Controller retrofit on SIG Blowtec Machine BLOWTEC SB 8

Controller retrofit on SIG Blowtec Machine BLOWTEC SB 8
with sequential coextrusion, radial gap adjustment and suction blow moulding.

Situation

The operation of the SIG Blowtec SB8 installation was vulnerable to faults and very slow. The available PLC program of the hydraulic and pneumatic slider could no longer be modified. Adjustments to required sequences were implemented in a complex manner by manual re-wiring at the valve plugs or through small additional controllers.

The PLC was a mixture of Beckhoff and Siemens components. Missing support from machine manufacturer, according to the customer.

Requirement

For the customer, it was important to have a contact and service partner that deals in detail with the operation of these machines for this complex coextrusion installation. The mix of Siemens, Beckhoff and further small controllers is to be eliminated in order to relieve the maintenance department. The customer already knew our clear visualisation pages and in particular the flexibility of our slider controller thanks to prior controller retrofits, e.g. on Battenfeld BFB8 machines.

Implementation

The electrical cabinets with components were kept, only all Siemens PLC components and the complex Profibus have been completely replaced by an EtherCAT bus. All PLC components are now standard parts from the Beckhoff company, significantly reducing the cost and time required for replacement parts acquisition.

IAn IPC was used in the main cabinet in order to deal with all control and visualization tasks. The communication with the decentralised I/O node occurs via the fast EtherCAT-bus. The 8 existing decentralised I/O nodes were reduced to 6. The terminals were kept for all I/O's equipped with Beckhoff terminals, only the bus coupler was replaced. The complex operating unit placed next to the machine was replaced by a 12 inch touch-panel on a carrying arm.

The available hydraulic/pneumatic sliders were re-wired. The freely configurable slider control designed by KAtech now allows the easy attribution of various functions to individual, freely selectable valves directly via the monitor. End-position-queries for the slider and locking are no longer an issue.

The installer easily manages the visualization with intentionally simple design. Form changes with slider attributions can now be done in the shortest times. The existing Willi Müller reservoir head with WDS gap adjustment and centre-adjustable RWDS nozzle was completely incorporated into the controller. Control of the Moog valves occurs directly via the Beckhoff control. Integration of the suction blow moulding installation with suction blow moulding curve via throttle valve position.

Commissioning

Here too, commissioning took place in collaboration with machine installers and the maintenance department. For the maintenance department, it was important to be able to deal in detail with the new hardware components. The interface for the handshake with the Reis robot, which is responsible for the retrieval of the blow-moulded articles, was also defined together.

Adjustments to the operability were directly adapted according to the desires of the installers. After retrofitting and commissioning in only 8 days, the machine could immediately be transferred back to the production department.