GB/T 28485-2012Coated adornment -- Detection of nickel release -- Method for simulation of wear and corrosion (English PDF)

4.1 Corrosion

4.1.1 Container

Container with a lid and with a device to make the test sample to be sudpendable. All parts

shall be made of inert material (e.g. glass or plastic).

4.1.2 Corrosive medium

Dissolve 50g of DL-lactic acid (purity >85%) and 100g of sodium chloride into 1000ml of

de-ionized water.

Appendix C

(Informative)

Examples of How to Attach Different Types of Samples

C.1 General

A retaining assembly is used to mount the test samples. This is inserted into the hexagonal

drum.

Materials which have been found suitable for fixing test samples in the retaining assembly are

silicone rubber sheet, silicone rubber straps, and nylon lines of different dimensions.

C.2 Attachment of samples with only one side in contact with the skin

Samples having one surface that can come into prolonged contact with the skin, and another

surface that is less likely to come into prolonged contact with the skin, should be mounted so

that they are fixed and cannot move inside the barrel. Examples are spectacle frames and

some watch straps. The test samples should be fixed so that they are positioned with the

surface that can come into contact with the skin turned towards the rotation axis, which is the

centre of the barrel, and with the other surface turned towards the wall of the barrel. If the

samples are relatively long, for example, spectacles or watch straps, then their long axis

should, if possible, be fitted parallel to the barrel axis. Samples for wear should be positioned

between 10mm and 30mm from the barrel walls.

C.3 Spectacle frames

GB/T 14214 (ISO 12870.2004, MOD) gives details on which parts of spectacle frames should

be tested.

The assembly consists of a threaded rod which carries three metal hexagonal plates - see

Figure C.1.The end plate (A) is drilled part way through with holes of nominal diameter 1.5

mm, or as appropriate, to take the ends of the tips of the sides. The next plate (B - see Figure

C.2) is perforated with holes of nominal diameter 5mm, or as appropriate, to take the joint

ends of the sides, together with an aperture of 40 mm nominal diameter to act as a filling hole

for the abrasive mixture. A silicone rubber sheet with small holes matching the position of

those in plate (B) holds the sides firmly to prevent them from rotating in the assembly. A

second, un-perforated, silicone sheet presses the sides into plate (A). The final plate (C) is

un-drilled apart from the hole for the threaded rod. A threaded nut on the inside of the last two

plates holds them the required distance from plate A, while a second nut on the outside

clamps the assembly together. The sides should be mounted with the inside surface towards

the axis of the assembly.

Spectacle fronts should be mounted so that one of the lugs is inserted into the holes in plate

(B). It may be necessary to straighten the lug or to twist the rim immediately either side of the

Figure C.3 Examples of How to Fix Different Types of Samples in Retaining Assembly

......