Sophisticated non-contract electronic equipment continuously monitors the electrical and mechanical properties of the primary conductor throughout all phases of production in the insulation extrusion line. For example, at critical locations on the line, monitoring devices provide the following information: conductor diameter, conductor temperature, wire line tension between the annealer and capstan, and wire line tension between the capstan and the take-up reel. In addition to diameter, the optical diameter gage also monitors for lumps, "neckdowns" (sudden changes in overall diameter), and other physical defects in or on the insulation. Additional gages monitor concentricity, eccentricity, and capacitance. An internal algorithm performs a Fast Fourier Transform (FFT) on measured insulation diameter and capacitance to further allow in-line monitoring of impedance performance.
A dielectric withstand test, which consists of an electrified ball-chain curtain through which the insulated conductor passes, is used to confirm insulation integrity. The ball-chain curtain is charged to a high voltage, typically 2.5 kV DC, and flaws in the insulation that reveal defective dielectric or bare copper cause a discharge to be detected.
Read more The process controller records the precise location of any defects detected by the in-line monitoring equipment. This allows for easy identification, removal, and analysis prior to subsequent manufacturing operations. The finished insulated primary conductor passes through an accumulator that maintains consistent wire tension as the product is spooled onto a take-up reel in lengths of up to 15,000 feet. Accumulators play an important role in that they maintain constant wire-line tension throughout the manufacturing process, including reel changes, to facilitate non-stop production. Telecommunications cables use twisted-pair construction to deliver superior transmission performance and electromagnetic compatibility (low radiated emissions and high signal immunity), as well as to support a strong and flexible product design. Twisted-pair cables are successful at rejecting noise interference (crosstalk) because their pair geometry supports differential signal transmission schemes. This means that the transmitted signal that appears across the two conductors (the tip conductor and the ring conductor) of a twisted pair is equal in voltage magnitude, but opposite in phase. Because of the twisted-pair geometry, noise that is coupled onto the two conductors from an outside source (either an adjacent pair or from the cabling environment) appears equal in voltage magnitude and equal in phase. Equipment receivers, engineered to detect the signal difference between the two conductors, see induced noise as two "like" voltages, which are simply subtracted out during the signal reconstruction process. By design, each pair in a four-pair UTP cable has a unique pair-twist rate, or "lay," to ensure crosstalk immunity from both outside sources and adjacent pairs. During the manufacturing process, particular attention is focused on maintaining uniform tension and the exact lay of the twisted pair. Twist lays for Category 6 cables are tighter and more stringently controlled than those specified for Category 5e and Category 3 cables. As a result, more precise and sophisticated twining equipment and slower process speeds are necessary to manufacture higher-performing UTP cables. Manufacturing data-grade twisted pairs requires the use of pre-twisting equipment to prepare the conductor for the twining operation. Pre-twist machinery employs rotating bows that add torsion to each conductor prior to twining. This torsion induces the primary conductors to self-wrap during the twining process. This mechanical enhancement better controls conductor center-to-center distance within the twisted pair, allowing for improved return loss and impedance performance. Twining equipment must apply equal tension to each primary conductor to ensure a balanced pair geometry. Data-grade primary conductors are twisted using double-twist twining technology. In this design, two bows rotate around a take-up reel. The conductors are fed through a lay plate into the bow spindles. As the conductors travel along the bow path, they pass over two deviation pulleys. Each pulley introduces one twist into the pair, hence the machine's name of "double-twist twiner." The advantages of this method are increased manufacturing throughput and twist lay accuracy. Double-twist gang-twiners employed for Category 5e cable manufacturing simultaneously twist four pairs, each with its own pair lay. A main drive capstan pulls the product from the payoff reels through twining bows rotating at a set rate (which is fixed through appropriate driveline components) that controls each of the four unique pair lays. The four pairs are cabled together as they are spooled onto a rotating take-up reel. Line speeds associated with this process are typically 300 feet/minute for Category 3 cable and 100 feet/minute for Category 5e cable cores. Category 6 twist technology requires the most precise line-drive controls available. Examples include servomotor controllers and AC vector drives that continuously monitor and maintain line speed. A precision double-twist twiner pre-twists each conductor and twists the pair in tandem, thereby offering infinitely adjustable pair-lay configurations. Optimized bow design minimizes performance degradation due to drag (windage) and/or tension on the pair. This process runs at a rate of up to 5,000 twists/minute and is the preferred method of pair manufacturing for Category 6 cables. Four twisted pairs are cabled together prior to final jacketing. In the cabling process, the twisted pairs and any filler materials, such as star-separators, are pulled through a lay plate and die, and cabled together. The cabling process adds flexibility and strength to the cable assembly, and serves to restrict pair movement and separation after jacketing. Jacketing a cable core primarily protects the finished product from handling damage and disturbance to the pair geometry. An optional ripcord may be incorporated over the cable core during the jacketing process. Jacket-compound selection affects the flame performance of the final assembly; LSPVC compounds are used for plenum-rated cables and PVC compounds are used for riser-rated cables. During the re-spool operation, ink-jet printers apply a print legend to the jacket. These markings typically include reverse sequential-footage, date of manufacture, and lot traceability identifiers. At the re-spool operation, the cable is cut from master-reels of up to 100,000 feet into final-package lengths that are typically 1,000 feet. Packaging options include plastic or wooden reels and "reel-less" boxes (commonly referred to by the brand name Reelex). Reel-less packaging requires special machinery to configure the finished cable into a self-supporting figure-8 form that allows tangle-free payout from a cardboard box fitted with a payout cone. Another option is to insert the reel into a holder and spindle assembly that is integral to a payout box (reel-in-a-box). To maintain the integrity and performance of UTP cables, installers should take care not to disturb or damage the cable conductors or pair geometry. In particular, the following guidelines are recommended to maintain optimum performance: If you want to learn more, please visit our website SUNUA. Twisted-pair cables have become the foundation of building telecommunications and data transmission today because of their design simplicity, ease of use, and robust performance. Advances in today's manufacturing techniques, coupled with conscientious installation practices, will help to ensure that the simple and economical twisted-pair stays at the forefront of telecommunications technology. Valerie Rybinski is engineering services manager with Hitachi Cable Manchester Inc. (www.hcm.hitachi.com). She holds a BSEE degree and has worked in the telecommunications industry for more than a decade.Twisted-pair design
Jacketing and packaging
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In our daily work, wire and cable must be extremely common. Without it, our life will lose a lot of colors. So what raw materials do we need when we produce wire and cable? Copper wire: As the carrier of conduction, copper wire is one of the indispensable components of wire and cable. Copper wire made by continuous casting and rolling process with electrolytic copper as raw material is called low oxygen copper wire and copper wire made by the above method is called oxygen-free copper wire. Alumi
In our daily work, wire and cable must be extremely common. Without it, our life will lose a lot of colors. So what raw materials do we need when we produce wire and cable?
Copper wire:
As the carrier of conduction, copper wire is one of the indispensable components of wire and cable. Copper wire made by continuous casting and rolling process with electrolytic copper as raw material is called "low oxygen copper wire" and copper wire made by the above method is called "oxygen-free copper wire".
Aluminum wire:
Like copper wire as the carrier of conductivity, aluminum wire is also one of the indispensable raw materials for wire and cable production, in which aluminum wire used for wire needs to be annealed and softened, while aluminum wire used for cable generally does not need to be softened.
(The diagram is a common PVC wire and cable)
PVC plastic particles
PVC plastic particles are made by mixing various additives (such as antioxidants, brighteners, flame retardants, antioxidants, etc.) with PVC resin as the basis. It is one of the essential raw materials for wire and cable. It has superior mechanical properties, chemical corrosion resistance, good weather resistance, good insulation, easy processing and so on.
PE plastic particles
PE plastic particles are made from refined ethylene polymerization, according to density can be divided into low density polyethylene, medium density polyethylene, high density polyethylene, is also one of the necessary raw materials for wire and cable production. Excellent insulation resistance, voltage strength, wear resistance, heat aging resistance, low temperature performance, chemical stability, water resistance and so on
XLPE (cross linked polyethylene) plastic particles
XLPE plastic particles are mainly divided into the following two types: one is called silane crosslinking material with silane as crosslinking agent, which is mainly used to make insulating layer of low voltage wire and cable; the other is used to make insulating layer of medium and high voltage cable with diisopropylbenzene peroxide as crosslinking agent.
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