SU1766699A1 - Method of moulding foam-plastic semi-cylinders - Google Patents

Abstract

The invention relates to the technology of making foam products and can be used to form elements in thermal insulation such as semicylinders. SUMMARY OF THE INVENTION surfaces with an increase in the mixture in volume with simultaneous removal of the filling head from the entrance to the formative The anal channel, the conveyor speed and the distance to which the filling head is removed, are determined from the conditions of the type of the article being molded. 3 il.

Description

WITH

with

- Usage: technology for manufacturing products from rapid-hardening foam mixtures.

The closest to the invention to the technical essence is a method of molding foam products, including feeding the foaming mixture of liquid components with a casting head at the entrance to the forming channel between two continuous surfaces forming one above the other, foaming it when the surfaces are synchronously moving in the longitudinal direction and selection of the finished product

The known method of molding foam products is unsuitable for molding from a fast-expanding and fast-hardening mixture, for example, high-quality semi-cylinders made of FRP-1 foam plastic. This is explained by the fact that in the process of foaming such a mixture, its free surface is not in a liquid state, but in the form of a crust of semi-hardened foam. Therefore, when the mixture is foamed in the gap between the forming surfaces at the moment when the mixture stops, the upper part of the semi-hardened surface into a convex cylindrical part. The increase in the mixture volume decreases in the upper forming surface, i.e. the frequency of its foaming decreases. This leads to a decrease in the intensity of the molding process, compaction of the resulting foam in the place of the smallest gap in height between the forming surfaces, the mixture does not reach everywhere.

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flat parts of the upper forming surface, therefore get a defect.

The known method does not allow intensively to form semi-cylinders from a quick-hardening mixture, to improve their quality and to ensure at the same time savings in material resources.

The purpose of the invention is to intensify the molding process from a quick-hardening mixture of half-cylinders, improving the quality and economy of the material,

The goal is achieved by the fact that according to the method of forming polycylinders from foam, including feeding the foaming mixture of liquid components with a filling head at the entrance to the forming channel between two continuous forming surfaces located one above the other, foaming it while synchronously moving these surfaces in the longitudinal direction and selecting the finished, According to the invention, the speed of movement of the shaping surfaces is reduced; product, feed the foaming mixture into the forming channel when it overlaps with a partition, then increase the speed of the forming surfaces while increasing the mixture in volume while simultaneously removing the filling head from the entrance to the forming channel, and the speed of movement of the forming surfaces and the distance that is removed filling head, choose from the following ratios:

ti

v 4h 0 H 0.51;

t2

in which

 12 (1 + t);

t2

where I is the length of the semi-cylinders from foam between adjacent transverse partitions;

g is the mixture flow rate;

ti, t2 is the time, respectively, from the moment it is supplied to the entrance to the gap between the forming surfaces to the time it starts foaming and to the end of hardening;

v is the speed of movement of the forming surfaces;

L is the length of the molding section; And, is the distance that the casting head is removed from the entrance to the gap between the forming surfaces; k is the expansion ratio of the mixture;

p irg is the density, respectively, of the mixture of liquid components at the moment of its supply to the entrance into the gap between the forming surfaces and the half-cylinder of foam plastic;

s is the cross-sectional area of the semi-cylinders made of foam plastic or the cross-sectional area of the gap between the forming surfaces;

2 - the length of the fill area.

Fig. 1 shows a schematic (general view) of an apparatus for carrying out a method for forming foam products; Fig 2 is the same, top view; in FIG. 3 - section A-A in FIG. one.

A device for molding foam products includes two conveyor 1 and 2 spaced apart with vertical transporting bodies 3 and 4 mounted with a gap 5 and provided with forming surfaces 6 and 7, partitions 8 located on the forming surfaces 6 of the upper conveyor 1, and the filling head 9 connected to the filling machine 10. The transporting body 4 of the lower conveyor 2 is provided with a tape 11, closed in a vertical plane, laid on the forming surface 7 of the upper branch 12 of the protractor organ 4

the lower conveyor 2 and interacting with partitions 8, and the end sections 13 and 14 of the belt are installed with respect to the longitudinal axis of the gap 5 between the forming surfaces 6 and 7 of the conveyors 1 and 2, and the lengths of the molding and pouring sections are determined from the following relationship:

45

L 12 (1 + -§-),

where ti and t2 are the time, respectively, from the moment the mixture is fed to the inlet 15 into the gap 5 between the forming surfaces 6 and 7 until the beginning of foaming and until the end of solidification;

2 - the length of the fill section 16;

L is the length of the molding section 17;

I is the length of the half-cylinder of foam between adjacent transverse partitions 8.

Conveyors 1 and 2 are plate-grooved. As transporting bodies 3 and 4 respectively

The lower and upper grooved conveyors 1 and 2 use, for example, two chains, enveloping drive and tension sprockets. To support the upper 12 and 18 and lower 19 and 20 branches of the transporting bodies 3 and 4 and belts 11, a support mill is located between the drive and tensioning stations (conventionally not shown),

In the lower conveyor 2, the cross-sectional shape of the grooves is made in the form of a semi-ring, and in the upper conveyor 1, the cross-sectional shape of the grooves is made in the form of a semi-ring with straight line segments at the ends located along one straight line.

The gutters 3 and 4 are attached to the transporting bodies so that they, adjacent to each other by adjacent ends, form the corresponding forming surfaces 6 and 7 on the lower branch 19 of the transporting body 3 of the upper conveyor 1 and on the upper branch 12 of the transporting body 4 of the lower conveyor 2.

The method is carried out as follows.

The liquid components according to the method are prepared (for example, they are heated to the required temperature in the respective sources, including component tanks, heating elements, pipelines, shut-off and regulating and safety bodies, as well as instrumentation devices (figures not shown in connection with the possibility of mass-produced products).

Then, from these sources, the liquid components in a predetermined ratio by the casting machine 10 through the filling head 9, in which they are mixed into the reaction mixture, in the form of foaming mixture, are fed into the gap 5 between the two closed in a vertical plane forming surfaces 6 and 7, which synchronously move in the direction of their longitudinal axes.

In order to intensify the molding process from a quick-hardening mixture of semi-cylinders, to improve their quality and to save material resources, this is done in the following way.

The heated components, for example, the FRV-1A resin and the VAG-3 product, are cast by the casting machine 10 through the casting head 9, and more precisely through its locking bodies, without mixing, i.e. separately, in addition to its mixer, they are supplied through recirculation hoses to the supply tanks. In this way, the suction and feed hoses, the filling metering pumps are heated up.

machines 10 and filling head 9, which includes a mixer, and subsequently provide to the gap 5 between the forming surfaces 6 and 7 a mixture of liquid components at a given stable temperature, which provides an intensification of the molding process of foam plastic products, improving their quality, eliminates scrap, saves material resources.

During warm-up by recycling

the liquid components of the casting machine 10 and the filling head 9 include a device for forming foam products for idle operation;

at the same time the forming surfaces b and 7.

Making sure that the casting machine 10 is in normal operation, having checked, for example, the dosage of liquid components, as well as the normal operation of the device for

product molding, semi-cylinders are made of foam. For this, the speed of movement of the forming surfaces 6 and 7 is reduced and, by opening the casting head 9, the foaming mixture

is fed to the inlet 15 into the gap 5 between them at the time of its cross section overlapping by a partition 8, and at the moment of increasing the mixture in the volume simultaneously increasing the speed of movement of the forming surfaces 6 and 7 and the filling head 9 is removed from the entrance 15 to the gap 5 between the forming surfaces 6 and 7. At the same time, the speed of movement of the forming surfaces 6 and 7 and the distance that the filling head 9 is removed from the entrance 15 to the gap 5 between them are selected from the following ratios:

40

T-v TNO AND 0,

gk / PI vs: IC / 5 At the same time, the mixture of liquid components at the filling site 16 enters the tape 11 closed in a vertical plane, which is provided with the transporting body 4 of the lower conveyor 3 and which is laid on the forming surface 7 of the upper branch 12 of the transporting body 4 of the lower conveyor 2 and interacts with partitions 8 located on the forming surfaces 6 of the upper conveyor 1, sections 13 and

14 tapes are installed with an excess relative to the longitudinal axis of the gap 5 between the forming surfaces 6 and 7 of the conveyors 1 and 2.

At the filling station 16 on the belt 11, the liquid components are foamed,

continuously from the filling head 9. At the same time, the mixture increases in volume and through the inlet 15 into the gap 5 between the forming surfaces 6 and 7 enters, completely filling its cross section. At the molding site 17, the mixture is located in a molding channel closed on all sides, formed by a gap 5 between the forming surfaces 6 and 7, at opposite ends limited by adjacent partitions 8. Thus, the molding section 17 passes through partitions 8 separated along the length of the forming channel into separate segments, there it finally foams up and cures. Finished products from polystyrene in the form of semi-cylinders of a predetermined length, equal to the distance between adjacent transverse partitions 8 located on the forming surfaces x 6 of the upper conveyor 1, emerge from the molding section 17.

The proposed method provides obtaining high-quality products such as semi-cylinders from a quick-hardening mixture, improves their quality and leads to the economy of the material.

Claims (1)

Claim Method A method for forming semi-cylinders from foam, comprising feeding a foaming mixture of liquid components with a filling head at the entrance to the forming channel between two continuous surfaces forming one above the other, foaming it when these surfaces move synchronously in the longitudinal direction and selecting the finished product that differs the fact that, in order to intensify the molding process from a quick-hardening mixture, improve the quality of the product and save material, reduce the speed of movement of the forming surfaces, carrying transverse partitions on the top of them for the length of the product being manufactured, feeds the foaming mixture into the forming channel when it is closed by a partition, then increases the speed of the forming surfaces while increasing the mixture in the volume while removing the filling head from the entrance to the forming channel , wherein the speed of movement of the shaping surfaces and the distance to which the filling head is removed are selected from the following ratio Nij: l / ti v L / t2; 0 h 0.51; v g k / s; K pilpi L 1 (1 + m); m ti / 12; where I is the length of the half-cylinder of foam; g is the flow rate of the mixture of liquid components; ti is the time, respectively, from the time of submission to the beginning of foaming; t2 is the time from foaming to cure; v is the speed of movement of the forming surfaces; L is the length of the molding section; p, pl is the density, respectively, of the mixture of liquid components at the moment of its supply to the entrance into the gap between the forming surfaces and the half-cylinder of foam plastic; s is the cross-sectional area of a half-cylinder of polystyrene or the cross-sectional area of the gap between the forming surfaces; And, is the distance that the filling head is removed from the channel entrance; K - the multiplicity of foam. OLG g; h-1 I Go Mr ABOUT Go L-f-- -S.  g. L and Y} hЈ1 1 iJ (; L  . Г i 1 || 66999Л1