How to Change the Gloss of PP Material?
1. What is the gloss of PP material?
PP material is a commonly used plastic raw material, which is widely used in many industries. For products made of PP materials, they are mainly composed of additives such as synthetic resin fillers, plasticizers, stabilizers, lubricants and colorants. Due to the different characteristics of raw materials and differences in production processes, plastic products usually have different gloss. In order to ensure the appearance quality of the product, it is necessary to use a glossmeter to detect the gloss of the PP material.
The gloss of the PP material mentioned here refers to the specular reflection ability of the material surface to light. It is a physical quantity that evaluates the ability of a material's surface to reflect light under a set of geometrically prescribed conditions. It is often measured using a professional glossmeter.
2. How to increase or decrease the gloss of PP materials?
If you want to change the gloss of PP material, you can add plastic brightener or matting agent.
The basic principle of plastic brightener is to form a thin film on the product surface, which greatly improves the smoothness and gloss of the product surface. Therefore, plastic brightener is generally not completely compatible with the resin.
The matting methods of PP materials mainly include: die matting, coating film matting and adding filler with matting effect.
(1) Mould extinction
Using the principle of mirror diffuse reflection or convex mirror diffuse reflection, the color change due to optical refraction or the wavefront light affects the imaging effect to achieve the purpose of extinction.
(2) Matting of the coating film
The powder coatings with different curing speeds are mixed by the dry mixing method, then the gloss of the obtained coating film is significantly reduced to achieve the matting effect.
(3) Adding matting fillers
Adding fillers such as ultra-fine silica, talc, etc., significantly reduces gloss. Especially the particle size of the filler has a great influence on the gloss of the plastic. The larger the particle size, the lower the gloss.
3. PP material glossmeter detection method
If you want to accurately evaluate the gloss of PP materials, you can test it according to the national standard GB / T 8807-1988 "Test method for plastic mirror gloss". This standard specifies three methods for measuring the specular gloss of plastics with 20 °, 45 ° and 60 ° angles, which are applicable to the measurement of plastic specular gloss. The 20 ° angle is mainly used for high-gloss plastic, the 45 ° angle is mainly used for low-gloss plastic. The 60 ° angle is mainly used for medium-gloss plastic. For the comparison of specular gloss, it is only applicable to the same type of plastic using the same method.
The 60-degree angle generally used on the market is like LS192, a universal 60-degree glossmeter from Linshang Technology, with a measurement range of 1000GU. High gloss and low gloss materials can be tested because the gloss is a relative value. When there is no uniform standard in the applied industry, it can be tested with the LS192 glossmeter. If the industry has a uniform standard, it is best to use the same angle of equipment to test PP materials. Therefore, when selecting the measurement angle, you should choose differently according to different situations.