RU2731224C1 - Method and device for production of decorative thermo-shrinking polymer cap - Google Patents

Abstract

FIELD: transportation, packaging and storage of goods.

SUBSTANCE: invention relates to production of thermosetting caps for sealing of vessels or bottles or for re-sealing of vessels or bottles closed with a pre-plug, cover or other closure. In particular, the invention relates to caps with a thermo-shrinking skirt, that are caps formed from a thermoplastic material, which when sealed are seated on the neck as a result of supply of heat energy.

EFFECT: technical result is wider range of shapes of manufactured cap.

3 cl, 3 dwg

Description

The invention relates to heat-shrinkable caps for sealing vessels or bottles or for resealing vessels or bottles previously closed with a stopper, lid or other closure. In particular, the invention relates to caps with a heat-shrinkable skirt, that is, caps molded from a thermoplastic material which, when sealed, shrink on the neck as a result of the supply of thermal energy.

Specifically, the invention relates to a novel method for making a decorative heat shrinkable polymer cap on a molding machine.

State of the art

A known method of manufacturing heat shrink caps on machines by blow molding, see US patent No. 5118460, from 02.06.1992. In this method, a tube of thermoplastic material is extruded and expanded in divided molds to form interlocking bottle caps, and then cut to form a pair of said bottle caps.

The closest source is the Russian patent No. 2279382 dated 07/10/2006, which discloses a method of manufacturing caps with a heat-shrinkable skirt. This method consists in forming a cap from a polymeric thread of a tube on the heating elements of the forming wheel, and then removing them.

The disadvantage of this device is a number of limitations:

1) the formation of caps only cylindrical or conical;

2) the possibility of manufacturing heat-shrinkable caps with a tear-off tab only at the top of the cap;

3) production of caps of only one standard size.

Disclosure of invention

The purpose of the invention is to produce heat-shrinkable caps of different shapes and with an additional cap option: with a tear-off tab at the bottom of the cap; and also manufacture of different standard sizes of caps at the same time.

This goal is achieved due to the fact that, in contrast to the nearest known technical solution, this machine allows you to preset any shape of the shrink cap on the preforming unit and bring this shape to the required dimensions in the heat tunnel.

The technical result is to expand the range of shapes of the produced cap.

The technical result is achieved by the fact that a method for manufacturing a decorative heat-shrinkable polymer cap on a molding machine consists in:

- mixing the components of the PVC mixture,

- heating and melting the PVC mixture,

- molding the melt in a ring head,

- forming a tube blank by extrusion,

- heating the tube blank,

- biaxial orientation of the tube blank to obtain a sleeve of a polymer tube,

- cooling the sleeve of the polymer tube,

- cutting the sleeve of the polymer tube into lengths equal to the height of the produced cap.

At the same time

- cutting the sleeve of a polymer tube is carried out both with a straight cut and with a shaped cut at the top of the blank with a tear-off tongue and / or at the bottom of the blank with a tear-off tongue to obtain cap blanks of different shapes, and then carry out

- installation of cap blanks of different shapes on the corresponding mandrels of at least one forming wheel,

- preliminary formation of caps of different shapes by heating cap blanks of different shapes in the area of the lower part of the mandrel, heating elements of the forming wheel,

- the passage of the preformed cap through the thermal tunnel, where, depending on the temperature and wheel speed, the final shape of the cap is given,

- removing the cap.

The device for manufacturing a decorative heat-shrinkable polymer cap includes a line for the production of a sleeve and a machine for forming a heat-shrinkable cap from a sleeve of a polymer tube. In this case, the line for the production of a sleeve includes: a cylinder of a worm press, an annular forming head, a cooling stage of an annular forming head, a pressure roller assembly, a heating and sleeve orientation unit, a second forming device, a winding unit and a control and adjustment unit for a tube production line, and the machine for forming a heat-shrinkable cap is made in the form of at least one frame with a forming wheel, on which mandrels are fixed along the entire length, a preforming unit, where the blank is initially heated, a heat tunnel through which the mandrels move during the rotation of the wheel and a block management.

In addition, mandrels of various shapes can be attached to the wheel.

The cut of the polymer tube is pushed onto a mandrel that is attached to the forming wheel. It is retained due to the fact that the thread diameter is almost equal to the lower diameter of the mandrel. In the preforming unit, the preform is initially heated, the shrinkage process begins, and the preform adheres tightly to the lower part of the mandrel; then the mandrel with the workpiece enters the thermal tunnel, where, under the influence of temperature, the workpiece shrinks and takes the form of a mandrel.

It is possible to manufacture caps of different standard sizes, since it is preferable to install several wheels at once on the molding machine.

The feed of the grooves to the wheels (putting on the mandrels) is carried out manually.

The forming mode can be set individually for each wheel.

Brief Description of Figures

The essence of the invention is illustrated by Figs. 1-3, which show Fig. 1, a line for the production of a sleeve of a polymer tube, Fig. 2, a machine for forming a heat shrink cap from a sleeve of a polymer tube, and Fig. 3, a mandrel of molding wheels of a machine for molding a heat shrink cap.

List of positions in Figures 1-2:

1 - cylinder of a worm press;

2 - annular forming head;

3 - cooling stage of the annular forming head;

4 - assembly of pressure rollers;

5 - unit for heating and orientation of the sleeve;

6 - the second forming device;

7 - winding unit;

8 - control and adjustment unit for the tube production line;

9 - frame;

10 - control unit of the molding machine;

11 - forming wheel;

12 - thermal tunnel;

13 - preforming unit.

Implementation of the invention

The claimed method is carried out by means of the following lines for the production of a sleeve of a polymer tube (figure 1) and a molding machine (figure 2)

The line (worm press) (1) is designed to manufacture a polymer tube in the form of a seamless sleeve by orienting, molding and fixing the parameters of the product.

The processed material is a composition based on PVC and various additives that affect the processing of the melt, as well as the operational properties of the finished product.

The cap manufacturing process is carried out as follows:

1. The composition based on PVC enters the material cylinder of the worm press 1, where it is melted and homogenized.

2. The resulting melt is formed in the gap of the ring head 2

3. The tube blank is formed at the exit from the annular head in cascade 3, where the initial cooling of the tube sleeve takes place.

4. Next, the tube enters the pinch roller assembly 4 and the sleeve heating and orientation unit 5, where the tube is reheated, biaxially oriented in the longitudinal and transverse directions, and to the second forming device 6, where cooling takes place. This gives the tube heat shrinkage properties. The heat-shrinking properties of PVC tubes are explained by the fact that when the tube comes into contact with high temperatures, it tends to return to its original dimensions, acquired earlier. Next, the tube sleeve enters the pinch roller assembly 4 again.

5. The cooled and oriented tube is wound around the winding unit 7 and a tube reel is formed.

6. The formed tube bobbin is transferred to a slicing machine, see FIG. This machine is used to produce a cut blank. Slicing can be either with a straight cut or with a tear-off tongue (either at the top of the workpiece or at the bottom of the workpiece)

7. The workpiece in the form of a cut is transferred to the forming wheel 11.

8. On the forming wheel 11 mandrels are installed (see figure 3), having the shape of the required cap

9. Blanks are put on the mandrels

10. During the rotation of the wheel, the mandrel with the workpiece put on it first enters the preforming unit 13, where the workpiece shrinks on the lower part of the mandrel under the influence of temperature; then the workpiece enters the thermal tunnel 12, where, under the influence of temperature, the final shrinkage of the workpiece occurs and it takes the form of a mandrel. This creates a heat-shrinkable sleeve that can be removed from the mandrel (either manually or using compressed air).

In this case, the bobbins of tubes are fed manually with the use of small mechanization means, first to the machine for cutting blanks, then the blanks are manually moved to the forming wheel.

The line operates in an autonomous mode, where a seamless sleeve of a polymer tube is continuously obtained from the PVC mixture.

The equipment is operated at a temperature of 10-30 ° C and a relative humidity of 45-75%. Power is supplied from the AC 380 / 220V, 50 Hz.

In addition, air is supplied to the line at a pressure of up to 6 atm. Cooling water comes from the water supply. Hot (up to 95 °) water is used to reheat the tube.

The line is based on the principle of extrusion and production of tubular film oriented in the longitudinal and transverse directions. The design of the line allows you to measure and control the temperature in the zones of the worm press, forming tool and water for re-orientation of the film. It is possible to control the rotation speed of the guide rollers. In addition, the control and regulation of the air pressure inside the sleeve (through the mandrel), as well as the pressure supplied to the pressure rolls (pneumatic supports) is provided.

The line works in automatic mode, with continuous tube extrusion.

The drive of the worm press 1 is carried out from a DC or AC electric motor through a V-belt transmission, a gearbox to the auger. In this case, the rotation speed is regulated by a rheostat or a frequency regulator from the control panel, respectively.

Maintaining the required heat balance and technological modes on the line is carried out by heating and cooling the established zones of the line.

Cooling of the loading zone of the worm press and the orientation unit is carried out with tap water. The temperature measurement and control system contains a control unit for the fans, which are switched on when the set value of the heating zone of the worm press is exceeded. When the temperature drops to the set temperature, the fans turn off.

Thermocouples serve as temperature sensors. The preset temperature is set on a narrow-profile regulating device located on the control panel.

The molding machine, see Fig. 2, consists of several independent frames 9. On each frame 9, an axle with a forming wheel 11 is mounted in supports. The forming wheels 11 are fixed on the axle so that it is possible to move them left-right to center the heating elements relative to the center of the heat tunnel 12.

Technically, it is implemented as follows: the wheel base is put on the axle and has locking mechanisms on the axle. If it is necessary to displace the wheel for the purpose of centering, then the locking mechanism is unscrewed, the wheel is shifted in the desired direction, the locking mechanism is twisted.

The molding machine makes it possible to produce a heat-shrinkable cap by forming a cap from a polymer tube or cutting on mandrels of the forming wheel 11, which repeat the required shape of the cap, when passing through the thermal tunnel 12. The machine device allows forming a cap with a diameter of 18.5 mm to 100 mm and a height of 15mm to 90mm.

In the upper part of the frame 9, a thermal tunnel 12 is fixed. Electric heaters, a fan and a thermocouple that monitors the temperature in the thermal tunnel 12 are mounted in the thermal tunnel 12. control unit 10 of the molding machine.

To the end part of the heat tunnel 12 is attached a cap preforming unit 13, in which the cap preforming temperature and the blank heating zone are controlled. At this stage, the blank for the production of the cap is fixed in the required zone on the heating element and approaches the specified dimensions of the cap, in order to further obtain the required shape when passing through the thermal tunnel 12. The temperature of preforming is (50-85) ° C. This, in turn, allows you to expand the range of shapes of the produced cap.

The forming wheel has spokes, at the end of which mandrels are fixed (see Fig. 3). The wheel rotates clockwise continuously. The blank of the polymer tube is put on the mandrel in the lower left position. The mandrel enters the preforming unit 13, where the blank is initially heated, the shrinkage process begins, and the blank adheres tightly to the lower part of the mandrel. Further, the mandrel with the workpiece enters the thermal tunnel 12, where, under the influence of temperature, the workpiece shrinks and takes the form of a mandrel.

Different cap shapes are obtained by using different shaped mandrels.

For the convenience of removing the cap from the heating element, an automatic blowing with compressed air is provided. The cap shifts by 5-10 mm.

This method of the invention is used to manufacture heat-shrinkable caps of various shapes and with an additional cap option: with a tear-off tab at the bottom of the cap; and also manufacture of different standard sizes of caps at the same time. For this, the blanks of the cap with a pre-cut tongue are put on manually or with the help of an applicator on the heating elements of the rotating forming wheel.

The use of the invention allows to expand the range of shapes of the produced cap.

Claims (17)

1. A method of manufacturing a decorative heat-shrinkable polymer cap on a molding machine, comprising: - mixing the components of the PVC mixture, - heating and melting the PVC mixture, - molding the melt in a ring head, - forming a tube blank by extrusion, - heating the tube blank, - biaxial orientation of the tube blank to obtain a sleeve of a polymer tube, - cooling the sleeve of the polymer tube, - cutting the sleeve of the polymer tube into lengths equal to the height of the produced cap, characterized in that - cutting the sleeve of a polymer tube is carried out both with a straight cut and with a shaped cut at the top of the workpiece with a tear-off tongue and / or at the bottom of the workpiece with a tear-off tongue to obtain cap blanks of different shapes, - installation of cap blanks of different shapes on the corresponding mandrels of at least one forming wheel, - preliminary formation of caps of different shapes by heating cap blanks of different shapes in the area of the lower part of the mandrel, heating elements of the forming wheel, - the passage of the preformed cap through the thermal tunnel, where, depending on the temperature and wheel speed, the final shape of the cap is given, - removing the cap. 2. A device for the manufacture of a decorative heat-shrinkable polymer cap according to claim 1 of the formula, including a series-installed line for the production of a sleeve and a machine for molding a heat-shrinkable cap from a sleeve of a polymer tube, while the line for the production of a sleeve includes: a cylinder of a worm press, an annular forming head, a cooling a cascade of an annular forming head, an assembly of pressure rollers, a heating and sleeve orientation unit, a second forming device, a winding unit and a control and adjustment unit for a tube production line, and a machine for forming a heat-shrinkable cap is made in the form of at least one frame with a forming wheel , on which mandrels are fixed along the entire length, a preforming unit, where the blank is initially heated, a thermal tunnel through which the mandrels move during the rotation of the wheel and a control unit. 3. The device according to claim 2 of the formula, in which mandrels of various shapes are fixed on the forming wheel.

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