research Micromechanics of Retention: The Influence of Polymer Chemistry, Natural Moisture, Capsule Placement Angle, and Twist Parameters on Capsule Retention (InvisiCaps Method)
In this study, researchers found that the primary cause of slippage and detachment of keratin capsules in hair extensions is the re-contamination by oily residues from the hairdresser's hands, rather than the use of hair care products like masks or conditioners.

