Pp-h, commonly referred to as homopolypropylene, is also known as a fracture adhesive due to its excellent resistance to breakage. Pp-h is a semi-transparent, semi-crystalline thermoplastic with high strength, good insulation, low water absorption, high heat-forming temperature, low density, and high crystallinity. Modified fillers typically include glass fiber, mineral fillers, and thermoplastic rubber. The fluidity of pp-h pipe fittings varies greatly depending on their application. Generally, the flow rate of pp-h falls between ABS and PC.

1. Plastic Processing: Pure PP-H is semi-transparent ivory white and can be dyed into various colors. PP-H coloring is only applicable with color masterbatch on standard injection molding machines. Huamida machines feature independent plasticizing elements to enhance mixing effects, and powder dyeing is also available. Outdoor products typically contain UV stabilizers and carbon black for filling. The use of recycled materials should not exceed 15% to avoid reduced strength and discoloration. Special drying treatment is generally not required for PP-H fittings and PPH flanges before processing.

2. There are no special requirements for the selection of injection molding machines. As PP-H has high crystallinity, a computerized injection molding machine with high injection pressure and multi-stage control is required. The clamping force is generally set at 3800t/m², and the injection volume ranges from 20% to 85%.

3. Molding and gate design: Mold temperature ranges from 50-90°C, with higher mold temperatures used for molds with stringent size requirements. Core temperature is at least 5°C lower than the cavity temperature. Turbine diameter is 4-7mm, needle valve length is 1-1.5mm, and diameter can be as small as 0.7mm. The shorter the side door length, the better. Approximately 0.7mm in depth, which is half the wall thickness, and twice the wall thickness in width. It gradually increases with the increase in the length of the melt flow inside the mold cavity. The mold must have good exhaust performance. Exhaust holes are 0.025mm-0.038mm deep and 1.5mm thick. To avoid shrinkage marks, large circular injection gates and circular channels should be used, with the stiffener thickness being relatively small (e.g., 50-60% of the wall thickness). Products made from homopolymer PP-H should not exceed 3mm in thickness, otherwise bubbles will form (thick-walled products can only use homopolymer PP-H).

4. The melting point of PP-H is 160-175°C, the decomposition temperature is 350°C, but the temperature setting during injection molding should not exceed 275°C. The melting section temperature is 240°C.

5. To minimize internal stress and deformation, high-speed injection should be chosen; however, certain grades of PP-H and molds are not suitable (bubbles and wrinkles may appear in the outer casing). If there are light and dark stripes caused by gate diffusion on the carved surface, low-speed injection and high mold temperature should be used.

6. The melt back pressure can be set at 5bar, and the colorant back pressure can be adjusted accordingly.

7. Employ higher injection pressures (1500-1800bar) and maintain pressure (approximately 80% of the injection pressure) for injection and pressure retention. Keep the pressure at around 95% of the full stroke, and utilize a longer pressure retention duration.

8. To prevent contraction and deformation caused by post-crystallization, the product usually requires soaking in hot water for post-processing.