Precise Cooating With Premetered Die Technology Maick N Nielsen TSE Troller Ltd., Aareweg 6, 4853 Murgenthal, Switzerland October 2010 PAGE 1

Transcription

1 Precise Co oating With Premetered Die Technology Maick Nielsen TSE Troller Ltd., Aareweg 6, 4853 Murgenthal, Switzerland PAGE 1

2 Target Showing of the premetered coating processes. What are the advantaa ages of these applications in practical use? Especially for new applications. PAGE 2

3 Content t 1. Coating Processess 2. Die Technology 3. Advantages Throu ugh Precise Production 4. Potential In The Future PAGE 3

4 Coating Processes TSE produces dies for the premetered coating processes. Conservation o of mas ss: the coating thicknesss (g/m 2 ) depends on the flow rate and the web speed at given coating width. PAGE 4

5 Coating Methods - Overview Self-Metered Simple methods Laydown depends on liquid properties and web speed Formulation changes affect laydown One layer applied at a time Example: Pan (Dip) Coating Pre-Metered More complex - Requires a die distributor Laydown is specified within operating range of process Formulation changes do not affect laydown Multiple layers coated simultaneously Example: Curtain Coating Web Die Curtain Liquid Inlet Inlet PAGE 5

6 Coating Processes Curtain slot die m/min. > 5 µm wet thickness mpas PAGE 6

7 Coating Processes Curtain slide die m/min. > 5 µm wet thickness mpas PAGE 7

8 Coating Processes Slide die m/min. > 50 µm wet thickness mpas PAGE 8

9 Coating Processes Slot die m/min. > 5 µm wet thickness mpas PAGE 9

10 Coating Processes Multi-layer layer slot die m/min. > 5 µm wet thickness mpas PAGE 10

11 Applications Photographic and Digital imaging Magnetic storage media Paper Thermal paper Carbonless paper Packaging Adhesives Paintings Cast films Membranes Optical films Electronic films Pharmaceutical Medical diagnostics Batteries Decorative foils Metal coil coating Fuel cells Solar technology Flexible electronics, and more Example ILFOCHROME CPA.1K 9 layers, total dry thickness = 23 µm Web = MELINEX No interaction between layers! PAGE 11

12 Liquid Preparation Liquid Preparation Ability y to disperse materials Liquid stability (Does liquid drop out?) Mixing Power requirements Bubble formation Purging Liquid Purging Efficiency of purging Ability to displace resident liquid Efficiency in product changes Pump Pumping Power requirements Back pressure Degassing Higher viscosities are more difficult Coating Range of operability May affect lay down Web PAGE 12

13 Distribution Geome etry Infinite Cavity Design Basic Idea: The resistance to flow in the metering slot is much higher compared to the distribution cavity (say by a factor of 100). So the pressure in the cavity as the driving force for pushing the liquid through the slot will be most equal across the width. Disadvantage: Small wall-shear -stresses in distribution cavity PAGE 13

14 Distribution Geome etry Coat hanger Design Basic Idea: Accurately calculate the pressure distribution in the cavity and adjust the length or the height of fthe metering slot such that the flow rate exiting the slot will be uniform. Advantage: Uniform high wall- shearstresses along the entire width of the distribution ib ti cavity. PAGE 14

15 Distribution Geome etry Dual Cavity Design Engineering Approach Idea: Combination of an optimized coat-hanger distribution system with a secondary distribution system (cavity and slot) in order to dampen potential nonuniformities in the cross- profile. Advantage: High uniformity of the outflow profile for a large range of applications regarding fluid properties and operating conditions. PAGE 15

16 Dimensioning of th e Die Dual Cavity Design definition of geometry w1 A1(x), β1 L1(x) L2 A2, β2 W w2 z y x A 1 (x) = Cross section cavity 1 A 2 = Cross section cavity 2 w 1 = Slot height slot 1 w 2 = Slot height slot 2 L 1 (x) = Slot length slot 1 L 2 = Slot length slot 2 β 1 = Shape of distribution cavity 1 β 2 = Shape of distribution cavity 2 W = Coating width PAGE 16

17 Dimensioning of th e Die Comparison of de esign possibilities 100 % die rmance of the d perfor 95 % Dual cavity design Single cavity coathanger design AP application points PAGE 17

18 Precise Production o Relation between flow ra ate and pressure drop 3 Q = pw 12µ L Q p = flow rate per unit width = pressure drop w = slot width X X w L = slot length µ = viscosity L PAGE 18

19 Precise Production o Influence of the slot heig ght precision to the cross profile Effect of Mechanical Slot Precision on Cross Profile Example: Nominal slot height: 300µm Variation of slot: ±1µm Cross profile: ±1% Cross Pro ofile [%] dw=µ m dw=0.25 dw=0.5 dw=0.75 dw=1.0 dw=1.5 dw= Slot Height, w [µm] PAGE 19

20 Precise Production o TSE offers several preci sion levels: quality B A AA AAA AAAA Tolerances 1. slot ± µm (± µin) tolerances 2. s lot ± µm (± µin) ( ) ( ) 4.0 ( ) 2.0 ( ) 2.5 ( ) 1.0 (39.370) (39.370) (19.685) (19.685) ( ) PAGE 20

21 Advantages of Optimized Dies Example of a functional layer: 5300 lbs/h 100% x4% = 212 lbs/h 1 lbs for 1 USD = 212 USD/h 212 x 24 x 7 = USD/week PAGE 21

22 Advantages of Optimized Dies Quick change over time - For width change - For cleaning - For liquid id change between products 12 minutes non-productive per change, one time per day, 30 USD per man-hour, 45 weeks production per year 0.2x30x7x45 = USD/year Two hours non-productive time per change, one time per day, 30 USD per man-hour, 45 weeks production per year 2 x 30 x 7 x 45 = USD/year PAGE 22

23 Advantages of Opti imized Dies Optimized die design means High wall shear stress = self-cleaning effect Reactive coating liquids can be applied Liquids tending to sediment or deposit particles Excellent cross profile over entire range of applications wide operating window No mechanical adjustments needed PAGE 23

24 New Applications Coating of plates wit th a curtain slot die PAGE 24

25 New Applications Intermittent t coat ing with a slot die PAGE 25

26 New Applications Coating of both sides with a slot die PAGE 26

27 Thank you for your attention I would be happy to answer any questions. PAGE 27