High-speed pinhole detection systems from EDS

Alessandro Linfante, EDS business manager

EDS (Electronic Design System s.r.l.) with headquarters in Italy was formed in 1984 and quickly became established as a supplier of inspection equipment to the steel and aluminium industries. The first EDS installation for pinhole inspection was delivered in 1994. With emphasis on process control, EDS effectively responds to industry-driven demands for continued enhancements of product quality. Flexibility and technical innovation are the company’s strengths and the means by which EDS consistently meets the specific requirements of its customers.

EDS technique incorporates the use of opto-electronics in process automation. The company’s main products are: pinhole detectors for use on steel sheet and in foil slitting lines, process lines, aluminium foil separating lines, foil containers, can inspection and other special detection devices.

What is pinhole detection equipment?

An EDS Pinhole Detector is a high-performance, opto-electronic device, based on laser or LED technology. It is specifically designed and constructed for the detection of pinholes in moving webs of steel, aluminium and other non-ferrous materials as well as webs for
packaging and a variety of converted products.

Even at high web-speeds (up to 2,000 m/min), EDS Pinhole detectors perform reliably and with high sensitivity, detecting holes down to 10 microns in size.

Some examples of the company’s pinhole detection products are:

• EDS Model CIS 7040 Can Inspection Stand:
  This model is an opto-electronic can inspection system designed for pinhole detection in coated, lacquered and painted cans. The system is of compact design and therefore, no special mounting arrangements are required. It can easily be fitted to any can making line.
• EDS Models CSM10 (LED) and CSM20 (Laser):
  These models are pinhole detectors for single foil and sheet, cutting and slitting lines, annealing lines, electrolytic tinning lines; PVC foil lines (non-transparent), aluminium foil lines and other web products.
• EDS Models CSM10D (LED) and CSM20D (Laser):
  These pinhole detectors are for use on aluminium foil separating machines, where two layers of ultra-thin foils are processed simultaneously.

Quality reporting

The real-time visualization and quality reporting generated by EDS Pinhole Detectorsis now a standard which is recognized by users in Europe and on other continents. EDS customers can offer their product with confidence and with the certainty of high quality and known porosity. Accurate software information about the position and distribution of defects is provided in real time through monitor display by Rolling Map, Cross-Web and Down-Web Trend.

Repetitive defects are reported on completely configurable alarm windows. The Cross-Web Trend constantly informs about the defect-distribution along the web from one side to the opposite one. For every defect class and for each inspection zone, the total number of defects encountered down the web is graphically displayed.

The Down-Web Trend constantly informs about the defect-distribution along the web from its leading-edge to its trailing-edge: for every defect class and for each meter position the total number of defects encountered cross web is graphically displayed. Since the main purpose of the EDS system is to supply real-time product monitoring in order to drive online corrective interventions and to certify the final product quality, the final report is designed to satisfy this purpose. As an example in the separator machines, the EDS system can work mainly in three different modes, supplying the quality report for each coil and strip:

The EDS Pinhole Detector can be integrated in all new separator machines as well as by retrofits. During the last 20 years EDS has developed several manual as well as automatic handling devices, reaching the state of the art with Kampf Schneid- und Wickeltechnik GmbH.

Why invest in a pinhole detector?

The benefits of a pinhole detector can be seen from two perspectives:

• Production-determined control of type, size and amount of pinholes. Here, an obvious application arises in the production of pharmaceutical packaging: ingress of oxygen and UV light alter the characteristics of chemical products such as tablets or pills. Essential, therefore, for the monitoring and control of the product quality, is the use of programmable and high-precision LED or laser based pinhole classes detection. Similarly, the requirements relating to the quality of food packaging, e. g. membrane for powdered milk (baby food), become more and more stringent, thus necessitating high precision foil inspection.
• Continues process improvement. Each separated material web is inspected. Amount, size and type of pinholes are analyzed respective to their origin. Why? During production, the formation of pinholes very often happens much earlier than their discovery so that upstream defects are carried through the entire production process – significantly driving up production costs. A pinhole detector permits an intensive and systematic process of evaluation and allows identification of upstream line defects, such as furnace cleaning, strip tension, inclusions such as silica particles and aluminates or salts, deficiencies in liquid metal treatment, unsuitable casting, rolling oil filtering inadequacies or mechanical damage / defects on backup or working rolls. All of these collected data is prerequisite to future process improvements. EDS identifies the main benefits of its PHD products from the following standpoints:
  • Compact size
  • Very solid construction, designed for harsh working condition
  • Easy installation and removal
  • Real-time continuous 100% inspection
  • Detection of 10 μm (5 μm as optional) holes at max. web speed (2,000 m/min.)
  • Alarm based on size and density
  • Edge mask: fully automatic edge recognition (no diaphragms or mechanical fingers)
  • Real time alert on periodic defects
  • Auto diagnostics facilities
  • Easy setting of detection parameters (size, density)
  • Inputs / outputs and Ethernet port for connection to switches PLC and computer
  • Real-time monitoring of product quality and defecttrend
  • Minimum maintenance, no calibration required
  • Generation of detailed quality reports for each product coil (reports of each mother coil, each rewind, each strip)
  • Statistical analysis of hole sizes and their percentage incidence on total production
  • Calibration unit for ISO 9000 quality certification; off-line test
  • Historical database for long term production evaluation
  • Perfect integration within aluminium foil separators or slitting lines.

R&D for the customer

With a close eye to technological advancements and constantly evolving technical needs of the markets, EDS pursues a rigorous research and development programme, which is supported by the participation of the Physics and Chemistry departments in the Faculty of Mathematics, Physics and Natural Science at The University of Genoa. This, in combination with the competence of Kampf experts concerning the integration of continuous pinhole detection systems into separating and slitting lines ensures the provision of the most advanced instruments for pinhole detection to EDS customers.

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