PCT Fibers
What is PCT?
PCT is a polyester fiber made with unique chemistry.  Combining dimethyl terephthalate (DMT or terephthalic acid (TA) with ethylene glycol (EG) produces conventional polyester (PET).  By substituting 1,4-cyclohexane dimethanol (CHDM) for the EG, a fiber can be produced with properties better suited to fulfill the needs of many applications.

                    PET = polyethylene terephthalate

                    PCT = poly 1,4-cyclohexanedimethanol terephthalate

Advantages of PCT over PET

PCT is less dense than PET so it offers greater bulk.

PCT provides softness inherent to the molecular composition.
PCT offers better release properties than PET which means that reusables wash and clean up easier.

PCT has better hydrolytic stability than PET so it better withstands the rigors of repeated washings and sterilization.

PCT has a higher melt point than PET
PCT has better chemical resistance to auto fluids and printed circuit board cleaning chemicals than PET.
Key Benefits of PCT

Long-term heat resistance

Surface mount and reflow soldering compatible
Shrinkage similar to PET and PA (nylon)

Flash-free processing

Low moisture absorption
Chemical resistance to auto fluids and printed circuit board cleaning chemicals
 

Typical Fiber Characteristics

  PCT 

 PET 

Specific gravity 1.23 1.38
 
Melt point ºC/ºF 290/555 250/480
 
Tenacity (grams/denier) 2.5-3.0 4.5
 
Elongation (% at break) 35 60
 
Work recovery
  from 2% extension 90 80
  from 5% extension 55 40
from 10% extension 35 20
 
Compression Recovery (%)
from 34.5 mPA (5000psi) 44 31
 
Shrinkage (%)
190 ºC (air) <1 <6
100 ºC (water) <0.5 <1
 
Safe ironing temperature (ºC) 205 145
 
Chemical Resistance
24 hour exposure at indicated conditions, rinsed, dried, and tested.  Reported values are % of tenacity and elongation prior to exposure.
 
Conc. Temp.       Tenacity         Elongation  
Agent              (%)    (ºC)   PET  PCT  PET  PCT
Sulfuric Acid 70 50 73 72 82 69
Hydrochloric Acid 38 50 66 66 80 65
Hydrofluoric Acid 48 25 93 105 125 105
Nitric Acid 40 50 55 71 71 95
Aqua Regia 25 50 108 98 101 97
Chromic Acid 25 50 100 96 98 92
Phosphoric Acid 85 50 111 96 101 104
Acetic Acid 85 50 100 90 104 100
Phenol 5 50 113 96 127 116
Formic Acid 89 50 107 94 114 99
Sodium Hydroxide 50 50 0 69 0 69
Ammonium Hydroxide 28 25 94 96 99 104
Acetone 100 25 103 99 100 114
Ethyl Acetate 100 50 112 100 110 107
Methylene Chloride 100 25 113 96 158 136
Trichloroethylene 100 25 107 101 102 121
Perchloroethylene 100 25 109 97 106 105
Stoddard Solvent 100 25 105 100 108 101
Toluene 100 50 110 94 113 101
Carbon Tetrachloride 100 25 98 90 101 94
Sodium Hypochlorite 5.25 50 94 92 94 93

 

 

Heat Resistance - PCT vs. PET

Stability of fibers under hot, moist conditions

(27 lbs. live steam)

 

 
PET (melt point = 250ºC/480ºF
 
PBT (melt point = 225ºC/440ºF
 
PCT (melt point = 290ºC/555ºF