Safety Integrated fulfills latest safety standards Perfect Precision

8 CASE STUDY
Saw Mills
Innovative saw mill solution with Profinet and Sinamics
Faster Alignment
A high yield of cut timber at a high processing speed is characteristic of
modern saw mills. Linck Holzverarbeitungstechnik, a leading manufacturer of
saw mill systems, offers concepts for cutting capacities of up to 1.5 million
solid cubic meters of timber per year. Linck further optimized the cycle time of
a trunk handler at a new factory located near Ingolstadt with a drive solution
that uses Sinamics and Profinet.
Machines from Linck are used in the
25 largest companies in Europe’s
timber industry. The product
portfolio of the international company located
in Oberkirchen includes round stock
stations and feeders as well as reducing,
trimming and profiling systems. The round
stock is fed into the system at the saw mill
either with the thick or thin trunk end first
(top end or stock oriented). A trunk handler,
which aligns the wood accordingly,
usually precedes the sawing line.
As one of the main suppliers, Linck delivered
a very fast, low-cost version of the
trunk handler, a so-called rotary star wheel
with control and drive technology from
Siemens, for the new, large saw mill of a
Tirolean timber company. The performance
of the handler was recently considerably
increased to accommodate more than
30 trunks per minute. One of the greatest
difficulties involved covering the wide load
range from the smallest to the largest piece
of timber.
Complex control drives with adequate
power reserves, a more accurate sequence
of movements and corresponding drive
profiles were stored. Shock absorbers used
with the elements under high-level stress
help to counteract material wear.
Maintenance-friendly system
The trunk handler is driven by a central
Simatic S7-416F-3PN/DP controller. The rotary
movement is controlled and monitored
in the PLC program. Users can parameterize
the drive profiles via a visualization system
with PC and operator panel.
The Sinamics S120 drive system handles
positioning tasks, for which a standard single
positioner is used. Since all of the data
are stored on a CF card, hardware is easily
exchanged and the solution is extremely
maintenance-friendly.
Data exchange in the entire system occurs
via Profinet. This has the advantage
that both the Profinet and the standard
TCP/IP communication can be handled over
the new bus system. The data rate has been
increased to 100 megabits per second, allowing
for fast data exchange between the
system parts. Profinet enables an increase
In the sawing hall, trunks are
prepared for machining on the round
stock stations
The trunk handler correctly positions
the wood for the sawing system
in the number of bus users to over 1,000,
as well as communication via Wireless
LAN, thereby saving cabling costs. It also
simplifies consistent commissioning while
making web topology diagnosis more efficient.
These strengths suggest that it would
make good sense to extend the modernized
automation and drive solution to the
entire sawing line – an option which the
saw mill owners are seriously contemplating
after the successful start-up of the system.
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More information:
www.siemens.com/profinet
E-mail: peter.hofsaess@siemens.com
spectrum LIGNA 2007
Pictures: Linck