Mold inserts compatible with KHS blow molding machines

The difference in thermal expansion between the aluminum mold shell and the steel insert causes micro-gaps at the joint interface, triggering micro-leaks of high-pressure cooling water that directly contaminate the bottle neck thread area and lead to subsequent filling and capping failure.

The core of eliminating leakage lies in the elastic compensation for thermodynamic deformation at the bi-metal interface. The coefficient of linear thermal expansion of aluminum (approx. 23×10⁻⁶/℃) is about twice that of the steel neck insert (approx. 11×10⁻⁶/℃). Under a mold temperature step of nearly 100℃, a significant axial relative displacement inevitably occurs at the joint. We designed a specific elastic compensation cavity within the insert seal groove and matched it with a high-temperature FKM O-ring, precisely setting its pre-compression ratio between 20%-25%. This parameter matching allows the rubber body to absorb micron-level axial slip while still maintaining a sealing contact pressure far above the leakage threshold under 5-8bar cooling water pressure, physically locking the water molecule penetration path to the neck thread area from the root.

Can be directly used as mold shell spare parts for blow molding and filling lines of brands such as KHS, Sidel, and Tetra Pak.

For pipeline interface protection, the cooling water inlet and outlet on the mold shell body abandon direct tapping in favor of an embedded copper transition threaded insert structure. This completely circumvents thread galling or wear caused by the insufficient hardness of the aluminum alloy substrate, guaranteeing absolute sealing reliability after high-frequency disassembly and assembly of water pipelines in the workshop. If you want to learn more about this product, please feel free to contact us for more information.

Sidel®,Tetra Pak®, Krones®, and KHS® are registered trademarks of their respective owners. Jihengfeng Precision Machinery (Shanghai) Co., Ltd. is an independent manufacturer and is not affiliated with, authorized, or endorsed by these companies.