- 32×120 / 25×90 / 28×70 mm
- Up to 500°C
- Binder-free borosilicate
- Acid & Solvent Resistant
- Soxhlet Extraction Ready
Availability: In Stock
Glass Fiber Thimbles
Description
What Are Glass Fiber Thimbles?
Glass fiber thimbles are cylindrical extraction devices manufactured from borosilicate glass microfibers without binders. They are designed to fit standard Soxhlet extractors and are used for high‑temperature extraction of solids, gravimetric analysis, and environmental sampling. Compared with cellulose extraction thimbles, glass fiber thimbles offer higher temperature resistance (up to 500°C), better chemical compatibility (acids, organic solvents), and lower background interference – making them the preferred choice for demanding analytical applications. Glass fiber thimbles are also referred to as glass fibre thimbles in the UK and European markets.
Product Overview
Hawach glass fiber thimbles are manufactured from 100% binder-free borosilicate glass microfibers. They are widely used in Soxhlet extraction, solvent extraction, gravimetric analysis, and environmental monitoring where high temperature resistance and chemical stability are required. Unlike cellulose thimbles, glass fiber thimbles withstand aggressive solvents, acidic gases, and temperatures up to 500°C with minimal background interference and very low ash contribution.
Glass Fiber vs Cellulose Thimbles – Which to Choose?
| Feature | Glass Fiber (Hawach) | Cellulose |
|---|---|---|
| Maximum temperature | 500°C | ~120°C |
| Binder content | None | None (cotton linters) |
| Chemical resistance | Excellent (acids, organic solvents) | Limited (degraded by strong acids) |
| Suitable for acidic gases | HCl, SO₂, NOx | Not recommended |
| Ash content | Very low | Low but variable |
| Best for | Soxhlet extraction, high-temp analysis, acidic samples | Routine fats, oils, pesticides at moderate temps |
Choose glass fiber thimbles for applications exceeding 120°C, aggressive solvents, acidic gases, or when minimal background is critical.
| Cat. No. | Dimensions (Ø×H mm) | Wall Thickness (mm) | Weight (g) | Packaging (pcs/pack) |
|---|---|---|---|---|
| 22032001 | 32×120 mm Glass Fiber Thimble | 1.5～2.0 | 1.8±0.2 | 30 |
| 22032002 | 25×90 mm Glass Fiber Thimble | 1.5～2.0 | 1.2±0.2 | 50 |
| 22032003 | 28×70 mm Glass Fiber Thimble | 1.5～2.0 | 1±0.2 | 20 |
Technical Parameters
| Max Temperature | 500°C | ||
|---|---|---|---|
| Flow Pressure (mmHg) | 14-16 (32×120) | 16-18 (25×90) | 18-20 (28×70) |
| DOP Retention | >99.99% (0.3 µm, GB6165-85 oil mist method) | ||
| Weight Loss | <0.2% (after 120 min at use temperature) | ||
| Background Composition | SiO₂:57.22%, Fe₂O₃:0.3%, Al₂O₃:14.63%, CaO:16.12%, MgO:3.66%, K₂O:0.16%, Na₂O:0.38% | ||
Physical Properties
| Property | Value |
| Material | Borosilicate Glass Microfiber |
| Binder | None |
| Retention | 0.8 μm |
| Max Temp | 500°C |
| Ash Content | Very Low |
| Weight Loss | <0.2% |
Why Choose Hawach Glass Fiber Thimbles
High Temperature Resistance
Operates up to 500°C – ideal for high-temp Soxhlet extraction and gravimetric analysis.
Binder-Free & Chemically Inert
100% borosilicate glass fibers, no binders or additives — no extractable contaminants.
Acid & Solvent Resistant
Suitable for aggressive solvents, acidic gases (HCl, SO₂, NOx), and harsh extraction conditions.
Low Weight Loss
<0.2% weight loss ensures accurate gravimetric results.
Uniform Wall Thickness
1.5-2.0 mm consistent thickness for reproducible extraction.
Multiple Size Options
Three standard sizes to fit common Soxhlet extractors.
Applications
Soxhlet Extraction
Pesticides, oils, fats, polymers, environmental contaminants from solid samples.
Gravimetric Analysis
High-temperature weight determination with minimal background.
Air & Waste Gas Monitoring
Collection of dust, soot, and particulate matter from industrial emissions.
Acidic Gas Sampling
Determination of HCl, SO₂, NOx in stack emissions (acid-resistant).
Biochemical Extraction
Extraction of organic compounds from biological matrices.
Selection Guide – Which Thimble Size to Choose?
| Thimble Size | Typical Soxhlet Capacity | Application Fit |
|---|---|---|
| 32×120 mm | Large-capacity (250-500 mL flask) | High sample volume, extended extraction cycles |
| 25×90 mm | Standard (150-250 mL flask) | Most common – general Soxhlet extraction |
| 28×70 mm | Small / deep well (100-150 mL) | Small sample volume, limited solvent |
Fit tip: The thimble outer diameter should be 1-2 mm smaller than the extractor chamber ID. Height should be 5-10 mm above the siphon tube top.
Technical Specifications
| Material | 100% borosilicate glass microfibers, binder-free |
|---|---|
| Max operating temperature | 500°C (932°F) |
| Wall thickness | 1.5 – 2.0 mm |
| Particle retention (nominal) | 0.8 µm |
| Chemical resistance | Excellent resistance to most acids (except HF) and organic solvents. Limited resistance to strong alkaline solutions. |
| Weight loss | <0.2% (120 min at use temp) |
| Packaging | 20, 30, or 50 pcs/pack (see ordering table) |
Ordering information:
22032001 – 32×120 mm Glass Fiber Thimble: 30 pcs/pack – for large-capacity Soxhlet extractors.
22032002 – 25×90 mm Glass Fiber Thimble: 50 pcs/pack – standard size, most popular.
22032003 – 28×70 mm Glass Fiber Thimble: 20 pcs/pack – compact for smaller extractors.
Instruction Drawing
Frequently Asked Questions – Glass Fiber Thimbles
What is the difference between glass fiber thimbles and glass microfiber thimbles?
The terms are often used interchangeably. Glass microfiber thimbles are manufactured from fine borosilicate glass fibers and are commonly used for Soxhlet extraction and gravimetric analysis. Hawach glass fiber thimbles are high-quality glass microfiber thimbles with binder-free construction.
Can glass fiber thimbles replace cellulose extraction thimbles?
Yes. Glass fiber thimbles are commonly selected when higher temperatures, aggressive solvents, acidic gases, or lower background interference are required. For routine fat, oil, or pesticide extractions at moderate temperatures, cellulose thimbles remain an economical choice.
What is the maximum temperature for these thimbles?
Hawach glass fiber thimbles can be used continuously at temperatures up to 500°C (932°F).
Why are binder-free thimbles better?
Binders can introduce extractable contaminants or ash, interfering with gravimetric analysis and sensitive extractions. Binder-free thimbles eliminate this risk.
Are these thimbles suitable for Soxhlet extraction with organic solvents?
Yes. Borosilicate glass is inert to most organic solvents used in Soxhlet extraction, including hexane, acetone, toluene, and dichloromethane.
How do I choose the correct size?
Measure the inner diameter of your Soxhlet extraction chamber. The thimble outer diameter should be 1-2 mm smaller. Height should extend 5-10 mm above the siphon tube top.
What is the weight loss specification?
Weight loss is less than 0.2% after 120 minutes at the use temperature, ensuring reliable gravimetric data.
Can I use these thimbles for acidic gas sampling?
Yes, they resist most acids (except hydrofluoric) and are widely used for sampling HCl, SO₂, and NOx from industrial stacks.
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