Main considerations and processes involved in plastic injection molding:
I. Injection molding product cycle: This includes injection time and product cooling time. Effective control of these times has a profound impact on product quality.
Before injection molding production, the product molding cycle should be determined through sample testing and other methods.
II. Injection mold temperature: Different plastic granules have different crystallization temperatures and speeds, and the product's appearance, deformation, dimensions, and mold release requirements are also different;
This means that the control of the injection mold temperature varies depending on the type of plastic used and the product requirements.
III. Molten plastic injection pressure: The plastic faces significant resistance during the process of filling the mold cavity. The magnitude of the injection pressure directly determines the product's size, weight, density, and appearance!
If any of these factors are affected, the product becomes scrap. This requires the injection engineer to reasonably determine the injection pressure control based on the product's overall factors.
IV. Injection speed: The speed of injection has a significant impact on the product's appearance quality.
Injection speed is generally controlled by adjusting the amount of oil supplied to the injection cylinder per unit time.
V. Barrel temperature and melt temperature: The melt temperature can be measured at the nozzle or using the air jet method. The melt temperature plays a major role in the flow properties of the melt;
Plastics do not have a specific melting point; the so-called melting point is a temperature range in a molten state.
The control of these two temperatures is also crucial to the quality of the product.
Case Study
Challenge:
A large metal finishing company needed massive custom polypropylene gears to rotate their large plating tanks.
HUIWEN Solution:
We started with 2-inch thick polypropylene sheets. Polypropylene sheets are unaffected by most of the harsh acids used in metal plating. Using a large CNC machining center, we cut 40-inch circular blanks and internal mounting brackets according to the customer's instructions. Finally, we accelerated our gear cutting tools and designed software instructions to cut the required teeth for proper gear meshing and rotation. Results:
A brand new, genuine large gear, 40 inches in diameter, 2 inches thick, with 106 teeth, everything perfectly spaced! Bolt it onto the barrel using our machined mounting holes and it's time for plating!
