Magazine July 2010

All the Latest Information from the Textile World

Product

  1. Hot gas filter hose

Material

  1. Nomex fabric
  2. 125 g/m² weight - close-woven
    1. Nomex fibers
    2. 200gr/m² weight per side
    3. Fiber gauge 2,8 dtex at 51 mm fiber length

Problem

  1. Overly high loss of tear strength after needling

Problem solution

  1. Optimised needling parameters and optimised structural design of the product;
  2. use of gentle needles with HL barb

General steps when carrying out an experiment:

  1. Analysis of structure:
    - Layer structure per side
    - Fiber gauge, cross-section, length, crimp type
    - Weight, density, surface, etc.
    - base material (type, structure, weight, etc.)
  2. Choice of needle types for the experiment series (barb size, layout, form, number, gauge and form of working part, etc.)
  3. Definition of needling parameters (E/cm², penetration depth, warping, layer structure per side, etc.)
  4. Definition of test methods and test sequences (e.g. semitests after individual layer needling, number of tests according to statistics plans, type of tests, such as warping, air permeability, density, surface monitoring and evaluation, etc.)
  5. Definition of further final tests with the user

Tests carried out on needled product:

  1. Tear strength (longitudinal/transverse)
  2. Delamination
  3. Air permeability
  4. Thickness
  5. Density
  6. Dimensional stability (shape retention)

This is just one example of many options that Groz-Beckert can offer its partners.

Nonwovens – Groz-Beckert offers comprehensive service

Manufacturer

  1. Oskar Dilo Maschinenfabrik KG

Type

  1. DI-LOOM OUG-II SB 15

Stroke rate

  1. 1,375 strokes/min

Working width

  1. 1,500 mm

Needle bar stroke

  1. 60 mm

Possible gauge

  1. 2,000 needles/lfm
    1. Single/double board operation above
  2. 3,000 needles/lfm
    1. Single/quadruple board operation above/below
    2. simultaneous, alternating, tandem
  3. 5,036 needles/lfm
  4. 8,000 needles/lfm

Needleboards

  1. ALPA design
  2. (aluminium-polyamide), transverse grooved

Feed system

  1. Nonwoven feed system Type CBF

Removal system

  1. Winder Type SW 15

Dilo machine

Manufacturer

  1. Textest Instruments

Type

  1. Air permeability FX 3300
  2. for air permeability tests

Manufacturer

  1. Zwick

Type

  1. Materials testing machine 1435
  2. For testing tensile strength and stretch

Manufacturer

  1. Sartorius

Type

  1. Scales TE 212
  2. Grammage determination

A device for measuring thickness is also available.

Process-water analysis in detail

Within the Jet Strips product group, analyses or process water can help to improve the production process. In the production of spunlace products, the quality of the process water plays a crucial role: its consistency influences the service life of various machine components and also that of the jet strips.

Furthermore, the process water not only influences hygiene article production but also has a decisive effect on the quality of the end product. Hygienically perfect water thus has to be used. As part of a comprehensive lab analysis at Groz-Beckert, the process water is examined with regard to important hydrochemical parameters.

Needle tests in detail

In this sector, the finished felting needle is tested for its mechanical properties. These include bending behaviour, hardness, layer thicknesses, surface roughness, barb dimensions, SEM, photographic documentation, and much more.

These procedures are mainly used to evaluate the surfaces of the needle and the fiber material. They occur during wear analyses of needles, customer problem documentation and new developments.

Photograph of an RF barb using a scanning electron microscope (SEM):

Unused RF-barb

One of the main sources of mechanical load that occurs during the needling of nonwovens is deflection forces influencing the needle and especially the working part. In the diagram below this has been made visible. The load is produced by the material that requires needling, and is constantly subtracted. In the specifications for felting and fork needles, Groz-Beckert has stipulated the maximum deflection of the needles up to breakage. This deflection is established by means of a bending test.

Wherever new developments, further developments or the search for solutions to problems are involved, Groz-Beckert is a strong and supportive partner to its customers - backed up by years of experience, know-how and, of course, the new Technology and Development Centre.