The expected lifespan of clear acrylic sheets under typical usage conditions can vary depending on several factors, including the quality of the material, environmental conditions, and how well they are maintained. Here are some general considerations:

Quality of Acrylic Sheet:

High-quality acrylic sheets, particularly those manufactured with UV stabilizers and other additives to enhance durability, can have a longer lifespan.
Cheaper or lower-quality acrylic sheets may degrade more quickly, especially when exposed to UV light and environmental stressors.
Environmental Conditions:

Indoor Use: Acrylic sheets used indoors in controlled environments can last for many years. They are less exposed to UV radiation, temperature fluctuations, and moisture, which can degrade the material over time.
Outdoor Use: Acrylic sheets used outdoors are more susceptible to weathering effects. Direct exposure to sunlight, rain, snow, and temperature changes can accelerate degradation, such as yellowing and loss of transparency.

Maintenance:

Regular cleaning and proper maintenance can extend the lifespan of acrylic sheets. Keeping them free from dust, dirt, and contaminants helps maintain optical clarity and prevents surface damage.
Applying protective coatings or treatments, if recommended by the manufacturer, can also enhance durability and UV resistance.
Usage and Handling:

Acrylic sheets that are subject to frequent handling, impacts, or abrasion may experience wear and tear more quickly. Proper installation and handling techniques can minimize physical damage.
Manufacturing Specifications:

The thickness and quality of the acrylic sheet itself play a role in its lifespan. Thicker sheets generally offer more durability and resistance to cracking or breaking.
Well-maintained clear acrylic sheets used indoors can last for many years, often exceeding a decade or more. Outdoor applications typically have a shorter lifespan due to exposure to environmental factors. It's important to consider these factors when choosing acrylic sheets for specific applications and to follow manufacturer recommendations for care and maintenance to maximize their longevity.