Household wire and cable manufacturing process

The manufacture of wire and cable is totally different from that of most electromechanical products. Electromechanical products are usually used to assemble parts into parts and then assemble multiple parts into a single product. The product is measured in units or pieces. Wire and cable is based on the length of the basic unit of measurement. All electric wires and cables are started from conductor processing. The outer layer of the conductor is insulated, shielded, cabled, sheathed, etc. to form wire and cable products. The more complex the product structure, the more layers are stacked.

Wire and cable product manufacturing process characteristics:

1. Large-length continuous superposition combined production methods Large-length continuous superposition combined production methods, the impact on the production of wire and cable is global and control, which involves and affects:

(1) Production process and equipment layout The various equipments in the production workshop must be reasonably discharged according to the process flow required by the product, so that the semi-finished products in each stage are transferred in turn. The equipment configuration must consider the production efficiency to be different and balance the production capacity. Some equipment may have to configure two or more units in order to balance the production capacity of the production line. Therefore, the rational selection and combination of equipment and the layout of production sites must be balanced based on the product and production volume.

(2) Production organization management Production organization management must be scientific, reasonable, accurate, and meticulous. The operator must strictly follow the process requirements. Any problems in any one of the links will affect the smoothness of the process and affect the quality and delivery of the product. Especially for multi-core cables, if the length of a certain pair or basic unit is short, or the quality is problematic, the entire length of the cable will be insufficient, resulting in scrap. Conversely, if a unit is too long, it must be sawn for waste.

(3) Large-scale continuous superposition of quality management The combination of production methods, so that any part of the production process, a point of a moment, will affect the quality of the entire cable. The more the quality defect occurs in the inner layer, and the failure to discover the termination of production in time, the greater the damage caused. Because the production of wires and cables is different from that of assembled products, they can be dismantled and replaced with other parts; the quality of any component or process of wires and cables is almost irretrievable and remediable for this cable. Afterwards, the treatment is very negative. It is not a matter of shortening or downgrading, or scrapping the entire cable. It cannot be opened and reinstalled. The quality management of wire and cable must go through the entire production process. The quality management and inspection department must carry out a thorough inspection of the entire production process, operator self-inspection, and mutual inspection of the upper and lower processes. This is an important guarantee and means for ensuring product quality and improving the economic efficiency of enterprises.

2. There are many types of technology in the production process, including the wide range of processes involved in the manufacture of material flow wires and cables, from smelting and pressure processing of non-ferrous metals to chemical technologies such as plastics, rubbers, and paints, textile technologies such as winding and weaving of fiber materials, and metalworking. The wrapping of the material and the longitudinal wrapping of the metal strip, the welding metal forming process and the like. The various materials used in wire and cable manufacturing are not only of different types, specifications, and specifications, but also large quantities. Therefore, the amount of various materials, reserves, batch cycle and batch must be approved. At the same time, the dismantling, recycling, recycling, and waste disposal of waste products are an important part of management, and do a good job in managing material quotas and paying attention to conservation. In the production of wires and cables, from the entry and exit of raw materials and various auxiliary materials to the storage, the flow of semi-finished products in each process is transferred to the storage and delivery of products, and the material flow rate is large. It must be rationally distributed and dynamically managed.

3. Special equipment Multi-wire and cable manufacturing Use special production equipment with the process characteristics of the industry to meet the requirements of the structure and performance of cable products, meet the requirements of large-length continuous and as high-speed production as possible, thus forming a series of special equipment for cable manufacturing. . Such as extrusion machine series, cable machine series, stranding machine series, around the charter series. The manufacturing process of wire and cable is closely related to the development of special equipment and promote each other. The new process requirements promote the generation and development of new special equipment; in turn, the development of new special equipment has boosted the promotion and application of new processes. Such as drawing, annealing, extrusion series line; physical foam production line and other special equipment, promote the development of wire and cable manufacturing process and improve, improve the cable's product quality and production efficiency.

The main process of wire and cable is made by three processes: drawing, winding, and cladding. The more complex the model specifications, the higher the repeatability.

1. Drawn in metal press processing. The technical process of forcing the metal through the die (pinch wheel) under external force, compressing the metal cross-sectional area and obtaining the required cross-sectional shape and dimensions is called metal draw. Drawing process points: monofilament drawing and strand drawing.

2. Stranding In order to improve the softness and overall degree of wire and cable, let two or more single strands be intertwined in the specified direction and called stranding. Stranding process points: conductor stranding, cable, weaving, wire mounting and winding.

3. According to different performance requirements for wire and cable, special equipment is used to coat different materials on the outside of the conductor.

Coating process:

A. Extrusion: rubber, plastic, lead, aluminum and other materials.

B. Vertical package: rubber, wrinkle aluminum strip material.

C. Wrapping: banded paper tape, mica tape, alkali-free glass fiber tape, non-woven fabric, plastic tape, linear cotton yarn, silk and other fiber materials.

D. Dipping: The basic technological process for the manufacture of plastic wire and cable such as insulating paint and asphalt. 1. Copper, aluminum monofilament wire and cable commonly used copper, aluminum rod material, at room temperature, the use of wire drawing machine through a die or several stretch die hole, so that its cross-section reduced, increased length and strength. Drawing is the first process of each wire and cable company, and the main process parameter of drawing is the matching technology.

2. Monofilament annealed copper and aluminum monofilaments are heated to a certain temperature to increase the toughness of the monofilaments and reduce the strength of the monofilaments in a recrystallization manner so as to meet the requirements of the wire and cable for the conductive cores. The key to the annealing process is to eliminate the oxidation of the copper wire.

3. In order to increase the flexibility of the wire and cable for the purpose of laying and installing the conductor, the conductive core is formed by twisting a plurality of monofilaments. From the twisted form of the conductive core, it can be divided into regular twisting and irregular twisting. Irregular stranding is further divided into bundle stranding, concentric twin stranding, and special stranding. In order to reduce the occupied area of ​​the wire and reduce the geometric size of the cable, a tightly-pressed form is adopted while the conductor is stranded, so that the ordinary round shape is mutated into a semicircle, a fan shape, a tile shape, and a tightly-pressed round shape. This type of conductor is mainly used in power cables.

4. Insulation extruded plastic wire and cable are mainly extruded solid insulation layer, the main technical requirements for plastic insulation extrusion:

4.1. Eccentricity: The deviation from the extruded insulation thickness is an important indicator of the level of extrusion technology. Most of the product's structural dimensions and their deviations are clearly defined in the standard.

4.2. Smoothness: The surface of the extruded insulating layer is required to have a smooth surface, and no unfavorable quality problems such as surface roughness, scorching, and impurities should occur. Density: The cross-section of the extruded insulation layer should be dense and solid, with no visible pinholes, to prevent the presence of air bubbles.

5. Cabling For multi-core cables, in order to ensure the degree of molding and reduce the appearance of the cable, it is generally necessary to twist them into a round shape. The mechanism of stranding is similar to that of conductor stranding. Because of the large diameter of the twisted section, most of the strands are not twisted back. The technical requirements for cabling are as follows: First, to prevent the twisting of the cable caused by the inconvenience of the insulated wire core; and secondly, to prevent the insulating layer from being scratched. Most of the cables are completed with the completion of two other processes at the same time: one is padding to ensure roundness and stability of the cable after the cable is laid, and the other is tying to ensure that the cable core is not loose.

6. In order to protect the insulated wire core from being damaged by armoring, the inner sheath needs to be properly protected. The inner sheath is divided into: the inner sheath (separator sheath) and the inner sheath (cushion). The padding layer instead of the binding band is synchronized with the cabling process.

7. The armoring is installed in the underground cable, and the work may be subjected to a certain positive pressure, and the inner strip armoring structure may be selected. When cables are laid in places where there is both positive pressure and tensile force (such as in water, vertical shafts, or soils with large gaps), the structure with internal steel wire armor should be used.

8. Outer jacket The outer jacket is the part of the structure that protects the insulation of the wire and cable from environmental factors. The main role of the outer sheath is to improve the mechanical strength of the wire and cable, prevent chemical corrosion, moisture, water leaching, and prevent the cable from burning. According to the different requirements of the cable, the plastic jacket is directly squeezed by the extruder.