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Zawartość zarchiwizowana w dniu 2024-04-16

DEVELOPMENT OF THE RUBBER BATCH MIXING PROCESS FOR OPTIMAL QUALITY.

Cel

The aim is to reduce the variability of the rubber mixes and to improve their quality level.
The objectives of the project are to determine close relationships between mixing parameters, dispersion measurements and mix properties, to develop an innovative closed loop control system capable of providing the quality of the mix in real time, to compare the efficiency of the 2 main types of internal mixer present on the market and to reduce the variability of the rubber mixes and to improve their quality level.
An improvement in batch variability has been found with the resulting problem of interpreting the results of the factorial experimental design. A new design is in progress to solve this problem. Dispersion measurement techniques show that electrical and dielectrical methods and image analysis have been improved significantly. An innovative control system has been designed and manufactured and promising results obtained, but the response time still remains to be reduced.

Three types of industrial rubber mixes, containing natural rubber, ethylenepropylene terpolymer rubber, and a blend of cis polybutadiene and cis polyisoprene rubbers, reinforced with carbon black, have been prepared. Using computer controlled Francis Shaw (FS) K1 intermeshing rotor internal mixers of 5.5 litres capacity, factorial experiments were designed to investigate the effect of mixer variables, ie rotor speed and mixing energy and/or mixing time, on physical properties and their interrelationships. A well instrumented 2 roll rubber mill was included in the experiment to investigate mill variables, ie mill speed, nip setting, friction ratio and number of passes through the nip.

A statistical package (GLIM) was used to analyse the results of a range of physical property measurements covering rheology, cure characteristics, carbon black dispersion and mechancial properties. The only significant effects were a dependence on mixer rotor speed and a difference between the performance of the similar mixers.

In addition, no significant relationships were found between pairs of physical properties which would have permitted reduced testing. It was concluded that mix inhomogeneity was masking mixer/milling effects, at least for failure properties, ie those particularly sensitive to residual aggregates of carbon black. Effort was therefore concentrated on reducing that inhomogeneity.

Several methods for determination of the all important carbon black dispersion have been evaluated and developed. Instruments are recommended for detection of poor to medium dispersions, and for quantifying good dispersions, on a routine production control basis. Another is recommended as a research tool for examining carbon black distribution using sample sizes of a few square millimetres.

A device has been developed and tested to enable measurements of compound viscosity to be made during the mixing process; the output of the device can be used to control the discharge of compound with the desired viscosity.

Consideration is now being given to maximizing the benefits of the new equipment and methodologies developed. Plants will be selected for initial implementations and their experiences will be used as case studies for training of other mixing plants.
In addition to waste reduction, the results will also enable operating costs to be reduced.

Serious consideration is also being given to the development of a commercially available sensor which will be incorporated into a closed loop system. Exploitation of the sensor is expected to extend to retrofitting to existing mixing installations, in addition to provision with new mixers.
There is a strong market requirement to increase the quality of the rubber parts as well as to tighten their performance.

Therefore the objectives of the project are:
-To determine close relationships between mixing parameters, dispersion measurements and mix properties.
-To develop an innovative closed-loop control system capable of providing the quality of the mix in real-time.
-To compare the efficiency of the two main types of internal mixer present on the market.

Temat(-y)

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Zaproszenie do składania wniosków

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System finansowania

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Koordynator

Hutchinson SA
Wkład UE
Brak danych
Adres
2 rue Balzac
75384 Paris
Francja

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Koszt całkowity
Brak danych

Uczestnicy (2)