BOPP FILMS
Simultaneous stretching technique using linear motors / Trend towards larger plants
Biaxially oriented polypropylene films (BOPP) are the most common packaging material worldwide. Highly developed raw materials of sufficient quality and quantity and a good price/performance ratio ensure that other polymers are only used in exceptional cases.If growth continues at an annual rate of 14%, as it has done for the last five years, a BOPP capacity of over 3m t/y is expected worldwide in 1998. These figures were given by Rudolf Heydecker, sales manager at the machine factory Brückner GmbH & Co KG (PO Box 1161, D-83309 Siegsdorf), in December 1996 at the conference "PP auf dem Wege", organised by the Süddeutschen Kunststoff-Zentrum, Würzburg. The main centres of growth with high market potential are in Asia and the USA.
Stretching technology for films has developed rapidly since the 1960s. Continual increases in plant capacity and reductions in production costs were the result. The average film thickness is currently 20m, but the trend is clearly towards even thinner films. The introduction of the metallocene catalysts will bring more specialised products and a further increase in productivity. Higher production speeds and improved reliability as well as a further reduction in the thickness of films are expected from the introduction of the simultaneous stretching technique using linear motors (LISIM). The extruded film is stretched simultaneously lengthways and widthways. In contrast to sequential stretching, the distribution of the overall stretch ratio across the length and breadth of the film is relatively variable for S-BOPP, which has a crucial influence on the physical properties of the film. Brückner has sold one plant (width 4.8m) with LISIM technology for stretching extremely thin PE films to DuPont in Luxembourg, and production should begin at the end of 1997.
Increases in capacity are also expected from larger plants. For about 10 years, 8 metre wide film production lines with wind-up speeds of over 300 m/min and a film capacity of about 3.5 t/hour for films which are 25 m thick have been used. The trend is towards 10 metre wide plants with a speed of 500 m/min and maximum flexibility in order to produce different film types. Brückner is to deliver a 10 metre wide plant with speeds of up to 450 m/min to Applied Extrusion Technologies, USA, towards the middle of the year.
READER SERVICE: SKZ paper: "BOPP films: market and technologies" (German) by R. Heydecker: PIE-No. 40515.
Stretching technology for films has developed rapidly since the 1960s. Continual increases in plant capacity and reductions in production costs were the result. The average film thickness is currently 20m, but the trend is clearly towards even thinner films. The introduction of the metallocene catalysts will bring more specialised products and a further increase in productivity. Higher production speeds and improved reliability as well as a further reduction in the thickness of films are expected from the introduction of the simultaneous stretching technique using linear motors (LISIM). The extruded film is stretched simultaneously lengthways and widthways. In contrast to sequential stretching, the distribution of the overall stretch ratio across the length and breadth of the film is relatively variable for S-BOPP, which has a crucial influence on the physical properties of the film. Brückner has sold one plant (width 4.8m) with LISIM technology for stretching extremely thin PE films to DuPont in Luxembourg, and production should begin at the end of 1997.
Increases in capacity are also expected from larger plants. For about 10 years, 8 metre wide film production lines with wind-up speeds of over 300 m/min and a film capacity of about 3.5 t/hour for films which are 25 m thick have been used. The trend is towards 10 metre wide plants with a speed of 500 m/min and maximum flexibility in order to produce different film types. Brückner is to deliver a 10 metre wide plant with speeds of up to 450 m/min to Applied Extrusion Technologies, USA, towards the middle of the year.
READER SERVICE: SKZ paper: "BOPP films: market and technologies" (German) by R. Heydecker: PIE-No. 40515.
31.03.1997 Plasteurope.com [19463]
Published on 31.03.1997