We start here a section of particular relevance for the safety of the Food and Beverages: the inspection of returnable and non-returnable glass empty bottles.  Field where Graphene staff has 24 years of direct experience.  Tens of Linear and Rotary Inspectors, some of them operating in extremal cases of production speed, overall price, layout complexity and amount of inspections.

Links to the pages:


Rotary EBI

EBIs: a historical briefer

  A rotary glass Empty Bottle Inspector in a Baltika® (Carlsberg® Group) brewery packaging line in Russia (image credit Baltika®, 2014)

EBIs is the international abbreviation for the long Empty Bottle Inspectors.   Their history, however, is a brief one. They were born along with Optoelectronics' development.   In 1958 it started to operate a first model whose imaging was not CCD-based.  CCD sensors were yet to be created and looking to the year 1970, you’ll discover that US-companies were nearly monopolizing the world wide productive sector of the Machinery to fabricate glass bottles.  Where were glass bottles production Lines, there it was a vital and welcome add-on the presence of an automated Quality Control.  There is an additional reason why the EBIs were initially developed in the USA.   Related to the fact that the original CCD-cameras (Charged Coupled Device), Optoelectronics' components were born classified as military top secret in end of the ‘60s.   CCDs were originally developed to replace the analog camera systems orbiting the Earth, aboard of the military espionage satellites.  They were born to count and precisely determine the location of ballistic missiles silos.    

The human alternative to the automated quality control

An Accountant point of view

“...one Operator is fully and truly capable to visually control the Quality of < 8000 bottles-per-hour”

The human brain still crushes any modern machines when it comes to tasks like vision or voice recognition. What's more, it manages to do so with less energy than it takes to power a light bulb. The alternative to the automated Quality Control, is the unavoidable massive presence of human Operators.  To have an idea of what presence, imagine that one Operator is fully and truly capable to visually control the Quality of only ~8000 bottles-per-hour (bph). Then, a modern Beverage Bottling Line, whose production speed is typically over 50000 bph, should require (50000/8000) Operator, say over 6 Operators.  But, considering that 6 Operators cannot stay in a shift 24 hours long, their amount result over three times bigger.  Over three times bigger because if the Food and Beverage packaging Line has three shifts in the twenty four hours, they’ll be however necessary  additional Operators as a reserve front of the possible unavailablity of those in the shift due to sicknesses, permits, accidents, etc.    

Because of this reason, the human inspection of the full and empty glass and PET bottles, cannot be accomplished economically wherever in the World.  India is one of the exceptions, where it is still common to see the human Quality Control of glass bottles. The employee, is frequently hired the same day of the activities.  In India whatever Bottler has, on practice, nearly 1 billion of reasons to choose human Quality Control inspection to Machine Vision EBIs: as many as the inhabitants of the country.  The total duration of the Operator’s activities is commonly limited to only one day.  In the figure below, one of these temporary Operators watches over the bottles passing front of a luminous white panel in a bottling line at Aurangabad Brewery.    In the following, they’ll be two briefly introduced two specific real cases where a single glass Empty Bottle Inspector (EBI) had been introduced in pre-existing Food and Beverage Bottling Lines.  Being real cases rather than estimations, they have to be considered a quantitative and precise hint to the human-alternative represented by a single EBI.  

Europe 1996: 1 EBI > minus 27 Operators @58000 bph

A well-known brewery, owning brands sold in nearly all of the countries, partner of one of the third greatest group of breweries the world. Cost-reduction reasons let a single EBI be introduced in a glass returnable bottling line whose Filler Machine runs at 58000 bottles-per-hours.  We witnessed that twenty-seven staff (27), all of them Operators on white luminous panels (see figure below) were replaced by that single EBI. 

America 1998: 1 EBI > minus 12 Operators @27000 bph

Another well known Brewery, owning a brand whose sale rank first in a single country (over 50 %), also partner of the greatest group of breweries the world. Cost-reduction reasons let a single EBI be introduced in a glass returnable bottling line whose Filler Machine runs at 27000 bottles-per-hours.  We witnessed that twelve staff (12), all of them Operators on white luminous panels (see figure below) were replaced by that single EBI. 

Limits of the Empty Bottle Inspectors

Where, in what field of applications, EBIs are the losers when compared to a human being ?

EBIs shows great limits in presence of glass of different colours, because in few plain and synthetic words, their Optoelectronic setup cannot inspect bottles of all colours and transparencies to the illumination spectrum with the same Signal/Noise ratio.  In the figure below, on the opposite, the impressive mix of colours of the glass transparent, brown and green, is not any impedement to the human brain.   The brain is equipped by the Nature with nearly 100 billion active neurons at the age of two months, slowly reducing the amount to ~83 billions as a side negative effect of the progressive aging. The majority of these neurons also strictly devoted to the most complex function of the brain (and of the EBIs): vision.  Say, to interface and translate in ideas the electromagnetic signalling incoming by the external world.

 In India it is common the human quality control of the glass bottles. Operators frequently hired the same day of the activity and activities limited to one day only, watch the bottles passing front of a white panel in a bottling line.  The mix of colours of the glass transparent, brown and green, is not an impedement to the human brain, equipped with ~80 billion of neurons.  The most widespread point of view is that this kind of inspection should be the “Past”.  But, keeping in due consideration macroeconomic and demographic trends which can only be perceived and understood along centuries, maybe this is the “Future".  Aurangabad Brewery is one of ten breweries owned by SABMiller India (credit: One Red Eye/Philip Meech)

Human vs. EBI. Biologic evolution versus Optoelectronics.  When associated to the same false rejects ratios, the human safety network around the Food and Beverage production is thinner than the one that today’s Optoelectronics may provide

But, there is an additional problem associated with this kind of human activity: after only 15 minutes our brain becomes tired, due to the activity's repetitivedness. In the reality, the absolute Quality of the human-made inspection fall progressively to minimum values: it makes no sense at all to keep 8 consecutive hours an Operator looking bottles.  

In the reality, tests made during past decades in several countries, have shown that:

  • after 20 minutes only, the human brain starts to reduce in a sensible way its metrologic response to bottles’ defects, like (dimensional) sensitivity, repeatability or accuracy;  
  • after 2 hours they’d have to be present 2 additionals, to keep the inspection Quality constant;
  • humans are nearly unaffected by the well-known negative tendency of their digital counterparts (the EBIs) to increase their false rejects over medium- to long-periods of time;

  Biologic evolution versus Optoelectronics.  When associated to the same false rejects' ratios, the human safety network around the Food and Beverage production is thinner and much more safe than that one today’s Optoelectronics may provide 

Human-inspection can be synthesized in the basic idea of a fishing net What above means that the human-made is a kind of Quality Control which cannot assure one of the most important requirements of Metrology and Quality Control: measurements' repeatability.   By these remarks, it is easy to understand how and why, as the production speed of Beverage Bottling Lines constantly grew, it became unavoidable to replace the human-inspection (Operators) with machine-made inspection also in the Beverage Bottling Lines.  The following brief video shows how closely related, in space and time, is electronic inspection to glass bottle fabrication.

Inspections’ nomenclature

The Empty Bottle Inspectors (EBIs) are Electronic Inspectors which, following the complexity of their configuration in terms of amount and kind of inspections, may arrive to include ~120 CPUs (an example, the Heuft® InLine™ model visible below).  CPUs' functions are specialized to fulfill different scopes.  Scopes related to the different parts of a glass (or, PRB) bottle.  Inspection is the name for each one physical measurement system, whose detectors and algorithms are specialized for the kind of defect to be detected and for the area of the container where it has to be detected.  Purpose of each inspection purpose is the Binary Classification.  Assembles of inspections build-up an Electronic Inspector.   The name of each one optic (CMOS- or CCD-camera) inspection reflects the area of the bottle where it acts. Then, to fully understand the name of each Electronic Inspection, it is necessary to start by the knowledge of the international bottles’ nomenclature.  

The figure below illustrates such a nomenclature:  

  To fully understand the name of each Electronic Inspection, it is necessary to strat by the knowledge of the international bottles’ nomenclature. The name of each optic (CMOS- or CCD-camera) inspection reflects the area of the bottle (image courteousy and credit Owens Illinois, Inc., 2014)

What follows has a validity extended to PRB (PET-Returnable Bottle) empty bottles, containers nearly only diffused in Central Europe (Germany, Austria, Slovakia, Czech Republic, and Poland).   Inspections for the newly introduced Empty Bottle Inspectors are constantly being developed by Vendors.  Those today fully established are (at least):

  1. Spots and other visible defects, on all of the external surface of glass and PET Returnable (PRB) bottles;
  2. Presence of foreign opaque objects in the base of glass (and, PRB) bottles;
  3. Presence of foreign semitransparent objects in the base of glass bottles;
  4. Presence of water-based liquids, into glass (and, PRB) bottles;
  5. Presence of mineral oils or paint into glass (and, PRB) bottles;
  6. Presence of logo on the external sidewall;
  7. Broken thread of returnable or non-returnable glass bottles;
  8. Broken crown-cork finish of returnable and non-returnable glass bottles;
  9. Opaque bodies over external and inner sidewall of returnable and non-returnable glass bottles;
  10. Too-thin or too-thick infeeding bottles;
  11. Closed infeeding bottles (metal or plastic caps);
  12. Non-correctly positioned clip-locks;
  13. Glass colour;
  14. Fallen infeeding bottles;
  15. Inclined infeeding bottles;
  16. Mineral ring in the neck area of glass returnable bottles;
  17. High scuffing of the external sidewalls of PRB and glass returnable bottles;
  18. Bottle dimensionally different than the one sorted and being produced;
  19. Contamination, i.e. by hydrocarbons, of returnable glass bottle (and, PRB), by mean of Rotary EBIs;
  20. Falsely triggered bottles: containers who lost their identity during transfer along conveyors and machines.
Heuft® InLine™ glass empty bottle-inspector

  A linear Empty Bottle Inspector assuring quality and safety of PepsiCo® beverages, in an image we shot during its commissioning phase

Empty Bottle Inspectors take care of our Environment

EBIs’ complexity pays back on the green side: a plus offered by the returnable glass bottles for which these Inspectors are thinked, lies in the nearly zero waste they represent.  Containers re-washed several tens of times, many of them lived decades, on the opposite of PET bottles and Aluminium cans.   The video below shows some data referred to the US about the amount of alternative PET bottle used to package water during 2009.  The situation today is getting worse.  Clicking the banner below, links the Australian Government Authority for recycling, offering plenty of materials and informations.

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