What is flat cable?

What is flat cable?

Flat cable is the standard arrangement of production, AC rated current 450V/70V and the following mobile electrical equipment, flat structure is especially suitable for often deformed places, no knots, expansion and neat, such as driving. YB, YBF, YBZ three products can meet the requirements of a variety of places. It is suitable for connecting household appliances between moving electrical equipment under extreme conditions such as power generation, metallurgical industry, chemical plant and seaport.

2. Technical standards for flat cables

1, AC rated current: Uo/U=450V/750V;

Uo: effective voltage between the conductor and the ground of any phase;

U: Effective value of intermediate voltage of any two-phase conductor.

2, the application of working voltage:

In the system software, the working standard voltage is not 1.1 times of the fixed current;

In DC system software, the working standard voltage does not exceed 1.5 times the fixed current.

3, core long-term operating temperature: not more than 65℃.

3, the main purpose of flat cable

1. Driving force core conductor

2. Insulation layer

3. Tape

4. Ground wire core electrical conductor

5. Insulation layer

6. Add layers

7. Control the core electric conductor

8. Insulation layer

9. Cable cover

4, flat cable performance parameters

1. When the grounding resistance of flat cable is calculated to the length of 1km and the temperature is 20℃, the driving force core should not be less than 30MΩ/km.

2, flat cable working voltage test, the middle of the driving force core should be able to withstand 50Hz, 2500V working voltage test for 5min, control

The center of the wire core should be able to withstand the working voltage test of 50Hz and 1500V.

3. The delivery length of flat cable should not be less than 150m, and the delivery length of long cable should not be less than 35m, and the total delivery shall not exceed 10% of the total delivery length. According to the agreement between the customer and the manufacturer, cable delivery of any size is allowed.

5. Flat cable forming method

As a kind of multi-core cable, flat cable is used in computers and instruments. Because of its advantages such as easy bending and small indoor space, flat cable is also widely used in domestic appliances such as phone and radio recorder. In order to better meet the requirements of different applications, some new flat cables have been developed and designed. The application of movable insulating layer RF connector makes the wiring of flat cable extremely convenient and reliable. At the same time, it also puts forward higher regulations on the geometric specifications of the core distance between the wires of flat cable, such as the dimensional tolerance of the core distance accumulation deviation and the thickness of the insulation layer, which further increases the difficulty factor of the production of flat cable.

The production process of flat cable is basically similar to that of plastic film wire. In flat cable forming generator set, in addition to lifting a flat cable forming equipment related to the main art of insulating layer material production and processing, double-ended single stranding machine, refrigeration stainless steel sink, fire detector, tractor and coil making machine and other facilities are almost similar to those used in plastic film wire manufacturing.

The forming method of flat cable is to clip a group of copper core cables evenly distributed at a certain interval between two pieces of plastic film, and bond the three into flat cable according to a certain way. There are two problems to deal with in shaping it. One is to create two layers of plastic film that can bond or melt with each other, and the other is to ensure that a group of power lines are consistently spaced and proportionally arranged.

The insulating layer of flat cable has fine polyethylene, polyester and cable material, etc. The production and processing properties of this polymer material organic compound are not the same, so it is necessary to use different production methods to make them formed. A wide variety of flat cable formers are manufactured, and although each has its own way of shaping, most fall into four broad categories.

1. Instant squeeze method. Choose plastic granulator immediately with mold shell extrusion flat cable, such as German KABLEMETAL flat cable machine and French MAILFLER flat cable machine.

2. Laminating method. According to a pair of roller power lines and plastic rolled into cable, this way can be divided into two ways according to the source of plastic film, one is called extrusion plastic film lamination method, such as Japan Heiseng cable cable strains of flat cable machine; The other is called prefabricated plastic film laminating method, such as the mechanical and electrical Department No. 23 research room with strip cable machine.

3. Bonding method. According to the adhesive, two pieces of plastic film and the transmission line are bonded and formed, and the above flat cable machine without 20 factories.

4. In the middle of the two forming methods, such as extrusion method and laminating method combined to shield the flat cable machine, many references to this matter have been reported.

5, flat cable manufacturing regulations

All kinds of flat cable forming methods have their own application fields and advantages and disadvantages. Which kind of forming method is used in the production and processing depends on the production and processing performance of insulating layer materials. There are some specifications of flat cables can choose two forming methods, such as UL2651 can adopt immediate extrusion method or laminating method; However, some flat cables can only choose one forming method, such as UL2468 and UL2877 only use immediate extrusion method, UL2902 only use bonding method. Various UL specifications and models Flat cable forming methods are specified in the UL document.

In order to manufacture flat cables in line with the standard, in addition to selecting the appropriate production mode according to the production and processing performance of insulation resistance, there are also many practical technical problems in the forming process (some are unique to flat cable forming, some are encountered in the general production and manufacturing of cable) must be dealt with, otherwise, although the appearance design of the commodity is similar and the performance of the electrical equipment can not meet the requirements, Or you can't apply it. The core distance is beyond the requirements, the transmission line is relatively serious axial force, the ground resistance is low and the flat cable is short and long. The thermal expansion coefficient of plastic is very large, soft polyethylene is 7.0~25X10-5/ C. Along with the temperature change, the core distance specification also needs to change with the change. When the flat cable molding mold is added as required, it cannot follow the temperature change. In order to facilitate the actual operation and reduce the cost of mold shell, the flat cable must be formed under the condition of small temperature change, and the temperature in the production workshop should be adjusted in the middle of 15~25℃.

The dimensional precision of flat cable is mostly ensured by mold precision. The standard tolerance, surface roughness and dimension tolerance of mold shell are very high, resulting in high cost of mold shell and poor practicability. When designing the mold shell, besides considering to ensure the precision of the product, it is also necessary to consider the process performance of adding soil and installing.