RU2484960C1 - Two-channel extrusion head for making polymer composite profile bar - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to production of articles from polymers and may be used in petrochemical industry for making composite profile rack. Extrusion head comprises split casing consisting of four sections. Recess for coolant circulation is arranged at the center between two sections. Note here that said sections compose two forming channels communicated with feed channel. Note here that forming channels feature composite profile sections with symmetric recess and ledges of triangular and ellipsoidal surfaces that form rack top surface. Cylindrical rods are fitted at the points of recesses in forming channels.

EFFECT: higher efficiency and quality.

2 dwg

Description

The invention relates to devices for the manufacture of products from polymeric materials and can be used in the petrochemical industry for the production of framing battens.

The known design of the extrusion head for the manufacture of profile rails, comprising a housing, a profiling bar, a holder, in which semi-cylindrical sections are pressed, having shaped grooves and combined with grooves and protrusions, forming a forming sleeve with a profile channel of the head [A.S. USSR No. 171393, MKI V29C 47/14, 03/07/1962].

The disadvantage of this device is the lack of a cooling system for semi-cylindrical sections, which reduces the quality of the manufactured profile products, and low productivity, since the extrusion head has one molding channel from which one profile is extruded.

The closest in technical essence and the achieved effect is a two-channel extrusion head for the manufacture of polymer profile products, comprising a housing made detachable with a cooling system and liners located therein. The liners form between each other a forming slit of a profile section, consisting of two forming channels communicating with the feed channel and enclosed between the profile and flat sections of the liners [a.s. USSR No. 148899, MKI V29C 47/12, 01/01/1967, prototype].

A disadvantage of the known extrusion head is the inability to control the extrudate velocities along the cross section when it extends from the forming channel, which can lead to distortion of shape and deterioration in the quality of the extrudable product.

The invention is aimed at solving the problems of increasing the productivity of product manufacturing and improving the surface quality of extruded profile rails.

These tasks are solved due to the fact that the two-channel extrusion head for the manufacture of polymer composite rails contains a detachable housing consisting of four sections. In the center between the two sections, a recess is provided for the circulation of the coolant, while the sections form two forming channels between themselves, communicating with the supply channel. Moreover, the forming channels are made of a complex section with symmetrically located hollows and protrusions of the triangular and ellipsoid surfaces that form the upper surface of the product. In places of protrusions in the forming channels, cylindrical rods are mounted.

The technical result provided by the two-channel extrusion head for the manufacture of a polymer composite profile is expressed in an increase in productivity and an improvement in the quality of the composite profile, due to the choice of the optimal cross-sectional geometry of the forming channels.

The optimal geometry of the cross section of the forming channels is selected due to the coordinated arrangement of the sections with triangular and ellipsoid grooves symmetrically located in them in the upper part of the channel, which form the upper surface of the extrudable product.

Structurally selecting the values of the above-mentioned groove parameters, they achieve a uniform distribution of velocities at all points of the cross section of the extrudable product, thereby reducing residual shear stresses, eliminating uneven output of the extrudate and warping of the manufactured product.

This ensures high dimensional accuracy and quality of the extruded complex profile rail.

The invention is illustrated by drawings: in Fig.1 is a cross section of a two-channel extrusion head for the manufacture of polymer composite rails; figure 2 is a cross section of the resulting complex rails.

The two-channel extrusion head for the manufacture of polymer composite rails, in accordance with figure 1, contains a detachable housing consisting of four sections 1, 2, 3, 4, in which there are forming channels 5, enclosed between sections 1 and 3, 2 and 4 with triangular 6 and ellipsoidal 7 grooves, with the forming upper surface of the product. Between sections 3 and 4, a recess 8 is made for circulating the coolant with the nozzle 9. At the places of the protrusions in the forming channels, cylindrical rods are mounted 10. All four sections of the housing are connected by bolts 11. The connection of the extrusion head to the extruder is not shown.

Figure 2 presents a cross section of a polymer composite rails, which shows triangular 6 and ellipsoidal 7 protrusions and holes in the rail 12.

Two-channel extrusion head for the manufacture of polymer composite rails works as follows.

The polymer melt injected by the screw of the extruder enters the feed channel, then the melt is pumped into the forming channels 5. The forming channels 5 give the polymer melt a shape in the form of a complex profile with triangular and ellipsoidal protrusions, in accordance with figure 2, using sections 1-4 . Sections of the housing 1-4 are made of steel 45 with a high class of surface treatment Ra0.8, which allows for the combination of these parts to obtain during assembly complete, without any gaps, profile forming channels 5, when forcing through which jet of polymer melt on the surface of a complex profile is not traces are formed from the places where the parts are connected, and a complex-profile rail leaves the forming channel with a glossy surface with a high purity class.

Between sections 3 and 4, a recess 8 is provided for circulating the coolant of the refrigerant through the pipe 9 into the cooling system of the extrudable complex profile rail through the forming channels 5. At the points of the protrusions in the forming channels, cylindrical rods 10 are mounted that form holes 12 in the product, in accordance with FIG. 2.

The present invention is useful in the production of complex rails, which will be used for wall cladding.

Experimental studies were carried out on a pilot plant with an ATL-45 extruder having a screw with a diameter of 45 mm and a length of 1125 mm.

The extrusion head had the following geometric dimensions: body width 240 mm, length 300 mm, height 230 mm, length of the forming channels 220 mm.

A composite rail made of polypropylene 01003 TU2211-020-0020-3521-96 with a width of 100 mm, a thickness of 15 mm on the protrusions, an opening in the product of 7 mm, a depth of 5 mm in the hollows was obtained on the specified extrusion head.

The optimal extrusion mode at a temperature in the range of 468-478 K and the generated extrusion pressure in the range of 4.0-4.5 MPa.

The proposed two-channel extrusion head for the manufacture of polymer composite rails allows to increase productivity and improve the quality of complex rails.

Claims (1)

A two-channel extrusion head for the manufacture of a polymer composite profile rail containing a detachable housing consisting of four sections, a recess for cooling water circulation is provided in the center between the two sections, while the sections form two forming channels interconnected with the supply channel, characterized in that that the forming channels are made of a complex section with symmetrically located hollows and protrusions of the triangular and ellipsoid surfaces that form in rhnyuyu surface of the article in areas projections in the form of channels mounted cylindrical rods.

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