FAQ

A weight-per-meter control system is a complete inline closed-loop installation mounted above the extruder feed port: the gravimetric weighing unit measures material usage in real time, converts it together with the haul-off line speed into weight per meter (kg/m), compares the result with the setpoint, and then automatically adjusts the screw speed and the haul-off speed to hold weight per meter and wall thickness within the target band. It consists of the controller, the weighing unit, the touchscreen HMI and the actuation linkage, and can complete the whole cycle of measure, decide, adjust and recheck on its own.

Weight per meter is the physical variable being controlled, in kg/m: how much material each meter of cable consumes. The weight-per-meter controller is the device itself, responsible for acquiring the weight and speed signals, calculating the weight-per-meter deviation and issuing the correction. The weight-per-meter control system is the complete solution, comprising the controller, the actuators, the HMI and data logging. Look at the controller when you buy equipment; judge the result in production by the whole system.

It is mainly a retrofit. On the existing extrusion line the system adds gravimetric weighing, signal acquisition and the HMI, and works with the existing extruder and haul-off drives; the whole production line does not need to be replaced. The exact scope of the modification is confirmed after an on-site survey; the prerequisite is that the extruder and the haul-off motor accept an external speed setpoint.

Weight-per-meter control accuracy is ±0.25%, weighing system accuracy ≤ 0.001% FS, dynamic correction at millisecond level, with 24-hour continuous operation. The parameters in the table are the standard configuration; special operating conditions can be customized, and actual supply is subject to the contract and technical agreement.

There are five models, NHY-M-7L / 22L / 48L / 52L / 60L, with hopper capacities of 7–60 L, sensor ranges of 10 / 20 / 30 / 50 / 50 kg respectively, and overall heights of 730–1150 mm. Lines with small cross-sections and frequent specification changes suit a small hopper, because material changes and cleaning are quick and changeover losses are small. Lines with high extrusion output that want long refill intervals suit a large hopper. The final choice is checked against the target weight-per-meter range and the maximum extrusion output.

Load the process parameter set for that product through specification confirmation and the switch is done; there is no need to tune from scratch every time. For a substantially different new product, we recommend observing in manual mode for a period and engaging automatic control only after stability is confirmed.

Taking material savings of 1%-5%, a common conservative estimate is 2.5%. For a 650 kg/h line running 16 h/day, 200 days/year, with material at 9.00 CNY/kg, the saving is about CNY 468,000 a year; at 350 kg/h about CNY 189,000; at 250 kg/h about CNY 121,500. Payback period = investment ÷ annual material saving. It also works the other way round: if a 2-year payback is acceptable, the case holds as long as the investment is less than twice the annual saving. Actual results vary with product specification, material and operating conditions.

The interface is designed around workshop operating habits: dark background, high contrast, large type for key values. Day to day, operators only need to check whether the current weight per meter is within range and whether a specification needs to be confirmed. The shift team is trained on operation at handover, and the handling of common exceptions is explained.

The system retains process trend and material usage records, logging length, weight per meter and output for each take-up reel, and supports 24-hour monitoring plus year-round records of operations, alarms, shifts and orders. The specific export method and retention period can be agreed during the proposal stage, together with your costing and traceability requirements.

Retrofit work is scheduled inside planned shutdown windows wherever possible, and delivered in four steps: on-site survey; hardware installation and weighing calibration; system tuning and closed-loop commissioning; operator training. During commissioning the line is observed in manual mode first, and automatic control is engaged only after stability is confirmed.

It is mainly used in the insulation extrusion process for power cable, control cable and special cable, and also on production lines in conductor workshops. The technical data sheet covers extrusion lines for optical fiber cable, submarine cable, power cable, extra-high voltage cable and automotive cable. Whether a given line fits depends on the extruder model, screw specification, product specification range and on-site installation conditions, and is subject to the conclusion of the on-site survey.

What weight-per-meter control stabilizes is material usage per unit length and the wall thickness target; it mainly suppresses thickness variation along the length. Eccentricity is a radial distribution problem, determined mainly by the concentricity of the die core and the die sleeve and by the material flow state. It has to be solved in the tooling and the process, and weight-per-meter control cannot replace that.

We recommend keeping it, though the frequency can be greatly reduced. Manual weighing changes role from the daily basis for adjustment to a check on whether the system has drifted: once a week, or once at each specification change, is enough.

Free solution customization, on-site installation and commissioning, one-to-one hands-on training, 7×12 online support, plus lifetime maintenance and free software upgrades. You can contact us at any time about parameters or control issues in use, and we provide parameter set updates and adaptation advice when product specifications change or a line is modified.

It supports operation from a phone app and from a PC at a remote location, and the user can switch this off. Control modes are single control and dual control, configured according to the number of lines and the number of extruders.

No. Automatic and manual mode switch with one click, and an operator takes over during commissioning or in abnormal conditions. The interface provides entry points for alarms and user permissions, so unauthorized personnel cannot change process settings by mistake.

We have installed systems at more than 20 cable plants in South China and 10 in Central China, over 30 in total, covering low-smoke halogen-free cable, high and low voltage cable, extra-high voltage cable, household wire and optical fiber cable extrusion lines, with both retrofits to existing lines and systems on new lines. On-site installation photos are on the Case studies page of our website: https://nhy-cicle.com/en/cases.html