Wrinkle formation in a shoe sole surface

Description:

Wrinkles or skin peeling occur on the surface of the shoe sole.

Affected Foam Parts:

Affected are polyester and polyether shoe soles, soles with single and two different densities, direct attach and unit soles.

What causes it:

Wrinkles or skin peeling can be caused by incorrect mould temperature or mould venting problems. In addition, improper use of the release agent, or poor mixing of the PU system is often the problem.

• Improper mould temperature
• Venting problem
• Improper release agent application
• Improper dilution ratio (if applicable)
• Improper mixing of PU system

Solutions:

Correct application of the release agent by increasing or decreasing the spray quantity often remedies wrinkling on the surface. A general suitability release agent test and a change in the dilution ratio can also improve the quality of the shoe soles. In addition, optimization of the process parameters, mould temperature or a check of the ventilation channels are often the solution to prevent wrinkling.

• Spray less/spray more
• Check the Release Agent type and dilution ratio (if applicable)
• Optimize mould temperature
• Check vent channels
• Check PU parameters

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