Black linear low density polyethylene sheath (LDH) instructions

2023-07-25

Product introduction: The black linear low-density polyethylene sheath material (LDH) produced by the company is processed by advanced technology with high-quality polyethylene resin, carbon black masterbatch and other processing aids and functional additives. It is mainly used for the sheath of communication cables, control cables, signal cables and power cables with high environmental stress cracking requirements, and the maximum working temperature is 70 ℃. This product has good processing and extrusion performance, which can meet the customer's high-speed extrusion at the same time, but also ensure the smooth and bright surface of the extruded cable, and completely solve the defect of surface melt crack / sharkskin shape of linear polyethylene during processing. This product is of high quality in the industry in terms of technical indicators and processing performance.
　
Executive standard: This product meets the requirements of GB/T15065-2009 standard.
　
Processing technology: It is recommended to use L/D=25:1 extruder production, refer to the extrusion temperature as shown in the following table

Warm zone	Mouth mold	Head	Neck	Zone 6	Zone 5	Zone 4	Zone 3	Zone 2	Zone 1
Setpoint	230	225	220	210	200	190	180	170	160

　
Product quality indicators:

Number	Indicator items		Standard value	Measured value
1	Melt flow mass rate, g/10min		≤2.0	1.6
2	Density, g/cm³		≤0.940	0.935
3	Tensile strength, MPa		≥14.0	16.5
4	Elongation at break, %		≥600	685
5	Low temperature impact embrittlement temperature, -76℃		Pass	Pass
6	Resistant to environmental stress cracking F₀，h		≥500	Pass
7	200℃ oxidation induction period, min		≥30	43
8	Carbon black content,%		2.60±0.25	2.61
9	Carbon black dispersion, grade		≤3	2.6
10	Thermal aging of air ovens	Tensile strength, MPa	≥13.0	15.6
10	Thermal aging of air ovens	Elongation at break, %	≥500	668
11	Dielectric strength Ed, kV/mm		≥25	28
12	Volume resistivity ρ_V，Ω·mm		≥1×10¹⁴	2.7×10¹⁴
13	Dielectric constant ε_r，		≤2.8	2.66