Pelletizer head

It is rare to use a Buss mixer for multi-stage compounding operations. In Figure 1-4, the output of the Buss mixer is directly fed into a feed screw machine where high pressure forces the compound through a die or into a pelletizer head. 

The Banbury mixer is ideally suited to the making of thermoplastic rubbers. Polystyrene/SBR blends can be mixed in 3-4 min and TPEs requiring higher temperatures in 5-6 min. The requirement is to have a mixer with high rotor speeds, e.g. 120 rpm for an 80-litre mixer, discharging into an extruder with an underwater pelletizing head. 

In a 500 ml. three-necked flask, equipped with a thermometer, mechanical stirrer and efficient reflux condenser, dissolve 16 g. of sodium hydroxide pellets in 95 ml. of hot methyl alcohol. Add 49 g. of guanidine nitrate, stir the mixture at 50-65° for 15 minutes, and then cool to about 20°. Filter oflF the separated sodium nitrate and wash with two 12 ml. portions of methyl alcohol. Return the combined filtrates to the clean reaction flask, add 69 g. of sulphanilamide (Section IX,9) and stir at 50-55° for 15 minutes. Detach the reflux condenser and, with the aid of a still-head ( knee-tube ), arrange the apparatus for distillation from an oil bath with stirring about 100 ml. of methyl alcohol are recovered. Add 12 g. of pure cycZohexanol. Raise the temperature of the oil bath to 180-190° and continue the distillation. Reaction commences with the evolution of ammonia when the uiternal temperature reaches 145°. Maintain the... 

Wire and Gable. PVC has been used in wire and cable appHcations since World War II, when the U.S. Navy demanded lower combustibiUty materials in constmction. These products are manufactured by cross-head extmsion, usually from pellet compounds on single-screw extmders. Some line speeds are 1524 m (5000 ft) per minute (60 mph). The compounds are optimized for the requirements, including low temperature flexibiUty, high use temperature, especially low combustibiUty, weatherabiUty, and high resistance to cutthrough. 

To a 3QQ-mL, round-bottomed flask fitted with a water separator, (Note 1) which contains 15 g of Linde 4A molecular sieve l/16-1nch pellets and Is filled with toluene, are added 7.3 g (0.04 mol) of cyclododecanone, 11.4 g (0.16 mol) of pyrrolidine, 100 mL of toluene, and 0.57 g (0.004 mol) of boron trifluoride etherate. The solution is heated under reflux for 20 hr. The water separator is replaced by a distillation head, and about 90 mL of the toluene is removed by distillation at atmospheric pressure. The residue containing l-(N-pyrrolidino)-l-cyclododecene (1) is used in the next step without further purification (Note 2). 

Plastic-Bonded RDX, Its Preparation By the Slurry Method , Holston Defense Corp, Term, Control No 20-T-16 Series A (PAC 1081) (1953) 8) A.J. Pascazio, The Suitability of a Bare PBX Booster Pellet In The 2.75-Inch HEAT Ml Rocket Head , PATR 2271 (1955) 9) H.W. 

Figure 5.3.8 displays a photograph of the actual combustion zone. The methane-xenon gas was mixed with air before entering the NMR detection cell in the probe head. The gas mixture was blown through an area with molecular sieve pellets (i.e.,... 

The feedstreams can consist of either neat reactants or their solutions. When the feedstreams consist of solutions, the reaction mixture is pumped into a polymerization vessel where the reaction that started in the mixing head proceeds to its conclusion. The polymer is subsequently precipitated from solution, separated, dried, and pelletized. Solvent-free mixtures of reactants are pumped directly to a mold where polymerization proceeds. In this case, other additives, such as, fillers or fire retardants, are co-mixed with the reactants in the mixing head. These additives are permanently incorporated into the finished molding. 

Most static-bomb calorimeters used are of the isoperibol type, such as the one in figure 7.1. Here, the bomb A is a pressure vessel of 300 cm3 internal volume. Combustion bombs are usually made of stainless steel and frequently have an internal platinum lining to prevent corrosion. In a typical high-precision experiment, the platinum ignition wire B connects the two electrodes C, which are affixed to the bomb head. A cotton thread fuse D (other materials such as polyethene are also used), of known energy of combustion, is weighed to a precision of 10-5 — 10-6 g and tied to the platinum wire. A pellet E of the compound... 

H.M. Talbot, R.N. Head, R.P. Harris and J.R. Maxwell, Distribution and stability of steryl chlorin esters in copepod faecal pellets from diatom grazing. Org. Geochem. 30 (1999) 1163-1174. 

C. The pressure is adjusted by a needle valve (G) to 100 rm (F remains closed). A solution of 12.3 g (0.22 mol) of potassium hydroxide pellets in 12 mL of water is placed in vessel (A) and cooled to 0 C. Neat (S)-2-chloropropan-l-ol, 11.8 g (0.125 mol), is poured at once into the alkaline solution (Note 10), and the reaction vessel is immediately fitted with still-head (B) and stirred vigorously with efficient cooling. Stopcock (F) is opened occasionally for a short period until the pressure in the closed system is reduced to 100 mm (Note 11). The ice bath is replaced by a water bath at 20°C. As the cyclization reaction proceeds a white precipitate of potassium... 

The A-A extruders are equipped with a flat perforated plate or screen, combined with two flat extrusion heads. The wet mass is pressed axially through the screen parallel to the feed screws. The extrusion forces are the highest, compared to other low pressure extruders, resulting in a hard and dense extrudate. It is commonly used in the extrusion of food, thermoplastics, and other industries, where a large pellet diameter and thermosetting properties are desired. 

A mixture of 63.1 g. (0.5 mole) of 2-methyl-l,3-cydohexane-dione (Note 1), 52.6 g. (0.75 mole) of methyl vinyl ketone (Note 2), about 0.25 g. (3 pellets) of potassium hydroxide, and 250 ml. of absolute methanol is placed in a 500-ml. round-bottomed flask fitted with a reflux condenser and a drying tube (Note 3). The mixture is heated under reflux for 3 hours, and the dione gradually goes into solution. At the end of this period, methanol and the excess methyl vinyl ketone are removed by distillation under reduced pressure (Notes 4 and 5). The residual liquid is dissolved in 250 ml. of benzene, a Dean-Stark phase-separating head is attached, and 20 ml. of solvent is removed by distillation at atmospheric pressure to remove traces of water and methanol. The solution is cooled well below the boiling point, 3 ml. of... 

Urine (5 ml) urine spiked with 0.2% (v/v) isopropylamine is placed in a screw-capped 15-ml vial [28]. Pelleted potassium hydroxide (3 g) is added before sealing the vial with an airtight polytetrafluoroethylene-lined septum cap. Potassium hydroxide raises the pH of the sample to ensure that the amines are present as volatile bases. The vial is heated in an aluminium block at 90 C for 20 min. While still in this block, 2 ml head-space gas is withdrawn through the septum with a disposable syringe and injected immediately on the gas chromatography column. The operating temperatures of the column, injector port and detector unit are 70 C isothermal, 150 C and 200 C, respectively, with nitrogen carrier gas at 60 ml/min. This allows quantification of TMA and other amines. TMA N-oxide is measured after quantitative reduction into TMA. For this, titanous chloride (30%, w/v 0.2 ml) is added to 2 ml urine in a screw-capped vial and incubated for 30 min at room temperature. The sample is then diluted ten-fold with distilled water and analysed as described above. The result represents the sum of TMA and TMA N-oxide present in the sample. 

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