Application of High Frequency Induction Heating Machine in Optical Cable Manufacturing

High-frequency heating machine-full name "high-frequency induction heating machine", also known as high-frequency induction heating equipment, high-frequency induction heating device, high-frequency heating power supply, high-frequency power supply, high-frequency welding machine, high-frequency induction heating machine, high-frequency induction Heater (welder), etc., it is mainly used for induction heating (non-contact) of metal; it can heat metal very quickly, with power saving, small size, convenient installation, convenient operation, safe and reliable, heating The advantages of high speed, etc., have a wide range of applications.

With the rapid development of Internet services, 3G (3rdGeneration third generation mobile communication technology) services and multimedia applications, the network traffic is expanding exponentially, which requires the network to have high bit rate data transmission capabilities and large Cross-over capacity of throughput. After the emergence of optical fiber communication technology, its huge potential bandwidth capacity of nearly 30THz has brought opportunities for vigorous development in the communication field. Especially since the introduction of the information highway, optical technology has begun to penetrate the entire communication network, and optical fiber communication has a directed all-optical network. The trend of advancing. Optical fiber communication has gone through more than 20 years in my country. The market is the lifeblood of the industry, and price is the lifeblood of an enterprise. How to reasonably reduce product costs, improve product quality, and ensure user requirements is the top priority of all enterprises. This article focuses on the comparison between traditional optical fiber cable ladle glue injection and a new process-high frequency induction heating.

 1. Introduction to the principle
It is well known that the water permeability of optical cable is an environmental performance index strictly required by users, and the steel-clad structure optical cable is prone to water seepage at the steel belt lap joint. The traditional method generally uses hot melt glue to fill the steel belt lap joint to prevent water seepage. . However, the traditional method has many disadvantages. For example, insufficient amount of glue will cause water seepage, and excessive amount of glue will cause bags to occur when the sheath is extruded. Therefore, it is difficult to control the amount of glue added; The ester film is not firmly bonded and accumulates at the core, causing the sheath to come out of the package. The new process uses the principle of high-frequency induction heating to melt the surface film of the steel strip, which not only makes the steel strip lap joints firmly bonded, but also improves the bonding strength between the steel strip and the sheath, and completely solves the water seepage problem and the sheath. Out of package phenomenon. The principle of high-frequency induction heating is that the dielectric material undergoes molecular polarization under the action of a high-frequency electric field, and is arranged in the direction of the electric field. Because the high-frequency electric field changes the molecular direction at a very fast speed, the dielectric material will be affected by the dielectric loss. fever. The high-frequency current flows to the heating coil (usually made of copper tube) that is wound into a ring or other shape. As a result, a strong magnetic beam with an instantaneous change in polarity is generated in the coil. When the heated material such as metal is placed in the coil, the magnetic beam will penetrate the entire heated material and generate large eddies in the heated material in the opposite direction to the heating current. Electric current generates Joule heat due to the resistance in the heated material, which causes the temperature of the material itself to rise rapidly. This is the principle of induction heating.

2. High-frequency induction heating machine is widely used
High-frequency heating function can quickly heat all metals, such as iron, steel, cast iron, stainless steel, copper, aluminum, tin, gold, silver, etc.
1. Hot forging and pressing industry --- whole forging, partial forging, and bit pressing.
2. Welding---brazing of various metal products, welding of knives and blades, and welding of copper pipes (in the optical cable manufacturing industry, it can be used for steel strip lap welding).

3. Heat treatment---metal quenching, annealing, and tempering; especially partial treatment (in the optical cable manufacturing industry, it can be used to peel off the sheath material and the metal strip).

4. Melting---casting smelting, precious metal smelting, small-scale laboratory smelting.

5. Other applications---powder coating, metal implantation of plastics, heating to degreasing (in the fiber optic cable manufacturing industry, it can be used to degreasing and impurity of steel wire extrusion cushion).

Three, the application of traditional hot melt glue machine and high frequency welding situation comparison
High-frequency induction heating machine belongs to high-frequency medium heating equipment. Place the steel-clad cable core between the electrodes produced by the device, and use alternating current to flow to the conductor (usually a copper tube) that is crimped into a ring, thereby generating a magnetic flux, and the steel strip is longitudinally wrapped and the cable core passes through the copper tube , The magnetic beam will penetrate the steel strip and produce eddy current (rotating current) in the direction of the magnetic beam. At this time, due to the induction effect, the resistance in the steel strip generates Joule heat (1 square R), which causes the temperature to rise rapidly. Induction heating. As a result, the steel strip can be heated in a non-contact state. (The heat is caused by Joule heat and hysteresis loss, but it is mainly caused by Joule heat.) When the steel strip is heated by high frequency, the polyester film on the surface of the steel strip is heated and melted, and the steel strip uses its own polyester film at the overlap. Realize bonding and achieve the water blocking effect of steel belt overlap. The outer sheath is directly bonded to the polyester film, which not only increases the bonding strength between the steel strip and the outer sheath, but also removes the problems of the steel-clad optical cable steel strip coating and the frequent packaging of hot melt adhesive.
According to the requirements of 4.3.2.2 in YD/T901-2001 Core Network Optical Cable-Stranded Outdoor Optical Cable Standard for Communication.
The peel strength between the aluminum (or steel) tape of the adhesive sheath (including the 53-type outer sheath) and the polyethylene sheath and the peel strength between the aluminum (or steel) tapes at the overlapped area shall not be less than 1.4 N/mm, but when the filling or coating compound is used to block water under the aluminum (or steel) belt, the value of the overlap of the aluminum (or steel) belt is not required.
Table 1 Comparison between traditional hot melt glue machine and high frequency welding
Fourth, the advantages and characteristics of high frequency induction heating machine

High frequency induction heating machine advantages:

1. Fast heating: Compared with other methods, it can be heated to the required target temperature in seconds.
2. Local heating is possible: only the steel belt is heated, and the surface polyester film is melted by the heat generated by the steel belt, without any harm to other parts in the optical cable.
3. Energy saving: In addition to working hours, only standby power is sufficient, which is a reasonable power saving.
4. It can operate automatically at a relatively stable temperature: even if the production personnel are not skilled enough, the normal operation of the equipment can be guaranteed.
5. Green and environmental protection: no harmful substances are produced.
6. ​​Adjust the high-frequency output according to the mass, heating time and temperature of the heated object.

High frequency induction heating machine features:

1. All solid-state IGBT frequency conversion and function adjustment, soft-switching resonance dual-control and frequency automatic tracking technology are the guarantee of high reliability;
2. Ultra-small size, saving customers 10 times of production space;
3. high efficiency and energy saving, high power factor and power efficiency in the full power range;
4. Broadband 1～20KHZ frequency automatic tracking adaptability, no need for on-site debugging;
5. 100% full load, 24 hours continuous working capacity;
6. ​​Constant output voltage/constant output power control selection function;
7.frequency, power, voltage and current are all displayed.