High-Temperature String Wound Filter Cartridge: Enduring Purity for Hot Fluid Processing

1. Introduction

Designed for high-temperature applications (up to 120℃), this String Wound Filter Cartridge combines absorbent cotton media with stainless steel skeletons. Its outer-loose-inner-dense winding resists thermal deformation, removing particles (5–100μm) from hot water, steam, and industrial oils. Ideal for petrochemical distillation, food sterilization, and power plant cooling—maintaining 90%+ retention efficiency even under thermal stress, while enabling repeatable steam cleaning for cost savings.

2. Core Features: Precision, Durability, and Safety

① Ultra-Precise Filtration Performance

• High Interception Efficiency: Boasts a retention rate exceeding 90% for target particles, with a filtration precision range from 1μm to 100μm—customizable to meet specific application demands (e.g., 1μm for electronics, 50μm for general industrial use).

• Deep Filtration Mechanism: The outer-loose-inner-dense structure first traps large particles, then captures finer contaminants in deeper layers, minimizing pressure drop while maximizing dirt-holding capacity.

② Robust Flow & Reusability

• Enhanced Pressure Resistance: The inner-threaded design bolsters structural integrity, withstanding operating pressures up to 0.5MPa and pressure differentials ≤0.2MPa.

• Washable & Cost-Effective: Compatible with chemical cleaning, steam sterilization, or online regeneration—extending service life and slashing replacement costs by up to 40%.

③ Food-Grade Material Compliance

• Safe for Sensitive Sectors: All components adhere to food-grade standards:

• Filter media: Polypropylene (PP) fiber, absorbent cotton, or glass fiber.

• Supports & structure: Polypropylene (PP).

• Seals: Silicone rubber, NBR, EPDM, or fluororubber—ensuring chemical compatibility across a pH range of 2–12.

④ Optimized Honeycomb Structure

• Large Dirt-Holding Capacity: The outer-loose-inner-dense winding pattern creates ample "pore storage" space, increasing contaminant retention by 30–50% compared to standard cartridges—delaying clogging and extending maintenance intervals.

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• 3. Technical Specifications: Tailored to Diverse Needs

• Parameter	Details
  Core Skeleton	Polypropylene (PP) or stainless steel
  Outer Diameter	Φ60mm, Φ65mm
  Inner Diameter	Φ28mm, Φ30mm
  Length	10”, 20”, 30”, 40” (customizable)
  Operating Pressure	≤0.5MPa
  Max Pressure Drop	≤0.2MPa
  Temperature Limit	- Polypropylene fiber + PP skeleton: ≤60℃ - Polypropylene fiber + stainless steel skeleton: ≤80℃ - Absorbent cotton + stainless steel skeleton: ≤120℃
  Filtration Media	PP fiber, absorbent cotton, glass fiber
  Filtration Precision	1μm, 5μm, 10μm, 20μm, 30μm, 50μm, 75μm, 100μm (customizable)

4. Working Principle: Layer-by-Layer Contamination Trapping

The string wound filter cartridge’s filtration efficiency arises from its dual-design advantage:

1. Controlled Winding Density: Textile fibers (e.g., PP, absorbent cotton) are wound onto the skeleton with increasing tightness from the outer to the inner layer. This forms a pore-size gradient—larger surface pores intercept coarse particles, while smaller inner pores capture fine contaminants.

2. Deep Filtration Path: As fluid flows through the cartridge, contaminants are trapped not only on the surface but also within the layered fiber structure (honeycomb-like), maximizing dirt-holding capacity. This "depth filtration" reduces pressure drop and extends service life compared to surface-only filters.

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4. 5. Application Fields: Ensuring Purity Across Industries

5. ① Pharmaceutical Industry

6. Use Case: Pre-filtration in water-for-injection (WFI) systems, removing particles and bacteria to meet USP <1231> standards.

7. Case: A Shanghai pharmaceutical plant reduced endotoxin levels from 0.5EU/ml to <0.25EU/ml using 5μm PP-wound cartridges, ensuring batch consistency.

8. ② Food & Beverage Industry

9. Use Case: Filtration of process water, juices, and syrups to eliminate suspended solids, mold, and yeast.

10. Data: A Zhejiang beverage factory achieved a turbidity of NTU <1 in product water using 10μm absorbent cotton-wound cartridges, extending shelf life by 20%.

11. ③ Electronics Industry

12. Use Case: Ultra-pure water (UPW) preparation for semiconductor manufacturing, removing particles ≥1μm.

13. Practice: A Guangdong electronics fab uses 1μm glass fiber-wound cartridges in RO pre-treatment, cutting UPW system downtime by 35%.

14. ④ Petrochemical & Lubrication Industry

15. Use Case: Filtration of lubricating oils and hydraulic fluids to remove wear particles and oxidation byproducts.

16. Result: A Shandong steel mill extended hydraulic oil change intervals from 6 months to 12 months using 20μm PP-wound cartridges, reducing maintenance costs by ¥200,000 annually.

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18. 6. Q&A: Addressing Key Customer Queries

19. Q1: How do I select the right filtration precision?
    A1: Align precision with your fluid’s purity needs:

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21. Electronics/Pharma: 1–10μm (removes fine particles).

22. Food/Beverage: 10–50μm (removes suspended solids).

23. Industrial Lubrication: 20–100μm (removes wear debris).

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25. Q2: Can the cartridge be cleaned and reused?
    A2: Yes! For non-abrasive contaminants, clean via:

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27. Water backflushing (for particles).

28. Chemical soaking (e.g., 5% citric acid for scale, 1% NaOH for organics).

29. Steam sterilization (for food/pharma applications).

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31. Q3: What’s the temperature limit for my application?
    A3: It depends on the media and skeleton:

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33. PP fiber + PP skeleton: ≤60℃ (ideal for general water).

34. PP fiber + stainless steel: ≤80℃ (for warm fluids).

35. Absorbent cotton + stainless steel: ≤120℃ (for hot water/steam use).

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37. Q4: Are the materials safe for food contact?
    A4: Absolutely—all components (PP, absorbent cotton, food-grade rubbers) comply with FDA 21 CFR §177 and EU 10/2011 regulations, making them safe for food/beverage applications.

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39. Q5: How long does a cartridge last?
    A5: Lifespan varies by application:

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41. Clean water (e.g., RO pre-treatment): 6–12 months.

42. Oily fluids (e.g., lubricants): 3–6 months.

43. Monitor pressure drop—replace when it exceeds 0.2MPa.

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45. If you are interested in this product or have any questions, please feel free to contact us at any time.