OneBoxVision Blog

Why purchase a 100% inspection system for flexible packaging?

This article highlights the main driving force behind purchasing inspection solutions, the benefits of AOI (Automated Optical Inspection) and also the return on investment for a flexible packaging production operation. 

What drives the purchase of inspection solutions?

Requirements from packaging buyers continue to change, becoming ever more demanding, seeking lower prices, better quality and just in time delivery. This is against the backdrop of ever increasing substrate costs, complex material structures, demanding graphics, stricter regulatory statutes and increasing operating costs. Suppliers to global consumer companies understand  the harsh contract penalties, where shipping sub quality products brings with it monetary losses through status downgrades ending in new business lost or even worse the cancellation of existing contracts, together with the cost of replacement and consequential damages.

Print Inspection Image

As packaging companies consolidate to achieve scale, and meet the multisite requirements for delivery, standardization becomes a necessity not a luxury. Standardization of business process quickly identifies the need of standardization of production processes. The key to achieving this is through the implementation of continuous process improvements across the organization.

So why purchase AOI - Automated Optical Inspection?
The key drivers are:

  • Stop embarrassing defects being delivered to customers.
  • Identify repeating defects as quickly as possible.
  • Improve the quality of substrates – Measure at production time and check again on incoming.
  • Reduce press waste, remove inline waste and push make ready waste to a minimum.
  • Improve yields by early intervention in the process and tools to enable improvements.
  • Support standardization across process lines and sites so as to guarantee consistency.
  • Empower CI and Lean Manufacturing requirements by providing up to the minute enterprise level statistics..

What are the benefits of AOI and the issues that flexographic printers need to solve?

The benefits that printers derive from AOI are far from unique to their industry. Nonetheless they constitute a compelling argument and are worth recapitulating in some detail. The printing process is subject to a number of faults.

The most common faults are:

  • Mis-registration - where one color impression is misaligned against others.
  • Color variations - where ink quality or operational conditions such as temperature or humidity changes the colors from those desired.
  • Defects - where physical incidents in the printing process such as ink shortage or excess at critical points, lead typically to streaks or blank patches. Intrusive dust particles are a common cause of defects.
Print Inspection Image

Prior to AOI, printers had only very weak tools available to inspect print jobs while they were in process. Strobe, rotating mirrors and video monitors can all give an image of print output. Ultimately, however, they all depend on operator attention, speed and competence. Operator attention is inconsistent even under ideal conditions. It is essentially reactive, declining once the print job has started and only rising once output quality has fallen below acceptable level and requires rectification. Attention starts to decline again once the fault has been rectified.

Human inspection is subject to a range of further disadvantages:

  • Inconsistent attention span. A problem compounded by the print industry’s traditional bias towards male workers.
  • Subjectivity of judgment as to what is acceptable.
  • Workplace distractions.
  • Insufficient sensitivity for process control.
  • Varying skill level from operator to operator.
  • Imprecision. The human eye is inevitably relatively insensitive in gauging variations.

The common issues that need to be addressed on flexographic printing presses are listed below.

 

Process                

CI            

Solutions               

Splashes                 

X

X

100% Inspection

Hazing

X

X

100% Inspection

Missing Print

 

X

100% Inspection

Dry In

X

X

100% Inspection

Scumming

 

X

Spectrophotometer

Color Variation

X

X

100% Inspection

Dirt

X

X

100% Inspection

Barcode legibility

X

X

100% Inspection

Mis-Registration  

X

X

100% Inspection

Lamination defects

X

X

100% Inspection

Color to color register

X

 

100% Inspection

Lacquer Register

X

X

Video Camera

Front to back cold seal

X

 

Video Camera

CI Register

 

X

Video Camera

Color delta

X

X

100% Inspection

Correct Plates/cylinder mounted

X

X

Proofing Software

Defective Plates/cylinder

X

X

Proofing Software


What is the solution that flexographic printers should deploy?

The table above lists the issues that need to be addressed in flexography. If an issue is to be solved the inspection solution must match the requirement. If color needs to be verified, the best tool is an offline spectrophotometer. Online versions are now being released but are expensive. Color is something that can be monitored on an audited basis. To look in high resolution at process variations such as register, lacquer or cold seal, video cameras with strobes that can zoom are essential. This technology is a must have on all high speed presses. Automated inspection is purchased so as to guarantee that no disasters are shipped. The 100% inspection solution addresses this requirement. It’s possible now to purchase complete systems that have all three technologies integrated. Bundled solutions can be attractive but there is always a compromise. With bundles you may not always get the best in breed for each category.


As the requirements have evolved, and the technologies that serve them have also changed, one key factor differentiates all the suppliers. Almost all inspection suppliers’ use similar off the shelf commercial cameras, lights, processing equipment, enclosures, drives etc. The key element is the application software. When purchasing inspection in 2016, you are purchasing a software application package. Look at the features, the planned upgrade path, the ease of use, the ability to adapt it to different products and substrates. Can the software support commercial cameras that can be purchased from local distributors? Can the software be licensed to run on one or more presses? What can I expect for the next 12 months in upgrades? Finally, can you download the software and try it out?


CapEx and the return on investment

The primary cost in the implementation of an inspection system is the cost of the equipment itself. This varies dramatically based on the type of system, its functionality and also the width and speed of the web it is to be installed on.

Let’s look at each type of system to see this spread

  1. Simple video camera for viewing register on narrow web presses typically cost $10,000 to purchase and install. For wider webs this can increase to $30,000 per side.
  2. Offline spectrophotometers cost $5,000 to $15,000 depending on features sets, but online versions can cost from $40,000 to $100,000.
  3. 100% Inspection systems vary between $35,000 to $65,000 for narrow web applications, and $65,000 to $120,000 for wide web applications.
  4. The cost from a vendor to install equipment typically is between 10%-15% of the equipment cost.
  5. When budgeting it is important to allow for shipping, making modifications to the equipment, the actual physical installation, as vendors normally only commission. This typically can be 30% of the equipment cost.
  6. Let’s look at an example: A 100% inspection system for a wide web press with a purchase price of $70,000. Allow a budget of $115,000 for project implementation to cover all costs including installation, vendor commissioning, changes to the press and shipping.

To justify a purchase it’s important to understand the return on investment. Often it is done only on waste and labour reduction. The hidden value in automation and optical inspection is the ability to use assets more productively. Operators will run equipment at higher speeds if they are confident that the quality of print is consistent. Optical inspection enables that. Typically asset throughput can be increased by 10%. Of course the key hidden value is the fact that inspection systems protect a printer’s business. Returns are not only costly but the damage to a client relationship can be detrimental and the loss of a contract fatal to a printing business. Typically printers are slow to retrofit assets with automated inspection until they have had issues. Very much like intruder alarms in our homes. Repeat purchases become the norm when it is realised that they pay back in waste reduction and asset productivity gains.


Looking at the ROI that flexographic printers should expect on waste reduction alone?

There are two examples below that are conservative. The assumption is that it is possible to reduce waste by 50% in a favourable scenario, and 25% by using a 100% inspection system by getting an early warning that defects are being produced.

Estimates ROI AND AOI    
Criterion  A B
Annual press throughout US$000 10,000 5,000
Material cost as a % of above % 60 50
Cost of material US$000 6,000 2,500
Wastage level % 12
Annual waste cost US$000 720 150
Projected waste reduction %  6% 2%
Projected annual savings US$000 360 50
Annual days worked  300 210
Average working hours per day 24 16
Annual working time hours 7,200 3,360
Press cost per hour US$ 400 250
Labour cost per hour US$ 100 50
Annual operating cost US$000 3,600 1,008
Projected increase in operating speed %  35 10
Projected annual saving US$000 1,260 100.8

Viewed in terms of the impact on printers’ profitability the case is compelling. Most printers spend about half of revenue on material. Wastage rates of 8-20% thus translate to 4-10% of revenue. With operating margins running at no more than 10% and down to 5% often enough, it can be seen that wastage can absorb the equivalent of the printer’s entire profit on a job.

In conclusion, it’s important to understand what issues are being targeted, selecting the appropriate technology, determining the appropriate budget based on the expected ROI, and then select the best vendor and product that will optimise that ROI. It’s clear that automated measurement and inspection solutions are vital to any company in the printing and converting industry if they are to remain competitive.

Our latest whitepaper gives an in-depth look into the inspection requirements of the printing industry. If you have any questions or would like more information do not hesitate to contact us.

Download Print Inspection Whitepaper > 

Topics: Plastic film inspection 100% Inspection