TDS stands for Technical Data Sheet, sometimes also called PDS (Product Data Sheet). It is a technical document provided to customers along with a product. It typically includes basic company information, product composition, product parameters, applicable national standards, company or industry standards, product chemical safety analysis data, product features (benefits), usage conditions and methods, operating requirements, general applications, precautions, product images, and more.

A Technical Data Sheet (TDS) is a document detailing specifications, performance, and application details of a product or material. It is like "identity card" of a plastic material. Provided by manufacturer, it details physical, chemical, and mechanical properties of material. A physical property sheet allows us to quickly understand performance characteristics of plastic raw materials, helping us select the most suitable material for processing and production. Much like reading a product's instructions, a physical property sheet makes it easy to find the one that meets our needs among a wide range of plastic raw materials.

 

If a physical property sheet is "identity card" of a plastic raw material, then what data does it contain? A physical property sheet contains a wealth of crucial information. It includes data on physical and chemical properties of various materials, including specific indicators such as density, viscosity, surface tension, solubility, critical value, vapor pressure, specific heat capacity, thermal conductivity, heat of vaporization, and heat of formation.

 

The most commonly used international standards for polymer physical property testing are ASTM and ISO. Due to differences in test conditions and test specimen dimensions, test data obtained from different standards cannot be directly correlated.
ASTM, American Society for Testing and Materials (ASTM), is an industry standard. Its standards are globally recognized and are crucial for ensuring product quality, facilitating trade, and promoting technological innovation. Standards are developed through extensive research, testing, and participation of industry experts, making them both authoritative and practical.
ISO is an international standard. It stands for International Organization for Standardization, a global, non-governmental organization comprised of national standards bodies. It develops international standards to facilitate global trade, improve product and service quality, ensure safety, and promote sustainable development.

Specific Gravity ASTM D792
Specific gravity is ratio of density (mass/volume) of a substance at 23℃ to density of still distilled water at 23℃. Specific gravity can be converted to density by multiplying it by 0.9975. Density is weight of a material per unit volume and is typically expressed in g/cm³.
During injection molding process, part weight can be converted to density to check quality of each molded product or to assess mold-to-mold uniformity. Part weight can be used as a checkpoint for quality and process control.
Two procedures are used to determine specific gravity:

Molding Shrinkage ASTM D955
When heated, thermoplastics become fluid and expand. When cooled, they solidify and shrink from their initial molten state. This change from liquid to solid, accompanied by a change in volume and density, is called material or mold shrinkage.
In injection molding, difference between dimensions of mold cavity and molded sample can vary depending on mold design and molding process. Factors such as mold and melt temperature, fill time, and filling conditions are known to significantly affect shrinkage.
Shrinkage rate = (cavity size - cooled product size) / cavity size * 100%
Melt Flow Index ASTM D1238
Melt flow index (MI) refers to relative fluidity of a plastic material in its molten state. It indicates flow properties during processing and is one of the most fundamental parameters used in plastics processing industry.
Melt flow index is commonly referred to as: MFI (Melt Flow Index); MI (Melt Index); MFR (Melt Flow Rate); MVR (Melt Volume Flow Rate)
Measurement Method: Under a specific load (kg) and temperature (℃), weight (in grams) of melt flowing through a tube of a certain diameter over a specified time (10 minutes) is measured. A higher MI value indicates better flowability; a lower MI value indicates poorer flowability. In practice, it's generally not necessary to wait 10 minutes for plastic to flow; instead, a 10 or 20-second time is used to estimate amount likely to remain in 10 minutes.

 

Tensile Strength & Elongation at Break ASTM D638
Tensile Strength: Under specified test conditions, ratio of maximum load to fracture to cross-sectional area of a specimen is tensile strength. Unit is expressed in kilogram-force per square centimeter or Pa. Area used in calculation is original cross-sectional area of specimen at point of fracture.
Elongation at break: Ratio of displacement at break to original length of specimen, expressed as a percentage (%).
Test method: A standard specimen is pulled at a constant speed on a testing machine until it breaks. Software displays applied stress and elongated length at break.

 

Flexural Strength & Flexural Modulus ASTM D790
Flexural strength: This refers to maximum stress a material can withstand under a bending load until it breaks or reaches a specified bending moment. This stress is maximum normal stress during bending and is measured in MPa (megapascals). It reflects material's ability to resist bending and is used to measure its bending properties.
Flexural modulus: Also called flexural modulus, it is ratio of bending stress to strain. It measures a material's ability to resist bending deformation within its elastic limit.
Test method: A standard specimen of test material is bent under a uniformly applied load. Maximum stress and strain it can withstand until it breaks or reaches a specified deflection are taken as flexural strength. Ratio of stress to strain is flexural modulus.

 

Rockwell Hardness ASTM D785
Hardness is a mechanical property that evaluates surface hardness of a material and measures plastic's resistance to indentation and scratching. (Note: Depending on test method, there are Barcol hardness, Brinell hardness, Rockwell hardness, Shore hardness, Mohs hardness, scratch hardness, and Vickers hardness.)

 

Impact Strength ASTM D256
Impact strength: This test reflects a material's ability to withstand impact loads. It measures ratio of energy consumed in breaking a material under impact load to cross-sectional area of specimen.
Test Method: Specimen is clamped to base of a pendulum tester in a cantilever configuration. Pendulum is released, energy consumed in breaking specimen is calculated from drop and swing heights of pendulum. There are three different specimen placement options:
Notch facing pendulum: This test simulates impact performance of a material with a notch or defect that may exist in actual use.
Notch facing pendulum: This test faces away from notch. This test evaluates impact performance of a material without influence of notch stress concentration.
Unnotched: This test evaluates impact performance of a material under ideal conditions.

 

Vicat Softening Point ASTM D1525
Temperature at which a 1mm² needle penetrates a specimen to a depth of 1mm in a liquid heat transfer medium under a specified load and constant temperature increase. This temperature reflects expected softening point of a material when used in a heating apparatus.
Test Procedure: Place test specimen in test apparatus with needle resting on its surface, at least 1mm from edge. Apply a load of 10N or 50N to specimen. Then lower specimen into a 23℃ oil bath. Raise bath at a rate of 50℃ or 120℃ per hour until needle penetrates 1mm.

 

Heat Deflection Temperature ASTM D648
Heat deflection temperature (HDT) is temperature at which a standard specimen deflects 0.21mm under a specified temperature increase rate and load. It can be used to compare relative performance of different materials under test conditions, is primarily used for quality control and development purposes.

 

 

▶ Surface Resistivity IEC 60093
Surface resistivity is ratio of DC voltage between two points on a material's surface to current flowing through it. It is a physical quantity that indicates ease with which charge transfer or current flow occurs on the surface of an object. Unit is ohm (Ω).
▶ Volume Resistivity ASTM D257
Volume resistivity is resistance of a material to electric current per unit volume and is used to characterize its electrical properties. Generally, the higher volume resistivity, the greater material's effectiveness as an electrical insulator. Resistivity commonly referred to is volume resistivity.
▶ Dielectric Strength ASTM D149
Dielectric strength is a measure of a material's ability to withstand high voltage without dielectric breakdown. Dielectric strength is measured by placing a specimen between electrodes and gradually increasing applied voltage until dielectric breakdown occurs. Result is expressed in kV/mm.
▶ Arc Resistance ASTM D495
Represents time it takes for a standard arc flame to cause carbonization on material surface, until surface becomes conductive and arc extinguishes.
Material Molding Parameters
Recommended molding parameters are included at the end of each physical property sheet. These are not mandatory settings, molders can adjust production based on these parameters and their machine to achieve optimal molding results.

 

TDS report for plastics is crucial for understanding and selecting plastic materials. By thoroughly understanding and effectively utilizing TDS reports, users can more intelligently select appropriate plastic type, optimize product design and manufacturing processes, ultimately improve product quality and market competitiveness.