Working Report No. 24 2007 – EDIPTEX - Environmental assessment of textiles

EDIPTEX - Environmental assessment of textiles

Annex 10: Data for buttons and zippers

Buttons

Buttons can be divided into three main groups:

Plastic
Metal
Natural materials

Plastic buttons are probably the most common, in the form of nylon buttons and polyester buttons.

They may be mass coloured where plastic granulates containing pigments are cast, or uncoloured/white buttons may be coloured in an aqueous dye bath.

Other types of plastic like melamine and urea, ABS (acrylnitril/butadiene/styrol) and MABS (methylmethacrylate/acrylnitril/butadiene/styrol) are not as common.

The weight will depend on size/shape/design: 0.2 - 1.2 g (a shirt button 0.2 - 0.4 g).

Metal buttons may consist of different alloys, sometimes with surface treatment (nickel plating, chromium plating, oxidised "antique" silver/brass/gold).

Some of the metals we have observed in metal buttons are:

Zamak (zinc, approx. 93-97 per cent with a little aluminium, magnesium and possibly a little copper)
Magnesite (magnesium carbonate)
Brass (copper approx. 85 per cent, zinc approx. 15 per cent)
German silver (copper approx. 64 per cent, zinc approx. 24 per cent, nickel approx. 12 per cent).

Weight will depend on size/shape/design and material: 1-5 g (one jacket button approx. 4 g).

Buttons of natural materials: wood, coconut, corozo nut (vegetable ivory), bamboo, mother of pearl, horn, leather. These materials are normally not dyed, i.e. they are used as they are, possibly with a varnish or other surface finish. However, corozo nut is sometimes also dyed (in aqueous dye baths).

Mother of pearl is sometimes also dyed, and a metal eye may be glued on instead of drilled holes.

Zippers

Fabric tapes of polyester or cotton are used. Teeth, slider, pull tab, bottom stop and top stop may be made of metal or plastic.

Plastic teeth may be moulded or made of a coil (polyester and/or nylon).

Zippers with a plastic coil and polyester tape are the lightest type, approx. 1 g per 10 cm; 30 cm zipper weighs approx. 3 g.