JPH04125112A - Kneading method - Google Patents

Abstract

PURPOSE:To enhance viscosity lowering efficiency and upgrade mixing productivity while retaining dispersion properties without lowering physical properties of a raw material rubber because of heat and peptizer by kneading repeatedly while the feeding temperature of kneaded rubber into a roll is cooled lower than the given temperature when the kneaded rubber discharged out of a closed type mixer is kneaded repeatedly while running through a cooling device and the roll. CONSTITUTION:Kneaded rubber W discharged out of a closed type mixer 1 is fed into an undermixer 2. A plurality of pass lanes 5 consisting of cooling devices 3 and rolls 4 are disposed in series in the undermixer 2, and the number of roll passes is retained same as the number of passes heretofore available to prevent the deterioration of dispersion properties, and the kneaded rubber is cooled by the cooling devices 3 installed in the undermixer 2 in a manner that the temperature of feeding the rubber W is 90 deg.C or under at all times and fed into the rolls 4. The viscosity lowering efficiency of the rubber W cooled by the cooling devices 3 is retained by running through the rolls 4 several times without winding on the rolls 4. Mixing productivity can be upgraded by said process.

Description

DETAILED DESCRIPTION OF THE INVENTION: Industrial Application Field The present invention relates to a kneading method that increases the efficiency of reducing viscosity and improves productivity without deteriorating the physical properties of raw rubber.

[Conventional technology]

Conventionally, a kneading method has been used in which kneaded rubber discharged from a closed mixer is kneaded in an under mixer, but in the case of this kneading method, the high temperature rubber discharged is fed into an under mixer. The mixture is then returned to the closed mixer for kneading.

[Problem that the invention seeks to solve]

However, since high-temperature rubber is not actively cooled even after it is directly put into the undermixer, the efficiency of reducing the viscosity of the rubber in the undermixer is low, and as a result, it is difficult to obtain initial processability. Preparation work such as extending the kneading time in a closed mixer, increasing the number of baths (adding decomposer, narrowing the roll cap, etc.) is required, and the physical properties of the rubber are adversely affected. There was a problem of giving.

[Purpose of the Invention] This invention was devised by focusing on the above-mentioned conventional problems, and aims to increase the viscosity reduction efficiency and maintain dispersibility without deteriorating the physical properties of raw rubber due to heat or peptizing agents. The object of the present invention is to provide a kneading method that can improve mixing productivity while at the same time improving mixing productivity.

[Failure to solve the problem]

In order to achieve the above object, the present invention cools the kneaded rubber to at least the roll input temperature to 90°C or lower when repeatedly kneading the kneaded rubber discharged from a closed mixer while passing it through a cooling device and a roll. The gist of this method is to repeatedly knead the mixture.

[Action of the invention]

This invention is configured as described above, and the rubber discharged from the undermixer is made into pellets or sheets,
By installing a cooling device in front of the rolls to keep the temperature below 90°C, preferably below 80°C, and by always keeping the temperature of the rubber to be kneaded at 90°C or below when it is fed into the rolls, the physical properties of the raw rubber can be reduced. It is possible to increase the viscosity reduction efficiency and improve mixing productivity while maintaining dispersibility.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows a schematic explanatory diagram of a kneading roll system showing a first embodiment of the present invention, 1 is a closed mixer, 2 is an under mixer, and this under mixer 2 includes a cooling device 3 and a roll. A plurality of bus drains 5 consisting of 4 are arranged in series, and the number of roll passes is maintained at the conventional number of passes to prevent deterioration of dispersion, and the temperature at the time of charging the rubber W is always below 90 ° C. , preferably at 80°C or below, 4
After being cooled to a temperature of 0° C. or higher using a cooling device 3 attached to the under mixer 2, it is fed into a roll 4.

Note that at temperatures other than the above (below 40'C, above 90°C), mechanical problems occur, so the rubber is fed into the roll 4 while maintaining the above temperature.

In addition, the cooled rubber W cooled by the cooling device 3 is not wound around the roll 4 (by passing it through the roll 4 several times, the viscosity reduction efficiency is maintained, and the roll 4 is wrapped around the same roll). There is no limitation, and other roles may be used.

The rubber W passed through the bus drain 5 and kneaded in this manner is made into sheets and stacked on a pallet 6 as shown in FIG. 1, and then transported out.

Further, FIG. 2 shows a second embodiment of the present invention, and this embodiment has a plurality of bus drains 5 each consisting of a cooling device 3 and a roll 4 arranged in series, as in the first embodiment. In this method, the rubber is repeatedly kneaded using one set of cooling devices 3a and 3b and the roll 4a.
In a and 3b, always keep the temperature of the rubber W at 90°C or lower when adding it.
Preferably, the kneading is repeated at a temperature of 80° C. or lower.

Other methods are the same as those in the above embodiment, so the same reference numerals are used and explanations are omitted.

〔Effect of the invention〕

As described above, when the kneaded rubber discharged from the closed mixer is repeatedly kneaded while being passed through a cooling device and a roll, the kneaded rubber is repeatedly kneaded while cooling the kneaded rubber to at least a roll input temperature of 90°C or less. Since kneading is performed, the physical properties of the raw rubber are not deteriorated due to heat or dissection.
It has the effect of increasing viscosity reduction efficiency and improving mixing productivity while maintaining dispersibility.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of a kneading roll system showing a first embodiment of the present invention, and FIG. 2 is a schematic illustration of a mixed roll system showing a second embodiment of the invention. 1... Closed mixer, 2... Under mixer 3.
...1lilf, 4...roll, 5...bass drain, W...rubber.

Claims (1)

[Claims] The kneaded rubber discharged from the internal mixer is mixed with at least one
In a kneading method in which the kneaded rubber is passed through a kneading drain of an under mixer equipped with a stand roll, when the kneaded rubber discharged from the closed mixer is repeatedly kneaded while being passed through a cooling device and a roll, at least the kneading is performed. A kneading method in which the rubber is repeatedly kneaded while being cooled to a temperature below 90°C.