A
UL is an American agencies and standards set up to address product safety testing to prevent electricity and fire incidents. Formally known as Underwriters Laboratories Inc, and Standards, there are certifications for synthetic resin materials, and the following five are related to synthetic resins.
1.UL-94
Combustion test for plastic materials: Depending on the thickness of the test piece, there is 94HB, 94V-2, 94V-1, 94V-0, and generally the thinner the wall thickness, the more easily it burns.
2.UL-746A
The following two are used in the specification for short-term physical property assessment of plastic materials: In the case of a thermoplastic resin, it is applied in a use environment in which a dynamic external force is applied, and is determined by a tensile impact value (Izod value in the case of a thermosetting resin).The labeling method is applied in a use environment in which only “Mech,with imp static” external force is applied, and in the case of a thermoplastic resin, it is determined by a tensile strength (bending strength in the case of a thermosetting resin), and the labeling method is “Mech,w/o imp”
3.UL-746B
The following are used in the specification for long-term physical property assessment of plastic materials: Rated temperature Indicates a constant temperature at which the initial physical properties (e.g., electrical and mechanical properties) drop to 50% when exposed to air at a constant temperature for 0.1 million hours. Indicates RTIs (Relative Thermal Index) at °C.
4.UL-746C
UL-ranked by the rating level in the standard for evaluating the electrical use of plastic materials. (PCL:Performance Level Categories) uses the following five.
1). Hot-wire ignitability: The degree to which the material is heated and ignited is evaluated in the number of seconds of ignition, and the indication is in five levels from 0 to 5 in the HWI (Hot-Wire Ignition) PCL-rank. The smaller the number, the better.
2). Large current arc ignitability: The degree to which the material ignites by arc discharge is evaluated by arc number, and the indication of HAI (High-Ampare Arc Resistance) PCL rank is better as the number is smaller in 5 stages from 0 to 4.
3). Arc Resistance: The degree to which a conductive path is formed, attributed to arcs according to ASTM D495, is evaluated in seconds, the indicia are shown as D495, and the PCL rank is 8 steps from 0 to 7, and the smaller the number, the better.
4). High-voltage tracking: Repeated high-voltage, low-current arcing on the surface of the material, evaluating the degree to which the material can cause a conductive path, evaluating at the tracking speed (millimeters/minute), labeling is HVTR(High Voltage Arc Tracking Rate.
5). Tracking Resistance: Evaluate the degree of voltage that causes the material to create a permanent carbonized conductivity path, the indication is CTI (Comparative Tracking Index), the PCL-rank is six steps from 0 to 5, the smaller the number, the better.
5.UL-746D
Standards for plastic-material assemblies