- Automation meets zero defect manufacturing
- Inspection module with laser sensor and cameras
- Sensor technology ensures high quality and consistent flow of good parts
- What is Zero defect manufacturing?
”Automation” and “zero defect manufacturing” are buzz words that are increasingly gaining importance for manufacturers of TPE, silicone and elastomer products. Automation and integrated control systems using sensors are prerequisites, as the company Maplan recently demonstrated. The machinery manufacturer delivered a new manufacturing cell to a development partner in the automotive industry for precision moulded parts. Here automation meets the zero defect manufacturing approach.
Production cell with elastomer injection moulding machine
At the core of the production cell is the Maplan MTF400/250editionS elastomer injection moulding machine with two hydraulic drives featuring Cool-Drive technology with servo actuation. The machine’s components enable a high level of energy efficiency and process reliability. To ensure fully automated manufacture of precision moulded parts with metal inserts, automated separation and feed of the metal parts was required. Overall, the system for automation is consisting of four main assemblies: Feed unit for metal rings, separation and postioning unit for metal rings, pick and place unit and sprue removal unit.
Inspection module with laser sensor and cameras
The machine’s inspection module comprises of a laser sensor for sprue detection and cameras that check the moulded parts in a multi-cavity mould. For tooling and ergonomic reasons, a wider clamping unit at an optimised operating height was specified. Thus providing ample space for large multi-cavity moulds. The optimised operating height guarantees the operator improved access for inspection and maintenance as well as for changing moulds.
Fully automatic production cycle leaves no room for errors
The precision moulded part is made out of rubber, as well one or more metal rings, which are placed in the mould by means of an automatically extendable hotplate shuttle. Since the whole cycle is fully automatic, there are practically no sources of error, according to the company. Productivity is maximised by means of multi-cavity moulds.
Laser sensor for sprue detection
A laser sensor is mounted on the sprue removal unit at the front of the machine. This device moves into the clamping unit of the machine on every cycle to grasp the sprue and then remove it on the basis of the “pick and place” principle. As it moves out of the machine, the laser sensor scans the sprue plate to check whether for example a sprue has not been removed from the mould. The metal rings are fed from a vibration hopper. This hopper supplies rings sequentially. In addition, it also separates the single or multiple rings and places them in the correct position onto a separation section, so that the rings are laid out in a matrix ready for the next cycle.
Automation meets zero defect manufacturing
The shuttle with the finished precision moulded parts is then moved to the rear of the machine. High resolution cameras are mounted between the rear shuttle and the machine for QA inspection purposes. The cameras check the positioning of all parts on the shuttle as it moves into the machine. When the shuttle plate moves into the machine again, the cameras check whether the moulded parts have been correctly ejected. The parts require sensitive handling. Due to their shape, it is absolutely essential that they are ejected obliquely from above. The parts then fall onto a conveyor belt below which transports them to the finished parts container. Such concepts are a logical step towards zero defect manufacturing.
Automation – a trend in elastomer processing
“The trend towards higher levels of automation in connection with sensor technology is steadily growing. Customer-specific requirements have considerably increased in the last three years”, comments Paul-David Betea, Sales Engineer of Maplan “Due to the high degree of globalisation of elastomer processing, in particular in the automotive industry, this effect can be seen in every region of the world”
What is Zero defect manufacturing?
Zero defect manufacturing is a production strategy aiming to achieve zero defects. This means faultless manufacturing with no waste or rework, since it’s not producing quality that causes avoidable expense but the removal of faults. Avoiding defects is applied even during the development and design phases and is carried out throughout the whole process chain. In plant engineering, zero defect manufacturing is understood as manufacturing where the process is monitored by sensors and automation technologies and if needed these can intervene in the control or process sequence, right up to modifying process parameters. In an ideal case, the part defines the process and ensures the outward transfer of faulty parts. In principle, this way quality is what happens during production as opposed to QA checking after the parts have been produced (ex-post checks). The results of such a zero defect strategy are usually lower QA costs, less QA work (including documentation), reliable deliveries, less waste and high customer satisfaction.