Binder
A chemical agent used to glue fibres together in some nonwovens.
Binder
A binder is an alternative to entanglement: fibres are fixed at their crossing points with a polymer, which is fast and inexpensive. The trade-off is a thin film distributed through the material, which can feel stiff as it dries and slightly tacky when wet.
Whether a web contains a binder is a direct question with a direct answer, and it belongs on the specification rather than in a conversation. It changes hand feel, and it changes what can be declared about the material.