Jeremy Rubin's Blog

Here you'll find an assorted mix of content from yours truly. I post about a lot of things, but primarily Bitcoin.

categories: Bitcoin, Shenzhen Journey.

Furniture Factory Tour

Shenzhen Adventure Day 23

For Day 23 we’re going to take a look at a furniture factory. This is a HUGE factory; probably the largest we saw on our trip, spanning many many hangars. Unfortunately I didn’t take too many pictures at this factory.

We start our journey in the furniture factory with some basic processing of raw materials:

The beams get cut up into little pieces and glued together.

All done!

Did I mention that it’s a large factory?


Two Kinds of Leg

Wooden Leg

Resin Leg



They make a lot of varieties of furniture!

These gorgeous wood tables are all for domestic market! Too big to ship.

Precision Casting Factory Tour

Shenzhen Adventure Day 20

The precision casting plant was really neat! They have some pretty major clients, which you might be able to guess from some of the photos (but probably best if this doesn’t show up in the search results).

This factory uses the cutting edge technologies to make über precise components.

A precision mold starts with precision materials. The materials they make use of here are void free, meaning that there are no microscopic pockets or bubbles in the material which would make it hard to machine precisely.

Pretty sure this specific piece is tungsten.

The blanks are then given a rough CNC cut, and then brought to a precision grinder where a worker uses a device to trim all edges. The device scales all of the workers movements by a large factor, and greatly magnifies the part. A bouncing rotary tool allows the worker to grind away slowly.

The next step is an ablation process which uses a super high current arc to blast off material bit by bit and polish the mold and give it a mirror finish (if I recall correctly).

The polished mold pieces are very pretty!

The finished pieces are then assembled into a mold housing.

The parts are made by injection molding a metal powder into the mold. These are very delicately held together, you could easily snap them with your bare hands.

They are then forged at high heat, which bonds the metal, making it very strong.

Hmm… where have I seen this part in the wild ;)

Overall, this is a process you could hope-to-afford one day when either prices come down, your company is doing really well, or you are operating in a niche that requires it. Despite being somewhat inaccessible, it was really cool to get to see how it all comes together!

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.

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.

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.

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