Polyester is a strong material and does not shrink easily. Unfortunately, when the polyester material is too large to fit snugly, its strong qualities will make it more difficult to shrink to size. However, shrinkage can occur if the polyester is exposed to very high temperatures. Here's what you need to do when you want to shrink polyester.
Step
Method 1 of 2: Using a Dryer
Step 1. Turn the fabric side over
Before washing or drying the fabric, you should turn it over to prevent the color from fading.
- While polyester is resistant to fading and discoloration, this resistance can be lost if you use very high heat. The heat that is high enough to shrink the polyester is also high enough to cause the color to fade, especially if you need to repeat this procedure several times.
- Turning the fabric side will reduce the amount of fading on the outer side of the fabric. However this will not have much effect on the color spread that occurs, so you should work on this strategy for polyester separately from other garments or only with garments of a similar color.
Step 2. Wash the cloth in very hot water
Set the washing machine on the hottest water setting and the longest wash cycle. Be sure to use hot water when washing and rinsing.
- You do not need to add detergent to the washing machine while the fabric is in the washing cycle. Adding laundry detergent won't interfere with the shrinking process, but it won't help either. So detergent is not important unless you also need to wash the polyester fabric.
- For polyester materials, significant shrinkage occurs only at temperatures exceeding 80 degrees Celsius.
- The polymer chains in polyester do not move if they are below the "glass transition temperature", that is, the state when the amorphous or amorphous chains in the polymer become rubbery. For polyester, the glass transition temperature is between 68 to 81 degrees Celsius. In other words, the water temperature needs to be within this range for shrinkage to occur.
- Avoid using boiling water. Boiling water can actually be too hot, and you run the risk of turning the polyester material too much so that it stiffens.
Step 3. Immediately transfer the cloth to a hot dryer
Dry the polyester fabric on the highest heat setting and the longest drying cycle.
Again, significant shrinkage can occur at temperatures exceeding 80 degrees Celsius. The effect is especially noticeable at temperatures above this range, so it is important that you expose the polyester material to the hottest possible temperature and as long as possible to increase shrinkage
Step 4. Repeat as many times as needed
Check the material for shrinkage after removing it from the dryer and letting it cool to room temperature. If additional shrinkage is required, repeat washing and drying to further reduce the size.
Step 5. Remember that the more often you wash and dry the fabric, the more visible the color will fade
Try to do it just a few more times. If you are unable to achieve significant shrinkage, consider trying the ironing method described below
Method 2 of 2: Using an Iron
Step 1. Turn the fabric side over
Turn the fabric side over before attempting to shrink it to prevent fading.
- Polyester material has a high resistance to color fading, but fading can occur at high and persistent temperatures. A temperature hot enough to shrink the fabric is also hot enough to cause the color to fade. This is especially the case if you have already put the fabric through several wash and drying cycles.
- Turning the fabric sideways won't prevent the color from spreading, so you should only wash it with clothes of a similar color.
- This method is a bit more extreme than the previous method, so you should only try it if the previous method was not effective enough.
Step 2. Wash the cloth in very hot water
Place the polyester fabric through its longest and hottest wash cycle. Wash and rinse cycles should use the hottest water available.
- Significant shrinkage of the polyester material will only occur at temperatures exceeding 80 degrees Celsius. Some shrinkage can occur at temperatures between 68 and 81 degrees Celsius, which is the "glass transition temperature" of polyester.
- You do not need to add detergent to the washing machine during this wash cycle. You can do this if you want to clean the fabric as well as shrink it, as detergent won't interfere with the process, but additional detergent is not necessary.
- Do not use boiling water. Boiling water can become too hard, causing the polyester to stiffen rather than shrink.
Step 3. Transfer the cloth to the ironing board
As soon as the washing cycle is complete, remove the polyester fabric from the washing machine and transfer it to the ironing board. The cloth will be still wet.
- Make sure the side of the fabric is still upside down to reduce the risk of color fading.
- Spread the ironing upholstery on top of the fabric. Exposing the fabric directly to the heat of the iron can expose the polyester to too much heat, causing it to harden.
Step 4. Iron on a low to medium heat setting
Continue ironing the cloth until it is completely dry.
- Only use a low to medium heat setting to prevent the polyester material from becoming stiff and unusable.
- Do not use the steam setting on the iron. Instead, use a dry iron on the fabric to allow it to dry thoroughly and quickly.
- Check for shrinkage in the finished ironing fabric. But don't repeat this process too often. It is safer for the fabric if you use the drying method multiple times rather than the ironing method.
