Answers

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  We need a small batch of SPCC cold-rolled steel coils for testing. Does your company have any MOQ requirements? If the initial order quantity is small, can you arrange production and shipment? Additionally, could you provide samples for our preliminary testing?
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  Hello, we are very interested in the ss coils on your website. Our company, located in Saudi Arabia, is looking for a reliable steel supplier for a long-term project. This is our first time importing directly from China, and we're not very familiar with the procedures, so we'd like to understand the process and any precautions.

  Thank you for your trust and inquiry. We have received your detailed inquiry regarding the import of steel from China and would like to provide you with the following professional and clear import process:
  
  Standard Import Process:
  1. Inquiry and Quotation - You provide the specific product specifications, quantity, and target port for the stainless steel coils. We will provide you with a detailed quotation including all costs.
  2. Confirmation and Payment - After both parties confirm the order, you will make payment according to the contract (usually a 30% deposit). We support secure payment methods such as T/T (telegraphic transfer) and L/C (letter of credit).
  3. Production and Quality Inspection - We have our own steel inventory and support customized production. After the deposit is paid, the factory will arrange production. We fully support third-party inspections and warmly welcome you to visit our factory.
  4. Booking and Shipment - After the goods are produced and pass quality inspection, we will work with the freight forwarder to arrange container loading, customs declaration, and obtain the bill of lading for you. We offer various trade terms such as FOB and CIF.
  5. Customs Clearance and Cargo Collection - After the goods arrive at your destination port, you can complete the formalities and collect the goods smoothly with the complete set of customs clearance documents provided by us.
  
  Key documents we provide include: commercial invoice, packing list, bill of lading, certificate of origin, quality certificate, and insurance policy (if applicable).
  
  We have long-term, reliable shipping partners and can arrange door-to-door international logistics services. We promise to provide complete quality documentation and fully cooperate with any third-party organization you designate for pre-shipment inspection (PSI).
  
  We understand that there may be concerns about importing from China for the first time. Please rest assured that we will act as your reliable partner and provide you with professional support throughout the process. We welcome you to provide your specific needs, and we will tailor the best import solution for you.

  
  
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  What are the standards for the chalking rate of color-coated steel sheets?

  The core reasons for chalking/fading of color-coated steel sheets:
  1. Raw material defects
  Substrate problems: Rust or incomplete cleaning of the steel sheet surface (residual oil/impurities) leads to poor coating adhesion, making it prone to chalking and peeling.
  Poor coating materials: Resin is not weather-resistant: Low-end polyester resin (PE) has weak UV resistance and is easily decomposed and chalked; Inferior pigments: Inorganic pigments have poor lightfastness (such as some red and yellow pigments), making them prone to fading.
  
  2. Substandard Production Process
  Insufficient Pretreatment: Incomplete degreasing, phosphating, or passivation results in weak adhesion between the substrate and coating; Uneven Coating Thickness: Too thin (≤15um) easily powders, too thick (>30um) easily cracks; Incomplete Curing: Insufficient baking temperature or time prevents sufficient resin cross-linking, reducing weather resistance.
  
  3. Environmental Corrosion: UV Radiation: Long-term exposure leads to resin decomposition (powdering) and pigment oxidation (fading). Acid/Alkali/Salt Spray Corrosion: Industrial exhaust gases and coastal salt spray corrode the coating surface. Large Temperature and Humidity Differences: Repeated thermal expansion and contraction cause coating cracking, allowing moisture to penetrate and corrode the substrate.
  
  Regular inspection of color-coated steel sheets is necessary to promptly detect and address issues such as coating peeling and corrosion, extending their service life. Regular cleaning of the color-coated steel sheet surface is also crucial to remove dust, dirt, and other contaminants, maintaining its appearance and weather resistance. At the same time, avoid using strong corrosive cleaning agents to prevent damage to the coating.

  
  

  The powdering rate not only affects the aesthetics of color-coated steel sheets but also directly impacts their service life and performance.
  
  The powdering rate of color-coated steel sheets refers to the degree to which the coating on the surface of color-coated steel sheets powders under certain conditions. Chalking refers to the phenomenon where fine powder appears on the surface of a coating, causing the coating to lose its gloss, change color, or even peel off. A higher powdering rate indicates a lower coating quality and a shorter service life.
  
  Factors affecting the chalking rate of color-coated steel sheets:
  1. Coating quality: The quality of the coating is a key factor affecting the chalking rate. High-quality coatings have better weather resistance, corrosion resistance and adhesion, and can effectively reduce chalking rate.
  2. Construction process: The construction process of color-coated steel sheets will also affect the powdering rate. A proper construction process can ensure a uniform and dense coating, thereby improving the coating's durability.
  3. Usage environment: The usage environment of color-coated steel sheets is also an important factor affecting the powdering rate. Harsh environments such as high temperature, high humidity, and strong ultraviolet radiation can accelerate the chalking process of the coating.
  
  Generally speaking, the chalking rate of high-quality color-coated steel sheets should be below a certain value, and the specific value varies depending on different products and application scenarios. When purchasing color-coated steel sheets, attention should be paid to the product's chalking rate index, and products that meet industry standards should be selected.