Shenzhen Blog (page 5)

How is Shenzhen so green?

Shenzhen Adventure Day 13

Watering trucks! Saw this during a night out. They go around and spray down all the fancy greenery.

Shenzhen Maker Faire

Shenzhen Adventure Day 14

We were lucky enough to overlap our stay with the Shenzhen Maker Faire!

Panorama of  the faire

Panorama of  the faire

There were a lot of drones…

Drones! Drones everywhere

I even ran into some friends!

Lizhou Sha MIT ‘18

Deb Weinswig, my cousin!

We finished off the day at the Hackaday pizza party.

What struck me most is that we were like an hour out of the city by subway but it still looked like this:


The amount of construction in the region is insane.

Leather Factory Tour

Shenzhen Adventure Day 17

Today we visited the PrimeAsia Leather Factory.

Welcome to PrimeAsia A warm welcome.

A ‘real’ welcome.

The leather comes in to the factory pre-treated. The tannery is (typically) these days co-located with the slaughterhouse. At the tannery they chrome treat the raw leather and then put it in a shipping container to wherever it is going.

Pile of raw leather “wet blues”, waiting to be processed

Quality Inspection

The leather is then cut through the middle (ie, reducing the thickness) to a top-grain piece and a suede piece.

The suede leather is then buffed down to standardize thickness. (the top-grain needs no buffing as it is cut to the right size).

The leather dust is then captured and put into random products, like asphalt.

Leather dust

The leathers are then dyed in these big tumblers. They can do any color – they mix chemicals on site.

Oh that tumbler was just a baby, for color testing and sample runs. No. This is a tumbler:

Look at the people to get a sense of scale

The dyed leather comes off the line

Post Processing

There’s a myriad of leather post processing steps depending on the finished product.

You can turn a cow into a crocodile:

This is done by melting a plastic sheet into the leather.

You can embed thermal-color change wax:

Bright pink dyed and super soft suede:



A really cool section was the testing facilities. This ensures the quality of the finished product.

There are machines that can test the rigidity, flexibility, waterproofness, etc.

Water Purification

Leather is notorious for pollution. At PrimeAsia, they have a big and fancy water purification plant on-site.

We start our tour from the control panel

Water starts out a bit frothy (I believe it’s a bacterial processing phase)

Water is cleaner!

Clean water comes out here.


Leather is cheaper than I thought. It was maybe $100 for a whole pelt.

There’s no natural leather color. After chrome tanning, all leather is blue-gray.

Zipper Factory Tour

Shenzhen Adventure Day 19

The Zipper factory tour was courtesy of Daniel Liang. This was one of the more detailed tours; there’s a whole lot that goes into a zipper! Daniel’s factory is also super large as it is essentially end-to-end, raw materials go in such as bulk plastic and metal, and finished spools of zipper material and zips come out.

Filament Making

Filaments are used to make the plastic zipping ribs.

They start out as raw plastic pelts.

If a black color is desired, a small amount of dye pellets are added.

The pellets go into the hopper (far left) to be melted down/mixed and then extruded.

Unfortunately, I didn’t get great pictures of this part, but the filaments are pulled through, cooled, and then spooled.

Maybe this picture will help you, but I can’t really make sense of it.

Tape Weaving

Tapes are woven from some nylon/cotton thread. I’m not sure if this is made on site or not, but I think if I recall it is a separate factory.

The thread goes into weaving machines.

Weaving machine, slowed down many times.

Many arrays of weaving machines. Each machine weaves several tapes at once.

Zip Integrating

These machines knit in the filaments into a plastic zipper. This is either onto a woven tape, or standalone (both are pictured below).

Slider Making

A Zipper Slider starts out looking like this:

Raw metal.

The metal is melted down and sent to die casting molds.

Die casting machines cranking out zips.

Live die casting, metal refil pouring in the background.

They make a lot of sliders!

Die cast pieces coming out of the mold.

Then the pieces go through multiple polishing phases.

Separated pieces going into the polisher. One of ~5 polish phases.

Lastly, some assembly of the flap and the zip.

Putting together the zipper metal components by hand.

Less specialized zipper assemblies are automated.

The alignment process involves a properly shaped “needle” and a vibrating, spinning bowl.


Chord spindling machine. Back and forth makes it tidy for sale!

Chord spindling machine release.

Mannequin Factory Tour

Shenzhen Adventure Day 20

A question you dread your child asking – where do mannequins come from?

Well in today’s blog, we’ll find out!

This factory was very perspective changing. Usually, people think of China as being for knock-off or unoriginal products, but the Mannequin Factory was somewhat akin to a pop-art-at-scale Andy Warhol-esque plant. There were a lot of original ideas and very skilled hand craftsmen. The company owner/head artist was a very charismatic Chinese man, he gave us a really wonderful tour of his facility!

Check out some of the really cool pieces designed here:

A mannequin starts with a sculptor making a small mockup to play with style and form:

Then the sculptor produces a master mannequin:

Wireframe model.

Shaping the form.

From that mannequin, molds are made:

From the molds, mannequins are cast:

Casts are done using fiberglass

A particularly sad looking mold curing.

The factory operates at a pretty large scale!

A lot of casts being made!

I like this show because you can see casts being freshly opened and queued for the next phase.

After casting, the mannequins are powdercoated/painted/glossed.

After painting, blemishes are marked and repaired:

Red tape is used to mark the faults.

Optionally, cosmetics (or other finishing touches) are applied:

The Archives:

They keep copies of various parts of mannequins that they have produced in the past, in case they want to reference old work.


Water Treatment

This factory also has an on-site water treatment facility

It was not quite as involved as the one at the leather treatment facility, but this factory does do a lot of sanding and painting so they treat their waste water on-site.


There are definitely odd things to see in a mannequin factory, or if not odd, visually striking sights. Here are a few images, left without comment:


I got a really fantastic parting gift at this factory… an arm!

This will be fun to take through customs…

I’d love to do a project with it like turn it into a handy desk lamp. It’s made of a very nice quality wood.

© 2011-2021 Jeremy Rubin. All rights reserved.