Yunli controls rubber and plastic products from incoming material inspection to final shipment. The quality management system is certified to ISO 9001:2015. Inspection requirements are established according to product specifications, approved samples, technical drawings, and applicable testing standards.
Inspection at Three Production Stages
Materials are inspected before entering production. Depending on the material and product, checks include hardness, viscosity, cure characteristics, specific gravity, color, and material composition.
Only materials meeting the specified requirements proceed to production.
During rubber and silicone extrusion and injection molding, production parameters and product dimensions are monitored against the approved specifications.
For custom sealing profiles, cross-sectional dimensions and geometry are checked during production to identify dimensional deviations before the batch is completed.
Before shipment, finished products are checked against the agreed requirements, including dimensions, hardness, physical properties, appearance, quantity, and packaging.
Finished rubber and silicone products are inspected for defects such as cracks, bubbles, deformation, and surface irregularities. Yunli's published quality procedures include 100% visual inspection of finished products.
Physical Property Testing
Testing is selected according to the material and application. Typical tests include hardness, tensile strength, elongation, and compression set.
For EPDM products, additional testing can cover ozone resistance, UV/weathering performance, and low-temperature performance where specified.
EPDM is tested in accordance with ASTM D2240 (hardness), ASTM D412 (tensile strength and elongation), and ISO 815‑1 (compression set).
Inspection to Customer Specifications
For custom rubber and plastic components, Yunli uses the customer's technical drawings, approved samples, dimensional tolerances, material requirements, and inspection specifications as the basis for production and quality control.
This applies to custom sealing profiles, molded rubber parts, silicone components, and injection-molded plastic parts.