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Qualitative Filter Papers - Wet Strengthened Grades
Home | Filter Papers | Cellulose Filters | Qualitative Filter Papers - Wet Strengthened Grades

These extremely strong filter papers have a high wet strength due to the addition of a small quantity of chemically stable resin. Normal qualitative applications will not introduce any significant impurities into the filtrate. The resins do, however, contain nitrogen so these grades should not be used in Kjeldahl estimations, etc. Some wet strengthened grades are available in folded (prepleated) forms.

Grade 91: 10 µm
A general purpose creped filter for less critical routine analysis. Widely used to assay sucrose in cane sugar and within pharmaceutical laboratories for routine filtration.

Grade 93: 10 µm
This filter paper is intermediate in speed and retention between Grades 1 and 4. Available in a dispenser pack, which can be attached to the wall or bench, placed on a shelf either upright or flat, and used as a normal carton or as a convenient dispenser. The envelopes are released individually for easy one-at-a-time removal. Package and envelopes are clearly marked for size and content.

Grade 113: 30 µm
Ultra high loading capacity with a particle retention making it ideal for use with coarse or gelatinous precipitates. Fastest flow rate of the qualitative grades. Creped surface. Thickest filter paper in the qualitative range. This filter is also available in the FilterCup, a convenient, disposable 70 mm filter funnel with a 250 mL capacity, molded from polypropylene with an integral, heat bonded filter. Also available as Grade 113V.

Grade 114: 25 µm 
Only half the thickness of Grade 113 and suitable for coarse or gelatinous precipitates. Smooth surface for easy recovery of precipitates. Also available prepleated as Grade 114V.

Grade 588
Fast filter paper. Stated in a number of standards and methods, e.g. Aflatoxin determination in animal feed (BS 5766-7) and Mercury determination in sludge (EPA method 105). Also available prepleated as Grade 588 ½.

Grade 1573: 12-25 µm 
A fast filter paper with high wet strength. It has a very smooth surface making it easy to scrape or wash off precipitate. Resistant against: sulfuric and nitric acid solutions (up to 40% at 50° C), hydrochloric (up to 10% at 100° C, 20% at 60° C, 25% at 20° C) and alkalis (up to 10% at 20° C). Also available prepleated as Grade 1573 ½.

Grade 1575: < 2 µm
Slow filter paper with high wet strength. This paper has the same chemical resistance characteristics as Grade 1573 (see under Grade 1573 above).

See Filter Papers for Technical Use section, for additional wet strengthened filter papers.

Typical Properties - Qualitative Wet Strengthened Grades
Grade Description Particle
Retention
in Liquid (µm)		 Filtration Speed
(approx.)
Herzberg (s)		 Air Flow
(s/100 mL/in2)		 Typical
Thickness
(µm)		 Basis Weight
(g/m2)
91 Creped 10* 70 6.2 205 71
93 Medium 10* 80 7 145 67
113 Fast, Creped 30* 28 1.3 420 125
114 Fast, Smooth 25* 38 5.3 190 77
588 Fast - - - 205 80
1573 Fast, Smooth 12-25** 25 - 180 90
1575 Slow <2** 850 - 140 95

*  Particle Retention Rating at 98% efficiency ** Approximate values  
Ordering Information - Qualitative Filter Papers - Wet Strengthened Grades
Catalog Number Description
Grade 91
1091-110 Grade 91 Circles, 110 mm 4000/pk (Subdivided into 100)
1091-125 Grade 91 Circles, 125 mm 4000/pk (Subdivided into 100)
1091-150 Grade 91 Circles, 150 mm 1000/pk (Subdivided into 100)
1091-165 Grade 91 Circles, 165 mm 1000/pk (Subdivided into 100)
1091-185 Grade 91 Circles, 185 mm 1000/pk (Subdivided into 100)
1091-190 Grade 91 Circles, 190 mm 1000/pk (Subdivided into 100)
1091-240 Grade 91 Circles, 240 mm 1000/pk (Subdivided into 100)
1091-500 Grade 91 Circles, 500 mm 100/pk
1091-920 Grade 91 Sheets, 480 x 480 mm 500/pk
1091-930 Grade 91 Sheets, 580 x 580 mm 500/pk
1091-935 Grade 91 Sheets, 610 x 610 mm 500/pk
1091-902 Grade 91 Sheets, 730 x 1280 mm 100/pk
1091-903 Grade 91 Sheets, 790 x 1280 mm 100/pk
Grade 93
1093-110 Grade 93 Circles, 110 mm 100/pk
1093-111 Grade 93 Circles, 110 mm 1250/pk (50 envelopes of 25 circles)
1093-125 Grade 93 Circles, 125 mm 100/pk
1093-126 Grade 93 Circles, 125 mm 1250/pk (50 envelopes of 25 circles)
1093-6212 Grade 93 Circles, 125 mm 4000/pk (40 bags of 100 circles)
1093-6215 Grade 93 Circles, 150 mm 1000/pk (10 bags of 100 circles)
1093-930 Grade 93 Sheets, 580 x 580 mm 500/pk
1093-935 Grade 93 Sheets, 610 x 610 mm 500/pk

Grade 113
1113-110 Grade 113 Circles, 110 mm 100/pk
1113-090 Grade 113 Circles, 90 mm 100/pk
1113-125 Grade 113 Circles, 125 mm 100/pk
1113-150 Grade 113 Circles, 150 mm 100/pk
1113-921 Grade 113 Circles, 180 mm with 35 mm central hole 100/pk
1113-185 Grade 113 Circles, 185 mm 100/pk
1113-922 Grade 113 Circles, 195 mm with 61 mm central hole 100/pk
1113-240 Grade 113 Circles, 240 mm 100/pk
1113-320 Grade 113 Circles, 320 mm 100/pk
1113-500 Grade 113 Circles, 500 mm 100/pk
1113-917 Grade 113 Sheets, 460 x 570 mm 100/pk
1113-991 Grade 113 Sheets, 490 x 1000 mm 100/pk
1600-113 FilterCup (Requires FilterCup Stem ,Catalog # 1600-900) 25/pk
Grade 114
1114-090 Grade 114 Circles, 90 mm 100/pk
1114-125 Grade 114 Circles, 125 mm 100/pk
1114-150 Grade 114 Circles, 150 mm 100/pk
1114-185 Grade 114 Circles, 185 mm 100/pk
1114-240 Grade 114 Circles, 240 mm 100/pk
1114-270 Grade 114 Circles, 270 mm 100/pk
1114-400 Grade 114 Circles, 400 mm 100/pk
1114-930 Grade 114 Sheets, 580 x 580 mm 100/pk
1114-935 Grade 114 Sheets, 580 x 580 mm 500/pk

Grade 588
10318220 Grade 588 Circles, 240 mm 100/pk

Grade 1573
10314711 Grade 1573 Circles, 125 mm 100/pk
10314712 Grade 1573 Circles, 150 mm 100/pk
10314714 Grade 1573 Circles, 185 mm 100/pk
10314720 Grade 1573 Circles, 240 mm 100/pk
10314726 Grade 1573 Circles, 290 mm 100/pk

Grade 1575
10314911 Grade 1575 Circles, 125 mm 100/pk
10314912 Grade 1575 Circles, 150 mm 100/pk
10314914 Grade 1575 Circles, 185 mm 100/pk
10314916 Grade 1575 Circles, 200 mm 100/pk
10314940 Grade 1575 Circles, 510 mm 100/pk
10314984 Grade 1575 Sheets, 400 x 400 mm 500/pk
10314991 Grade 1575 Sheets, 1100 x 1100 mm 100/pk

FilterCup Stem
1600-900 FilterCup Stem 1/pk

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