BASF opens pilot lines

Housing what is believed to be the globe's fastest coating line, a newly modernized centre for pressure sensitive adhesives was opened by BASF last month at its Verbund site in Ludwigshafen, Germany.

In addition to the new 1,500m/min coating plant for aqueous pressure sensitive adhesives, the facility also boasts a UV hotmelt adhesive plant operating at a speed of up to 700m/min. Development and modernization costs of the centre, which was designed and built in co-operation with Pagendarm BTT, totalled €5M. BASF claims to be world leader in pressure sensitive adhesives supply.

Adding value

"The ultra modern coating centre guarantees our skills advantage in coating technology and at the same time strengthens our position as an innovative producer of pressure sensitive adhesives," stated Dr Martin Brudermüller, head of BASF's functional polymers division. "Now we can design the joint trials we carry out with our customers even more flexibly and efficiently. We can vary the interaction between coating technology, machine speeds, carriers and pressure sensitive adhesives to an extent never previously achieved. This makes us the ideal partner for customers wishing to optimize their production processes for the manufacture of self adhesive products such as adhesive tapes or labels. We can create even more value for our customers and for ourselves."

When BASF asked Pagendarm in 1998 if it could upgrade its old coating line built by the company in 1975 and make it run at 1,000m/min or even faster, the German coating and drying machinery specialist had to say 'no'!

"So they decided to invest in a new state of the art adhesive coating line for emulsions," revealed Ralph Pagendarm.

The emulsion line was required to produce labelstock material with paper, PET or BOPP liners, protection films, tapes and directly coated PVC films.

Commissioning began in December, 2002, and the first coating run at 1,000m/min took place on February 2 - and the first at 1,500m/min a week later. Since March, the machine has been used for trials with different liners, different face materials and coating weights. Some days have seen 25 successful trials.

"A speed of 1,500m/min is not a problem for a machine builder if the materials to be coated have a working width of 1,650mm or 2,400mm. The extreme difficulty when building this coating line was to combine its small working width of only 570mm with the need to ensure control at speeds of 1,500m/min and allow no lateral offset in a dryer with a length of 54m," explained Ralph Pagendarm.

In other words, the challenge was to build a machine with extremely high speed capability and hence extremely fast rotating drives for a very small web width, which made lateral alignment virtually impossible. "You can compare this with building a Formula One racing car that has only a quarter of the usual width, but is supposed to run perfectly straight at 280km/h.

Opportunity

"Another difficulty was the required dynamic response of the drive with an acceleration of only 6s per 100m/min. Total acceleration time allowed from 0 – 1,500m/min was only 90s in order to perform as many test runs as possible with one roll of liner. We at Pagendarm were well aware that here was the opportunity to build the world's fastest coating machine for water based adhesives."

The concept comprises: unwinder with maximum diameter of 1,500mm, dancer roller control range 1:100, corona Softal 9KW, coating head twin-chamber AGS 2500S, curtain coater and others, vacuum roller tension range 380N/m, dryer 48m Speed-Star Vacutex System (eight sections, each to have separate top/bottom control), asymmetrical heating and control systems, automated heat booster during acceleration, cooling zone 6m Speed-Star Vacutex System, vacuum roller tension range 380N/m, laminator adjustable lamination line, vacuum roller for direct wound materials, face-run unwind, dancer roller, corona Softal 9 KW, rewind 1,500mm diameter maximum and flying splice.

"Customers who have bought the AGS 2500 S have realised that formation of micro foam is minimal or non existent and they have experienced improved coating quality due to high transparency and smooth coating surfaces. And the coating weight can be set easily without roller change, by means of only pressure variation," said Ralph Pagendarm.

"The dryer is 48m long, comprising eight sections each 6m long. The two air circulation systems are totally independent of each other. Between each pair of nozzles – top and bottom – there are generously dimensioned central extraction ducts. So there are no lateral return air flows, and mixing of the two air circulation systems is avoided as far as possible."

BASF Tel: +49 621 60-0 www.basf.com

Pagendarm Tel: +49 40 890960 www.pagendarm.com