kind of woolen fabric
罽 refers to a specific kind of woolen fabric. Its meaning is narrow and concrete, without a broader conceptual center.
罽 combines 罒 (net) with 㓹 (a phonetic component), suggesting a fabric made from net-like wool. The exact historical development is uncertain.
The top 罒 looks like a net, and the whole character represents a woolen fabric. Imagine a net woven from wool threads.
For ケイ, picture a woolen fabric shaped like the letter K: K -> ケイ, and the fabric is a kind of woolen material.