Quality control when sourcing AAC/ALC from China is not a one-time check before shipment — it is a multi-stage process embedded in every production stage. Our company has worked with several partner factories for over 10 years and has established a standard quality control procedure.
Stage one — factory audit before contract signing. We verify ISO certificates, production capacity (number of autoclaves, cutting lines, drying chambers), testing laboratory and export history. This filters out factories with unstable quality.
Stage two — raw material and recipe control. AAC consists of sand (or fly ash), cement, lime, gypsum, aluminum powder and water. We verify that the recipe matches the declared density grade (B05/B06/B07) and strength grade (A3.5/A5.0). Recipe deviations directly affect the final block characteristics.
Stage three — production inspection. Our inspector visits the factory during production of your batch: documents the pouring process, mass cutting, autoclave loading. Autoclave temperature and pressure, curing time are verified. Every stage is photographed.
Stage four — finished product inspection before shipment. We measure geometry on a sample basis (length, width, height, flatness deviation), check for chips and cracks, weigh for density control. Upon customer request, additional compressive strength and thermal conductivity tests are conducted in an accredited laboratory.
Stage five — loading control. The inspector is present during container or truck loading, verifies correct stacking (not exceeding permissible stack height, presence of spacers), seals the container and sends the buyer a complete photo report with the seal number. This prevents batch substitution in transit.
The entire process is documented: inspection report, photos of every stage, factory certificates, test protocols. The buyer receives a complete document package before shipment and can request additional verification at any time.
