To understand physical property table of plastics, you first need to understand main physical and chemical properties it contains. These properties usually include but are not limited to following categories:
Mechanical properties: such as tensile strength, flexural strength, impact strength, etc. For example, in physical property table of Mitsubishi Engineering Plastics PC/7020IR, data on tensile strength (60.8 MPa) and flexural strength are provided.
Thermal properties: including melting point, heat deformation temperature, thermal conductivity, etc. These data help evaluate performance of materials in high or low temperature environments.
Dimensional stability: such as shrinkage, which refers to change in volume of material during solidification process from liquid to solid.
Electrical properties: such as resistivity, conductivity, etc., suitable for applications where electrical properties need to be considered.
Optical properties: such as transparency and refractive index, are very important for applications that require specific visual effects.
Chemical stability: including chemical corrosion resistance, flame retardancy, etc., which determines whether material can resist erosion of certain chemicals and whether it has fireproof properties.
Other special properties: such as weather resistance, UV resistance, etc., are particularly suitable for materials used outdoors.

 

Physical property table of injection molding materials is provided by material manufacturer. Physical property table records detailed information of plastic. Common physical property tables include performance physical property table, processing parameter table, and material safety data sheet (MSDS), as shown in figure.
Material property table, also known as TDS, Technical Data Sheet technical data sheet, physical property table should not be confused with following instructions when using, COA, Certificate Of Analysis material certificate, MSDS, Material Safety Data Sheet chemical safety data sheet.
Physical property table composition - horizontal materials, performance test conditions, units, test methods (ISO, ASTM, GB, DIN, JIS) Factors affecting TDS data:

If you are a research and development engineer, you need to choose appropriate raw material grade according to your needs. When you come into contact with a new grade of material, the first thing you need to look at is physical property table (Technical Data Sheet, referred to as TDS), which contains several main indicators:
l Density
l Melt index
l Melting point
l Softening point
l Yield tensile strength/elongation
l Break tensile strength/elongation
l Simply supported beam impact energy
l Elastic modulus
l Material manufacturer's description: what processing method this material is suitable for, what superior performance it has, etc.

 

2. Correct use of data in physical property table
We often compare different materials, and some properties are inversely related, such as density and impact strength. This comparison has a prerequisite: that is, it must be compared under same catalyst system and same comonomer conditions. For example, if you use this rule to compare materials with same ZN catalyst and C4 comonomer density of 0.934 and 0.938, it is OK and conclusion is correct. But if you compare ZN, C4, density 0.934 and metallocene C6, density 0.940, it is incorrect.
When comparing performance indicators of two materials, you should pay attention to whether test methods used are same. When using processing parameters in physical property table, values of mold temperature, melt temperature, drying temperature and other temperatures are more accurate. For injection pressure, injection speed, back pressure, and screw speed, they only serve as a reference and cannot be applied mechanically.

When setting injection molding process conditions, each injection molding worker needs to understand relevant properties of plastic used in order to scientifically set process conditions and analyze problems in injection molding production process.
A. Type and brand of plastic (factors to be considered when understanding composition and performance of plastic);
B. Density of plastic (factors to be considered when setting position of multi-stage injection);
C. Hygroscopicity and allowable water content of plastic (factors to be considered when setting drying conditions);
D. Glass transition temperature, melting point and decomposition temperature of plastic (factors to be considered when setting barrel temperature);
E. Melt index FMI of plastic (factors to be considered when setting injection pressure and back pressure);
F. Crystallinity of plastic (factors to be considered when setting mold temperature and material temperature);
G. Allowable injection pressure range of plastic (factors to be considered when setting injection pressure);
H. Allowable residence time of plastic in barrel (factors to be considered when setting residual material and stopping)
I. Molding shrinkage of plastic (factors to be considered when setting mold temperature, material temperature and pressure);
L. Mold temperature range during plastic molding (factors to be considered when setting mold temperature);
K. Other properties (such as chemical resistance, heat deformation temperature, etc.) to be considered in post-processing of plastic parts.