Лако-красочные материалы — производство

The degree of chalking of a coating is measured by the quantity of loose pigment particles. It may be determined by three methods:

1. KempfMethod. For standards, see Table 1.1 (“Chalkingdegree: Kempfmethod”). Water-treated photographic paper is applied to the coating (with the humid gelatin side facing the coating surface) and pressed by means of a special stamp device. The gelatin coating picks up loose pigment particles that are not attached to the binder. The degree of chalking is judged visually (for scale of measurement see Table 1.1, “Test evaluation”). See also Section 1.2.2. Appa­ratus: Kempf stamp equipment.

2. Adhesive Tape Method. For standards, see Table 1.1 (“Chalking degree; Adhesive tape method”). Loose pigment particles are picked up by transparent adhesive tape. The degree of chalking is determined from a reference scale (see Table 1.1, “Test Evaluation” and Section 1.2.2) or by using a comparative scale that is agreed upon by the interested parties.

3. Photographic Methods. For standards, see Table 1.1 (“Chalking degree: Photo­graphic method”). Chalking prints on paper are compared with photographic standards.