Formation and Improvement of White Lines in catheter tipping

Formation and Improvement of White Lines in Tip Molding

The appearance of white lines (also known as stress whitening, stress cracks, or flow lines) in the tip forming process of a catheter is usually caused by the material being subjected to excessive stretching or stress concentrations. This phenomenon occurs most often in plastic or polymer materials, especially in high stress areas such as bends or molded tip sections. Solving this problem usually requires a combination of material, design and molding process.

The following are some of the common causes of white lines during the molding of conduit tips and the corresponding solutions:

Causes and solutions:

1. Overstretching:
– During the tip forming process, the material may be overstretched in certain areas, resulting in stress concentrations.
– Solution: Optimize the molding process to reduce the stretching of the material in this area, or increase the heating time to make the material softer and easier to mold.

2. Stress concentration:
– Poor design can lead to stress concentrations in certain areas.
– Solution: Redesign the shape of the catheter tip to disperse the stress, or change the molding process to reduce the stress concentration.

3. Improper material selection:
– The material used may not be suitable for high bending or molding itself.
– Solution: Select a material that is more suitable for high bending or molding, or adjust the material formulation to improve its flexibility.

4. Improper cooling rate:
– Excessive cooling may cause internal stresses in the material, resulting in the formation of white lines.
– Solution: Adjust the cooling rate to ensure that the material cools uniformly to minimize internal stresses.

5. Inappropriate molding temperature:
– Too low a molding temperature may lead to insufficient material flow, while high temperatures may lead to material degradation.
– Solution: Adjust the heating temperature to ensure that the material flows and molds at a suitable temperature.

6. Excessive molding speed:
– Excessive molding speed may lead to internal stresses in the material.
– Solution: Adjust the molding speed so that the material can flow and relax sufficiently during the molding process.

7. Processing equipment problems:
– Inaccurate control of the molding equipment may also lead to stress concentrations.
– Solution: Calibrate equipment to ensure accurate temperature and pressure control.

Preventive measures:

– Pre-testing : Thoroughly test the material and molding process to determine the optimum parameters prior to production.
– Monitoring and feedback: Monitor critical parameters during production and establish a feedback mechanism to make adjustments as soon as problems arise.
– Regular equipment maintenance: Ensure that the molding equipment is in good condition and is regularly maintained and calibrated.

Through precise control and optimization of the molding process, we can significantly reduce or eliminate the problem of catheter white lines during the tip molding process and ensure the quality of the final product.

Send us your ideas and we’ll get in touch with you within 24H!

Share this post!

Request A Quote