Cable Basics Seminar
First, the wire and cable Introduction
Wire means a simple structure and a small number of core electrical wire transfer.
Cable means multiple stranded complex manufacturing process, or to pass a few more core electrical wire.
Wires and cables are not strictly distinguish between the two, generally speaking, as long as the signal can transmit electricity or physical wire, wire and cable can be called.
Developments in the wire and cable
Development of wire and cable, mainly related to the development of an insulating material and conductor. Insulating material consists of the most primitive bare enameled wire plastic wire rubber synthetic material line; the progressive development of the current types of cable. Platinum copper and aluminum conductors also have cable and so on successively.
Third, the classification of wire and cable
Wire Industry Association, according to Japan in 1977 on the classification of wire and cable: 1, bare 2, reel 3, 4 communication cable, power cable 5, covered wire.
1. bare wire ---- name suggests, non-insulating material, a conductive material mainly as: gold, silver, aluminum, platinum and the like.
2. reel ---- similar to the current wired telephone handset cord, CE factory car charger cable.
3. Communication cable ---- mainly used in communications wire and cable, telephone lines apparently is the most obvious example.
4. The high-voltage power cables ---- usually pass wires.
5. ---- covered wire is generally low pressure transmission wires.
Wires and cables can be divided into five categories above. However, depending on the specific material, shape, structure, purpose can be divided into PU CABLE, PVC CABLE, round wire, flat wire, MOUSE CABLE, alarm wire, etc.,
Fourth, the production of wire and cable and process Introduction
Copper → stretch of copper (wire drawing) → granulation → → assembly processing wire processing
1. Application of copper cathode copper law currently copper industry.
2. Copper and Brass (extension line)
2.1 Copper classification: 1. 2. bare copper tinned copper
Bare copper soft, small resistance, good for bending;
Tinned copper easy to weld, not easily oxidized.
2.2 Copper and Brass divided into three stages: rough stretch (8.0 → 3.2 ~ 2.6 mm), the extension
(3.2 ~ 2.6 → 1.2 ~ 1.0 mm), thin stretch (1.2 ~ 1.0 → 0.08 ~ 0.05mm)
3. Granulation: Formulation and color.
4. Cable processing: wire, insulation, collections (taping, filling, ground), winding (eds
Weaving), outside, packaging (CD bar package, shaft-mounted)
Packaging and other processes).
Fifth, the wire and cable related specifications described
1. The description of wire and cable specifications.
Example: UL 2725 28AWG (7 / 0.127 AS) × 6C + E + A + B
12345678910
1. --- indicates the UL.
2. --- represents AWG (American Wire Gauge American Wire Gauge) number, use AWG number may refer to Annex I, II.
3. --- indicates purchase as conductor, the entry of fine copper wire conductor consisting of seven shares.
4. --- "/" means 7 shares thin copper wire is twisted together, "×" said the 7-strand thin copper wire is straight together. In general, direct telephone line conductors put more.
5. --- represents a single copper wire diameter is 0.127mm.
6. --- "A" represents the bare copper wire ("T" indicates tinned wire), "S" indicates fine stranded copper wire.
7. --- "C" (core) indicates the number of cores.
8. --- "E" (earth) represents ground.
9. --- "A" (al / mylar) represents clad thin mylar ("P" represents wrapping paper).
10 .--- "B" (braid) indicates the knitting ("S" (spiral) represents winding).
Six conductor related knowledge
6.1 twist pitch (Pitch), the concept of the rate of twist
* Copper conductor wire of the twisted by a number of stocks are generally made of fine copper wire, stranded conductor in two ways: Concentric Stranded Stranded. Prior to understand them, we first look at the concept from the twist. Engineering colleagues studied the concept of clear screw pitch, studied science colleagues clear concept wavelengths, twisted away from the pitch, the wavelength similar to the distance on the plane also has two of the same nature. As shown below:
In general, twisted away from the smaller Binding better, but more expensive twisted away from the smaller price.
* Obviously, the conductor of the same size, the thin strand of copper wire than the direct discharge of thin copper wire length. Here the rate of twist concept exists. We use the length of conductors multiplied by a coefficient K (K is 1.02 when the general, greater than 61 to take 1.03), we get the actual length of the strand, where K is twisted into the factor.
Six conductor related knowledge
6.2. Conductor Stranding calculated diameter
Accurate calculation of the amount of each material, which is a plant efficiency is very important. Therefore, the conductor stranding diameter it is necessary to calculate the. Whether it is a conductor or wire that there are two strands: Concentric twist, twist beam. Truly, Concentric twist refers to one or more copper single line as the center, the left and right directions interactive layers of twisted around it. The total number of each single line more than an inner layer 6 (the number of 3n (1 + n) +1). Stranded is all single track, according to the same direction of the stranding. Other also has a composite twisted like. When the number of conductor strands (core line number) 7,19,37,61,95 and twisted when the concentric twist (number of 3n (1 + n) +1); the remaining shares (number of cores) of the beam twist. Conductor Stranding diameter is calculated as follows:
Concentric stranding twist the outer diameter D = (1 + 2n) × dn of conductor layers from the inside to the outside;
Stranded Stranded outer diameter D = √N × 1.155 × d D is the outer diameter stranded; N is the number of conductor strands; it is worth mentioning that, with the conductor wire twisted twist is the same principle, but we call it twisted wire for the core collection, the following describes the concept of a lower layer core diameter, the layer core diameter stranded OD - single diameter, as shown below (D 'is the layer core diameter):
Seven commonly used insulation materials and properties
Commonly used insulation materials are:
PP (Polypropylene) material - lighter, stiffer, burning smoothly, without too much smoke, there is dripping phenomenon. Lower prices, specific gravity: 0.91.
SR-PVC (Semi Rigid-Polyvinyl chloride) material - a darker, softer, burning a lot of soot. Expensive, specific gravity: 1.45.
PE (PolyEthylene Resin) material - very bright, soft and difficult to process, combustion without dripping phenomenon. Expensive, specific gravity: 0.93.
The factory production of ordinary telephone lines used by the insulating material is PP material coupled with the EVA, the weight ratio of 10: 1, and the mouse SR-PVC material commonly used material. Of plastic material, whether it be an outer insulating material or wire material has some important mechanical properties, chemical properties and the like, which can refer to the "Chemical Dictionary." Gravity is also very important in wire and cable design, he directly affect how much dosage.
Eight, a collection of related knowledge
* Composition: the collection of specific configuration, need to list from inside to outside.
For example: 4C + F + E + A represents 4C + padding + ground + aluminum foil collection.
* Twisted away from: the need to provide for collection in accordance with the following provisions lay length.
UL: layer core set of trails * 35 (reference value) shall reference the various UL
Standards set.
Non UL: layer core set of trails * 40 (reference value).
Special requirements: depending on the specific circumstances.
Nine, taping and taping material knowledge
Reason 9.1 package with the choice
1. the wire into a cylindrical shape (some do not need to always twist the core wire, the outside layer of the package with vertical package);
2. To prevent loose wires;
3. shelter, so that the signal without interference;
4. between the conductor and shield wire from the insulation effect;
9.2 taping material
1. Al-mylar (ρ = 1.872 ≈1.9), 2. mylar (ρ = 1.4)
3. The tissue band (ρ = 0.8)
In addition to these three packages with material as well as copper (ρ = 8.89), PE band (ρ = 0.93),
PP foam tape and so on.
9.3. Taping way
Package with way points longitudinally and cross-packet, the packet is divided into horizontal and diagonal wrapping packages in two ways. It is shown below:
Vertical bag with the flat wire and twist the wire need not always be the case, the cross-packet softness better; longitudinally flexible
Softness poor.
Select Bandwidth: when wrapping w = 3D, oblique bag w = 4 ~ 5D, and reference the package with the company procurement
Material width (w is the bandwidth, D for the package with front wire diameter, also known as package vaginal discharge diameter). Package with overlap
It depends on wire diameter, in general, no more than 1/4 of the arc length.
Ten, winding and winding knowledge
As already mentioned joint action is wrapped with braided shielding, electromagnetic wave isolation to the outside world; to ensure uninterrupted internal signals, and if the winding and weaving the ground, then the internal signal does not leak.
10.1. The wound on the calculation
Wound required several (N):
N = (D '× π / d) -3 = {[(D1 + d) × π] / d} -3
Where: D '--- layer core diameter (mm), d --- winding copper wire diameter (mm), D1 --- path winding down, 3 is experience, ensuring beautiful appearance after winding wire, otherwise due copper wire wound endure more closely while prone staggered phenomenon, leading to the outer surface of the wire extrusion appear lump, bumpy.
Winding Representation
For example:. 32 / 0.1T POC = 85%
A B C
Description: A. indicates the number of winding;
B. expressed winding wire is 0.1mm tinned copper wire;
C. indicates wound shielding rate (winding ratio of the number of theoretical values of percentage).
XI, winding and weaving knowledge
10.2 weaving process
Knitting machine specifications, currently there are 16 wire factory, 24 two kinds of American knitting machines,
It constitutes braid typically by using this representation:
For example: 16/5 / 0.1T 8 mesh
A B C D
Description: A. represent the number of spindles, "16" indicates that 16 knitting machines;
B. represents the number of shares on each spindle conductor;
C. represents copper braid single wire diameter and material;
D. represent knit mesh.
The number of shares and can not be arbitrarily mesh becomes too large or too small, but still can change. To achieve the same shielding rate case, you can increase the mesh, reducing the number, while weaving speed reduced accordingly.
XII coat and relevant knowledge
11.1 coat material
Our materials are commonly used outside are:
PU (polyurethane) Material: good elasticity, abrasion resistance, the price is more expensive than PVC, burning a pungent odor;
PVC materials: dark color, elastic material than PU worse, burning smell. Our PVC material more widely used, commonly used keyboard cable, mouse material, charger and so on. (The factory low toxicity of the materials are PVC material)
TPR material: good elasticity, abrasion resistance, price and PU fairly, hard, burning a pungent odor;
In addition to these materials outside are several commonly used, but there are still rubber, TPE and other materials can also be reused as, outside the physical properties of the material and chemical properties Please refer to the "chemical dictionary."
XII coat and relevant knowledge
11.2 outer escorted out:
Our escorted out of the way to have the outside:
--- That enrich extrusion line directly through the outer core was taken out of the molding, through no taping, weaving and the like
Processing. Such as telephone lines;
--- Braided Extrusion Extrusion is actually semi-tubular, semi-finished wire braided (or twisted) after being outside
Extrusion, such as USB CABLE;
--- There are special tubular extrusion die extrusion, extrusion of the outer tube is shaped into a round, such as network cable
Nine, taping and taping material knowledge Basic KnowledgeBasic KnowledgeBasic KnowledgeBasic KnowledgeBasic KnowledgeBasic KnowledgeBasic KnowledgeBasic KnowledgeBasic Knowledge