MIRALLOY® For the Clothing Industry

Copper-tin-(zinc) electrolytes as nickel-free alternatives

Since 1981, MIRALLOY® has been a good alternative for nickelfree coatings in the clothing industry. Today, our customers all over the world profit from more than 30 years of experience and the continuous further development of the product series.

With MIRALLOY®, electrolytes are used to deposit copper-tin(-zinc) coatings in rack and barrel plating. The colour of the coatings is white – similar to silver.

Plated garment accessories, such as zips and metal buttons, offer a very high level of resistance to everyday wear.

A further plating layer with gold, rhodium, palladium or other precious metals, as well as tarnish protection if required, can be added problem-free by choosing a suitable process and with the right pre-treatment.

Electrolyte characteristics

Electrolyte type

Alkaline-cyanide

Metal content

8.5 g/l Cu
34.0 g/l Sn
0.75 g/l Zn

pH value

> 13

Operating temperature

60 °C

Current density range

0.5 (0.3 - 1.0) A/dm²

Plating speed

Approx. 0.12 μm/ min at 0.5 A/dm²

Anode material

MMO (type PLATINODE® 167, graphite)

Coating characteristics

Coating

Copper-tin-zinc

Alloy composition

55 wt. % Cu
30 wt. % Sn
15 wt. % Zn

Colour of deposit

White

Brightness

Bright

Hardness

550 HV

Max. coating thickness

5 μm

Density of the coating

8.2 g/cm³

Advantages

  • Copper-tin-(zinc) alloy coatings
  • Bright white coatings (similar to silver)
  • Diamagnetic
  • Nickel-free (§27 of REACH, Ann. XVII, Reg. (EC) No 1907/2006, Standard 100 by OEKO-Tex®)
  • Free from heavy metals like Cr, Pb, Co, Th etc.
  • Resistant to tarnishing and corrosion
  • Excellent layer thickness distribution
  • Wide operating range
  • Can be lacquered
  • Can be combined with precious metals
  • The coatings are RoHS compliant
  • Tried and tested process by many zip manufacturers

Applications

  • Zip parts
  • Metal buttons
  • Bra fasteners
  • Buckles
  • Haberdashery

MIRALLOY® Copper-Tin-(Zinc) Electrolytes for the Clothing Industry:

  • MIRALLOY® 2841 (white) for rack and barrel operation
  • MIRALLOY® 2844/LC/E (white) for barrel and rack operation
  • MIRALLOY® 2850 (white) for rack and barrel operation


European Nickel Regulation
In Europe 15 to 20 per cent of all women and about five percent of all men are allergic to nickel. For this reason, legislators issued the 7th change to the Consumer Goods Act; the European Nickel Act (§27, Ann. XVII, Reg. (EC) No 1907/2006): Earrings and comparable objects remaining in a wound during the healing process may not contain more than 0.5 % by weight of nickel.

Objects intended to come into direct and prolonged contact with the skin (e. g. earrings, necklaces, rings, watches, buttons etc.) were not permitted if the part of the product that would come into prolonged contact with the skin released more than 0.5 µg/cm²/week of nickel.

When using nickel-free plating, it must be guaranteed that the part of the product that will be in direct and prolonged contact with the skin does not release more than 0.5 µg/cm²/week of nickel in two years under normal circumstances.


Definition of Prolonged Skin Contact (ECHA Q&A no935)
The ECHA (European Chemical Agency) developed a scientifically supported interpretation of 'prolonged skin contact': Prolonged contact with the skin is defined as potential content between the skin and items containing nickel for more than

  • 10 minutes for three or more occasions within two weeks, or
  • 30 minutes for one or more occasions within two weeks.


Apart from clothing accessories, this regulation affects a number of consumer goods such as costume jewellery, craft tools, writing utensils, spectacle frames, work tools, kitchen appliances and electronic devices.

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Questions about the product?

Markus Legeler

+49 7171 607 204

For inquiries and additional information
please contact

Umicore AG & Co. KG
Rodenbacher Chaussee 4
63457 Hanau-Wolfgang
Germany

Tel.: +49 (6181) 59 6005
Fax: +49 (6181) 59 2970
Email: chemistry@umicore.com
Website: www.chemistry.umicore.com

The information and statements contained herein are provided free of charge. They are believed to be accurate at the time of publication, but Umicore makes no warranty with respect thereto, including but not limited to any results to be obtained or the infringement of any proprietary rights. Use or application of such information or statements is at the user´s sole discretion, without any liability on the part of Umicore. Nothing herein shall be construed as a license or recommendation for use, which infringes upon any proprietary rights. All sales are subject to Umicore´s General Conditions of Sale and Delivery.