Does spun polyester shrink?

The following explains the actual situation regarding shrinkage of spun polyester:

I. Basic Characteristics: Generally does not shrink, but there are exceptions.

• Usually does not shrink

Spun polyester is essentially a plastic fiber, made of the same material as water bottles, and is not prone to shrinking even with high-temperature washing.
It generally returns to its original size after drying, making it suitable for work clothes and curtains that require dimensional stability.

• May shrink slightly in special circumstances

Blended fabrics: If blended with cotton or wool (e.g., 65% spun polyester + 35% cotton), the cotton portion may shrink, causing the garment to deform.
Poor processing: Small factories may skip the "heat setting" process to save costs, and the fabric may shrink by 3%-5% when exposed to high temperatures.

II. What actions can cause shrinkage?

• Incorrect ironing

Ironing at temperatures ≥150℃ (especially with a steam iron) can cause localized shrinkage, hardening, and wrinkling.

• Harsh drying

High temperature and prolonged tumbling in a dryer can cause the fibers to tighten (especially for thin fabrics).

• Boiling water immersion

Washing with boiling water to remove stains can cause some fibers to twist and deform.

III. Key methods to prevent shrinkage

• Correct washing:

Water temperature ≤40℃, gentle hand washing.
Select the "synthetic fiber wash" mode on the washing machine, avoiding strong spin-drying.

• Drying techniques:

Shake the wet garment flat and hang it in a cool, shaded place, avoiding direct sunlight (UV rays damage fibers).
Do not wring dry; rolling it in a towel to absorb water is safer.

• Absolutely prohibited:

High-temperature drying in a dryer, boiling water washing, and direct ironing.

IV. What to do if it has already shrunk?

• Warm water soaking and stretching

Soak in 30℃ warm water with conditioner for 10 minutes, gently stretch the shrunk area, and let it dry (effective for slight shrinkage).

• Repurposing

If it shrinks to a child's size → repurpose it as children's clothing.
If severely deformed → use it as a rag or stuffing material.