WCA January 2022

Technology News

Performance yarns Fil-Tec, Inc offers a complete line of performance yarns for applications in power cables, copper and fibre-optic telecom and speciality cables. Products include binder yarns with water blocking; non-wicking, flame-retardant/

Mixing station systems are required when precise dosing is necessary over the complete speed range of the extruder, if very small amounts/percentages of additives are to be dosed or if non-visible additives are to be handled. In this type of system, all materials are dosed and controlled. Mixing stations work independently of the extruder speed and material consumption. Woywod Kunststoffmaschinen has developed this technology to supply Plasticolor equipment to the market. Two main versions are available: Plasticolor volumetricmixing stations and Plasticolor gravimetric mixing stations (loss-in- weight principle). Advantages of the volumetric and gravimetric mixing stations include good handlingof plasticmaterials, ranging from free-flowing powder and microgranules to coarse regrind; precise dosing of each individual component at any stage of production; quick cleaning and short changeover times; a low volume of pre- mixed material; and adherence to the preset recipe over the full rpm range of the extrusion line. For special applications and for the extru- sion of special materials, synchronised Plasticolor mixing stations that offer a constant material level in the neckpiece are available. Woywod Kunststoffmaschinen GmbH Since the 1970s, and a cleaner working environment for the operator. The technology produces a water- swellable binder with higher yield. Having more metres per package allows longer runs without a break and a more efficient stranding process overall. The system can run at 5,000 rpm without unwanted vibration. Various swell factors give design engi- neers the flexibility to choose the yarn size and swell factor that best suits the cable. Fil-Tec, Inc www.fil-tec.com

and changeover periods were reduced. Handling was improved and the spread- ing of material around the equipment was stopped. In comparatively basic production methods, when the speed of the extruder is rarely changed (ramping) and the requirements of the quality of the mixture are minimal, this way of having a dosing unit synchronised to the speed of the extruder is still common. However, as property requirements increase, new products need highly precise dosing solutions. Cross-linked products require a uniform cross-linking over the entire production run, and foamed (chemical foaming) products need a uniform cell structure and a regular foaming result. low-smoke finishes; core yarns; ripcords; filler yarns; marker yarns; and fibreglass reinforcement yarns. The company’s newest products are dry core yarn for dry core cable designs; virtually dustless water-blocking binder yarns for high speed; and a line of water-blocking yarns for power cable applications. Fil-Tec’s water-swellable binder and core (wrap around the FRP) yarns offer a range of benefits that include lowdust – extend- ing the life of bearings and other moving parts of the equipment; less downtime due to mechanical maintenance related to SAP dust problems; less clean-up time;

Fil-Tec produces performance yarns for cable applications

Dosing for extrusion of cross-linked and foamed insulations

Some cable manufacturers still prepare material mixtures by hand: the risk of wrong mixtures or separation of material is high, and reproducibility cannot be guaranteed. of automation for the dosing of materials was the implementation of disc dosing units, mounted on the main material hoppers. Disadvantages included high mainte- nance, comparatively difficult handling and the risk of material separation. These systems were gradually replaced by screw feeding dosing units, installed between the main material hopper and the material inlet of the extruder. The separation of material was eliminated, Among the earliest methods

& Co Vertriebs-KG https://woywod.de

Gravimetric mixing station

Volumetric mixing station

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January 2022