​ Nylon is a hygroscopic material, and as such is affected by variations in moisture levels.

​ For peak performance and for the as designed and tested conditions nylon should be stored at a controlled 73℉ and at 50% Relative Humidity. This storage results in a moisture conditioning of the nylon of 2.5%. While one realizes the realistic limitation of these conditions, nevertheless these are the optimum as designed and tested conditions.

​ Nylon can vary from 0% moisture to a fully absorbed moisture maximum condition of about 8%. The process of absorption is reversible and nylon will desorb depending on the environmental conditions. This factor makes packaging and handling prior to installation most important.

​ When dry, nylon is stiff and brittle, and when moist it is pliable and tough. We like to say that moisture is what gives nylon cable ties their toughness.

​ Most nylon cable tie brittleness problems come about from exposure to dry conditions and as a result the moisture in the tie is fully desorbed. This is accentuated in hot arid and dry cold climates. January and February are the months when most brittleness problems occur in the domestic Unite States. Nylon is also notch sensitive and dryness amplifies this sensitivity. Cable tie design by necessity has several areas where this notch sensitivity can be found.

​ Ties undergo significant stress during installation. Dry ties will exhibit several failure modes. The most common failures under dry desorbed conditions are the pawl breaking out of the head and/or the strap snapping.

​ In addition, any color or UV inhibitors added to the natural nylon resin will compound the problem of brittleness caused by dryness.

​ Dry ties can be returned to fully functional and specification condition by storage under proper conditions. The ties can be soaked in hot water to rapidly return them to a pliable tough tie.

​ Improperly designed or molded cable ties will normally not return to serviceable condition by simply remoisturizing the ties.

​ For a more analytical approach to this and other characteristics of nylon a review of DuPont’s nylon resin design guide is recommended.