Double glazing glass

When evaluating double glazing (Insulated Glass Units - IGU), you must prioritize the U-Value, which measures thermal heat gain/loss; a lower value indicates better insulation. Additionally, check the Solar Heat Gain Coefficient (SHGC) to manage solar radiation. Ensure the spacer bars are 'warm edge' technology to prevent condensation, and verify that the gas filling (typically Argon or Krypton) reaches at least a 90% concentration level for optimal energy efficiency.

For the US market, products must meet ASTM E2190 and SGCC (Safety Glazing Certification Council) standards. For the European market, EN 1279 (Parts 1-6) and CE Marking are mandatory. If you are sourcing from China, ensure the supplier holds a valid CCC (China Compulsory Certification) and check for ISO 9001 to guarantee consistent manufacturing processes.

Request a Dew Point Test report to ensure the internal air space is dry and the primary/secondary seals (usually PIB and Silicone/Polysulfide) are airtight. Inspect for optical distortions or 'roller wave' in tempered glass, which should not exceed 0.05mm. For high-end projects, ask for Heat Soak Testing (HST) to minimize the risk of spontaneous breakage due to Nickel Sulfide inclusions.

Discuss the use of Low-E (Low Emissivity) coatings, which can be 'hard coat' or 'soft coat' depending on your climate needs. You should also specify the glass thickness (e.g., 6mm+12A+6mm) and whether you require laminated glass for soundproofing or tempered glass for safety. Many suppliers on Made-in-China.com offer custom shapes, silk-screen printing, and integrated blinds between the glass layers.

Glass is highly fragile; therefore, you must mandate custom-made fumigated wooden crates or A-frame steel racks. Ensure the glass sheets are separated by cork pads or plastic spacers to prevent scratches. It is highly recommended to use CIF (Cost, Insurance, and Freight) terms or purchase independent marine cargo insurance that covers 'all risks' including breakage.

Focus on the Total Landed Cost rather than just the FOB price. Request a detailed breakdown of the bill of materials (BOM), including the brand of the sealant and the type of Low-E coating used. For large orders, negotiate a staged payment plan (e.g., 30% deposit, 70% after third-party inspection but before loading) to maintain leverage over quality control.

Utilize the Secured Trading services provided by Made-in-China.com to protect your payments. Always conduct a factory audit or hire a third-party inspector (like SGS or Intertek) to perform a Pre-Shipment Inspection (PSI). This ensures the quantity, dimensions, and quality match your Proforma Invoice before the goods leave the port.

Check for Anti-Dumping Duties (ADD) or Countervailing Duties (CVD) in your specific country, as some regions impose high tariffs on Chinese architectural glass. Ensure the supplier provides a Certificate of Origin (CO) and a detailed Packing List to facilitate smooth customs clearance and potentially benefit from preferential trade agreements.