Key Parameters to Consider When Buying an Injection Molding Machine

Key Parameters to Consider When Buying an Injection Molding Machine

When acquisitions in injection molding, it's essential to understand the nuances that ensure a successful integration. The choice of an injection molding machine hinges on several critical parameters which are carefully examined to meet the specific needs of your application. This article discusses the primary factors to consider during the procurement process.

Selecting Your Application Needs

The first step in choosing an injection molding machine involves understanding your application requirements. Whether it's for producing precious or common products, the type of material you're working with, and the volume of components you aim to produce are key considerations. The application needs will guide you in determining the machine's specifications, such as the size of the injection unit and the required clamping force.

Determining the Clamping Force

The clamping force is a critical parameter in injector molding, as it ensures that the parts remain stable during the molding process. You need to consider the height, wall thickness, material, core, and projection surface to determine the necessary clamping force. Manufacturers typically offer corresponding standards for clamping force, but custom considerations are often needed for specific applications.

Evaluating Space Requirements

When selecting an injection molding machine, ensure that there is sufficient space to accommodate the mold. This involves verifying the horizontal, vertical, and closed height to match the selected clamping device. In some cases, you may need to increase the clamping mode to fit larger molds. This step is crucial in preventing mold damage and ensuring a smooth molding process.

Understanding the Injection Machine Cycle Time

The cycle time is the total time required to complete a molding cycle. This includes the filling, packing, and cooling process. Understanding the approximate cycle time helps in determining the operating specifications of your machine. Factors such as the wall thickness, ribs, flanges, and core determine the filling and packing times, while the clamping stroke and core action influence the mold opening and closing times.

Evaluating Clamping and Injection Speeds

The clamping and injection speeds are essential for achieving the desired performance of the machine. The fixed mode locking should be sufficient for your needs. If higher performance is required, consider whether a faster traverse speed is appropriate and useful. Adjusting these speeds may involve increasing the options for speeding up the pinch and choosing the right settings.

Selecting the Injection Unit

The injection unit is a vital component of the machine. It determines the machine's ability to accommodate the injected dose. The volume of the injection unit generally ranges from 10% to 80% of the total required volume. It's essential to verify that the selected unit can produce the required output, calculated in pounds per hour. If the current unit cannot meet the output, you may need to increase the length and diameter ratio and then review it again.

Evaluating Production Capacity

Injection Molding Machine Output Weight per Hour

Verify that the selected injection unit is capable of producing the required output weight in pounds per hour. If the selected unit is unable to meet the required output, you may need to increase the length and diameter ratio and then review it again. If the length-to-diameter ratio is ineffective, consider increasing the size of the injection unit and the diameter of the screw to achieve the desired results.

Extraction Rate and Re-Cycle Rate

The extraction and re-cycle rates are crucial for efficient operation. The minimum refill or re-cycle time is determined using the selected die set and pump. If the contact bar intermittent time is greater than the refill time plus 0.5 seconds, proceed to the next step. If the contact bar is intermittently combined with both refilling and spiral decompression, check the options below to recalculate the refill time.

Required Injection Rate

The required injection rate is determined based on the material, wall thickness, flow distance, and approximate mold temperature. The required injection rate is calculated using the required fill time and injection volume. If the calculated filling time is less than the desired filling time, refer to the options listed to recalculate the fill time. Continue to refer to the listed options until you achieve the desired results.

In conclusion, carefully considering these key parameters ensures that you select the right injection molding machine for your application. Understanding your needs and requirements will help you make an informed decision that meets your specific needs, leading to a successful and productive injection molding process.