The manufacturing process of plastic insulated power cables is a process route arranged in sequence based on the structure of each product, the processes involved, and the equipment used. In principle, each product should have its own independent process flow, but in practical production, the process flow of structurally similar products is often combined to form a process flow for a class of products.
Process flow:
1. Wire mold
The wire drawing die is an important tool in the wire drawing process. The main part of the wire mold is the mold hole, which is generally composed of four areas that are smoothly connected to each other: lubrication area, working area, sizing area, and outlet area.
Lubrication area. The lubricant stays here and is brought into the work area.
Work area. The metal undergoes deformation (thinning, lengthening) in this area, and the actual part in contact with the metal is called the deformation segment.
Fixed diameter area. Make the wire size accurate, the shape meet the requirements, and the diameter of the mold hole is the diameter of the sizing area.
Export Zone. Do not scratch the wire coming out of the sizing area, while preventing wire breakage caused by rebound during shutdown.
2. Preparation of wire blank
Before pulling the copper wire blank, there should be no oxidation marks on the surface of the blank. Due to the high hardness of metal oxides, which reduces the quality of wire drawing and the lifespan of molds and equipment, acid washing is required to remove the oxides.
The surface oxide layer of the aluminum rod has no harmful effects and does not require acid washing.
When welding wire blanks, the time should be short to avoid excessive oxidation. After welding, it is necessary to cool down and repair the weld seam. The wire can only be pulled after repeated bending twice.
When the surface of the copper wire blank is severely oxidized, it should be pre peeled.
To ensure the smooth passage of the wire blank through the mold hole, it is necessary to roll the end of the wire blank finely on the head press in advance.
3. Determination of deformation degree
The degree of deformation should be selected based on the properties of the processed metal, equipment conditions, process conditions, and mold quality.
Under the premise of equipment capability and metal plasticity, try to use a larger degree of deformation to reduce the number of annealing cycles and shorten the production cycle.
Due to the low strength of the welding joint, a smaller degree of deformation should be used for the pass (mold).
For the same metal, the degree of deformation of larger specifications is greater than that of smaller specifications. The degree of deformation during a single stretch is greater than the degree of deformation during multiple stretches (molds).
Metals with good plasticity and annealed metals have a high degree of deformation, while metals with poor plasticity have a low degree of deformation.