I. Overview of wire and cable
1. What is wire and cable
For the transmission of electrical energy, information and products to achieve electromagnetic energy conversion
2. The distinction between wire and cable wire and cable
Wire: Rated voltage is low, the structure is relatively simple, relatively small size
Cables: wire and vice versa. No clear boundaries, generally known as
3. Classification of wire and cable wire and cable
Action by using three categories:
(1) power wires and cables - electric power systems use overhead wires and cables products are mainly bare wires, power cables, power equipment, electrical equipment, wire and cable.
(2) --- for information communications wire and cable wire and cable transmission systems are mainly telephone cable, TV cable, electronic cables, RF cables, fiber optic cables, data cable, or other composite cables.
(3) magnet wire - used to implement the electromagnetic energy conversion cable, wire, silk envelope.
By wire and cable industry categories within the five categories:
(1) bare wire - pure metal conductor without insulation and jacket layers, such as ACSR, power lines, locomotives, ground cord.
(2) power cable - there are insulated, armored, protection layer (the following five core complex structure), the product mainly used in hair distribution, transmission, transformation, power lines in the strong electric power transmission, the current through a large (tens of thousands of security to security), high voltage (220V to 500kV and above).
(3) electrical equipment, cables - many varieties and specifications, wide range of applications, typically electric terminals of electrical equipment, the use of higher voltage 1kV and below, oil / cold / temperature / wear-resistant cable, medical / agricultural / mining cable, thin wall electrical wiring.
(4) communication cables - two-wire telephone lines to several thousands of words on the cable, coaxial cable, optical cable, data cable, or even combination of communications cables and so on. Specifications of such products are usually small and uniform size, high precision manufacturing.
(5) magnet wire - mainly used for a variety of electrical, instrumentation and so on.
Second, the standard code used wire and cable
GB-the national standard; JB-machinery standards; SJ-electronic non-standard; YD-MPT standards; GY-Radio Film and Television; / T-as the recommended standard
UL-USA; VDE-Germany; BS-British; JIS-Japanese
PVC plastic wire GB 5023-1997 JB8734-1998 P); flame-retardant wire and cable series GB/T19666-2005; LSZH cable JB/T10941-2004; road vehicle wire JB / T 8139-1999; indoor telephone line YD / T840-1996; general-purpose RF coaxial cable GB/T14864-1993, JB/T10941-2004; network cable YD/T1019-1999; cable conductor GB 3956-1997
Third, the structure and material of wire and cable
1. Cable structure
Wire and cable products, the vast majority of cross section (cross section) exactly the same shape (ignoring the error caused due to manufacturing), an elongated strip of the product, which is due to the system or equipment as constitute a line or use the characteristics of the coil determined. Therefore, the structure of the composition of cable products, just to observe and analyze their cross sections.
Wire and cable products, structural elements, on the whole can be divided into wire, insulation, shielding and sheath components of the four main structural elements and commitments, and pull-filled components. According to the product requirements and applications, and some product structure is very simple.
2. Cable Material
In a sense, wire and cable manufacturing industry is a materials finishing and assembly industry. First, a huge amount of material, cable products material costs to account for 80-90% of the total cost of manufacturing; the second is the type of materials used, the variety is very large, particularly high performance requirements, such as the conductor of copper, the purity of copper required to In 99.95%, and some product to use high-oxygen copper; third manufacturing process will use the material, product performance and service life played a decisive impact.
Meanwhile, the benefits of cable manufacturers also material selection, processing and production management can save the material is closely related to scientific.
Therefore, wire and cable products in the design and material selection must be the same time, in general, use of several materials, and performance through the screening process and after the test identified.
Cable products to use parts of their materials and function, can be divided into conductive material, insulation material, sheath materials, shielding materials, filling materials. But some materials are a few common structures. Especially thermoplastic materials, such as polyvinyl chloride, polyethylene and other components as long as the change in part of the recipe can be used in the insulation or sheath.
Manufacture of cable products in the category of material involved in a wide range of different specifications (grade) is particularly high.
3. The name of the product structure and material
(1) lead wire is the product for current or electromagnetic transmission of information essential to the basic function of the main components.
Main materials: conductive wire core wire is short, with copper, aluminum, copper clad steel, copper clad aluminum and other nonferrous metals made of good conductive properties, the optical fiber as a conductor.
A bare copper wire, tinned wire; single extension, stranding; twist after the tin line.
(2) insulating layer is coated around the wire perimeter play the role of electrical insulation components. That is able to ensure the transmission of electric current or electromagnetic waves, light waves travel not only to flow out along the wire, the conductor has the potential (ie the formation of the surrounding objects, the potential difference, ie voltage) can be isolated, that it is necessary to ensure normal transmission wire function, but also to ensure that the external objects and personal safety. Wire and cable insulation layer is constituted products (except for bare wire type) must have two basic components.
Main material: PVC, PE, XLPE, polypropylene PP, fluoroplastic F, rubber, paper, mica tape
(3) the cable shield is a product of the electromagnetic field with the outside world to isolate the components of electromagnetic field; cable products from the different lines in its internal pair (or line group) between the need for mutual isolation. Can be said that the shield is a "magnetic separation screen." High voltage cable conductor shield and insulation shield is to all of the electric field distribution.
Main materials: bare copper wire, copper clad steel wire, tinned copper wire
(4) Protecting run when installing wire and cable products in a variety of different environments, you must have the product as a whole, especially for the protective effect of insulation components, this is the sheath.
Because the requirements of the various insulating materials have excellent electrical insulation properties, you must request materials, high purity and impurity content is minimal; often can not take into account their ability to protect the outside world, so for the outside world (ie, installation, use and use in situations ) under a variety of mechanical force or resistance, resistance to atmospheric resistance, chemical or oil, the prevention of biological attack and to reduce fire hazard and so care must be made by a variety of layer structure to bear.
Main material: PVC, PE, rubber. Lead, aluminum, steel
(5) filled with a lot of wire and cable products, the structure is a multi-core, these insulated core of a cable or line (or group several times a cable), the first shape is not round, the second is between the left is insulated core large gap, it must be filled are added into the cable structure, the structure is filled into the cable diameter to make the relative benefit of the package with round, squeeze jacket.
Main material: PP rope
(6) tensile elements. A typical structure is ACSR, such as fiber optic cables. In short, in recent years the development of special small, soft-type, and requested several times bent and twisted use of the products, the tensile component plays a major role.
Main material: steel wire
Fourth, the naming of wire and cable
1. The name of wire and cable
Wire and cable products, has named the following principles: Product names, including the contents of the
(1) product applications
(2) type of material or product mix;
(3) the importance of product features or additional features
(4) The size of the class name of the product by schema name from the inside out by the principle: product occasions> Conductor> Insulation> within the sheath> armor type> outer sheath> Additional Features> size of the class name.
Such as: rated voltage 300/300V Copper core PVC insulated PVC sheathed copper wire shielded cable
2. Wire wire model
As the product name is too long, well written and called, for instead of using models
Wire and cable composition and order of the model are as follows:
[0: Use the characteristics of] - [1: category, purpose] [2: conductor] [3: Insulation] [4: Inner jacket] [5: Structure] [6: outer sheath or derivative
0-5 items with the alphabet letters, polymer materials were first place in English letters, each letter can be 1-2; No. 6 is 1-3 digits.
0 items are a variety of special occasions or use of additional specific requirements of the mark, in order to highlight the item, write to the top. In the "-" mark prior to the phonetic alphabet. Such as the ZR-(flame retardant), NH-(fire), WD-(halogen), FY-(anti-termite), FZ-(branch) and so on.
Models of the omission of principles: Copper wire and cable products are mainly used in the conductor material, so that Copper T provinces to write code, but the bare wires and bare except for conductor products. Bare wires and bare conductor products category, class power cable, magnet wire code categories of products does not indicate, electrical wire and cable equipment classes and communication cables not listed class, but out code, such as small class or series. (1) Category Code: A-install the line; B-wire cloth, compensation line, frequency; D-computer cable; F-fluorine plastics, aircraft line;; H-phone line (communication cable), nuclear power;; N- agricultural, fire; P-signal cable; Q-car line; S-RF cable, TV cable, water lines; R-connector; Z-retardant.
(2) Insulation Type: V on behalf of polyvinyl chloride; X on behalf of rubber; Y on behalf of polyethylene; YJ representative of cross-linked polyethylene; YW behalf of polyethylene foam; F on behalf of fluorine plastics.
(3) conductor material: L on behalf of Al; T (omitted) represents the copper.
(4) jacket: V on behalf of PVC jacket; Y polyethylene sheath.
(5) characteristics: R soft; P shielding. - Temperature level (number) (number indicates the cable is also used)
4. We will produce the type of wire and cable
Plastic insulated wire and cable BV, BVR, RV, RVV, RVVP, AV, AVV; nylon jacket line BVN; vehicle cable QVR, QB; computer cable DJYPVP; frequency cable BPVVP; communication cable HYV, HBV, HBYV, HSYV; RF cable SYV, SYWV
Fifth, the technical characteristics of wire and cable
1. Cable structure
(1) the number of conductor / single wire diameter
(2) insulation thickness
(3) into the cable, filling, with packages
(4) weaving a set number / root / single wire diameter
(5) sheath thickness
2. Electrical properties:
(1) the DC resistance of conductor
(2) Insulation resistance
(3) AC spark test voltage
(4) Power frequency voltage withstand test
3. Mechanical properties
(1) tensile strength, elongation
(2) thermal aging properties
(3) low temperature performance
(4) can flex
4. Special performance
(1) flame retardant
(2) Fire Resistance
(3) water resistance
VI, wire and cable production process
1. Wire and cable production process characteristics:
(1) The length of the continuous overlay mode of production: starting from the conductor, each layer is superimposed to the process, the more complex cable structure, the more layers superimposed
(2) multi-category production technology, material flow rate: involving chemical, metal processing
(3) special equipment and more
2. The main process of wire and cable: wire and cable is through drawing, stranding, covering three processes to produce complete, the more complex model specifications, the higher repeatability.
(1) drawn
Under external force to the metal forced through the die (pressure roller), the metal cross section is compressed, and obtain the required shape and size of cross-sectional area of technical processing method known as the metal drawn.
(2) stranding
In order to improve the flexibility of wire and cable, the overall degree, so that two or more single-line, according to the direction of the provisions of intertwined as stranding.
Stranding process points: Conductor stranding, cabling, weaving and winding.
(3) coated
Based on the performance requirements of different wire and cable, the use of special equipment in the outside conductor coated with different materials. Coating in minutes:
A. Extruded: rubber, plastic, lead, aluminum and other materials.
B. Vertical Package: Polyester film, film strip plastic composite materials.
C. Wrapping: strip the tape, mica tape, E-glass fiber tape, non-woven fabrics, plastic tapes, line of cotton, silk and other fiber materials.
2. The basic plastic wire and cable manufacturing process
The use of features, the laying of occasions, working conditions, requirements are different, the structural composition of their products are in various forms. The basic structure of wire and cable is normally provided by: conductive core, the insulating layer, protective layer of three parts.
(1) copper, aluminum, single strands System
Commonly used copper wire and cable, aluminum material, at room temperature, using a drawing machine or the number of road stretching through the die hole, so that cross-section decreased, length increased, the intensity increased. Drawing is the first of the wire and cable company procedure, drawing of the main process parameters with mode technology.
Quality of key points: size failed, the surface failure
(2) single wire annealing
Copper, aluminum filament heated to a certain temperature in order to improve the way recrystallization monofilament toughness and reduce the strength of a single wire, wire and cable to meet the requirements of the conductive wire core.
The key is the quality of annealed copper wire to prevent oxidation.
(3) conductor stranding
To improve the flexibility of wire and cable in order to facilitate the laying of installation, conductive core taken from multiple single-stranded wire. Stranded wire core from the conductive form, the rules can be divided into strands and irregular strands. Irregular Stranded Stranded is divided into concentric stranded complex, a special stranded and so on.
The key is the quality of monofilament with the wrong size, lack of root number, jumpers, burr.
(4) Insulation extrusion
Plastic wire and cable type used mainly extruded solid insulation, plastic insulated the key out of the main quality:
A. Eccentricity: the thickness of the insulation out of the deviation is embodied an important indicator of the level of the extrusion process, most of the product structure, size and standard deviation values are clearly defined.
B. Smoothness: out of the surface of the insulation layer required to be smooth, with no surface roughness, burning, poor quality of impurities
C. Density: Extrusion cross section of insulation to dense and firm, not allowed to have visible pinhole to eliminate the presence of air bubbles.
(5) into the cable
For multi-core cable in order to ensure shape, smaller cable shape, generally need to be twisted a circle. Stranded conductor stranding mechanism similar to the larger diameter section of the stranding, they use a method without back twist.
Quality Key: First, roundness; second is to prevent insulation from being scratched.
Most of the cable into the cable at the same time with the completion of two processes: one is filled, to ensure that after the cable into the cable round and stability; one is binding, and to ensure that the cable core is not loose.
(6) shield
Block external electromagnetic interference (RF Line) or to prevent the cable in the high frequency signal generated on the outside interference (signal line) and the interference between pairs (computer cable).
The key is the density of substandard quality or uneven joints have glitches.
(7) outer sheath
Outer sheath to protect the wire and cable insulation to prevent the erosion of the structure of part of the environmental factors. Outer sheath of the main role is to enhance the mechanical strength of wire and cable, anti-chemical corrosion, moisture, water immersion, to prevent burning, and other capabilities. According to the different requirements of the cable directly extruded by extrusion machine plastic sheath.
Quality Key: (with the insulating layer) is the eccentric, the surface is not smooth, broken, dense.