Water Purifier Flow Plate PP Plastic Pellets

Zhejiang Lisu's PP plastic pellets for water dispenser flow plates primarily use food-grade polypropylene (PP), with glass fiber reinforced and antibacterial modified PP materials being the most critical. PP material has become the mainstream choice for manufacturing water dispenser flow plates because it balances safety, durability, and cost-effectiveness. However, depending on the water dispenser's function (room temperature/hot and cold) and positioning, the specific PP pellets used can vary significantly in formulation and performance.

1. Core Characteristics: Why PP?

From a material properties perspective, PP pellets have natural advantages as water-contact components:

High food safety: PP material is non-toxic and odorless, complying with food contact grade standards, and will not release harmful substances into water. This is the prerequisite for its use in drinking water equipment.

Good chemical stability: resistant to corrosion from most acids, alkalis, and salts, ensuring no chemical reactions or rusting occur in long-term water contact environments, guaranteeing water purity.

Heat resistance and dimensional stability: PP has a wide long-term service temperature range (typically up to approximately 100°C), meeting the hot and cold water tolerance requirements of water dispensers. It also offers good rigidity and dimensional stability, ensuring flow plates are resistant to deformation under temperature changes.

Excellent processability: PP material has good flowability and is easy to injection mold, suitable for producing flow plates with complex internal channels and precision structures.

2. Differentiated Characteristics for Different Applications

The flow plate is the "central nervous system" of a water dispenser, with different positions placing different demands on materials. In practice, PP pellets are typically modified according to requirements, mainly falling into the following three categories:

| Material Type | Key Characteristics and Performance Advantages | Main Application Scenarios |
|---|---|---|
| Food-grade PP | Basic properties: non-toxic and odorless, chemical corrosion resistant, good weldability. | Main flow plates for ordinary room-temperature water purifiers; non-pressure-bearing components with low heat resistance and strength requirements. |
| Glass fiber reinforced PP | High strength and rigidity: through the addition of glass fiber (e.g., 30% GF), strength, rigidity, and creep resistance (resistance to deformation under long-term stress) are far superior to ordinary PP, with better resistance to hot water. Certification assurance: typically able to pass international drinking water system standard certifications such as NSF/ANSI 61. | Components near the heating tank in hot and cold water dispensers; pressure-bearing structural components (such as water pump brackets and high-pressure water circuits), preventing softening at high temperatures or cracking under pressure. |
| Antibacterial modified PP | Long-lasting antibacterial effect: antibacterial agents such as tetrapod-shaped zinc oxide are added, eliminating bacteria by releasing zinc ions or physically piercing cell membranes, with no risk of heavy metal migration. | Drinking equipment with high hygiene requirements, such as antibacterial flow plates, used to inhibit biofilm formation inside water circuits and ensure end-point water quality. |

3. Key Material Selection Points and Precautions

Several points deserve special attention in practical application and processing:

Certification is the first threshold: PP materials used in drinking water systems must comply with relevant hygiene standards. Professional material suppliers typically provide NSF (National Sanitation Foundation) or national standard GB/T 17219 certification reports, which serve as the "identity certificate" of material safety.

Always use virgin material: the industry strongly emphasizes the use of "virgin material" (commonly known as "first-hand material") for producing flow plates. Recycled materials contain more impurities and have already suffered molecular chain damage, leading to brittle and easily cracked products with a grayish-dark appearance, posing risks of water leakage or even bursting.

Welding process must be compatible: water dispenser flow plates are typically formed by welding upper and lower plates together using hot plate or ultrasonic welding. PP welding rods of the same material must be used during welding, with strict temperature control, otherwise weak welds and cracks can easily occur, leading to water leakage.

Beware of low-temperature brittleness: ordinary PP's toughness drops sharply in low-temperature environments (below approximately -10°C), becoming brittle and prone to cracking. This should be taken into consideration if water dispensers are transported or stored in cold northern regions, or toughened modified PP materials should be selected.

Pay attention to long-term hydrolysis resistance: PP materials face the risk of slow hydrolysis and aging in long-term high-temperature and high-humidity environments. Therefore, glass fiber reinforced PP is a more reliable choice for hot water dispensers and pipeline water dispensers, significantly extending the material's long-term service life in hot water environments.

Summary

In simple terms, the PP pellets used to manufacture water dispenser flow plates are fundamentally a combination of "safety" and "durability." Ordinary food-grade PP is suitable for basic models, while glass fiber reinforced PP is the mainstream choice for hot and cold water dispensers. For higher-end antibacterial functionality, antibacterial PP can be considered.