Extrusion International 1-2017

Extrusion International 1/2017

High-performance mixer aspiration

ensures constant process conditions

www.mti-mixer.de

Little or no deposits minimise the time and cost of clean-

ing the mixing system and all additional equipment, while

a constantly high product quality reduces scrap. Together,

these three benefits can provide significant cost savings

and extended maintenance intervals, thereby resulting in

a clearly increased availability of the entire production line.

Closed-loop control for constant drying performance

More traditional aspirator systems would not take into ac-

count changing process parameters but instead activate/

deactivate the exhaust air system as dictated by the pro-

cess, with filter cleaning being performed at fixed pre-

defined trigger points. This approach is typically linked

with disadvantages such as diminishing air output due to

progressive filter contamination, causing quality variations

in the final product. MTI Mischtechnik’s Vent tec

2.0 aspi-

ration systems, in contrast, continuously monitor all actual

operating conditions via key parameters such as intake air

and system air temperatures, air pressure, humidity and,

with high significance, the aspiration air flow rate. Their

electronic controller continuously analyses these variables

and adjusts the aspiration system accordingly with due

regard to the filter status, keeping aeration airflow con-

ditions constant. In addition, the system reports incipient

wear of the process filter at an early stage, thereby al-

lowing preventive maintenance to be carried out. Thus,

Vent tec

2.0 aspirator systems are key to both constantly

high drying performance and product quality.

Main applications include the production of rigid and soft

PVC dryblends and natural fibre compounds (WPC/NFC/

PPC) as well as thermal processes where Vent tec

2.0 de-

vices serve to dehumidify the mixture and/or to reduce the

volatiles content. The new generation aspirator systems are

available in various sizes for all mixing volumes and accom-

modating nearly all ATEX environments and mixer designs.

Thanks to their autonomous control technology, they can

also be retrofitted on other manufacturers’ machines.

Prevents deposits, saves time and cost

At process temperatures markedly exceeding the boiling

point of water, even low humidity levels may interfere

with the process. This is even more relevant for PVC recipes

containing hygroscopic stabiliser systems. Without a high-

performance aspiration capability, the result may often be

massive deposits on the interior surfaces of heatingmixers,

cooling mixer walls and extruder dies, as well as in calibra-

tion devices. The potential consequences may include a

diminished mixing quality, extruder problems and fluctua-

tions in the final product. In all such situations, Vent tec

mixer aspiration technology by MTI Mischtechnik provides

the necessary uniformly high dehumidification rates for

constant production results. Compensating effectively for

variations in raw material moisture and seasonal influ-

ences on the processing properties of the mixture, these

systems provide an unvaryingly high dryblend quality with

ultimate humidities ranging down to below 0.05%.

For the manufacturer, this high performance leads to com-

pelling advantages. Thus, an almost fully dehumidified dry-

blend will permit a high output of downstreammachinery.

With the launchof Vent tec

2.0,MTIMischtechnik presents a newgenerationof its provenhigh-

performance aspiration systems for heating/cooling mixer combinations. Unlike conventional

solutions, these devices are the first ever to control their operation autonomously as a function

of actual process parameters, thereby providing constant processing conditions irrespectively

of changes in process and ambient conditions. Accordingly, they significantly facilitate the task

of maintaining uniformly high product quality in the plastics processing and chemicals industry.

Unlike conventional systems, the new Vent tec 2.0 high-performance aspiration systems

for heating/cooling mixer combinations control their own performance independently as

a function of actual process parameters. They are thus key to achieving constantly high

product qualities in the plastics processing and chemical industries

PERIPHERY