### Author Topic: 9 dot heel codes on glas bottles  (Read 1210 times)

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#### cloidnerux

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##### 9 dot heel codes on glas bottles
« on: October 13, 2019, 07:53:42 pm »
Hi everyone,

If you look at the heel of a glass bottle you will find different casting marks defining the bottle shape, production date and a "dot code" defining the casting number(Regulated by DIN 6121 for example). For the dot code, there are different codings(9 dots, 8 dots, 10 dots, 6 dots mini code). They encode the mold number, which is oftentimes printed in plain text alongside. But there is no information on how the dot code encodes the number. There is the patent for the code reader itself(EP0256804B1) which gives some clues. There are two start and end dots, there are always 9 positions in between, for which 5 are always set. There is a maximum of two consecutive not set positions. This gives around 71 different possibilities(might be wrong, drunk back of the envelope calculation).
I am looking for the encoding scheme or the knowledge, that there is none and it is just a look-up table.

#### amyk

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##### Re: 9 dot heel codes on glas bottles
« Reply #1 on: October 14, 2019, 02:04:38 am »

#### Monkeh

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##### Re: 9 dot heel codes on glas bottles
« Reply #2 on: October 14, 2019, 02:26:58 am »

#### IanB

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##### Re: 9 dot heel codes on glas bottles
« Reply #3 on: October 14, 2019, 02:28:17 am »

They don't photograph well. But pick up a random glass bottle (wine, beer, mixer, ...) and feel around the side with your thumb at the bottom of the bottle. You will observe (feel) a sequence of raised dots in a line with variable spacing between them. These are them.
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#### Rick Law

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##### Re: 9 dot heel codes on glas bottles
« Reply #4 on: October 14, 2019, 03:07:18 am »

They don't photograph well. But pick up a random glass bottle (wine, beer, mixer, ...) and feel around the side with your thumb at the bottom of the bottle. You will observe (feel) a sequence of raised dots in a line with variable spacing between them. These are them.

Holy cow!  Learned something new - Things around us that we don't notice...  Now I am very curious...

I just picked up a Snapple Ice Tea bottle, a Syrup bottle, a soy source bottle, and a worcestershire source bottle.  They all have it. The code is however absent from the Tabasco Source bottle, a made-in-Taiwan Hot Pepper Oil bottle, and a (square bottom and side) A1 Steak Source bottle.

#### Red Squirrel

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##### Re: 9 dot heel codes on glas bottles
« Reply #5 on: October 14, 2019, 03:27:53 am »
Never gave those much thought but cool to know what purpose they serve.  I wonder if this can also help in the recycling process, maybe the sorting machines can use them at some point.  Then again I think by the time bottles make it there they are mostly broken from being dropped in the recycling truck.

#### Halcyon

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##### Re: 9 dot heel codes on glas bottles
« Reply #6 on: October 14, 2019, 04:21:00 am »
These marks are used to identify the mould from which the bottle was produced from at the factory. Bottles are tested for defects using an automated system and this system can recognise these dots and in the case of a problem, the particular mould from which the defective bottles were produced can be identified. It's like a batch code. The number of dots and spacing between the dots are decoded into some form (I'm not exactly sure if there is a specific encoding standard). They are generally used on glass bottles and jars.

#### babysitter

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##### Re: 9 dot heel codes on glas bottles
« Reply #7 on: October 14, 2019, 05:29:58 am »
These marks are used to identify the mould from which the bottle was produced from at the factory.

Not exactly related, but sometimes you find tiny numbers embossed on injection molded plastic parts, they also tell you which mold they are from. Often the tools for the molding machine have several cavities (often 2^n for good symmetry), the number can give a clue about how many parts each injection cycle yields.

Also, there are small bottles in at least in germany used for alcoholic drinks with numbers embossed on the bottom, these can be used for games like "Who has the highest No."
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#### cloidnerux

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##### Re: 9 dot heel codes on glas bottles
« Reply #8 on: October 14, 2019, 05:44:16 am »
Quote
Also, there are small bottles in at least in germany used for alcoholic drinks with numbers embossed on the bottom, these can be used for games like "Who has the highest No."
As stated in my initial post, these numbers are defined by the DIN 6121 and related standards.

However, I still don't know how these dots encode the numbers.

#### soldar

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##### Re: 9 dot heel codes on glas bottles
« Reply #9 on: October 14, 2019, 01:49:51 pm »
However, I still don't know how these dots encode the numbers.

While there might be some standard interpretation I do not think it is strictly necessary. Suppose in my company we just agree to use "1" for presence of dot and "0" for absence. So we could just interpret those in binary or whatever. "1010101" could be interpreted in binary or whatever and probably we would have a lookup table to know it was mold #3.
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#### frozenfrogz

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##### Re: 9 dot heel codes on glas bottles
« Reply #10 on: October 14, 2019, 02:02:43 pm »
At least in the German Wikipedia there is a discussion about bottle markings and how to read the dot code.

So after asking the HVG-DGG (a German association for glass production), the answer seems to be: There is no standardization for the dot code. Encoding is on a per manufacturers basis.

Edit: Anyway, thanks for bringing this up.
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#### HwAoRrDk

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##### Re: 9 dot heel codes on glas bottles
« Reply #11 on: October 14, 2019, 06:24:51 pm »
Huh. TIL. I always thought that it was braille, for blind people.

#### soldar

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##### Re: 9 dot heel codes on glas bottles
« Reply #12 on: October 14, 2019, 07:56:09 pm »
Huh. TIL. I always thought that it was braille, for blind people.

It does not look anything like Braille. Besides, what would they encode? "Beer comes out other end of bottle"?
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#### cloidnerux

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##### Re: 9 dot heel codes on glas bottles
« Reply #13 on: October 15, 2019, 05:39:45 am »
Quote
So after asking the HVG-DGG (a German association for glass production), the answer seems to be: There is no standardization for the dot code. Encoding is on a per manufacturers basis.
Well, that's a bummer.
However, there seems to be some standardization by the reader machine manufacturer.
Emhart Glass says their reader can read some various "standards"(http://old.emhartglass.com/files/TNB108RevK.pdf) and there is a mention of the " 16049A. Specifications for Emhart Inex Mold Number Reader" which seems to contain some information on the codes themselves.

#### Berni

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##### Re: 9 dot heel codes on glas bottles
« Reply #14 on: October 15, 2019, 06:05:18 am »
This dot code is used for recycling.

Decoding it will just get you a meaningless number. But you will find that the same shape bottles from the same vendor and in the same geographic area will have the same dot code.

Over here and in a lot of Europe most glass bottles are so called "returnable packaging". This means that you can bring the empty bottles back to the store and in return you will get a coupon for the value of the bottles you returned. This coupon can then be used for your next purchase at the store. The vendor takes back these bottles, washes them, applies new labels and reuses them.

So this results in the problem that for a given bottle the store must know what vendor it belongs to so they can sell the bottles back to them. So to reliably identify bottles even with torn or missing labels these dot codes are used. Since doing this manually is time consuming the stores use automated packaging return machines. As you stick bottles in it the machine reads the dot code (No idea how, some laser scanners or machine vision or whatever) and decides what to do with the bottle. If its a bottle that the store can't sell back to the vendor it returns it right back out of the machine in less then a second, if it can sell it then the bottle continues inside where it gets sorted accordingly and adds it to the discount coupon it prints out at the end.

The same is done for the plastic creates that hold multiple bottles. The machine takes the crate in and determines who it belongs to (Don't know how, im guessing there is a dot code on those too that i have not noticed yet). You can even put in a crate with bottles it it and it will read all of them (bottom of the crate has large holes so the dots on the bottles are visible) and reject the crate back out if any bottles are not eligible for return, otherwise it takes the whole crate in and sorts it.

Quite a neat system if you ask me.

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#### Halcyon

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##### Re: 9 dot heel codes on glas bottles
« Reply #15 on: October 16, 2019, 09:50:38 pm »
This dot code is used for recycling.

You'll find the "dot code" being discussed here refers to the small raised dots which are formed as part of the bottle moulding process. It's used to trace defects back to a particular mould at the bottle plant and the codes/patterns seem to be manufacturer specific.

Many recycling plants still employ a manual sorting process but some have moved to automated systems. Older systems read the bar codes on the bottles/cans to determine which product it is and could determine the packaging that way (the same way a store can determine the differences between different sized products, i.e.: A 375mL aluminium can vs. a 600mL PET bottle). This is how public container deposit systems work in Australia (they reject any can/bottle where the bar code cannot be read or recognised).

Newer systems use optical sensors to identify different materials. This is far more effective as it no longer relies on the package to be in good condition, have a readable bar code and the optical system can recognise materials regardless of physical orientation (they just whizz by on a conveyor belt). These optical systems can recognise the difference between glass, metal packaging (i.e.: Aluminium and Iron), plastics (Polyethylene terephthalate and High-density polyethylene) and other materials like liquid paperboard. Veolia's SALTO system can recognise and sort 14 different types of packaging using optical sensors and machine learning.

Some systems like the ones designed by German company Secopta use lasers and other sensors to determine the elemental composition of materials and sort that way.

#### cloidnerux

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##### Re: 9 dot heel codes on glas bottles
« Reply #16 on: October 21, 2019, 06:45:24 am »
Quote
Emhart Glass says their reader can read some various "standards"(http://old.emhartglass.com/files/TNB108RevK.pdf) and there is a mention of the " 16049A. Specifications for Emhart Inex Mold Number Reader" which seems to contain some information on the codes themselves.
Well, I had the chance to look at the 16049A and got some more information on the codes themselves. They are more or less lookup tables with not to much math behind them. They just encode the form number in a machine readable form. I could not find any information on the inception of the codes, but better than nothing.

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