Introduction
The simplest and cheapest way to check for the closing status of a container, where the closure is metallic, is the inductive-digital. The sensor is then an inductive one, its output an NPN polarity, on-off signal.
The one figured on side shows an example of this basic solution, where the cap sensor is referred to a Trigger photosensor obscured by the container along its passage, before it starts to be detected by the inductive sensor.
Metal closure inspection, by mean of a proximity sensor, referred to a prior trigger
The crown cork metal closure of this bottle, is a typical application for the inductive presence inspection
Disadvantages
The system is very cheap but it presents a relevant disadvantage.
It can be detected only:
- cap presence;
- cap absence;
- metal caps (e.g., aluminium, steel or tin).
This meaning that a container capped by, i.e. a cap inclined 45º, then a container surely open, shall be considered correctly closed and passed to the Market.
The signal outcoming by these sensors is normally a quite fluctuating one: impossible to act on the signal duration, when trying to detect mal-positioned closures.
Advantages
However simple, this system has however several important advantages:
- capable to reach also the highest production speed, typically > 140000 cph;
- economy; a sensor like the one partially visible in the image (Pepperl+Fuchs®) or one of the many equivalent by different Vendors, is very cheap (< 100 $);
- is always available wherever in the World.
The Staff in this Heineken brewery at Mons-en-Baroeul (France) is aware that digital (on-off) inductive lid presence inspections do not allow to know if a can is really closed, nor if it presents micro-holes. Micro-holes are a typical problem affecting this kind of aluminium packaging. To detect and reject cans whose inner pressure is too low or too high or presenting micro-holes, it is necessary a different technology adopting analog inductive detectors (image credit L’Enquête, JDE Edition Nord-Pas-de-Calais, 2009)
An example of the sensitivity adjustment for an inductive or optic Closure Presence inspection. Measuring distance parameter has to be set coherently with the shape of what we want to detect and with the particularly geometry of the related state Closure-Detector we’ll create during the measurement. Upper limit and lower limit for measuring distance are the parameters deciding the cut-off between a Positive (defective) and a Negative (non-defective) Closure. The signal is a zero volt, logic “1” due to the NPN polarity of the digital Input gating it. In this case, a signal has been detected along 18 mm in an inspection window 54 mm wide
Links to other pages:
Inner Pressure Inspectionby UltrasoundsIntroductionIn these web pages we have frequently remarked the necessity to answer the fundamental question: …is it safe, can be sold that bottle ?thus attacking the basic problem …
LASER inspection of slanted caps   The added value to apply a LASER slanted cap inspection to a Vision cap check Links to other pages:This website has no affiliation with, endorsement, sponsorship, or support of Heuft Systemtechnik GmbH, MingJia Packaging Inspection Tech Co., Pressco Technology Inc., miho Inspektionsysteme GmbH, Krones AG, KHS GmbH, Bbull Technology, Industrial Dynamics Co., FT System srl, Cognex Co., ICS Inex Inspection Systems, Mettler-Toledo Inc., Logics & Controls srl, Symplex Vision Systems GmbH, Teledyne Dalsa Inc., Microscan Systems Inc., Andor Technology plc, Newton Research Labs Inc., Basler AG, Datalogic SpA, Sidel AG, Matrox Electronics Systems Ltd.
IntroductionThe simplest and cheapest way to check for the closing status of a container, where the closure is metallic, is the inductive-digital. The sensor is then an inductive one, its output an NPN polarity, on-off signal. …
Ultrasonic fobbing systemsWhy the ultrasonic fobbing systemsCommon disadvantages of the closure optic inspection systems: Optic, with 1, 2, or 3 CCD-camerasTamper evidence band Missing closure, inclined and high closure…
Caps' colour inspectionTo perceive the rationale for the inspection of the caps’ colour, we recommended to see the video below. It has been filmed in a PepsiCo plant and in a beverage Bottling Line where, at the time of the film our staff commissioned twelve different formats, personalized by twelve different colours for the cap. …
Dewatering systemsThe relevance of a drop of waterRefer to the figure on right side, where a green colour scanning line intercepted a water drop scanning, and measured its distance to the bottle’s plastic, greater than toward the closure top surface: a wrong distance. …
Optic Closure Presence inspection, with analog photosensorsIntroductionThe optic closure inspection, with analog photosensor, is one of the simplest inspections existing. It adopts an analog photosensor, with a projector irradiating passing closures by the top and a receiver giving out to an operational amplifier a signal whose extension, the duration counted in encoder pulses, is proportional to the reflection. …
  Broken Tamper Evident Rings, missing and inclined cap, cap too high or too low are the controls most commonly performed by mean visual cap camera systems Links to other Closure controls pages:…
  Links to other Closure controls:This website has no affiliation with, endorsement, sponsorship, or support of Heuft Systemtechnik GmbH, MingJia Packaging Inspection Tech Co., Pressco Technology Inc., miho Inspektionsysteme GmbH, Krones AG, KHS GmbH, Bbull Technology, Industrial Dynamics Co., FT System srl, Cognex Co., ICS Inex Inspection Systems, Mettler-Toledo Inc., Logics & Controls srl, Symplex Vision Systems GmbH, Teledyne Dalsa Inc., Microscan Systems Inc., Andor Technology plc, Newton Research Labs Inc., Basler AG, Datalogic SpA, Sidel AG, Matrox Electronics Systems Ltd.…
- Ultrasound bottle and cap leakage inspection
- Slanted cap, with laser
- Inductive closure & lid inspection
- Ultrasonic fobbing systems
- Cap colour inspection
- Caps inspection and water drops
- Optic closure presence inspection, with analog photo scanner
- With 1 camera
- Optic closure check with 2 cameras
- Excessive Height, with fiber optic photosensors
This website has no affiliation with, endorsement, sponsorship, or support of Heuft Systemtechnik GmbH, MingJia Packaging Inspection Tech Co., Pressco Technology Inc., miho Inspektionsysteme GmbH, Krones AG, KHS GmbH, Bbull Technology, Industrial Dynamics Co., FT System srl, Cognex Co., ICS Inex Inspection Systems, Mettler-Toledo Inc., Logics & Controls srl, Symplex Vision Systems GmbH, Teledyne Dalsa Inc., Microscan Systems Inc., Andor Technology plc, Newton Research Labs Inc., Basler AG, Datalogic SpA, Sidel AG, Matrox Electronics Systems Ltd.