18g pet preform

For an 18g PET preform, the most critical factors are weight consistency (tolerance within ±0.2g), neck finish type (e.g., PCO 1810, 1881, or 30/25), and wall thickness uniformity. Ensure the preform has high transparency and is free from bubbles or black spots, as these defects will expand during the stretch-blow molding process, leading to bottle failure.

You must verify that the supplier uses 100% virgin PET resin that is BPA-free and complies with FDA (US) or EFSA (EU) food-grade standards. Request Migration Test Reports and SGS/TUV certifications to ensure no harmful chemicals leach into the liquid, especially if the final bottle is intended for mineral water or carbonated soft drinks.

Prioritize suppliers using Husky injection molding systems or high-precision multi-cavity molds (e.g., 48 to 96 cavities). These technologies ensure low AA (Acetaldehyde) levels, which is vital for maintaining the taste of bottled water, and provide excellent gate quality to prevent leaks at the bottom of the finished bottle.

The 18g weight is a standard for 330ml to 500ml water bottles. To optimize costs, look for suppliers on Made-in-China.com that offer tiered pricing; typically, orders exceeding 100,000 units can reduce the unit price by 10-15%. Additionally, consider the IV (Intrinsic Viscosity) value—a higher IV (0.80-0.84) allows for stronger bottles but may increase material costs.

PET preforms are sensitive to high temperatures. Ensure the supplier uses heavy-duty corrugated boxes with PE inner bags and request container temperature monitoring if shipping through tropical zones. For large volumes, palletized shipping with stretch wrap is recommended to prevent crushing and facilitate easy unloading at your facility.

Focus negotiations on raw material price indexing. Since PET resin prices fluctuate with global oil markets, suggest a formula-based pricing model. Also, negotiate for free mold maintenance or a spare parts kit (nozzles, heaters) if you are purchasing the blowing molds alongside the preforms.

Always use Trade Assurance services provided by platforms like Made-in-China.com to protect your payment. Before the final balance payment, hire a third-party inspection agency (like V-Trust or QIMA) to perform a Random Sampling Inspection to check for weight accuracy, neck dimensions, and moisture content.

Check for Anti-Dumping Duties (ADD) on PET resin or finished products in your specific country (e.g., some regions have high tariffs on Chinese PET). Ensure the HS Code (typically 3923.30) is correctly declared on the Bill of Lading and Commercial Invoice to avoid customs delays and ensure you are applying for the correct preferential tariff rates if applicable.