SU1512787A1 - Screw plasticizer for processing thermosetting materials with fibrous filler - Google Patents

Abstract

The invention relates to equipment for processing plastics and can be used for kneading and accurate dosing of thermosetting materials with fiber filler when they are pressed into products. The purpose of the invention is to improve the reliability of the plasticizer by eliminating the possibility of cutting the material with coils along the conical surface of the bunker in the area of grooving and the absence of dead zones when adjusting the performance of the axial movement. The plasticator contains a vertically positioned material cylinder 1, a conical loading hopper 2 with a cylindrical neck and longitudinal grooves 3 along the inner surface, and a screw with a conical section (CS) 4 cut from the top of the cone at a distance of 0.5-0.85 maximum depth the longitudinal groove from the transition line of the conical part of the hopper 2 into the cylindrical mouth with the lowest position of the CS mounted in the hopper and with the cylindrical section 5 located in the material cylinder. 2 Il.

Description

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The invention relates to the field of equipment for processing plastics and can be used for kneading and accurate dosing of thermosetting materials with fiber filler when they are pressed into the product.

The purpose of the invention is to increase the reliability of the plasticator.

FIG. 1 shows a kneader, a general view; in fig. 2 - zone of the copy screw section, section.

The screw kneader contains a vertically located material cylinder 1, a conical feed hopper 2 with a cylindrical neck, on the inner surface of which grooves 3 are made, a bacon with screw thread made with a hollow conical section 4 truncated from the apex of the cone at a distance of 0.5-0 , 85 maximum depth of the longitudinal groove from the transition line of the conical part of the hopper 2 into the cylindrical neck, and the cylindrical section 5 connected to the rotational drive 6. The cylindrical section 5 of the screw is located in the material cylinder 1, and the floor of the conic section 4 is mounted in the loading m hopper 2 with the possibility of axial movement relative to the longitudinal axis by means of a screw load 7, made with a profile corresponding to the profile of the screw thread 8 of the cylindrical section 5. Zola the conic section 4 is connected to the cylindrical section 5 by means of two spline joints 9 and 10, by means of which the axial interposition of the conical section 4 is fixed while adjusting; nosti kneader. The plasticator also contains receiving chambers 11 and 12 with hydraulic cylinders 13 and 14 of counterpressure, mounted at the outlet of the material cylinder 1 with the possibility of reciprocating in the horizontal plane from the hydraulic cylinder 15.

The operation of the kneader is carried out as follows.

The material being processed is fed to a hopper 2 by a loading device (not shown). A conic section 4 of the screw captures the material in zone I (Fig. 2) and, rotating, moves it to the zone of the cylindrical section 5.

In the upper part of the truncated conical section 4 of the screw (in zone 1), the material particles freely move relative to each other due to the lack of sufficient compaction and slip relative to the surface of the hopper 2.

The movement of material in the zone of location of the grooves 3 (in zones 2 and 3, fig. 2) occurs along the grooves, and this causes pressure in the material and it compresses.

The fluctuation in the performance of the transporting devices (screw feeders, conveyor belts, etc.), despite the tendency of the fibers to clumping, does not lead to a sharp over-compaction of the material in the area of the grooves 3 and the powering down of this plasticizer. This is explained as follows.

In the area of the slots 3 in the conical section of the hopper 2, below the truncation plane of the conical section 4 of the screw (in zone 3, fig. 2), the material is not cut off by conical cutting of the screw, since the distance from the transition line of the conical part of the loading hopper to the cylindrical neck up to the truncation plane of the conic section 4, it cannot be less than 0.5 of the maximum depth of the longitudinal groove, but is forced downwards and toward the center, from which, being caught by the turns of the cylindrical section 5, is transported into the material cylinder I.

In the cutting zone of the grooves 3, above the truncation plane of the conical section 4 of the screw (in zone 2, fig. 2), the material cannot rotate together with the screw, slip relative to the walls of the hopper 2, and is not cut by the turns of the conical section 4 of the screw because of the absence sufficient compaction capable of stopping the material in the grooves 3. This ensures that the material is continuously fed into the zone below the plane of truncation of the conical section 4 and there are no dead zones there (zone 3, Fig. 2).

In the upper part of the bunker 2 (in zone 1, fig. 2), the material freely slips relative to the walls of the bunker 2 and moves down only after the normal values of pressure are established in the cutting zone of the grooves 3 (in zones 2 and 3, fig. 2), which provides self-regulation feed material.

As the material is fed and moved by the cylindrical section 5 through the material cylinder 1, the material is heated, plasticized, and fed into the receiving chamber 11. During the set of the prescribed dose, the backpressure of the hydraulic cylinder 13 is displaced down by the pressure applied in the dose. When the hydraulic cylinder 13 of the counterpressure reaches the lower position, the rotational drive 6 is automatically turned off, the material supply is stopped, and the receiving chambers 11 and 12 together with the hydraulic cylinders 13 and 14 of the counterpressure move to the extreme right position (Fig. 1) by the hydraulic cylinder 15.

When the receiving chambers 11 and 12 are moved, the dose is cut and it is pushed out by the cylinder of the hydraulic cylinder 13 when it is moved to the highest position. At the same time, the drive 6 is turned on and the dose is set into the receiving chamber 12, which is located under the material cylinder 1.

After a dose is set in the receiving chamber 12, the hydraulic cylinder 15 moves the receiving chambers 11 and 12 to the extreme left position (FIG. 1). In this position, the dose is ejected from the receiving chamber 12 by the piston of the hydraulic cylinder 14 and the dose is set into the receiving chamber 11. The cycle then repeats.

To regulate the performance of the plasticizer by moving the conical section 4 by means of screw cuts 7 and 8 and installing it in a certain position with the help of spline joints 9 and 10, it is necessary, as the practice of using screw plasticizers shows, to have a range of movement of the conical section 4 by 6-8 mm. From the condition of the absence of dead zones, it is necessary that, with the indicated regulation, the conic section 4 does not rise higher than 0.5 of the maximum depth of the longitudinal groove from the plane of the beginning of the grooves 3 to the truncation plane of the conical section 4. From the extreme auger diameter of 40 mm (from conditions of the minimum length of the grooves in the conical section of the bunker) and the maximum depth of the longitudinal groove on the surface of the bunker 15 mm (from the condition of the maximum height of the truncated conical section) for the required range of adjustment of production efficiency

Q 5 5

0

moving the 8 mm conical section will remain 12.5 mm for truncating the conical section, which is 0.85 of the maximum depth of the longitudinal groove.

Claims (1)

Invention Formula Screw plastikator for processing thermosetting materials with fibrous filler, containing a vertically positioned material cylinder and a conical feed hopper with a cylindrical neck and longitudinal grooves on the inner surface, screw screws with a rotating drive and made with a cylindrical section placed in the material cylinder, and a hollow conical section, truncated from the side of the cone tip, mounted in the hopper with the possibility of axial movement Especially the longitudinal axis of the material cylinder, characterized in that, in order to increase the reliability of the plasticizer, the conical section of the screw is truncated at a distance of 0.5-0.85 maximum depth of the longitudinal groove from the transition line of the conical part of the hopper to the cylindrical mouth at the lowest position conical section.