Polypropylene Ball | PP Ball | 5mm to 310mm | Chemical Resistant, Lightweight, FDA
Polypropylene (PP) balls are lightweight, solid plastic balls valued for their excellent chemical resistance, low moisture absorption, and low density. With a density of approximately 0.90 g/cm³, PP balls are lighter than water, allowing them to float. This buoyancy makes these polypropylene check spheres ideal for level indicators, backflow prevention float valves, and vapor barrier blankets (vapor blankets) in open chemical storage tanks. Polypropylene is highly resistant to aggressive chemicals, including concentrated acids, alkalis, and organic solvents, making it a cost-effective alternative to fluoropolymers for low-to-moderate temperature systems.
Applications
Level Indicator Floats
Floats on water-based liquids to activate switches or show fill levels in indicator tubes.
Chemical Storage Vapor Barriers
A layer of PP balls on open tank surfaces reduces chemical fumes, heat loss, and evaporation.
Sanitary Cosmetic Pumps
Acts as check balls in lotion dispensers, liquid soap pumps, and spray nozzles.
Backflow Prevention Valves
Used in sewer and industrial drainage systems as float check valves to prevent backflow.
Acid Pickling Bath Covers
Floated on hot acid plating baths to control steam and acidic mist release.
OEM Laboratory Equipment
Inert check components in clinical chemistry analyzers and medical dispensers.
Features
Low Density & Buoyancy
Density of ~0.90 g/cm³ allows PP balls to float on water, ideal for float level valves.
Chemical Resistance
Excellent resistance to inorganic acids, bases, alkalis, and salts.
Low Moisture Absorption
Absorbs virtually no moisture, maintaining physical dimensions in aqueous environments.
Thermal Limit
Continuous operating temperature limit up to +100°C in non-stressed applications.
Highly Cost-Effective
Extremely economical compared to PTFE, Delrin, or PEEK.
FDA Compliant
Natural polypropylene resin is safe for food processing and medical contact.
Good Sphericity
Rigid enough to machine to standard check valve tolerances.
Impact Strength
Resists impact cracking, providing long operational life in liquid transfer lines.
Technical Specifications
| Property | Value |
|---|---|
| Material | PP (Polypropylene — Homopolymer or Copolymer) |
| Diameter Range | 5mm – 310mm |
| Grade | ISO 3290 Grade G10 |
| Temperature Range | -10°C to +100°C |
| Specific Gravity | 0.90 – 0.91 g/cm³ (lightest engineering plastic) |
| FDA Compliance | Yes — food and pharmaceutical grade |
| Chemical Resistance | Acids, alkalis, alcohols, most solvents |
| Moisture Absorption | Less than 0.1% |
| Color | Natural white / Grey / Custom |
| Export Markets | UAE, Germany, USA, Japan, Singapore, Brazil, Turkey, Middle East |
Available sizes
We supply polypropylene balls in several metric and fractional inch sizes. Below are standard stock sizes.
| Size | Metric | Inch | Tolerance |
|---|---|---|---|
| 1/4″ | 6.00 mm | 0.250″ | ±0.04 mm |
| 3/8″ | 9.52 mm | 0.375″ | ±0.04 mm |
| 1/2″ | 12.70 mm | 0.500″ | ±0.05 mm |
| 3/4″ | 19.05 mm | 0.750″ | ±0.05 mm |
| 1″ | 25.40 mm | 1.000″ | ±0.06 mm |
| 1-1/2″ | 38.10 mm | 1.500″ | ±0.10 mm |
| 2″ | 50.80 mm | 2.000″ | ±0.12 mm |
Manufacturing Process
Resin Sourcing
We source high-purity, unreinforced polypropylene homopolymer resin to ensure chemical stability.
Extrusion/Injection Molding
PP resin is extruded into solid profile rods or injection-molded into spherical preforms.
Annealing Step
Molded parts are annealed to relieve molding stresses and prevent warping during finishing.
Precision Grinding
The preforms are ground using precision centerless grinders to achieve roundness and a smooth finish.
Quality Checks
Sphericity and weight/density are verified to guarantee proper float performance in fluid systems.
Material comparison
Compare Polypropylene (PP) balls with Nylon (PA) balls to determine the best choice for your assembly.
| Characteristic | Polypropylene (PP) | Nylon |
|---|---|---|
| Density / Buoyancy | Lightweight (~0.90 g/cm³, floats on water) | Higher (~1.13 g/cm³, sinks in water) |
| Chemical Resistance | Excellent (resists strong acids and bases) | Moderate (attacked by strong acids and alcohols) |
| Moisture Absorption | Zero (Hydrophobic) | Moderate (absorbs water, causing swelling) |
| Wear Resistance | Moderate (softer surface) | High (tough, wear-resistant polyamide surface) |
Compliance & Standards
IEC registered. FDA-compliant Polypropylene grade. ISO 3290 Grade G10. Floats on water (SG 0.90). Note: PP has limited temperature resistance (max +100°C) — for higher temperatures, use PEEK or PTFE Balls. Regular export to UAE, Germany, USA, Japan, Singapore, Brazil, Turkey, and Middle East.
Frequently Asked Questions
Are PP Balls food grade and FDA compliant?
Yes. We supply PP Balls in FDA-compliant food-grade Polypropylene compound — non-toxic, safe for direct contact with food, beverages, and pharmaceutical products. Widely used in food processing, dairy, and pharmaceutical pump check valves and flow control equipment.
What is the largest PP Ball you manufacture?
We manufacture PP Balls up to 310mm diameter — one of the widest size ranges for Polypropylene Balls globally. Large PP Balls serve float valve assemblies, water tank level control, and large-bore water infrastructure check valves.
Do PP Balls float on water?
Yes. PP has a specific gravity of 0.90 g/cm³ — less than water — so PP Balls float. This makes them ideal for float valve assemblies and water tank level control applications.
Do polypropylene balls float on water?
Yes. Polypropylene has a density of approximately 0.90 g/cm³, which is less than water (1.00 g/cm³), allowing the balls to float reliably.
What is the maximum operating temperature for PP balls?
The maximum continuous operating temperature is approximately +100°C. For applications under load, the temperature limit is lower.
Can PP balls handle strong acids?
Yes. Polypropylene has outstanding resistance to most inorganic acids, alkalis, and salts, making it suitable for acid pickling and chemical feed lines.
Are PP balls food-grade compliant?
Yes. Natural, unpigmented polypropylene resin is FDA compliant and safe for direct food contact applications.
How do you prevent the balls from absorbing water?
Polypropylene is naturally hydrophobic and has nearly zero moisture absorption, meaning it will not swell or distort in water.
What is the standard lead time for bulk PP ball orders?
Standard diameters are kept in stock for immediate shipment. Custom production batches typically take 10 business days.
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