strength and elongation decay

These results help manufacturers:

Improve formulations

Compare additives such as UV stabilizers, antioxidants, pigments

Confirm supplier quality

Predict outdoor service life

Establish warranty data

Cost-Effective and Standards-Compliant

LIB UV chambers comply with:

ASTM G154

ISO 4892-3

JIS plastic weathering standards

They provide a cost-effective alternative to xenon arc systems when UV-only testing meets the application requirements.

Any customization can be made. LIB offers a 3-year warranty and lifetime service. Any issues that cannot be resolved during the warranty period will be replaced free of charge. 24/7 English-speaking after-sales team. Fast shipping within 7-15 days.

Contact LIB Industry to develop a professional and efficient solution tailored to your specific standards and stringent requirements.