초록

Hydrogel particles are produced by a drying step followed sequentially by precomminuting, grinding, separating, and further drying of coarse particles.

대표청구항 ▼

1. A process for drying a hydrogel, which comprises the following successive steps: a) drying said hydrogel by contact or convective drying b) precomminuting the contact or convectively dried hydrogel c) grinding the precomminuted hydrogel using a coarse or crusher roll mill d) separating off

1. A process for drying a hydrogel, which comprises the following successive steps: a) drying said hydrogel by contact or convective drying b) precomminuting the contact or convectively dried hydrogel c) grinding the precomminuted hydrogel using a coarse or crusher roll mill d) separating off the moist resilient hydrogel particles which have a water content of more than 10% by weight e) afterdrying said moist resilient hydrogel particles. 2. A process as claimed in claim 1, wherein said drying of said hydrogel is effected using a can dryer or a belt dryer. 3. A process as claimed in claim 1, wherein said precomminuting of the dried material is effected using a knuckle-type crusher. 4. A process as claimed in claim 1, wherein said grinding of the precomminuted dried material using a coarse or crusher roll mill is effected using a nip setting such that the dry particles have an average diameter of 0.1-10 mm after grinding. 5. A process as claimed in claim 1, wherein the moist resilient particles are separated off using a sieve vibrating at a frequency of 10 to 50 Hz to an amplitude of 1-10 mm and at an inclination of from 5 to 45° with regard to the horizontal. 6. A process as claimed in claim 1, wherein the moist particles which have been separated off are added to the hydrogel to be dried. 7. A process as claimed in claim 1, wherein the moist particles separated off are directed into a separate dryer for afterdrying.