SU1636242A1 - Head of extruder for manufacture of rubber-coated metal cord sheet material - Google Patents

Abstract

The invention relates to extruders for the manufacture of rubberized metal cord fabric. The purpose of the invention is to improve the quality of rubberized fabric and expand the technological capabilities of using the extruder head. For this, the extruder head includes a housing with a channel for feeding the rubber compound. The liner with the comb and the mouthpiece are installed in the case. The working surfaces of the mouthpiece and the channels are curved and contiguous. By adjusting screws it is possible to move the parts of the mouthpiece relative to the tangent to the adjacent surfaces of the comb. The radius of curvature of the surface of the mouthpiece is 0.3-0.5 of the radius of curvature of the channel surface. This ratio provides the pressure needed to form a firm bond between the rubber and the metal cord fabric. This eliminates the possibility of vulcanization of the rubber mixture in the extruder die. 4 il. with s

Description

The invention relates to equipment for the production of pneumatic tires and can be used to make extrusion carcass and belt breaker blanks.

The purpose of the invention is to improve the quality of rubberized fabric and expand the technological capabilities of using the extruder head.

Figure 1 shows the extruder head, a general view; figure 2 is the same, front view; in FIG. 3 - section A-A in FIG. one; figure 4 - node I in figure 2.

The extruder head includes a housing 1 made of two parts - the lower part of the housing 1 and the cover 2. Parts of the housing 1

connected to the bolts 3. In the housing 1 there is a channel 4 for feeding the rubber compound. An insert made of two parts 5 and 6 and two parts 7 and 8 of the mouthpiece are installed between parts 1 and 2 of the body. Between parts 5 and 6 of the liner, a comb 9 is fixed, in which holes 10 are made. From the entrance to the die plate 11, working surfaces A and B of parts 7 and 8 of the mouthpiece are made curvilinear and are tangentially aligned with curved working surfaces C and D of channel 4 housing 1.

Parts 7 and 8 of the mouthpiece are mounted to form a die 11 with the ability to move relative to the comb 9 along

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tangent to mating surfaces in slots 12 and 13 of housing 1 by means of adjusting screws 14 and 15, between which parts 7 and 8 of the mouthpiece are installed.

The radii RI of the curvature of the surfaces A and B of the mouthpiece are selected within 0.3-0.5 of the radius R2 of the curvature of the surfaces C and D of the housing 1, and the planes D and E of the sockets 12 and 13 are tangent to the surfaces A, B and C, D .

The R2 / R1 ratio in the range of 0.3-0.5 provides the pressure necessary for the formation of a durable compound of the rubber mixture with the metal cord fabric and eliminates the possibility of vulcanisation of the rubber mixture in the extruder head.

These ratios of radii RI and R2, which provide smooth transitions of surfaces to surfaces C, D, when moving the mouthpiece along surfaces D. E of the nests 12 and 13, are chosen from the following considerations. As is well known, the bond strength of substrates in the case of rubber mixture and metal cords strands depends on pressure and contact time. At small values of RI (5-10 mm), the pressure in the mixture rises sharply at the entrance to the die plate, which leads to a strong connection of rubber with a cord cord. For large values of R2, to achieve the same effect on the strength of the joint, a longer contact time is required, i.e. an increase in the length of the spinneret 11 is required. In the latter case, the mixture can be pre-cured in the die 11, which will lead to a decrease in the strength of the joint and reliability in operation. Thus, the RI value should be in the range of 5-10 mm, i.e. commensurate with the thickness of the lining. If Ra is less than 2 RI (RI / R2 ratio of 0.5), then there is a danger of turbulence of the rubber mixture at the surfaces A and B of the housing, which can lead to scorching, deterioration of the quality of the lining and reliability of the extruder head in operation. On the other hand, if R2 is more than 3Ri (Ri / R2L O ratio, 3), the residence time of the mixture in channel 4 of housing 1 is increased, which can also lead to vulcanisation of the rubber compound and undesirable consequences. Thus, the selected ratio Ri / R2 in the range of 0.3-0.5 is a necessary and sufficient condition for improving the quality of the rubberized web, increasing reliability in operation and expanding the possibility of using the extruder head.

The extruder head operates as follows.

Threads 16 of the steel cord are inserted into the holes 10 of the comb 9. Comb 9 is installed between the liner parts 5 and 6. The strands 16 are conducted between portions 7 and 8 of the mouthpiece. The mouthpiece (parts 7 and 8) and liner (parts 5 and 6) in the collection are placed in the lower part1

housing 1 and cover with lid 2. Parts of housing 1 are bolted 3. With screws 14 and 15, adjust the position of the die 11 relative to the holes 10 of the comb 9. For example, simultaneously twisting

0 screw 15 and screwing the screw 14, move parts 7 and 8 of the mouthpiece down. At the same time, a smooth transition is maintained between the radii RI and R2 (Fig. 3). From the extruder, the rubber mixture is fed through channel 4 of housing 1.

5 The rubber mixture passes along the surfaces A, B, C, D, E and E in the spinneret 11, while the rubber mixture envelops the yarns 16, forming a rubberized canvas. In case of displacement of parts 7 and 8 of the mouthpiece with the spinneret

0 11 down, for example, the thickness of the lining with a rubber mixture at the bottom of the steel cord 16 will be greater than at the top. In this way, the thickness variation of the rubber cord web is ensured.

5After the end of the extruder, in

If you change the brand of cord or rubber compound, unscrew the bolts 3. Lift the lid 2, disassemble the liner into parts 5 and 6 and the mouthpiece into parts 7 and 8. Clear from

0 rubber mixture channel 4 of housing 1, die plate 11, parts 7 and 8 of the mouthpiece, holes 10 of the comb 9. Then, metal cord 16 is inserted into the holes 10 of the comb 9 and the process is repeated.

5 The proposed extruder head allows to expand the range of use by making it possible to manufacture rubberized steel cord fabric with both the same and a different lining with a rubber mixture of breaker layers of advanced tire designs. The extruder head improves the quality of the rubberized steel cord fabric by eliminating local

Claims (1)

5 resistances to the flow of rubber mixture in the body by smooth transition of the surfaces of the channels of the body and the cover to the surfaces of the mouthpiece from the entrance to the die plate. Invention Formula 0 The extruder head for the manufacture of rubberized steel cord fabric, comprising a housing with a rubber feed channel formed therein, mounted in the housing an insert with a comb, 5 adjustment screws and a mouthpiece with the spinneret installed between the screws, which is so that, in order to improve the quality of the rubberized web and expand the technological capabilities of using the extruder head. with sto5 1636242 .6 Rions of entry into the die plate are the working surfaces of the working surface of the channel of the body, and the munmunshtuk and the channel are made with curvilinear-pieces installed with the possibility of changes, moreover, the radius of curvature of the surface-scheni relative to the comb along The mouthpiece has been chosen in the range of 0.3 times the radius of curvature of the interface that is tangent to these adjoining surfaces, 5 and 5 cm. H sh, u 1A 1 P P 13 Fig.Z