HG/T 4768.4-2014 "Evaluation of dispersibility in pigment and extender plastics, Part 4: Determination of dispersibility of white pigment in polyethylene (PE) by two-roll method" The standard specifies specific steps and methods for assessing the dispersibility of white pigment in polyethylene (PE) plastics using a two-roll method. This standard applies to evaluating the dispersion of pigment in polyethylene (PE) plastics. Measurement of pigment distribution uniformity in plastic substrates by simulating actual production processes. The standard covers the operating requirements under laboratory conditions, sample preparation, testing process, data recording and result evaluation, etc., to ensure good compatibility and uniform dispersion of pigments with plastic substrates to meet the mass and performance requirements of plastic products.