EoW July 2008

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EuroWire – July 2008
taping, armouring & sheathing of cables
54
Multitaping with controlled
film tension
The product range of Maschinenfabrik Niehoff includes double twist stranding
machines for the production of data and special cables. The product line includes tape
pay offs, which are used to apply tapes of different material under precisely controlled
film tension to the stranded conductor.
Films are important for the design of data and special cables consisting of insulated
conductors. Films reinforce the wire insulation, protect the conductors against
electromagnetic interferences or prevent the adhesion of extruded jacketing material
to the stranded product. The first tape film is applied before the stranded product
enters the stranding machine. During the stranding process high forces act on the foils,
therefore, tension control of the film is critical and essential for high quality products.
A pre-twister, placed between the tape payoffs and the stranding machine, helps
achieve and maintain constant and accurate tension control.
Niehoff has developed manufacturing lines that address these tasks. These lines can
be used to manufacture cables for industrial applications consisting of conductor pairs,
three conductors or conductor quads. Over the last few years several of these lines
have been successfully supplied to data cable producers in Europe.
Depending on the cable construction, such lines consist of several payoffs type ATP630,
three tape payoffs type ALB600 and a pre-twister type VVD180 or type VVD250.
These components have the following tasks:
The ATP630 tangential payoffs with separate drive are
designed for the uncoiling of high-quality cables, insulated
single conductors, pairs and quads with a maximum diameter
of 3mm. The payoffs are driven by a dancer-controlled spool
drive with adjustable wire tension; the maximum haul-off
speed is 300 m/min (Figure 1).
A dancer-controlled AC motor drives the ALB600 longitudinal
tape payoffs with tape forming. They are designed to enable
an easy and rapid film insertion and tensioning. The film
tensile force is adjusted separately, and the forming tools
for overlapping on the right or on the left can be quickly
exchanged. The payoffs can be operated with payoff spool or
film cassettes and are suitable for films with a maximum width
of 40mm and a maximum thickness of 65mm. The maximum
haul-off speed is 300 m/min (Figure 2).
The VVD pre-twisters (VVD180 and VVD 250) have been developed for the
cost-effective production of insulated wires, pairs, quads and cable cores
with 5- or 7-conductor design with three or more films applied in S or
Z twist direction by double twist stranding machines.
The pre-twist devices enable the application of tapes under a reduced,
controlled and constant tension.The devices can accommodate tapesmade
from all kinds of films used for the production of data and special cables.
The speed can be infinitely adjusted and controlled.
The VVD pre-twisters are designed to handle stranded products with a
maximum diameter of 10 or 15mm (Figure 3 ).
The double twist stranding machines of the DSI series (DSI631 and
DSI1001) are designed for stranding of insulated cores to twins and
quadders and for the stranding of four conductor pairs to form LAN cables
and other special cables (Figure 4).
The DSI machines are built for a wide conductor cross section at a maximum stranding diameter of 8mm or 15mm and can be
combined with numerous other production equipment to produce all types of data and special cables including LAN cables of all
categories – current, under development and in the future – with the highest precision.
Maschinenfabrik Niehoff GmbH & Co KG – Germany
Fax: +49 9122 977 155 Email: Website:
Figure 3 ▲ ▲ : VVD pre-twister
Figure 1 ▲ ▲ : ATP630 tangential payoff
Figure 2 ▲
▲ :ALB600 longitudinal tape payoff
Figure 4 ▲ ▲ :DSI1001 double twist stranding machine