Keltan 6251A A Versatile Sponge Grade

Transcription

1 Keltan 6251A A Versatile Sponge Grade Graham Choonoo, Michiel Dees and Philip Hough Lanxess Elastomers Presented at the RubberCon 2012 Meeting of the Norwegian Institute of Rubber Technology Oslo, Norway May 14-16, 2012

2 Introduction Manufacturing of weatherstrips is complex; Co-Extruded multiple compounds/metal carrier Cured simultaneously at high speeds Unsupported, tight tolerances Sponge bulb most critical and challenging Low viscosity compound to allow blowing Med/high Mw polymer for shape retention and properties Stringent performance requirements from OEM s Door closing Med/high Mw polymer + Low Mvmatrix = Long mixing times / 2 step mixing 2

3 Changing Environment Present X Cost reduction and other trends Surface Quality Weight/s.g. Door close/s.g. C.set Loadings Requires higher Mw and higher ENB Improvements in mixing technology Cost reduction Continued demands on performance Reduced environment of innovation Less technical staff Less capital investment Fewer new materials New very high Mw O/E EPDMs 3 Difficulty in meeting demands

4 Customer Survey Questions on; polymers, formulation, mixing, curing, finishing Ranking of Lanxess grades vs competition Problems encountered in meeting goals for improvement Range of Sponge Polymers Used by Customers; Medium Mooney (medium Mw) C = High Mooney non oil extended (high Mw) ML(1+4)@125 C = Oil extended high Mooney (very high Mw) ML(1+4)@150 C = Different Issues/Roadblocks Experience for Each Mooney 4 Range

5 Sponge Improvement Actions EPDM Category Medium Mooney Goal Reduce cost. Improve properties. Improvement Action Increase filler and plasticizer loading and use higher Mw polymer to compensate for properties. Use higher Mw polymer. Roadblocks Poor dispersion Poor dispersion 5 High Mooney (non-oil extended) Oil Extended High Mooney (very high Mw) Reduce cost. Reduce cost. Improve aesthetics and reduce defect scrap. Improve aesthetics and physical properties. Reduce surface defect scrap. Improve aesthetics and reduce defect scrap. Reduce cycle time of 2 pass mix or even go to single pass mix with existing polymer. Reduce cycle time of 2 pass mix or even go to single pass mix with lower Mw polymer. Use lower Mooney polymer. Use oil extended high Mooney polymer. Increase mixing shear. Increase mixing shear. Poor dispersion Inadequate physical properties. Inadequate physical properties. Poor dispersion Inadequate mixer capability. Inadequate mixer capability.

6 Initial Polymer Characteristic Proposals Polymer Characteristic High Mw Controlled long chain branching High ENB Amorphous Oil extended Properties Affected 1. Good collapse resistance. 2. Excellent physical properties. 1. Improved mixing. 2. Good collapse resistance. 1. Ultra fast vulcanization to allow high extrusion rates. 1. Superior low temperature properties. 1. Lower apparent viscosity. Intended Affect On Roadblocks 1. Allows higher filler loadings and improved properties vs. medium Mw polymers. 1. Easier to mix than non-oil extended high Mw grades allowing potential for reduced mixing times or single stage mixing and improved surface finish. 2. As easy to mix as medium Mw grades, preventing dispersion problems experienced when compounding for higher loadings or improved performance. 6

7 Polymer Properties First Trial Properties Mooney Viscosity Units MU Pilot Sample A Pilot Sample B Commercial Grade C Commercial Grade D Competitor Grade E ML (1+4) 125ºC 150ºC Ethylene content wt.% Est ¹ 58 ENB content wt.% Molecular Weight Distribution Medium (CLCB) Medium (CLCB) Medium Medium Bimodal Oil content phr ¹ML(1+8)

8 Recipes First Trial Ingredients Pilot Sample A Compound A 110 Compound B Compound C Compound D Compound E Pilot Sample B 115 Commercial Grade C Commercial Grade D Competitor Grade E N550 Black Oil White Filler Acc. + Blowing Agents Total (phr)

9 Mixing & Testing First Trial Single stage mixed 5.5 liter GK 5 Intermeshing Mixer Upside down Dump at 95 C 3 passes through 2 roll mill (5mm nip gap) Extruded on an HF ES 30 Quality testing extruder Pixargus Profile Control PRC 20/40 surface roughness analyzer Basic rheologic and physical tests 9

10 Surface Defect Comparison Surface Defect Intensity GK Relative Intensity (%) >0.6 mm <0.6 mm 0.0 Compound A Compound B Compound C Compound D Compound E 10

11 Rheologic & Physical Properties Test Compound C Mooney C t5 [min] C Compound A Compound B Compound C Compound D Compound E MH-ML [N.m] tc 90 [min] Hardness [ShA] Tensile Strength [MPa] Elongation [%] *Physical testing performed on solid samples 11

12 Polymer Characteristics Keltan 6251A Properties Mooney Viscosity ML (1+4) 125ºC Ethylene content Units MU wt% Typical Value ENB content wt% 9.0 Molecular Weight Distribution Oil content wt% phr Medium (CLCB)

13 Polymer Properties Second Trial Properties Units Keltan 6251A Competitor Polymer F Competitor Polymer G Mooney Viscosity ML (1+4) 125ºC MU Ethylene content Wt.% ENB content Wt.% Molecular Weight Distribution Medium (CLCB) Bimodal Medium Oil content phr

14 Recipes Second Trial Ingredients Compound B Compound F Compound G Keltan 6251A 115 Competitor Polymer F 115 Competitor Polymer G 100 N Oil White Filler Acc. + Blowing Agents Total (phr)

15 Surface Defect Comparison Surface Defect Intensity GK Relative Intensity (%) <0.6 mm >0.6 mm 0 Keltan 6251A Competitor F Competitor G 15

16 Large Surface Defect Comparison Large Surface Defect Intensity GK Relative Intensity (%) mm 1.7 mm 1.9 mm 0 Keltan 6251A Compound F Compound G 16

17 Photographs of Extruded Strips Keltan 6251A Compound F Compound G 17

18 Rheologic & Physical Properties Test Compound C Mooney C Keltan 6251A 41 Compound F 41 Compound G 39 t5 [min] MDR@180 C MH-ML [N.m] tc 90 [min] Density (g/cm³) Tensile Strength [MPa] Compression set (%) 24h@23 C Compression Load Deflection F/10% (N) F/20% (N) F/30% (N) F/40% (N)

19 Customer Validation 1. Keltan 6251A Oil extended competitive polymer 19

20 Customer Validation 2. Blend of a very high Mw polymer with a medium Mw polymer Experienced issues with dimensional instability of extruded profile Would sometimes remix the compound and observe improvement in dimensional control Substituting the blend with Keltan 6251A eliminated shape instability and scrap 3. Customer cannot single stage mix their current high Mw polymer Keltan 6251A with similar Mw can be mixed in one pass without dispersion problems No need to cut new extrusion dies or change extruder line settings. 20

21 Single Stage vs Two Step Mixing Procedure Weighing of ingredients Transport to mixer Internal mixing procedure Dumping on mill Mill / Stock-blender mixing Straining via Gear pump Cooling / Batch-off Slab / strip storage *** Single stage X X X X X X X X 2-Step X XX* XX** XX XX X XX X (X) Typical cycle time min * Rubber slabs/strips without curing / blowing agents are transported back for second step mixing ** 2 steps: curing / blowing agents are added to mixer during second step *** With second step mixing, slabs / strips are added directly after cooling or after 24 hrs storage (extra disadvantages: contamination and logistical issues) 21

22 Conclusions Keltan 6251A can facilitate improved dispersion for customers older mixers state of the art mixing equipment The improved dispersion can be translated into reduced mixing cycle times reduced scrap levels single stage mixing ability Keltan 6251A can reduce cost by extending total loading without sacrificing properties or quality Keltan 6251A is a versatile sponge polymer 22

23 Thank You for Your Attention

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