from about 0 3 to about 3 0 weight percent of cellulose is present in the collagen dispersion the mixture is aged for from 4 to 16 hours and then treated by shearing action to further reduce particle size the mixture is then again aged for from 18 to 60 hours homogenized and filtered optionally a second homogenization and filtration is used the range of collagen content in the low solids slurry is between about 3 and about 8 weight percent and preferably between about 4 5 and about 6 weight percent in a second of such processes known as the fibrous slurry process collagen containing material e g corium layers are stored for long periods e g up to about 30 days in alkaline state e g ph gt 11 5 subsequently the collagen material is chopped or diced a strong inorganic acid e g hydrochloric acid is added to the collagen pieces to swell them prior to the input of mechanical actions to separate the collagen fibers sufficient acid is used to obtain a ph of from about 2 0 to about 3 0 the fiber separation is usually accomplished by a crushing step such as may be obtained by a roll mill the product obtained from the crushing step is then mixed with a suitable mixer e g a blade mixer such as a sigma blade mixer the resulting product is diluted and may include further addition of strong acid to obtain a target ph of from 2 5 to 3 0 if desired.