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CONTAINER GLASS FEEDERS : RECENT DEVELOPMENTS IN THE CHOICE OF REFRACTORY MATERIALS

CONTAINER GLASS FEEDERS : RECENT DEVELOPMENTS IN THE CHOICE OF REFRACTORY MATERIALS. AFGM Edsa Shangri-la MANILA SEPTEMBER 21, 2006. It is clearly understood that feeders play a crucial role in the quality of glass produced by the furnace.

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CONTAINER GLASS FEEDERS : RECENT DEVELOPMENTS IN THE CHOICE OF REFRACTORY MATERIALS

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  1. CONTAINER GLASS FEEDERS :RECENT DEVELOPMENTS IN THE CHOICE OF REFRACTORY MATERIALS AFGM Edsa Shangri-la MANILA SEPTEMBER 21, 2006

  2. It is clearly understood that feeders play a crucial rolein the quality of glass produced by the furnace. • Any defects generated in the feeder zones could wellbe found in the finished product, since the glass at thisstage works at relatively low temperatures and has a low capacityto absorb any flaws. • In addition, market demands for quality are constantly on theincrease. Defects and flaws which were acceptable in the recentpast are now often cause for rejecting the glass. This jeopardizesboth yield and profitability of glass production. • Regardless of the design used to channel the glass from thedistributor to the machines,and to condition it thermally for forming,the choice of the refractories in glass contact is increasingly important.

  3. SAINT-GOBAIN SEFPRO GLASS CONTACT PRODUCT RANGE

  4. Out of these 5 types of products, which one is the best technico-economical candidate to be used as feeder channel blocks for containers?

  5. Corrosion curves as a function of temperature ( PFT test ) Corrosion in mm 12 ER 1681 9 6 JARGAL M 3 BPAL ZA33 1200° 1300° 1400° 1500° 1600° 1350° Temperatures in ° Celsius

  6. These curves show clearly that, for feeder applications, where temperatures commonly occur between 1200°C and 1280°C, corrosion resistance difference between BPAL/ZA33 and fused cast AZS or Alumina is very low. • For campaigns 8 – 12 years, which is the usual lifetime in containers, no need to use fused cast channel blocks.

  7. What about « CAT SCRATCHES »? • One of the types of flaws most often encountered in container glass are flaws known as « cat scratches ». • Market sensitivity to this flaw is constantly growing, and the flaw affects not only white and flint glass, but also colored glass.

  8. CAT SCRATCHES : definition • Vitreous defect, • Band of fine parallel cords, • Located at the outside surface of the article, • Diameter between 5 and 30 µm. Microprobe analysis are done on the cat scratches section

  9. CAT SCRATCHES: refractory characteristics Throat Feeder Working end Melting / Refining Decrease of the glass potential to dissolve defects 1350°C Corrosion rate or temperature 1550°C 1200°C Main characteristic Defect formation potential Corrosion

  10. Based on several decades of experience in expert appraisals of glass inclusions, the research teams at Saint-Gobain SEFPRO have developed highly precise typology of these cat scratches. • In 85% of the cases, they are characterized by the simultaneous presence of significant amounts of zirconia and alumina.

  11. Research into the ZrO2/Al2O3 ratio, and the presence of certain elements which clearly show a fusion origin (V2O5 for example in the case of fuel-heated furnaces) have helped identify the origin, which, in 80% to 90% of the cases, is the end zone of the furnace : distributor and feeders. • This understanding has led many glassmakers to reduce the use of Zircon-Mullite type materials as much as possible, and generally speaking to reduce the use of any material with significant amounts of zirconia, in their feeders.

  12. As a consequence of these results: • A good way to significantly decrease AZS cat-scratches is to remove ZrO2 from « cold-end »: • -Working end = JARGAL M / SCIMOS M • - Feeders = BPAL

  13. BPAL channel blocks feasability TO-DATE : inside width: 1500 mm 60 ’’ bottom/walls thickness : 150 mm 6 ’’ lenght:610 mm 18 ’’ inside height:300 mm 12  ’’ Bigger sizes on request.

  14. BPAL references ABOUT 500 FEEDER LINES SINCE 1990 WORLDWIDE

  15. BPAL

  16. BPAL

  17. BPAL

  18. Baby-food/flint glass/8.5 years campaign BPAL

  19. Baby-food/flint glass/8.5 years campaign BPAL

  20. LAST DEVELOPMENT (2005-2006) ON BONDED ALUMINA FEEDER CHANNEL BLOCKS HPAL Even better corrosion resistance vs BPAL + Almost no blistering in contact with extra-white soda-lime glass

  21. SEFPRO SEFPRO SEFPRO HPAL Brand Name BPAL JARGAL M Sintered Product Sintered Fused 3.2 Bulk density (gr/cm3) 3.1 3.17 17 Open Porosity (%) 14 3 160 Cold crushing strenght (Mpa) 190 200 95 Chemical analysis Al2O3 93 95 2 SiO2 6 0.5 0.1 Fe2O3 0.1 0.1 115-120 Corrosion resistance index @ 1300°C - 170h 100 125 New alumina product for feeder

  22. ABOUT BLISTERING • Beside « cat scratches » , market can also be sensitive to another type of flaw, particulary for white glass: Blisters. • In the bonded Alumina range of products for channel blocks one can find differences on blistering, going more deeply in the laboratory testing.

  23. Blistering test “Le Pontet” • - 1100°C – 1h : immersed sample in the glass • - Scale : 0-1 (very low blistering)  10 (very high blistering) • 1100°C – 1h, white / flint soda lime glass (Fe2O3 = 1000 ppm) : • No big differentiation HPAL 2 0 JARGAL M 1 BPAL

  24. New crucible blistering test - 1250°C – 30h or more : glass inside crucible, like in the feeder. - Scale : 10 (low blistering) 100 (high blistering). - Closer to feeder running conditions (T°, air, …) - More blistering differences than in “LP” test. - Need more tests in order to have a large data base

  25. New crucible blistering test 1250°C – 30h – white / flint soda lime glass : More differentiation high Alumina product JARGAL M BPAL HPAL 20 30 40 50 60 70 80 90 100 10

  26. New crucible blistering test 1250°C – 30h – extra-white soda lime glass (Fe2O3 < 300 ppm) : JARGAL M high Alumina product BPAL HPAL 20 30 40 50 60 70 80 90 100 10

  27. 1100 mm New alumina product for feeder HPAL First two orders to be delivered end 2006

  28. NEW PRODUCTS IN THE FIELD OF EXPENDABLES • Spouts with Zirchrom 85 inserts • ZA33 LB : Low seeding after starting up • ZA33HR : Higher thermal shock resistance to prevent fracturation

  29. SPOUT with ZIRCHROM 85 insert ZA 33 (11 % ZrO2) or ZIRAL 61 (19 % ZrO2) Patented high chrome product (83,5 % Cr2O3) with better thermal shock resistance than any other More than 3 times the life of monolithic spouts

  30. Spouts with bonded chrome insert (ZIRCHROM 85) Case story 1 - Cascade bowl ZA 33/ZIRCHROM 85 insert - soda-lime glass CHR - spout temperature : 1225° C - average pull : 80/100 T pd - average ring changes : every 8 weeks - spout change : 8 hours, glass to glass - Service life : 26 months (furnace repair) - ZA33/F.C insert life (average) : about 12 months

  31. Spouts with bonded chrome insert (ZIRCHROM 85) Case story 2 Pre-heating procedure 6 h 6 h 6 h Daily pull 50 tpd 40 tpd 15 tpd Gob temperature 1170 °C 1180 °C 1280 °C Glass flint flint flint Average job changes/ Months 4 2 7 Service Life 20 to 26 months ZA 33 mono service life 6 to 8 months

  32. Expendables : ZA33LB Reduction of Seeding after starting up and during production • Target : table-ware / flaconnage : • - short runs • - critical problem : mainly with plungers « seeding » during 1 to 10 h or more after starting, whatever the supplier • production losses : 8 to 12 K EUR/hour (EUROPE)

  33. Refractory sample Glass JARGAL M Blistering test for expendables Test conditions : @ 1250°C, after 30h or with a record of the blistering during the test.

  34. 333 ZA33 LB Blistering after 30 h Test conditions : Extra White soda lime glass, @ 1250°C – 30h Index 4 • 333 : seeding during the starting hours (>30h within conditions of the present test) • ZA33 LB : Lower blistering, decreasing with time Index 1 blisters

  35. EXPENDABLES : new product ZA33 Tubes fracturation during production • worldwide problem with any type of tube from any supplier : - breakage during heating-up - breakage after 1,2,3 … weeks of production - breakage frequency unpredictable • difficulties to differentiate products (333, ZIRAL 61, competition) with standard thermal shock tests (USA thermal shocks test) • a specific test has been developed by R & D in order to differentiate products

  36. A new thermal shock testing method Methodology Our methodology is based on the study of the impact of the thermal shock on the mechanical properties of the materials. Samples of the material are first submitted to one or multiple severe thermal shock (rapid heat up to the test temperature followed by a thermal quenching in cold water) and then mechanically characterized (typically flexural strength MOR). The residual MOR of the material is compared to the original strength of the material, and a characteristic ratio is calculated : TR (%) = ( MOR before quenching – MOR after quenching ) x 100 MOR before quenching The lower the ratio, the better the material withstands thermal shocks. Among a family of materials having the same crystallographic properties, the best material thermal shock wise is the one with the lowest MOR loss ratio and higher residual strength after quenching. *MOR=Modulus of rupture

  37. A new Thermal shock testing method Equipment • Samples : • 120 x 20 x 20 mm bars are sampled and dried in oven @ 110 °C • Procedure : • Samples are machined, 2 sets of 5 from same bloc • 5 samples are loaded in the furnace preheated at the test temperature, and soaked for 20 mn • samples are removed from the furnace and immediately quenched in water • once cool, samples are dried in an oven • flexural modulus of rupture are measured at room temperature on both sets of samples Cold Water box for quenching Electrical furnace

  38. New product ZA33 Whatever the quenching temperature is, the new product presents always lower MOR losses (and so a better thermal shock resistance). *MOR=Modulus of Rupture

  39. New product ZA33 This better thermal shock resistance remains available after 1, 2 or 3 shocks.

  40. Standard THERMAL SHOCK 1250 °C- 20°C New

  41. Saint-Gobain SEFPRO is permanently looking for high perfomance refractories in partnerships with customers thank’s to it’s strong R&D, dedicated to glass industry. Saint-Gobain SEFPRO has the largest Research Center in the world specialising in refractories and their interactions with different types of glass. 140 engineers and technicians in the R&D use the most progressive, multidisciplinary technologies. Saint-Gobain SEFPRO - R & D

  42. Thank you

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