SU564169A1 - Extruder screw conveyer - Google Patents

Description

one

The invention relates to machine building, namely to screw presses for kneading, homogenizing and extruding plastic masses.

A famous screw construction mailer, which has two independent cut channel. The width of the first (supply) channel gradually decreases, the width of the second channel gradually increases to the full width l. The disadvantage of this screw is the spatial isolation of both channels, as a result of which, there is no pressure, necessary to obtain high productivity, from

Especially noticeable in the so-called wetting materials, which do not move well on their own.

Also known is an extruder screw, made in the form of a core with a screw thread and one or more spirals whose elevation angle is different from the angle of elevation of the screw screw helix 2. In such a screw, the molten part of the polymer does not spatially separate from the unmelted one, which makes it difficult energy control, i.e. molten material due to improper geometrical design of the sections of the coils; processed with the same intensity, 1sak and melted. The purpose of the invention is to increase the degree of melt homogenization. This goal is achieved by the fact that the helix, made on the screw core, adjoins the thread of the screw thread in the form of a protrusion with an outer diameter ,, smaller than the outer diameter of the BINT screw auger, and with a width increasing in the direction of melt movement. Due to this, the volume between the screw pitch and the ecotruder cylinder is divided into two or more cavities, which ensures even introduction of energy into the material to be melted using the heat generated by the material itself and the heat supplied from the outside, and also gives the material the necessary physical condition inside screw on a relatively short section. Thanks to this constructive difference is achieved

high degree of homogenization of the polymer material. "

FIG. 1 shows a single entry screw; in fig. 2 - auger with spirals, libi filled in the form of protrusions; Fig. 3 auger with spirals made in the form of a BjjiaTynoB and recesses; in fig. 4 — auger with axial i radial holes; in FIG. 5 — a circular seam screw; in fig. 6 two non-screw augers; in fig. 7 a screw with alcohol made in the form of protrusions with grooves and grooves; in FIG. 8 is a section along A-A in FIG. 7,

Odkoza.hog.N- has a core 1 (see, fig, 1) with screw thread 2 and alcohol; el 3, made from a vice protrusion adjacent to a thread of thread that has an elevation angle different from that of the cutting helix auger with more; mna lifting the cutting line auger just so that after 9 turns takes almost the entire width of the auger pitch. Spiral 3 divides the interturn auger volume into ciiie cavities a and c.

The screw 4 (cf. Fig. 2) is made with two spirals 5.6, whereby the mega-turn volume is divided into three cavities c, d and e,

The screw 7, according to FIG. 3, has spirals 8, made in the form of a protrusion, and two spirals 9k lOj look out in the form of depressions. Moreover, the step of cutting the grooves can be single or different.

The screw 11, having a core with a screw thread and a helix, shown in FIG. 4, has holes: axial 12 and radial 13 "

The screw 14 (see fkg, 5) is two-way with helix 15, made in the form of a protrusion, starting from the front side of the thread of screw thread.

In a twin-screw extruder, screws 16 (see FIG. 6) are made non-chained, and each is provided with a spiral 17.

The screw 18 (see fig. 7) is made with two spirals 18 and 20, provided with grooves 21. The axis of the sleeves 10 and 20 is inclined to the axis of the screw, and between the projection of the spiral 2O and the 1zK thread, the grooves 23j have 1osh , not in cross section of a semicircle.

The solid material is transported by the screw and enters the cavities a and b, and as it progresses, the material melts under the influence of frictional heat and heat; supplied from the outside, its volume decreases, the intercellular volume decreases accordingly, the melt gradually increases in the cavity during the process of kneading, the volume

the cavities a and b when they change along the screw should correspond to the change in the volumes of solid material and melt, despite the absence of spatial separation between the cavities a and b, the material is separated ;; by physical condition into equipments: different patterns of their movement.

The screw 4 (see Fig. 2) transports the material to cavities c, d, and e. The crude material is transported primarily to 1, a,: a deeper cavity, e.

During plasticization, the material assumes a visco-elastic state, passing into a liquid state.

Such an embodiment of the screw is of interest for materials having, besides two physical states: solid and viscous, intermediate, for example, viscoelastic.

Melt material as it progresses enters the zone of discharge of the screw 18 (see Fig. 7). In this case, up to the zone of control, the volatiles are removed through the holes 12.13 (see, Fig. 4). Tire 18 (see Fig. 7) transports material which, as it heats up, partially melts.

The material moving in the deep cavity to the turns is heated and partially melted. The melt of material formed on the hot inner surface of the core is cut off by a spiral 19 and collected on its front side surface, where the mixture is mixed with small hard particles and partially already melted particles of material and flows into the cavity e.

Due to the grooves 21, the two streams caused by the rotation of the screws, one of which is directed along the grooves 21, and the other tangentially to the helix 19, are achieved. As a result, high shear forces are created in the material, which are the prerequisite for good homogenization. The latter is enhanced by mixing both laminar flows along the grooves 23.

As the material melts completely, it flows into the cavity towards the second helix 20. In this cavity, two streams also overlap, also caused by grooves 21 and rotation and 1k. Thanks to the groove 23, which is made for technological reasons, flow alignment also occurs here. The grooves 21 can pass as. until the end of the auger, and finish a few turns to the end of the auger: as shown in Fig. 7. The remainder of the loading zone is cf.

Then, according to the geometric ratios that are usual for an extruder screw. The proposed screw allows for the implementation of complex technological operations, such as coloring natural-colored materials with soluble and insoluble dyes and pigments at a relatively low cost. At the same time, such a screw achieves good homogenization with high-quality kneading and stability of the transportation process.

Claims (2)

1. Journal Hunsleioffe. 1968, Nc 11, p. 781-782, fig. 1, pos. 6 and fig. 2, pos. 12. 2. USSR author's certificate hfe 215465, cl. At 29 1/06, 1968. 1564169 T l xi. ,