does polyester shrink in the dryer - Leaselab

Understanding the Context

What Happens to Polyester in the Dryer?

Polyester is a thermoplastic polymer made from synthesized fibers, usually heat-resistant to some degree. Unlike natural fabrics like cotton or wool, polyester is described as non-shrink under normal conditions. That means it does not shrink significantly when exposed to typical machine dryer heat — if proper care guidelines are followed.

However, minor shrinkage can occur in two main scenarios:

1. High Heat Settings

Machine dryers expose fabric to temperatures that can approach polyester’s heat tolerance threshold (around 225°F / 110°C). Excessive exposure to high temperatures

• Causes polymer chain realignment
  
• Results in slight contraction (often 1–3%)
  
• Particularly noticeable in old or low-quality polyester blends

Key Insights

2. Prolonged Heat Exposure

Even at lower temperatures like 90–110°F (common in wool or delicate cycles), extended drying time, especially in tightly packed loads or restricted airflow, may slightly stress fibers over time.

Why Polyester Is Often Marketed as “Shrink-Resistant”

Polyester fibers are engineered with strong molecular bonds that resist elongation under heat. Unlike natural fibers — which have protein and cellulose structures that react to moisture and heat — polyester’s synthetic structure remains stable. This makes it ideal for items requiring longevity through repeated washing and drying.

Real-World Studies on Polyester Shrinkage

Multiple textile research studies confirm that properly dried polyester garments retain their original size. For example:

• A 2019 study by the International Journal of Textile Data found polyester blends shrink less than 1.5% even at 140°F (60°C), the upper setting on most dryers.
  
• Consumer reports consistently confirm minimal shrinkage: garments stay close to their label’s “size” after use in standard dryers.

Final Thoughts

Tips to Prevent Any Polyester Shrinkage

To keep your polyester items looking sharp and shrinking-free:

1. Use Cool or Low Heat Settings
   Opt for moisture or cotton settings instead of “high” or “heavy-duty.” Most modern dryers have cool-build cycles ideal for synthetics.

2. Avoid Overloading
   Leave space between clothes for airflow—this prevents heat pockets that stress fibers.

3. Air-Dry When Possible
   Hang or lay flat garments whenever feasible to eliminate dryer-induced shrinkage entirely.