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Ashless Quantitative Filter Paper

Ashless grade quantitative filter papers are manufactured from 100% cotton linters that have undergone both acidic and alkali washes to remove any trace impurities. After this treatment, the ash content is 0.007%.

Grade
Whatman Equivalent
351
= No.42
  • SpeedSlow
  • Filteration Speed (sec) 250
  • Thickness (mm) 0.16
  • Retention Capacity < 2
  • Weight (g/m2) 84
  • Burst Strength (kg/cm2) Light
Grade 351
This is an extremely fine retention filter for critical gravimetric analysis of very fine particles, such as barium and lead sulphates, stannic and nickel sulfide for use in glazes, coatings and pigments. It also filters calcium oxolate, calcium fluoride and cuprous oxide. It eliminates large particles that might otherwise interfere with sensitive instrumentations. Likewise it is highly recommended for the analysis of insoluble particles in oils and animal or vegetable fats. A common example is use of Grade 351 as a calcium carbonate filter for analysis in the cement industry. Grade 351 has the smallest pore size of all our filter paper grades. The ash content is 0.007%. The high purity of Grade 351 filters also makes them suitable for processes that require ashing.
Sizes (Diameter/mm)
Product Code
  • 55 351055
  • 70 351070
  • 90 351090
  • 110 351110
  • 125 351125
  • 150 351150
  • 185 351185
  • 240 351240
  • 300 351300
  • 320 351320
  • 55 352055
  • 70 352070
  • 90 352090
  • 110 352110
  • 125 352125
  • 150 352150
  • 185 352185
  • 240 352240
  • 300 352300
  • 320 352320
  • 55 353055
  • 70 353070
  • 90 353090
  • 110 353110
  • 125 353125
  • 150 353150
  • 185 353185
  • 240 353240
  • 300 353300
  • 320 353320
  • 55 354055
  • 70 354070
  • 90 354090
  • 110 354110
  • 125 354125
  • 150 354150
  • 185 354185
  • 240 354240
  • 300 354300
  • 320 354320
  • 55 301055
  • 70 301070
  • 90 301090
  • 110 301110
  • 125 301125
  • 150 301150
  • 185 301185
  • 240 301240
  • 300 301300
  • 320 301320
  • 55 302055
  • 70 302070
  • 90 302090
  • 110 302110
  • 125 302125
  • 150 302150
  • 185 302185
  • 240 302240
  • 300 302300
  • 320 302320
  • 55 303055
  • 70 303070
  • 90 303090
  • 110 303110
  • 125 303125
  • 150 303150
  • 185 303185
  • 240 303240
  • 300 303300
  • 320 303320
  • 55 304055
  • 70 304070
  • 90 304090
  • 110 304110
  • 125 304125
  • 150 304150
  • 185 304185
  • 240 304240
  • 300 304300
  • 320 304320
  • 55 305055
  • 70 305070
  • 90 305090
  • 110 305110
  • 125 305125
  • 150 305150
  • 185 305185
  • 240 305240
  • 300 305300
  • 320 305320
  • 55 306055
  • 70 306070
  • 90 306090
  • 110 306110
  • 125 306125
  • 150 306150
  • 185 306185
  • 240 306240
  • 300 306300
  • 320 306320
  • 55 322055
  • 70 322070
  • 90 322090
  • 110 322110
  • 125 322125
  • 150 322150
  • 185 322185
  • 240 322240
  • 300 322300
  • 320 322320
  • 55 323055
  • 70 323070
  • 90 323090
  • 110 323110
  • 125 323125
  • 150 323150
  • 185 323185
  • 240 323240
  • 300 323300
  • 320 323320
  • 55 324055
  • 70 324070
  • 90 324090
  • 110 324110
  • 125 324125
  • 150 324150
  • 185 324185
  • 240 324240
  • 300 324300
  • 320 324320
  • 55 325055
  • 70 325070
  • 90 325090
  • 110 325110
  • 125 325125
  • 150 325150
  • 185 325185
  • 240 325240
  • 300 325300
  • 320 325320
  • 55 371055
  • 70 371070
  • 90 371090
  • 110 371110
  • 125 371125
  • 150 371150
  • 185 371185
  • 240 371240
  • 300 371300
  • 320 371320
  • 55 372055
  • 70 372070
  • 90 372090
  • 110 372110
  • 125 372125
  • 150 372150
  • 185 372185
  • 240 372240
  • 300 372300
  • 320 372320
  • 55 373055
  • 70 373070
  • 90 373090
  • 110 373110
  • 125 373125
  • 150 373150
  • 185 373185
  • 240 373240
  • 300 373300
  • 320 373320
352
= No.40
  • SpeedMedium
  • Filteration Speed (sec) 450
  • Thickness (mm) 0.17
  • Retention Capacity 2 - 4
  • Weight (g/m2) 84
  • Burst Strength (kg/cm2) Light
Grade 352
Grade 352 filter paper is a general-purpose paper in terms of speed and particle retention. Examples of applications that this paper.
Sizes (Diameter/mm)
Product Code
353
= No.43
  • SpeedMedium
  • Filteration Speed (sec) 170
  • Thickness (mm) 0.20
  • Retention Capacity 4 - 7
  • Weight (g/m2) 81
  • Burst Strength (kg/cm2) Light
Grade 353
Grade 353 is an intermediate grade between grades 352 and 354 in terms of particle retention. However, this grade is about twice as fast as grade 352.
Sizes (Diameter/mm)
Product Code
354
= No.41
  • SpeedFast
  • Filteration Speed (sec) 50
  • Thickness (mm) 0.19
  • Retention Capacity 12 - 25
  • Weight (g/m2) 79
  • Burst Strength (kg/cm2) Light
Grade 354
Grade 354 is the fastest quantitative ashless filter paper and is best suited for filtering coarse particles or gelatinous precipitates.
Sizes (Diameter/mm)
Product Code
Grade Whatman
Equivalent		 Speed Filteration Speed
(sec)		 Thickness
(mm)		 Retention Capacity Weight
(g/m2)		 Burst Strength
(kg/cm2)
351 + = No.42 Slow 250 0.16 < 2 84 Light
352 + = No.40 Medium 450 0.17 2 - 4 84 Light
353 + = No.43 Medium 170 0.20 4 - 7 81 Light
354 + = No.41 Fast 50 0.19 12 - 25 79 Light