What is a scraper seal and how does it work?

Understanding Scraper Seals: Essential Knowledge for Seal Manufacturing Professionals

Scraper seals, also known as wiper seals, play a pivotal role in hydraulic and pneumatic systems by preventing contaminants from entering cylinders and damaging internal components. This article delves into key aspects of scraper seals, addressing common questions and providing insights essential for professionals in the seal manufacturing industry.

What is a Scraper Seal and How Does It Work?

A scraper seal is a sealing element installed at the end of a hydraulic or pneumatic cylinder, designed to remove dirt, debris, moisture, and other contaminants from the rod surface as it retracts into the cylinder. By effectively scraping off these foreign particles, scraper seals protect the internal components of the system, such as piston seals and bearings, from damage and ensure the longevity and reliability of the equipment.

What Are the Different Types of Scraper Seals?

Scraper seals come in various designs to suit different applications:

• Single-Acting Scrapers: These seals function in one direction, typically used to prevent external contaminants from entering the system.

• Double-Acting Scrapers: Capable of sealing in both directions, these seals provide additional protection by retaining the lubricant film and preventing contamination from both external and internal sources.

• Metallic Scrapers: Constructed with metal components, these seals are ideal for harsh environments where heavy or tenacious contaminants, such as ice or mud, are present.

What Materials Are Used in Scraper Seals?

The choice of material for scraper seals depends on the specific application and operating conditions:

• Elastomers (Rubber): Materials like Nitrile (Buna-N) and Fluorocarbon (FKM) offer good resistance to various fluids and are suitable for a wide range of temperatures.

• Polyurethane (PU): Known for its excellent wear resistance and durability, PU is often used in scraper seals exposed to abrasive conditions.

• PTFE (Polytetrafluoroethylene): PTFE seals provide low friction and high chemical resistance, making them suitable for applications involving aggressive fluids.

How Are Scraper Seals Installed?

Installation of scraper seals requires careful consideration to ensure optimal performance:

1. Groove Design: The groove dimensions must match the seal's specifications to ensure proper fit and function.

2. Orientation: The sealing lip should face outward to effectively scrape contaminants from the rod surface as it retracts.

3. Material Compatibility: Ensure that the seal material is compatible with the operating environment, including temperature, pressure, and chemical exposure.

What Are the Maintenance Requirements for Scraper Seals?

Regular maintenance is crucial to extend the lifespan of scraper seals:

• Inspection: Periodically check for signs of wear, damage, or deformation.

• Cleaning: Remove any accumulated debris from the seal and surrounding areas to maintain effective scraping action.

• Replacement: Replace seals that show signs of significant wear or damage to prevent contamination of the system.

How Do Scraper Seals Interact with Other Components in a System?

Scraper seals work in conjunction with other sealing elements to maintain system integrity:

• Primary Seals: Scraper seals prevent contaminants from entering the system, thereby protecting primary seals from damage and ensuring their longevity.

• Guides and Bearings: By keeping contaminants away, scraper seals help maintain the performance and extend the life of guides and bearings.

What Are the Key Considerations When Selecting a Scraper Seal?

Selecting the appropriate scraper seal involves evaluating several factors:

• Operating Conditions: Consider temperature ranges, pressure levels, and the presence of aggressive chemicals or abrasive materials.

• Seal Material: Choose a material that offers compatibility with the operating environment and desired performance characteristics.

• Seal Design: Determine whether a single-acting or double-acting scraper is more suitable for the application.

• Installation Requirements: Ensure that the groove design and seal orientation are appropriate for effective sealing.

What Are the Advantages of Choosing Polypac Scraper Seals?

Polypac offers a range of scraper seals designed to meet the diverse needs of the seal manufacturing industry:

• High-Quality Materials: Polypac's seals are made from premium materials, ensuring durability and reliability in various applications.

• Customization: With a focus on customer satisfaction, Polypac provides tailored solutions to meet specific operational requirements.

• Expertise: Leveraging years of experience, Polypac offers valuable insights and support in selecting and implementing scraper seals.

• Comprehensive Support: From installation guidance to maintenance recommendations, Polypac supports clients throughout the lifecycle of the seal.

By choosing Polypac, professionals in the seal manufacturing industry can ensure optimal performance and longevity of their hydraulic and pneumatic systems.

References:

• Zatkoff Seals & Packings. (2025). RWS Seal-Guard® Metallic Rod Wiper/Scraper. Retrieved from

• Hänssler Kunststoff- und Dichtungstechnik GmbH. (2024). Scrapers - Hydraulic seals. Retrieved from

• France Joint. (2024). BECA 478 - Wiper seal - Scraper seal - Ice wiper - Hydraulic seal. Retrieved from

• Mykin Inc. (2024). MH5 Scraper Seals, PTFE Double Lip Seals. Retrieved from

• DMS Seals Technology Co., Limited. (2024). Scraper Seals Manufacturer, Wiper Seals Supplier. Retrieved from

• Trelleborg Sealing Solutions. (2024). ZURCON® HEAVY DUTY SCRAPER WAE. Retrieved from

• Seals-Shop.com. (2024). Scraper SA. Retrieved from

• Seals-Shop.com. (2024). Scraper DA17. Retrieved from

• Seals-Shop.com. (2024). Scraper DA22-LBI Dust seal-DH wiper seal-dust seal. Retrieved from

• Deere & Company. (2024). F698808: Scraper Ring Seal. Retrieved from

• Deere & Company. (2024). F698812: Scraper Ring Seal. Retrieved from

• Eastern Seals UK. (2024). Wipes Seals / Scraper Seals. Retrieved from

• Machine Design. (2024). Exclusion Seals. Retrieved from

• HanDeYeYa. (2024). Hydraulic Cylinder Wiper Seal. Retrieved from

• FPE Seals. (2024). What is a Wiper Seal? Function & Benefits. Retrieved from

• DMS Seals Technology Co., Limited. (2024). What Is Scraper Seal? Retrieved from

• Jinbond Seal. (2024). How do Scraper Seals interact with other components in a system? Retrieved from

• Polypac. (2024). Company Overview. Retrieved from