Injection end position deviation in a China injection moulding machine can lead to defects, wasted materials, and reduced production efficiency. This issue occurs when the machine fails to stop at the correct position after injecting plastic into the mould. Common causes include incorrect injection speed, insufficient pressure, poor lubrication, and calibration errors.
In this guide, we’ll discuss why this problem happens and how to fix it using precise adjustments, proper maintenance, and optimization techniques.
Common Causes of Injection End Position Deviation
Several factors contribute to injection end position errors in China injection moulding machines. Below are the key reasons and their potential impact on production:
1. Incorrect Injection Speed
- Too fast: Causes excessive momentum, making it difficult for the machine to stop at the correct position.
- Too slow: Leads to inconsistent filling, affecting final product quality.
- Solution: Adjust the injection speed to match the specific moulding requirements and ensure stable operation.
2. Insufficient Injection Pressure
- Low pressure: The molten plastic fails to fill the mould completely, causing incomplete products.
- Solution: Optimize the injection pressure settings to ensure the plastic fully fills the cavity without excessive force.
3. Unreasonable Mould Structure
- Poorly designed or misaligned moulds can lead to end position errors.
- Solution: Ensure the mould design is precise, properly lubricated, and aligned to avoid inconsistencies.
4. Poor Lubrication & Excessive Friction
- High friction in the moving parts of the machine can cause incorrect stopping points.
- Solution: Regularly lubricate essential components to ensure smooth movement.
Step-by-Step Guide to Fix Injection End Position Deviation
To fix this issue, follow these essential steps:
1. Checking and Adjusting the Injection Scale
The injection scale (e-scale) plays a crucial role in maintaining precision. If it is misaligned, injection accuracy will be compromised.
How to Check the Injection Scale:
Observe whether the material storage position has shifted.
Check if the e-scale readings fluctuate unexpectedly.
If discrepancies exist, proceed with recalibration or replacement.
How to Adjust the Injection Scale:
- Access the injection moulding machine’s computer interface.
- Enter the electronic scale setting menu.
- Ensure the scale correctly reflects the machine’s real-time position.
- If misaligned, recalibrate or replace the scale for better accuracy.
2. Calibrating the Zero Position of the E-Scale
Zero position calibration ensures that the machine properly recognizes the start and end points.
Calibration Steps:
- Turn on the machine interface and open the e-scale settings.
- Set the Zero Position:
- Go to the movable mould scale section.
- Enable the ‘Function’ by setting it to ‘Use’.
- Enter the total length from the scale’s nameplate.
- Move the mould mechanism into a fully straightened position.
- Take the zero point reading and confirm by pressing ‘Input’.
- The scale should now display ‘0’, marking the new zero position.
By doing this, the China injection moulding machine will stop precisely at the intended end position.
3. Optimizing the Holding Pressure Setting
The holding pressure determines how well the plastic is injected and maintained in the mould cavity. Incorrect settings can cause position deviation.
Steps to Optimize Holding Pressure:
- Check the current setting: If the injection stops too early or overshoots, check the holding pressure.
- Make gradual adjustments: Avoid abrupt changes—modify parameters slightly and observe results over several mould cycles.
- Maintain consistency: If the end position remains stable, avoid unnecessary alterations.
Proper holding pressure prevents shrinkage and ensures uniform product dimensions.
How to Prevent Future Injection Position Deviation
While fixing existing issues is important, preventive maintenance ensures long-term stability. Here are some best practices:
1. Maintain a Stable Melt Temperature
- Unstable melt temperature affects plastic flow, causing inconsistent shot volume and position deviation.
- Solution: Use PID temperature control to maintain a stable melt temperature.
2. Inspect and Replace Injection Nozzle & Rod
- Worn-out nozzles and injection rods lead to inconsistent positioning.
- Solution: Regularly inspect these parts and replace them if worn or damaged.
3. Use High-Quality Moulds & Fittings
- Poorly designed or loose-fitting moulds contribute to injection errors.
- Solution: Use high-precision moulds and regularly lubricate moving parts.
4. Maintain the Hydraulic System
- An unstable hydraulic system (oil leaks, pressure fluctuations, or clogged pipelines) disrupts accuracy.
- Solution: Change hydraulic oil regularly and clean oil pipelines to maintain pressure stability.
5. Inspect the Circuit System
- Electrical failures can cause inconsistent injection positioning.
- Solution: Check circuit connections and controllers for wear or faults and replace them when necessary.
Injection end position deviation in a China injection moulding machine can lead to product defects, waste, and production delays. However, by identifying the causes and implementing precise adjustments, manufacturers can improve accuracy and efficiency.
Key Takeaways:
Check & adjust the injection scale to prevent misalignment.
Calibrate the zero position to maintain accuracy.
Optimize holding pressure to avoid end-position variations.
Maintain melt temperature, inspect nozzles, and monitor hydraulic & circuit systems for long-term stability.
By following these best practices, you can enhance production efficiency, reduce defects, and ensure high-quality plastic moulding.
FAQ’s
Top manufacturers include Daoben Machinery, Haitian, Borch, and Yizumi.
Daoben Machinery is the leading mold maker in China.
Daoben, Yizumi, and Borch are among the most reputable brands in China.
Prices range from $5,000 to $100,000+, depending on tonnage and features.
