Buss kneaders

Anonymous, Buss Kneader Lines, Bulletin Nos. 0075, 2152, 2282, Buss A.-G. Basel (1989). 

Single screw extruders Buss-Kneader Twh screw extruders Multiple screw extruders ... 

M. Y. Lyu and J. L. White [Polym. Eng. ScL, 38, 1366-1377 (1998)] studied residence time distributions for melting and flow of chemoplastic resins in a Buss kneader. For an experiment involving injection of a spike of 5 g of aluminum flakes into polystyrene, they reported the following data for a feed rate of 22.7 kg/h. 

Another class of mixers for producing fluxed formulations are continuous mixers, examples of which are the Farrell Continuous Mixer (FCM) (121 the Buss Kneader (131), or compounding extruders such as the Kombiplast(132). 

Twin screw compounders or Buss Kneaders are used for fully mixed and melted compounds for injection molding because heat history has less effect on otyect molding as long as the process temperatures and times are adjusted to accormt for the use of lower molecular weight resins in the formulations. For flexible compounds, Banbury mixers, continuous mixers, or compounding extruders preceded by static mixers can be employed successfully. 

Continuous Mixers FCM Buss Kneader Uniform mix, geared for higher productivity, requires free-flowing preblend. Low heat/shear history compounds possible. 

The open buss kneader (Fig. 2.186) works with an external screw bearing in the production of pastel colors in the urea and melamine com-poiuids. When processing epoxy, polyesters (with or without glass fibers), and phenolics, the external bearing is not required. Both the open buss kneader and the Werner Pfliederer compounding imit will process the compounds and also control the granulation and flow properties. 

Figure 5.8 Influence of the relative deformation time and the relative diffusion time on the selectivity. The shaded area was the working area of a Buss kneader.

Figure 5.8 shows this selectivity as a function of the relative deformation time and the relative diffusion time. Troelstra (11) measured the selectivity in a Buss kneader for a system consisting of NaOH as component A, HCl as component B, and ethylchloroacetate as component C. The area of his results for different operating conditions is also indicated in Fig. 5.8. 

II. CASE PRODUCTION OF A TERPOLYMER WITH A BUSS KNEADER... 

The second plant is based on reactive extrusion in a single Buss kneader with a diameter of 200 mm. According to experiments on a 50-mm kneader a conversion of 95% could conveniently be obtained. The remaining 5% of monomer are removed by similar devolatilization extruders as in the first plant. 

As an alternative for the solution polymerization, the process flow diagram for a continuous reactive extrusion process is given in Fig. 14.2. As reactor a Buss kneader was chosen. 

According to reaction kinetics measured by Maeder (3) and experiments of Troelstra (1) a conversion of over 95% can be achieved within a residence time of 4 min in the extruder. This corresponds with a flow rate of 80 kg/h for a Buss kneader with a diameter of 100 mm and a flow rate of 640 kg/h for a Buss kneader with a diameter of 200 mm. The process is designed for a conversion of 95%. The remaining 5% of monomer is removed with a degassing extruder (E2). The monomer vapor is condensed in a condenser (H7) and stored (VI). The monomers are subsequently purified by means of a batchwise distillation. 

Buss kneader) Extruder E1a-f E2 180 with water Electric 8 X 0.0054 0.010 Jacketed... 

Table 14.6 Cost Price Evaluation per Metric Ton Terpolymer of MMA, HEMA, and n-BA. Extrusion Reaction in One Buss Kneader with a Diameter of 200 mm...

C) Buss-Kneader PR46-11D Co-Kneader with 3.5D discharge screw 46 11 Kneading screw of 1 ID and discharge screw of 3.5D... 

Figure 9.19 Modern Buss Kneader oscillating modular screw...

It has come to be realized that the Buss Kneader is an excellent distributive mixer and outstanding for mixing in glass fibers. In recent years. Buss AG and Werner and Pfleiderer were combined together in a new firm called Coperion. Reviews on the Kokneter have recently been written by Case [87] and White [88]. 

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