Medical, optical or electronic components under clean room conditions
Typical end products: Components for dialysis, medical small parts such as bottles, cups or bone screws.
Typical materials: PA, PET, PEEK, PLLA/PDLA, PC
Typical throughputs: 0.2-15 kg/h
Process description
An article is referred to as a “medical product” when it is used for medical, therapeutic or diagnostic purposes for humans. Unlike medicine, the intended primary effect is not pharmacological, metabolic or immunological but physical or physicochemical.
When manufacturing these products, contact with ambient or open air or any other non-certified material components must be avoided. Therefore, production of medical parts must take place in a so-called clean room.
Clean room design guarantees that the number of airborne particles reaching or created in the room is as low as possible. Depending on use, only the number of particles and/or the number of germs is monitored as required during the production of pharmaceutical products for example. In general, other parameters such as temperature, air humidity are kept constant in order to create comparable conditions at any time.
In principle, with regard to the air flow in clean rooms, a difference is made between a turbulent dilution flow and a low-turbulence displacement flow:
In turbulent dilution or mixed flow, the filtered clean air is whirled into the clean room and generates a continuous dilution of the particle concentration. When personnel practices meet clean room standards, the required clean room class is maintained. Please note that particular attention must be paid to the fact that particle generating objects and procedures in the clean room are minimised.
In low-turbulence displacement flow, also called "laminar flow", the clean air flows with low turbulence, and in principle, vertically into the clean room with the effect that contamination of sensitive work areas and machines is kept as low as possible. In general, the air escapes on the opposite side through the perforated double floor and is led to the air re-circulation system for repeated filtering.
Materials which are used in clean rooms must have abrasion-proof surfaces. Systems and units in the room may disturb the laminar air flow to a minimum. Parts and machines which are to be brought into the clean room must be cleaned beforehand. Normally, a clean room is charged with overpressure (overpressure ventilation). In special cases, clean rooms are operated with low pressure preventing dangerous substances or germs from reaching the outside.
Clean room classes are standardised according to EN ISO 14644-1 (until November 29, 2001: US Federal Standard 209E). For injection moulding applications – with reference to EN ISO 14644-1 (class 100 bzgl.US Fed.Std. 209E) - we meet clean room class 6. The number of particles which are measured in 1m³ air is max. 102000 particles sized ≥ 0.3µm.
The following quality standards are compulsory for these applications in the areas "Drying" and "Conveying":
- The clean room itself may not house valves, blowers, filters, dryers or drying bins. These components must be installed outside the clean room. The only thing which leads into and out of the clean room is the ductwork
- Ductwork is made of 1.4301 stainless steel or glass
- In addition to connection couplings, pipe connections are also connected with thin stainless steel bands to guarantee dissipation of electrostatic charging
- Tubing is in food-grade standard (FDA)
- Blowers are oil-free
- A purge cycle is connected after every conveying cycle.
- HEPA-class H14 dust filters (separation efficiency of 99,995 % with > 0,3 µm particles according to DIN EN 1822) are used
- The ETA plus® procedure is used to reach a high degree of drying quality (and to prevent the risk of over or underdrying)
- motan-colortronic recommends a big bag solution with telescopic suction probe and fitted HEPA filter to make sure that there is no contamination risk at the material source
- The compression struts of the pneumatic cylinders may not get into contact with the processing material (abrasion and material contamination with lubricants)
- Hopper loaders are electro-polished and have a 1200µm coarse screen to let the fine dust pass through
System layout
1=Dryer, 2=Clean room, 3=HEPA H14 filter for suction line, 4=After cooler in return air, 5=HEPA filter in return air, 6=HEPA H14 filter in dry air, 7=HEPA H12 filter in dry air after heating, 8=HEPA H14 filter in feed air, 9=Vacuum valve for hopper loader, 10=Return air of blower station
Customer benefits
- The motan-colortronic portfolio consists of many, special components for clean room applications.
- Customised versions of drying, conveying and dosing technology through modular design and flexibility in application.
- The new ETA plus® drying procedure combines the latest energy-saving technologies for a cost-efficient, energy-saving drying which at the same time offers maximum protection of the material.
- Among other things, the new ETA plus® drying procedure uses the known options i.e. the DryingOrganizer together with air flow control and the previous ETA-process® resulting in considerable advantages for the customer.
- The profound knowledge of process engineering and process-oriented overall know-how makes motan-colortronic the ideal partner for you in clean room applications.