& nbsp; & nbsp; & nbsp; 1、 The core function and material properties of weld sealant


  & nbsp; & nbsp; & nbsp;& zwnj; Basic performance requirements&zwnj< br />
  & nbsp; & nbsp; & nbsp; Weld sealant must have the following characteristics:< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Sealing and anti-seepage: Preventing water, air, dust, etc. from entering the interior through the body welds, improving waterproofing and NVH performance< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Durability‌: After curing, it forms an elastic body that is corrosion-resistant and wear-resistant, with a tensile strength greater than 0.8 MPa and an elongation at break greater than 120%< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Construction adaptability: High thixotropy, does not flow after coating and can maintain edges, supports manual or robot coating< br />
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  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Material composition&zwnj< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; PVC type‌: Mainly made of polyvinyl chloride resin, with low cost and mature technology, but high-temperature incineration may release hydrogen chloride< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Acrylic type‌: Environmentally friendly materials, non polluting incineration, suitable for vehicles with high environmental requirements< br />
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  & nbsp; & nbsp; & nbsp;& zwnj; 2、 Typical application scenarios and construction techniques

 
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  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Key application areas&zwnj< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; External surface weld seam‌: The top cover water channel and the folded edges of the four doors and two covers need to balance sealing and appearance flatness< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Internal structural seams: Concealed areas such as floors and front panels should focus on rust prevention and sound insulation< br />
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  & nbsp; & nbsp; & nbsp;& zwnj; Construction Technology&ZWNJ< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Hand coating‌: Relying on operator experience can easily lead to uneven adhesive layer thickness or bubble problems< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Robot glue coating‌: High precision and efficiency, suitable for large-scale production, but with strict requirements for adhesive viscosity< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Curing process‌: It needs to be synchronized with the coating drying line, with a temperature usually between 120-160 ℃ and a time of 20-30 minutes< br />


  & nbsp; & nbsp; & nbsp;& zwnj; 3、 Common quality issues and solutions

  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Adhesive layer cracking&zwnj< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Reason‌: Excessive baking temperature leads to colloidal shrinkage, insufficient construction thickness, and poor material elasticity< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Countermeasures: Optimize the drying curve, adjust the pressure of the glue gun to ensure that the thickness of the glue layer is greater than 2mm, and select high elongation rubber material< br />


  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Bubbling and bulging&zwnj< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Reason‌: Residual air inside the adhesive, oil stains or moisture on the surface of the substrate that have not been cleaned< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Countermeasures: Add pre plasticization treatment to the adhesive material, strictly clean the surface of the weld seam, and optimize the coating speed< br />


  & nbsp; & nbsp; & nbsp;& zwnj; 4、 Future Development Trends

  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Environmental Protection: Promote the replacement of PVC adhesive with acrylic adhesive to reduce environmental burden< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Intelligence‌: Combining AI visual inspection technology to achieve real-time monitoring of adhesive quality< br />
  & nbsp; & nbsp; & nbsp;& zwnj;& zwnj; Lightweight&ZWNJ;: Develop low-density adhesive materials to meet the lightweight requirements of new energy vehicles;.