Troubleshooting of wrinkling or wavy edges on the surface of the rolled mesh

The surface wrinkling and wavy edge (also known as "lotus leaf edge") phenomenon that occurs during the production or use of rolled mesh is a typical defect that affects the flatness, performance, and appearance of the product. Its roots are complex and intricate, involving multiple links such as raw materials, equipment, processes, and operations. The following is a systematic troubleshooting and resolution path.

Good sales stage: phenomenon diagnosis and preliminary positioning

Firstly, it is necessary to clarify the specific form and occurrence process of the defect:

Is it an online defect during the production process, or does it occur after a period of use?

Is it a widespread appearance on the entire mesh, or only at the edges?

Are waves regular (such as periodic fluctuations) or irregular distortions?

Excellent stage: Systematic root cause investigation and solution

Based on preliminary diagnosis, conduct in-depth investigation along the following four paths:

Path 1: Focus on raw materials and pre-processing

Checkpoint 1: Uneven mechanical properties of silk material

Problem: The yield strength, elastic modulus, or hardness of incoming metal wire (especially warp wire, also known as rolled wire) may fluctuate or be inconsistent in the length direction. The softer parts are more prone to deformation under weaving tension and subsequent stress release.

Countermeasure: Strengthen incoming material inspection, conduct multi-point mechanical testing on the same batch of silk materials to confirm uniform performance. Clarify technical specifications with suppliers.

Checkpoint 2: Poor surface condition of silk material

Problem: The surface of the silk material has thick oil stains, severe oxidation layers, or uneven coatings, which cause a sudden change in friction coefficient during embossing or weaving, resulting in local wire feeding difficulties or uneven tension.

Countermeasure: Increase the online or offline cleaning process of the wire, and confirm that the surface of the wire is clean and consistent before entering the embossing machine.

Path 2: Examining the embossing process (core link)

Checkpoint 3: Wear or improper design of embossing molds

Problem: The tooth profile of the embossing wheel is worn or broken, or the tooth pitch and depth of the upper and lower embossing wheels are not matched, resulting in uneven wave bending shape, scale, and pitch when pressed out. This is a common reason for the occurrence of regular wave defects.

Countermeasure: Stop the machine for inspection and provide attentive service or replace the embossing wheel. Confirm that the alignment of the upper and lower wheels is accurate and the gap adjustment is consistent. For new products, it is necessary to re evaluate whether the mold design (tooth profile angle, compression ratio) is suitable for the wire diameter material.

Checkpoint 4: Unstable embossing process parameters

Problem: Improper or unstable settings of the wire speed, wire feeding tension, and clamping force of the embossing machine. The tension is too low, and the silk material is prone to slipping and twisting; Excessive tension, exceeding the excellent elasticity of the material, will generate internal stress.

Countermeasure: Optimize and lock in process parameters. Use a tension controller to confirm that the wire feeding tension is constant. Check whether the roller bearings and transmission system are stable, and cancel the vibration.

Path 3: Verify the weaving and tension control system

Checkpoint 5: Uneven tension of warp threads

Problem: During warp knitting, the initial tension of each warp filament is not adjusted uniformly, or the tension of a single or local warp filament is too high or too low due to the failure of the warp feeding mechanism (such as tension pads, brakes) during the weaving process. The area with high tension tightens the mesh, while the area with low tension relaxes and wrinkles.

Countermeasure: Recalibrate the warping machine and confirm that the tension of the threads on all warp shafts is uniform. Check and maintain the warp feeding system and tension compensation device of the weaving machine.

Checkpoint 6: Tension fluctuations introduced by warp yarn (rolled yarn)

Problem: The weft fork, rapier, and other weft insertion mechanisms do not move smoothly, or the guide rails are worn, resulting in inconsistent tension when each rolled wire is introduced.

Countermeasure: Inspect the weft insertion mechanism to ensure smooth movement and accurate positioning. Check and clean all guide wire holes and guide wire wheels to prevent jamming.

Checkpoint 7: Mismatch between winding tension and weaving tension

Problem: When the mesh formed in the weaving area is pulled by the winding shaft, if the winding tension is much greater than the weaving tension, it will forcibly pull the mesh that has not yet stabilized, causing the edges or the whole to be wrinkled.

Countermeasure: Adjust the torque of the winding motor or the friction of the clutch to make the winding tension slightly greater than and smoothly follow the weaving tension, forming a gentle traction.

Path 4: Post evaluation Processing and Environmental Factors

Checkpoint 8: Improper heat treatment

Problem: If the wire mesh needs to be annealed to relieve stress, uneven annealing temperature and rapid heating/cooling rate will result in the generation of new and uneven thermal stresses, which will manifest as wave deformation after cooling.

Countermeasure: Adopt a controlled atmosphere continuous annealing furnace and strictly regulate the heat treatment curve. Confirm that the mesh is uniformly heated inside the furnace.

Troubleshooting point 9: Cutting or edge punching process issues

Problem: Using passivated blades for cutting or stamping molds with excessive clearance can cause significant plastic compression and deformation at the cutting edge, leading to stress release and inward extension, resulting in edge wrinkling.

Countermeasure: Use sharp blades or grind molds to confirm that cutting is "cutting" rather than "tearing". Optimize mold clearance and punching speed.

Checkpoint 10: Environmental humidity and stress response time

Problem: For certain materials of wire mesh, drastic changes in environmental humidity may cause slight size changes, which can be combined with internal residual stresses and induce deformation.

Countermeasure: Store and process delicate products in a constant temperature and humidity environment. For important products, stress aging treatment (natural placement or low-temperature baking) can be carried out to fully release residual stress before finishing.

Phase Three: Summary of Investigation Process and Prevention

Suggest following the troubleshooting sequence from simple to complex, from online to offline:

Immediately check: the status of the embossing wheel, the tension display of each link, and the cutting tool.

Traceability verification: Inspection report of this batch of silk materials and recent records of process parameter changes.

Systematic testing: segmented sampling (such as just after embossing, weaving, and cutting) for comparison, to identify the specific workstation where defects occur.

Establish a prevention mechanism: develop regular inspection and replacement plans for key molds, implement a point inspection system for tension systems, and strengthen batch management of raw materials.