High temperature resistant wire and cable
High temperature resistant wires and cables are needed in aerospace, locomotives, energy, iron and steel, non-ferrous metal smelting, petroleum mining, electric motors and other fields. Long-term continuous working temperature of 125 degrees, 135 degrees, 150 degrees, 180 degrees, 200 degrees, 250 degrees and 250 degrees or more resistant to high temperature wire and cable, at present commonly used are radiation crosslinked polyolefin, silicone rubber, fluorine resin, polyimide, mica, magnesium wire and cable, etc. Are introduced; Two new high temperature resistant wire and cable.
1. The polyether sulfone (PES) insulated wire Has excellent heat resistance, physical and mechanical properties, electrical insulation, extrusion molding, especially can be used in high temperature continuous and rapid temperature changes in the environment can still keep stable performance and other prominent advantages: thermal deformation temperature at 200-200 degrees, continuous use temperature is 180-200 degrees, UL temperature index of 180 degrees; Can withstand 150-160 degrees of hot water or steam, under high temperature, not acid, alkali erosion; The elastic modulus is almost constant at -100--200 degrees, especially over 100 degrees, which is better than any thermoplastic resin. The linear expansion coefficient is small and its temperature dependence is small. Non-toxic, approved by the FDA of the United States, also in accordance with the requirements of the ministry of health of Japan no. 434 and no. 178. With self-extinguishing property, no flame retardant additive has excellent refractory property and can reach grade ul94v-0 (0.46mm).
2. Polyether ketone (PEEK) insulated wire polyether ketone is a super heat resistant thermal plastic resin. The long-term continuous service temperature is 250 degrees, and the UL temperature index is 250 degrees. PEEK is a flexible resin with good creep resistance. With self-extinguishing property, the requirements of ul94v-1 (thickness 0.3mm), 94v-0 (thickness 1.5mm) and 94v-5 (thickness 3.2mm) can be reached without any flame retardant.
Special purpose and structure of electric wires and cables
1. Low inductance cable
There is the difference between strong electricity and weak electricity. Here we introduce a kind of low inductance cable for strong electricity. The cable with a heat dissipation device, used for all kinds of resistance welder, arc welder and pneumatic electrode holder connected between the new type of low water cooled cable, has simple and reasonable structure, large cooling water circulation, will not become blocked block and the limit of flow phenomenon, good heat dissipation effect, long service life, etc.
The new type of low sensing cable also includes the joint fixed on the cable and cable end, and the cable is also composed of the positive and negative terminals installed in the outer rubber tube. Because this kind of sense of low cable is generally used in voltage of 25 to 50 v, current situation, between 7000-12000 - a short circuit conductive in the cooling water in the cable almost negligible, so in this sense of low cable didn't use the isolation of the positive and negative cable conductor cable core rubber hose, just set up a special cross-sectional spokes shaped (commonly known as the "plum blossom core") core frame, the heart of round and round into the space between adjacent "spokes" in longitudinal groove is formed along the axis direction, core frame longitudinal grooves and the positive cable conductor of the cable configured at the same total number of root, The cable part is composed of the positive and negative terminals respectively placed in the longitudinal grooves of the core frame and the external rubber hose. The positive and negative ends of the cable core cable core head respectively with a collection into a bundle of clip is the core in the clip, and then fixed on the connector, cable outer hose end head suits at the end of the joint, and set out hose outside tightening banding seal
2. Low noise cable
Under the action of bending, vibration, impact, temperature change and other external factors, the cable itself generates pulse signal less than 5mV, which is called low-noise cable, also known as shock-proof instrument cable. It is used for the measurement of small signal in many fields such as industry, medicine and national defense. With polyethylene insulation low noise cable, F46 low noise cable insulation, radiation resistance low noise, low capacitance, low noise cable, hydrophone cable, watertight low noise cable etc. Various specifications of the cables.
The reasons for the noise in the cable include: 1) molecular friction within the medium itself; 2) change of cable capacitance; 3) piezoelectric effect of cable media; 4) the charge is generated by the friction between the conductor and the medium in the cable, that is, the separation of charge is generated when the contact between the conductor and the insulation is damaged.
In crowded on a layer of thin polyethylene insulation surface semi-conducting (0.20 0.30 mm) thickness of low noise cable got rapid development, its value in 2-3 mv, noise for low noise cable working in 400 degrees, can use high temperature resistant half conductive fiber winding and ways to solve, the noise can be up to 5 mv.