The main materials for chemical buckets are HDPE and PP. Although both are polyolefins, their rheological behaviors differ significantly: HDPE has higher melt strength but different shear thinning characteristics; PP has higher shrinkage and is more temperature sensitive. Many general purpose injection molding machines, when switching between these materials, suffer from uneven plasticizing or flow marks.

LiSong’s screw for the chemical bucket machine is not a simple “general purpose” design. Instead, it is optimized to handle both HDPE and PP:

•  The L/D ratio and compression ratio are chosen to balance the characteristics of both polymers, ensuring good plasticizing quality for most grades.
•  The screw tip incorporates a special mixing section to improve melt uniformity and reduce color streaks or flow marks.
•  The feed throat has a grooved design to increase solids conveying efficiency and prevent HDPE slippage.

In actual production, users can switch from HDPE to PP without changing the screw – only adjusting temperature and back pressure. This is highly valuable for chemical bucket plants, because when raw material prices fluctuate, they can flexibly choose HDPE or PP based on cost. Distributors can highlight this to customers: LiSong’s machine offers a wider material window, helping customers stay cost competitive when resin markets change.

Additionally, LiSong provides distributors with a reference table of recommended process parameters for common materials (different MFI HDPE, copolymer PP, etc.). When assisting a customer with first trials, distributors can quickly find a good starting point, saving substantial debugging time. This technical empowerment builds a reputation that “LiSong truly understands chemical bucket materials”, distinguishing them from competitors selling only general purpose machines.