EFFECTS OF FREEZE DRYINGON PAPER: EFFECTS OF FREEZE DRYING ON PAPER


INTRODUCTION: INTRODUCTION OBJECTIVES MATERIALS USED EXPERIMENTAL SETUP TREATMENT OF SAMPLES TEST METHODS RESULTS AND DISCUSSION CONCLUSION 2


INTRODUCTION: INTRODUCTION 3


INTRODUCTION: INTRODUCTION to investigate how freeze drying effects paper characteristics critical to preservation of archive and library materials to determine how freeze drying might effect the mechanical strength and ageing stability of paper 4


INTRODUCTION: INTRODUCTION 5


MATERIALS USED: MATERIALS USED 6


MATERIALS USED: MATERIALS USED 7 Groundwood paper / Paper 1


MATERIALS USED: MATERIALS USED 8 Cotton paper / Paper 2


MATERIALS USED: MATERIALS USED 9 Coated paper / Paper 3


EXPERIMENTAL SETUP: EXPERIMENTAL SETUP 10


EXPERIMENTAL SETUP: EXPERIMENTAL SETUP 11


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 12 Soaking in demineralized water


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 13 Freeze drying by cold chamber wall


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 14 Freeze drying by warm chamber wall


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 15


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 16 Accelerated ageing


TREATMENT OF SAMPLES: TREATMENT OF SAMPLES 17 Accelerated ageing 12 days (288 hours) 90 ºC 50 % RH


TEST METHODS: TEST METHODS Moisture content SCAN P 4:63 Alkali reserve ISO 10716 Folding endurance SCAN P 17:77 Tearing resistance SCAN P 11:73 Zero span tensile Cowan/TAPPI 231 (dry and wet determination) 18


RESULTS & DISCUSSION: RESULTS & DISCUSSION freeze drying particulary influences moisture content, folding endurance and tearing resistance freeze drying and accelerated ageing influence moisture content, folding endurance and tearing resistance in the samples, but differently from one paperquality to another the effect on alkali reserve and zero span tensile strength is relatively small 19


RESULTS & DISCUSSION: RESULTS & DISCUSSION 20 Folding endurance Groundwood paper / Paper 1 Log 10 / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 21 Zero span dry Groundwood paper / Paper 1 Nm/g / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 22 Tearing resistance Groundwood paper / Paper 1 mNm2/g / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 23 Moisture content Groundwood paper / Paper 1 Moisture content % Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 24 Folding endurance Cotton paper / Paper 2 Log 10 / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 25 Tearing resistance Cotton paper / Paper 2 mNm2/g / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 26 Folding endurance Coated paper / Paper 3 Log 10 / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 27 Tearing resistance Coated paper / Paper 3 mNm2/g / GM Reference


RESULTS & DISCUSSION: RESULTS & DISCUSSION 28


RESULTS & DISCUSSION: RESULTS & DISCUSSION 29 Retention of folding endurance and tearing resistance after accelerated ageing Retention %


RESULTS & DISCUSSION: RESULTS & DISCUSSION 30 Retention of zero span tensile strength after accelerated ageing Retention %


CONCLUSION: CONCLUSION 31


CONCLUSION: CONCLUSION 32 freeze drying particularly influences moisture content, folding endurance and tearing resistance freeze drying and accelerated ageing effect moisture content, folding endurance and tearing resistance differently in various paperqualities freeze drying of groundwood paper and alum-rosin sized paper with a high amount of fillers reduces the mechanical strength


CONCLUSION: CONCLUSION 33 freeze drying of cotton paper with a high content of calcium carbonate has a relatively limited effect on mechanical strength and ageing stability freeze drying of coated paper particularly reduces folding endurance


CONCLUSION: CONCLUSION 34


ACKNOWLEDGEMENT: ACKNOWLEDGEMENT 35 Jonas Palm, The Royal Library Grethe Jørgensen, The School of Conservation Jørn Bredal-Jørgensen, The School of Conservation Anette Linde, Swedish Pulp and Paper Research Inst. Poul Jensen, The National Museum Julie Fryd Johansen, The Royal Library Stora Papyrus, Grycksbo


Thank you for yourattention: Thank you for your attention 36