How to provide intelligent cleanroom solutions

Cleanroom design and manufacture specialists, Connect 2 Cleanrooms (C2C), talks about its experiences with high-tech plastic parts and components manufacturer, Promolding, to provide an intelligent cleanroom solution.

C2C were approached by Promolding to provide an intelligent cleanroom solution in order to protect a medical device manufacturing contract that runs until 2032.

The overall objective was to provide particulate protection throughout the whole process from product mould tool face to assembly and packaging to ISO class 7 14644-1:2015, whilst accommodating tool changes to the machines x two (with the ability to increase to four, to facilitate future contract growth and project profitability) in a continuous protected environment. Thus, Promolding required environmental particulate protection to the injection moulding machines.

C2C developed a reliable and intelligent cleanroom solution which connects with Promolding’s Engel machines and robots through Industry 4.0 design. design features have been optimised to ensure cleanroom performance is maintained for years to come.

The facts

• ISO 14644-1:2015 class 7
• Overall footprint: 279.42m² (19.27m x 14.5m x 2.825m). Internal clearance of 2.5m
• Internal change area: 13.86m² (6.860m x 2.02m)
• 99no. air changes per hour at an air speed of 0.45m/s in the main area
• Light emitting diode (LED) lighting
• Variable speed controlled HEPA ceiling fan filters delivering decentralised air handling
• Roller door for goods in/out
• ECO control system with automated HEPA-lite canopies
• Pendant stations control each automated HEPA-lite on the injection moulding machines. Each have manual overrides for safety reasons
• Proximity switches to the side of the HEPA-lite have LED lights to give a visual indication when the canopies are in situ. The canopies also feature a safety mechanism which deactivates actuators if the canopy is obstructed

The process

1. One shot injection moulding machine (80 tonne) produces one plastics component
2. Two shot injection moulding machine (300 tonne) produces the second component, made up of two plastics (injected, rotated then injected again)
3. Robots pick up moulded parts, drop them onto the motorised conveyor and transport them into the main environment
4. The two parts are then assembled and welded, then they progress to packaging

The solution

Each moulding machine has two High Efficiency Particulate Air (HEPA) filtered, overhead canopies; one fixed and one actuated. They are driven by a linear actuator that is operated by programmable logic controller controls to drive the filter system to an open or closed position.

HEPA-lite claims to be economical, adaptable and efficient. It attempts to effectively maintain the quality of air at points where the product is exposed, and thus negates the need for the entire production line to be fully enclosed within a cleanroom.

The canopies feature effective safety mechanisms and are able to send infra-red signals across the actuators. If the signals are interrupted, for instance by the robot or by an operative’s hands, the canopy will deactivate movement, preventing any accidents.

Industry 4.0

Industry 4.0 is the fourth industrial revolution - the digital transformation. In this example, C2C applied Industry 4.0 techniques and designed a cleanroom with automated canopies to work in cooperation with Promolding’s robotics. The robotics aim to reduce the risk of human error and improve the quality and consistency of the end product.

The cleanroom also features an intelligent digital system, in the form of C2C’s ECO control system. The system is designed to ensure that the cleanroom operates at optimum effectiveness by constantly monitoring the operating conditions in real time within the critical environment and raising alarms if any of these parameters vary beyond a user specified threshold.

All relevant control parameters for each three zones are graphically displayed on a human machine interface allowing users full control and the ability to run diagnostics and locate faults. All system performance data is logged and is downloadable, for audit purposes and traceability.

The intelligent moulding machine is able to recognise faults with a product and drop the affected products into stainless steel drop drawers for inspection. The personnel door is interlocked with the moulding machine during manufacture. The sample drawers are accessible from outside the HEPA-lite, meaning the faulty parts or samples can be safely removed without interrupting manufacture.

There are plans to have all of the processes within the main cleanroom area fully automated in the future.

Challenges and successes

The main cleanroom area was installed under a mezzanine, so the ceiling was suspended from the walkway above. This secured the roof and ensured an open plan layout. 

There was an effective collaboration with injection moulding machine manufacturer Engel allowing C2C to integrate HEPA-lite with injection moulding machines so floor supports weren’t necessary.

HEPA-lite is a registered trade mark of Connect2Cleanrooms.