The manufacture of wire and cable is completely different from the way most electromechanical products are produced. Electromechanical products are usually assembled into parts, multiple parts and assembled into a single product, which is measured in number or number of pieces. Wire and cable are based on length. All wire and cable are made from the processing of conductors, and the wires and cables are made by adding insulation, shielding, cable-forming, sheathing, etc. layer by layer on the outer periphery of the conductor. The more complex the product structure, the more layers are stacked.
First, the large-scale continuous superposition combined production mode, the impact on the production of wire and cable is global and control, which involves and affects:
(1) Production process and equipment layout
All kinds of equipment in the production workshop must be discharged according to the technical process required by the product, so that the semi-finished products in each stage can be transferred in sequence. The equipment configuration should balance the production capacity in consideration of different production efficiencies. Some equipments may have to be configured with two or more units in order to balance the production capacity of the production line. Therefore, the reasonable combination of equipment and the layout of the production site must be balanced and comprehensively considered according to the product and production volume.
(2) Production organization management
Production organization management must be scientific and reasonable, thorough and accurate, strict and meticulous, operators must be meticulously implemented according to the process requirements, any problem in one link will affect the smooth flow of the process, affecting 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 if there is a problem with the quality, the length of the entire cable will be insufficient, resulting in scrapping. Conversely, if a unit is too long, it must be sawed to cause waste.
(3) Quality management
The production method of continuous stacking of large lengths causes any problem in the production process and instantaneously, which will affect the quality of the whole cable. The more the quality defects occur in the inner layer, and the production is not discovered in time, the greater the loss. Because the production of wire and cable is different from the assembled product, it can be disassembled and replaced; the quality of any part of the wire and cable or the process is almost irreparable and compensated for. After-the-fact processing is very negative, not short-cutting or downgrading, or scrapping the entire cable. It cannot be disassembled and reassembled.
The quality management of wire and cable must run through the entire production process. The quality management inspection department shall conduct inspections of the entire production process, self-inspection of the operators, and mutual inspection of the upper and lower processes. This is an important guarantee and means to ensure product quality and improve the economic benefits of the enterprise.
2. More production processes, large material flow
Wire and cable manufacturing involves a wide range of processes, from smelting and pressure processing of non-ferrous metals to chemical technologies such as plastics, rubber and paints; textile technology for wrapping and weaving of fiber materials, wrapping of metal materials and metal strips. Longitudinal package, welded metal forming process, etc.
Various materials used in wire and cable manufacturing are not only in categories, varieties, and specifications, but also in large quantities. Therefore, the amount of materials used, the amount of spare, the batch cycle and the batch must be verified. At the same time, the decomposition, recycling, recycling and waste disposal of waste products, as an important part of management, do a good job in material quota management and pay attention to conservation work.
In the production of wire and cable, from the entry and exit of raw materials and various auxiliary materials, the flow of semi-finished products in each process to the storage and delivery of products, the material flow is large, and must be rationally laid out and dynamically managed.
3. More dedicated equipment
Wire and cable manufacturing uses special production equipment with the characteristics of the industry to meet the structural and performance requirements of cable products, to meet the requirements of large length continuous and as fast as possible, thus forming a series of special equipment for cable manufacturing. Such as extrusion machine series, wire drawing machine series, stranding machine series, winding machine series.
The manufacturing process of wire and cable is closely related to the development of special equipment and promotes each other. New process requirements to promote the generation and development of new special equipment; in turn, the development of new special equipment has promoted the promotion and application of new technologies. Such as drawing, annealing, extrusion series line; physical foam production line and other special equipment, promote the development and improvement of wire and cable manufacturing process, improve cable product quality and production efficiency.
Second, the main process of wire and cable
Wire and cable are made by three processes: drawing, twisting and cladding. The more complex the model specifications, the higher the repeatability.
In metal press processing, a technical processing method in which a metal is forced to pass through a mold (pressure roller) under an external force, a metal cross-sectional area is compressed, and a desired cross-sectional area shape and size is obtained is called metal drawing.
Drawing process: single wire drawing and strand drawing.
In order to improve the softness and integrity of the wire and cable, it is called twisting by interlacing two or more single wires in a predetermined direction.
Twisting process: conductor stranding, cabling, weaving, wire mounting and winding.
Depending on the different performance requirements of the wire and cable, special equipment is used to coat different materials on the outside of the conductor. Coating process points:
A. Extrusion: rubber, plastic, lead, aluminum and other materials.
B. Vertical package: rubber, corrugated aluminum strip material.
C. Wrap: tape-like paper tape, mica tape, alkali-free glass fiber tape, non-woven fabric, plastic tape, etc., linear cotton yarn, silk and other fiber materials.
D. Dip coating: insulating varnish, asphalt, etc.