1. Ash content test

Ash content: During high-temperature burning, the polymer undergoes a series of physical and chemical changes, and finally the organic components evaporate and escape, while the inorganic components (mainly inorganic salts and oxides) remain. These residues are called ash content. In general modified products, ash content refers to inorganic minerals such as silica, calcium carbonate, talc powder, glass fiber, titanium dioxide, etc Test method: Calcination method (burning organic matter and treating its residue at high temperature until constant weight), burning in a muffle furnace at 600 ℃ for 10 minutes, and weighing its residue Ash content expressed as a percentage by mass: (M1-M0) × 100/M

M represents the weight of the sample, M1 ash content and the weight of the cup, M0 cup weight

Purpose: To determine the content of inorganic substances in plastic, as a basis for judging the authenticity of the material and evaluating the material's performance. For example, in plastics with glass fiber, higher plastic material rigidity increases, heat resistance increases, but toughness decreases. Conversely, toughness increases, and rigidity heat resistance decreases

2. Moisture test

Moisture: refers to the water contained inside an object.

Testing principle: mainly divided into: infrared rapid moisture measurement and halogen rapid moisture measurement

Infrared moisture testing principle: Infrared heating method uses the thermal effect and strong penetration ability of infrared heating objects to quickly evaporate the moisture of the tested object and lose weight. By using the initial mass of the object and the mass of the object after evaporation of moisture, the moisture content of the tested object at a specific temperature can be obtained.

Rapid moisture determination of halogen:

Calculation formula for testing: Let G be the weight of the sample before drying, and g be the weight of the sample after drying;

; L is the moisture content of the sample, R is the drying of the sample; LR is the moisture regain of the sample, and OR is the wet weight of the sample. Therefore,

L=G-g/G (1)

R=g/G (2)

0R=(G-g)/G (3)

OR=G/g (4)

Test purpose: Moisture content is an important factor affecting the processing technology, product appearance, and product characteristics of resins such as polyamide (PA) and polycarbonate (PC). During the injection molding process, if plastic particles with excessive moisture content are used for production, some processing problems may arise and ultimately affect the quality of the finished product, such as surface cracking, reflection, and reduced mechanical properties such as impact resistance and tensile strength

3. Melt Index Test

Melt Index: A numerical value that represents the flowability of plastic materials during processing.

Test method: First, let the plastic particles melt into plastic fluid within a certain time (10 minutes), at a certain temperature and pressure (different material standards), and then pass through the weight or volume of a diameter circular tube. The representation methods include MFI: fluid mass; MVR: Fluid volume

Meaning: Indicates the processing flowability of the plastic material. The larger the value, the better the flowability, and vice versa, the worse; At the micro level, the larger the melt index, the lower the viscosity and molecular weight of the plastic. Conversely, it represents a higher viscosity and molecular weight of the plastic