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MECHANICAL STABILITY

Mechanical stability is a vital property in nonwovens. It describes their resistance to tearing or breaking caused by mechanical influences. In many applications, nonwovens are subject to strains such as vibrations during processing and use or to compression. Mechanically stable nonwovens withstand these forces, being tear-resistant and having low elongation values in machine and cross machine directions. 

  • Wipes: Variants featuring reduced elongation for household and industrial cleaning support even heavy-duty applications.
  • Filtration: Mechanically stable nonwovens resist the volume flow in use as well as vibration in the filtration plant. 
  • Technical applications: Mechanically stable nonwovens are used for sheathing and other reinforcements. 

To determine a material’s mechanical stability, maximum tensile force and maximum elongation in machine and cross-machine directions are measured at varying parameters according to WSP 110.4. Mechanical stability also embraces several properties specific to the respective application:

Abrasion resistance

In car seats, in furniture, in technical applications and even in cleaning wipes nonwovens are subject to abrasion, which may weaken the nonwoven’s structure. Since the nonwoven is made up of single fibres, these fibres have to be well anchored in the fibre matrix to provide appropriate cross-directional stability. In this way, abrasion resistance is achieved. In the production of nonwovens, Sandler relies on fibres with a high resistance to breakage, thereby fulfilling these requirements.

The abrasion resistance of a nonwoven can be determined using the so-called Martindale test method or according to the DIN EN 530 standard. The materials are classified in requirement categories, depending on the number of scrub cycles as determined by testing. The more cycles endured by the nonwoven, the higher its abrasion resistance. This test can be carried out by our external partners if required. 

No fibre shedding and minimised fibre breaking

Sandler nonwovens are made of synthetic fibres that do not shed and due to their elasticity and resistance to breakage, result in the minimum of fibre debris. These media do not cause skin irritation and present no health risks—for example in the automotive industry or in construction. Sandler nonwovens thus meet the requirements of product class 1 of the Oeko-Tex® standard 100, bearing the “Confidence in Textiles” label.

In filtration, this characteristic is of paramount importance: If the fibres are brittle, fibre fragments may become detached and contaminate the source of the clean air stream. 

Bending stiffness

Materials featuring high resistance to bending demonstrate high stability even under strain. This property is particularly relevant for use in self-supporting structures intended to be installed overhead using only few fastening points. Vibrations may develop in use, transposing the component’s weight into a strain. Stiff materials do not deform under load and do not sag. They retain their residual stiffness over the long term. 

  • Automotive: Nonwovens featuring high bending stiffness are in demand for moulded parts such as headliners. 
  • Construction industry: Stiff nonwovens are applied for acoustic ceiling panels and other ceiling structures. 

At Sandler, bending stiffness is determined using the three-point-method according to DIN EN ISO 14125: A sample is deformed at a constant rate; the applied force and the deflection are measured. This test is performed in our own laboratory. 

Tread-proof

In roof construction, the raw materials are literally being walked on. Sandler nonwovens for insulation laid on the rafters or bituminous strips feature a pressure- and tread-proof upper side for safety in roof work. Even under pressure they remain firm, due to their high bending stiffness.