Case Studies

A DOUBLE TWIST BUNCHER/ STRANDER TO WIDEN THE PRODUCT RANGE OF LOW VOLTAGE CABLES

A DOUBLE TWIST BUNCHER/ STRANDER TO WIDEN THE PRODUCT RANGE OF LOW VOLTAGE CABLES

Baldassari Cavi is internationally renowned for the quality of its cables, the result of years of research and experimentation, and a constant attention to the technological innovation of manufacturing processes.

With the goal to get a constant growth of its product range of low voltage electrical cables, Baldassari Cavi turned to MFL Group, its long-lasting partner, for a new machine able to produce aluminum cable with larger sections.

Due to the lack of space in length, the 37 double position coils pay off in rows disposition was the best solution for Baldassari Cavi, which is now capable of manufacturing constructions up to 37 wires in nonstop mode. To allow a high flexibility in the type of produced conductors, we enabled the possibility to bypass the external capstan (also changing the pulleys by sheaves path, in first and second torsion) and redirect 19 wires directly to the secondary 19 wires closing die, and after to the Double Twist Strander with an increased TPM, working in pure bitorsion mode.

For bigger sections, 61 wires can be used leveraging the double position coils pay off in single position or by optimizing the layout in the factory.

MFL Group responded to the request of its client with the DTO 2000, a double stranding machine characterized by reliability and super-fast stranders to produce Unilay copper and aluminum conductors. DTO 2000 is produced under the OM LESMO brand. The OM LESMO brand belongs to the Wire & Cable Machinery Division and its origins date back to 1962. MFL GROUP seized an opportunity and acquired the brand along with all its valuable Intellectual Property (IP). The OM LESMO brand is recognized for its wide range of Rotating Equipment including Double Twist Bunchers, large Double Twist Stranders, innovative Single Twist Cablers and Bow Skip Stranders.

DOUBLE TWIST BUNCHER/STRANDER’S HIGHLIGHTS

The double twist buncher/ strander is a highly productive machine used for the production of Unilay copper and aluminum conductors, used for low voltage (LV cables) and medium voltage (MV cables) cables.

MFL Group provides a wide range of double twist bunchers to match any kind of cable assembly configuration and then satisfy any need from our customers.

Here are some of the main features that have enabled our double twist bunchers/stranders (DTO 2000) to create and consolidate a reputation among the Wire & Cable industry:

· Wide range of wire diameter: round compressed and compacted for LV and MV cables Up to 400 mm2 Cu / 500 mm2 Al (Up to 630 mm2 Cu with the special external capstan) · Several extras can be offered to improve conductor quality according to the type of cable being manufactured:

Ø Compacting rollers, placed inside the cradle for straight sectoral shape conductors.

Ø Preformers, placed at the closing die and Postformer, placed inside the cradle for treatment of Alloy conductors, ACSR, etc. Ø Back Twist pay off, also needed for ACSR constructions.

Ø Inclinable rollers, to substitute the standard deviation sheaves in the first and second torsions for an ease laying up, combined with the external capstan, or a pretwister in case of the smallest double twist dimensions, increases the quality of insulated conductors and Class 5&6 conductors. Ø Deviating pulleys in first and second torsion when working only the double twist without external capstan to improve the productivity manufacturing with 19 wires.

Ø Waterblocking products (tapes, yarns, compounds, etc.) can be easily applied in a specially designed large multiple layer cable forming unit for up to 61 wires, provided with dividing plates with tungsten carbide eyelets, conveying sheaves and closing dies with independent AC motor synchronized with the rotating speed of the strander to close the different layers. All closing dies and dividing plates can be displaced independently to vary the closing angle of each lay, allowing high flexibility for the cable manufacturers.

· Production speed: with some ingenious engineering solutions, MFL machinery can achieve higher speeds than the current standards. (Max. Line Speed without external rotating capstan 170 m/min – 130 with external capstan).

· High productivity (specifically when operated with non-stop coil pay offs, double position)

· Unilay construction which results in smoother surface · Energy saving by using a single bow and the DC Bus supply, which allows return energy to the factory power grid during stop operation.

· Remote assistance via Internet connection

· Touch screen operator panel with recipe for easy control of the line

· High compaction degree

CUSTOMER BENEFITS OF USING MFL GROUP DOUBLE TWIST BUNCHER/STRANDER

Thanks to this new line, Baldassari Cavi entered a new market with reliable machinery which allows to:

· Produce compacted conductors up to Cu 300 mm2 / Al 300 mm2 (purchased 37 wires equalizer and closing die)

· Have a high-quality final product

· Increase production speed up to 170 m/min (line speed)

· Reduce energy consumption

· Further improve machine performance with the support of one of our experienced technologists who optimized the machine settings according to the Baldassari Cavi’s specific needs

OUR SOLUTIONS FOR LOW and MEDIUM VOLTAGE CABLES PRODUCTION

Through the last years, MFL Group has gained know-now and decades of experience in the Wire & Cable Machinery Industry by the acquisition of three companies (CM Caballé, OM Lesmo, Eurodraw Energy) that complement Frigeco strengths and bring extremely valuable intellectual property into our Wire and Cable division.

Low voltage cables come in a variety of sizes, materials, types, and applications. The combination of our extensive portfolio and our ability to anticipate customers’ requirements has got your specific needs covered, whatever they are.

Medium voltage cables are used to distribute the electrical energy of power grids. With the help of these cables, we are able today to transport energy from A to B across the country and varying terrain. On our machines, these special cables are pulled to ensure the energy infrastructure of tomorrow.

Specifically, for MV cables, the big double twist stranders match the specific requirements and they are the most efficient solution to produce conductors up to 61 wires.

The combination of the different strengths of each brand led to a complete and highly reliable offer which includes:

· limited slip rod breakdown machine

· multiwire drawing machine

· annealer for copper and/or aluminum/alloy wire

· rigid cage stranding and screening machine

· double twist buncher/strander

· drum twister for laying-up, armoring and screening

· double twist buncher

· insulation line for building wire

· insulation line for data cables

· insulation line for power cables

· single twist machine for laying-up, armoring and screening

· tubular stranding and closing machine

· planetary stranding and closing machine

Do you need more information about our machines and services? Fill the form here and one of our experts will show you more about solutions of MFL GROUP for Drawing, Stranding-Screening-Armoring and Extrusion in the Wire, Rope and Cable fields.

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