Cuprammonium rayon

Cuprammonium rayon is a rayon fiber made from cellulose dissolved in cuprammonium solution.
It is produced by making cellulose a soluble compound by combining it with copper and ammonia. The solution of this material in caustic soda is passed through a spinneret and the cellulose is regenerated in hardening baths that remove the copper and ammonia and neutralize the caustic soda. Cuprammonium rayon is usually made in fine filaments that are used in lightweight summer dresses and blouses, sometimes in combination with cotton to make textured fabrics with slubbed, uneven surfaces.
The fabric is commonly known by the trade name "Bemberg", owned by the J.P. Bemberg company. The fabric may also be known as "cupro" or "cupra". It is also known as "ammonia silk" on Chinese fashion retail websites.
History.
Cuprammonium rayon was invented in 1890.
Properties.
There are many properties of cuprammonium rayon:
Production.
Cellulose is dissolved in [Cu(NH3)4](OH)2 solution and then regenerated as rayon when extruded into sulfuric acid.