Part 2

1. The Metallic material of eyeglasses and sunglasses.

1.1: cupronickel /copper-nickel/ Nickel silver.

Cupronickel or Copper-Nickel (CuNi) is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. The copper content typically varies from 60 to 90 percent, Nick silver or German silver also is a copper alloy with nickel and often zinc, So mostly we put those two materials in one name when doing the eyeglasses frames and sunglasses frames, no matter you called them cupronickel or cooer-nickel or Nickel silver. (the definition reference Wikipedia,).

In copper alloy family, Cupronickel is better resistant to corrosion, easy to change the shape, re-making and solider, meantime, the material price is lower, So It was extensive use on eyeglasses field, especial the front frame or the metal temples, and better to adjust the in the right shape.

Easy-adjust in other words, It is kind of soft (when you use the hard strength adjust the front frames you can feel it) when doing the eyeglasses frames, normally the eyeglasses factories choose the thicker and width size doing to keep it stronger.

Meanwhile, thicker and width will cause the frames will more heave, we all know, If the frames were heave, like more than 150g weight, after wearing it on the face, there will leave a mark on your nose in basic, also when compression the nose long time, people will feel uncomfortable and a little dizzy.

How deal with this? Yes, there have many ways, if you look the glasses frames carefully you will find out. Doing this kind of glasses, Most of the factories choose one piece doing the front frames, Plenty of using on half frames eyeglasses to lost the weight, also on the frames there are bevels to lease the weight but keep them stronger.

So every designer knows when designing eyeglasses on this material, a good choice is the half-frame and do more bevels.

This material was not only using on the front frame but also the trim which to decorate the frames (on the acetate eyeglasses and sunglasses you will easy to see), small piece, cut many shapes.

Raw cupronickel also has a cold and wears re-make function, It can be many different shapes like a sheet, belt, peep, stick, line status shapes, etc.

There are many choices to choose raw material, how the factories chose them, different parts of eyeglasses will use different raw material shape. All shape fit for the OEM and ODM.

Let us show you the above shapes of raw-cupronickel to match the right parts of eyeglasses.

Sheet shape like the picture, thin and width size, but all this kind of shape has there specification, this one always be used on doing the front frames by pressure.

What pressure technic is? There are a big machine and modes, The modes always come with two parts, one is up, one is down, after installing the mold on the machine up and down, Putting the material in middle and then start the machine to press the eyeglasses parts which follow the mold shapes, Also this is one important step in doing accessories.

This picture shows what the pressure machine looks like, there still have any kind of style pressure machine, warm pressure machine, cold pressure machine, four axes, 400 tons, 500 tons and 2000 tons, even more tons, In doing the eyeglasses we chose the cold pressure machine according to the cupronickel have the re-making function.

Other small tons of machines:

This picture to show what the molds look like, two parts, one is up, one is down, All molds made of the iron material (why chose the iron as the mode material? Because the iron is harder than the copper, and also it is hard to deform) by CNC cut. Doing the mode is a very important step to cost time, you can see there so the complex and small pattern on iron like the picture, even the CNY knife is Tungsten steel but have to keep going slowly. If going faster, the knife will easy to broke, so it was not easy, Estimate time of making the mold cost around 15-20 days.

The process of making eyeglasses frames are below, this is a production circle, also the quality control is in start and end:

1. In accessories factory:

A: buy sheet material.

B: cut the in the small piece to fit the frame.

C: make a mold, pressure the rough shape.

D: cut the extra parts from frame shape.

F: polishing accessories.

2. In eyeglasses factory:

A: After receiving the accessories, quality control in the first step, if find the defect ones, return them to the accessories factory to re-make, and keep the quality is right for the order.

B: then bend the endpiece.

C: bought the existing hinges, (also most of hinges made in the same material and same tech).

D: soldering the hinges.

E: polishing.

3. In the plating supplier factory.

A: After receiving the goods from eyeglasses factory, first quality control, if find the defect ones, return them to eyeglasses factory to re-bend and re-solider or re-polish.

B: wash them to remove the oil, make the surface clean, also for easy plating.

C: confirm which way to plating, there are two normal ways for metal plating, Water plating, and vacuum plating.

D: after plating need quality control to find out whether have the defect ones, if yes, re-plating.

E: send back to eyeglasses factory

The line status shapes like the picture, this one shape was used on making the metal temples.

There are two options to make the temples, One is same as doing the front frame, so here we avoid it, just show the other one.

This picture is showing how the metal temple looks like after finishing. The process of making them are: Choose the sheet shape, cut a rough piece close to the metal temple, the head part keeps the shape, just change the end parts by wire machine.

According to the size of the temple we chose the different size raw-material, The key point is to find the right raw material and the right technic, also factories have to think to save the cost ways.

Above raw material shape are eyeglasses factories common use, there are different shape raw materials, just show you the pictures:

PS: Wrote this in the end, all descriptions of our articles are from the experiences which from the real work, Maybe some of the words are not professional, we just want to show the whole system how we made the eyeglasses and sunglasses with different materials.