RU2338643C1 - Two-channel extruder die for polymer structural shape rail manufacturing - Google Patents

Abstract

FIELD: building.

SUBSTANCE: extruder die contains detachable two-sectioned body equipped with cooling system forming moulding channels of profile section with upper and lower sections of head body. Moulding channels are connected with supply channel. In upper section there are formed cavities hollow surface of which is shaped as truncated cycloid. On insert mounted between two sections the oval flanges are provided symmetrically to surfaces of curve hollows of upper section. Lower section of body contains grooves for refrigerant duct.

EFFECT: allows for improved quality of extruded polymer structural shape rail.

3 dwg

Description

The invention relates to devices for the manufacture of products from polymeric materials and can be used in the chemical industry for the production of building profile rails.

A known design of the extrusion head for the manufacture of molded products, comprising a housing, a profiling bar, a holder, in which semi-cylindrical sections are pressed in, having various shaped grooves and combined with grooves and protrusions that form a forming sleeve with a profile channel communicating with the feed channel of the head . [A.S. USSR No. 1717393, MKI V29C 47/12, 1992, Bull. No. 9].

The disadvantage of this device is the lack of a cooling system for semi-cylindrical sections, which reduces the quality of molded products.

Since there is one forming channel in the extrusion head from which one profile is extruded, the productivity of the head is naturally low.

The closest in technical essence and the achieved effect is a two-channel extrusion head for the manufacture of polymer cladding, containing a housing made detachable with a cooling system.

The liners form two forming channels of a profile section between themselves. The inner surface of the profile insert is formed by a sinusoidal curve. At the concavity of the indicated surface, rods are longitudinally located [RF patent No. 2189314, MKI B29C 47/12, 1992, Bull. No. 26, prototype].

A disadvantage of the known extrusion head is the complexity of construction and installation, since the head consists of two sections and two inserts, which require the necessary accuracy during installation, i.e. compliance with the alignment of relatively longitudinally located rods, which can lead to distortion of the cross section of the profile shape and deterioration in the quality of extrudable products.

The invention is aimed at solving the problem of simplifying the design of the extrusion head and improving the quality of extruded profile rails.

This problem is solved by a two-channel extrusion head for the manufacture of a polymer building profile rail containing a housing made of two sections with a cooling system, forming forming channels of profile section with upper and lower sections, in which, in contrast to the prototype, grooves are made in the upper section, the surface of the recess of which has the shape of a shortened cycloid, and on the liner mounted between the two sections, oval-shaped protrusions are formed that are located symmetrically the surfaces of the curved depressions of the upper section, and the lower section of the housing contains a recess for the flow of refrigerant.

The technical result provided by the two-channel extrusion head for the manufacture of polymer building profile rails is expressed in simplifying the design and improving the quality of the profile rails due to the choice of the optimal cross-sectional geometry of the forming channels.

The choice of the optimal geometry of the cross section of the forming channels is ensured by coordinating the location of the upper section of the housing and the liner, which form the forming channels of the profile section, the inner surface of which is formed by an oval curve in the center and a curve in the form of a shortened cycloid.

The shape of the surface recesses in the form of a shortened cycloid in the upper section and the radii of the oval curve of the protrusions of the liner in each individual case are selected constructively depending on the width and thickness of the rail made.

When selecting the shape of the curved surface in the form of a shortened cycloid, depending on the width and thickness of the manufactured profile rail, they achieve a uniform distribution of speeds at all points of the cross section of the extruded product. This ensures greater dimensional accuracy and quality of the extruded 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 building profile rails; figure 2 is a longitudinal section along aa; figure 3 is a cross section of the resulting profile rails.

The two-channel extrusion head for the manufacture of a polymer building profile rail in accordance with figure 1 contains a detachable casing consisting of two sections: upper 1 and lower 2, between the sections there is an insert 3 forming forming channels 4, profile grooves are made in the form of a shortened upper section cycloids 5, oval protrusions 6 are formed on the insert.

The forming channels 4 are equipped with a cooling system; a recess 7 is provided for the flow of the refrigerant in the lower section of the housing 2.

The upper section 1 and the lower section 2 and the insert 3 are interconnected by bolts 8. The forming channels 4 communicate with the supply channel 9, at the input of which a filter grill 10 is installed.

The extrusion head is connected to the extruder using a connecting flange 11.

Two-channel extrusion head for the manufacture of polymer construction profile rail works as follows.

The polymer melt injected by the screw of the extruder enters the feed channel 9, then into the forming channels 4 formed by the upper section 1 and the insert 3. The forming channels 4 give the polymer melt the shape of a profile rail 12 in accordance with figure 3, while the upper section 1, the liner 3 and the lower section 2 are made of steel 45 with a high class (▽ 10- ▽ 12) of surface finish, which allows for the combination of these parts to obtain during assembly complete, without any gaps, profile forming channels 4, when forcing through which jets of races Chapter polymer on the surface of the profile rail is formed by connecting points trace components and rake profile exits the mold channel 4 with a glossy surface with high purity class.

In the lower section 2 of the housing of the extrusion head, a recess 7 is provided for cooling the extrudable profile rail by supplying and discharging the refrigerant through nozzles (not shown).

The present invention is most useful in the manufacture of building profile rails.

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 dimensions: width 370 mm, length 340 mm, height 210 mm, length of forming channels 275 mm.

Received a profile rail made of polypropylene grade 01003 TU211-020-0020-3521-96 75 mm wide, 15 mm high, 5 mm thick in the center.

The optimal extrusion mode at a temperature of 468-478 K and the generated extrusion pressure in the range of 3.5 ÷ 4.0 MPa.

The proposed two-channel extrusion head for the manufacture of polymer construction profile rails can improve its quality.

Claims (1)

A two-channel extrusion head for the manufacture of a polymer building profile rail, comprising a housing made of two sections with a cooling system, forming forming channels of profile section with upper and lower sections of the head housing in communication with the feed channel, characterized in that grooves are made in the upper section, the surface of the recesses of which has the shape of a shortened cycloid, and on the liner mounted between the two sections, oval-shaped protrusions are formed, located symme ary depressions curves surfaces of the upper section and the lower section of the housing comprises a recess for the coolant flow.

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