SU1255450A1 - Device for making porous articles - Google Patents

Description

The invention relates to the processing of plastics, including secondary plastics, in particular to forming tools, extrusion units for the production of polymer products.

The aim of the invention is to improve the quality of products and expand the technological capabilities of the device by ensuring the manufacture of porous products of a given density.

FIG. 1 shows a device for making porous products with a smooth surface, a general view; in fig. 2 - the same, in the manufacture of products with a rough surface; in fig. 3 shows section A-A in FIG. one.

The device contains successively installed on the flange of the extruder 1 adapter 2, case 3 and interchangeable mouthpiece 4. In case 3, a mandrel mounted as external 5 and internal 6 parts, between which cavity 7 is formed. Parts 5 and 6 are rigidly fastened to each other. In parts 5 and 6 of the mandrel, annular channels 8 are provided, communicated with cavity 7 by means of radially arranged holes 9. The annular channels 8 are arranged to move the ball 10. The gas supply means is made in the form of tongues 11 mounted tangentially to the annular channels 8. The device has a transition zone 12, a zone 13 between, the inner surface of the housing 3 and the outer part 5 of the mandrel and the exit zone 14. The housing 3 and the mandrel are mounted movably relative to the adapter 2, and the mouthpiece 4 is mounted longitudinal movement relative to housing 3.

At the outlet of the mouthpiece 4, there is an ultrasonic sensor (not shown) of the density of products associated with throttles (not shown) for controlling the supply of the gas-blowing agent.

The device works as follows.

The polymer melt from extruder 1 flows through adapter 2 into zone 12, separates and flows partially into zone 13 formed by the housing 3 and the outer part

5 a mandrel, and into the cavity 7. In zone 14, the material is bonded and fused.

Under the influence of a jet of gas supplied under pressure through fittings 11, balls 10, which are in a closed circuit and form a ball gear, having received a force directed tangentially to the annular channel 8, transmit this force to each other, start to move, alternately blocking the orifice 9 of which short gas jets release gas. In this way, pores are created in the polymer melt passing through the cavity 7. The dimensions of the gas bubbles depend on the volume of the inter-sphere space in the annular channel 8. The dimensions of the gas bubbles can be controlled by the speed of rotation of the balls 10 by varying the gas supply pressure. After the parts of the melt alloy TC in zone 14, the melt comes out through the mouthpiece 4, forming a product having a porous structure inside and dense smooth

 outer surface.

When the relative position of the housing 3, the mandrel, its outer part 5 changes relative to the adapter 2, on which the housing 1 is screwed up to the stop

5 parts of the mandrel in the adapter 2, the device works as follows (Fig. 2).

Polymer melt from extruder 1, through adapter 2, goes directly into cavity 7. To prevent polymer melt from entering zone 13 from

The Q of the mouthpiece 4 from the entrance zone 14 is also screwed only through the cavity 7, i.e. In the pore formation zone, the polymer melt gets a porous structure throughout the entire cross section of the material, and the product acquires a porous structure inside and a rough

surface.

The ultrasonic sensor continuously measures the density of the porous material and, through the control unit, reduces or increases the gas supply pressure so that the product has the desired properties.

Products can be produced with various modifications of porous structures without stopping the production process line.

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FIG. 2

Editor O. Yurkovtsku Order 4767/20

Compiled by M. Fitisova Tehred I. VeresKorrektor V. But ha

Circulation 640 Subscription

VNIIPI USSR State Committee

for inventions and discoveries

113035, Moscow, Zh-35, Raushsk nab. 4/5

Branch PPP "Patent, Uzhgorod, st. Project, 4

Claims (1)

DEVICE FOR MANUFACTURE OF POROUS PRODUCTS, comprising sequentially installed adapter, body and mouthpiece mounted in the mandrel body with gas sample feed means, characterized in that, in order to improve the quality of products and expand the technological capabilities of the device by ensuring the manufacture of porous products of a given density, the mandrel is made in the form of external and internal parts mounted with the formation of a cavity with annular channels communicated with the cavity by means of a radially split bored holes, and is equipped with balls placed in the annular channels with the possibility of movement, and the means for supplying the gas of the sampler are in communication with the annular channels in the outer and inner parts of the mandrel, the housing and the mandrel mounted to move relative to the adapter, and the mouthpiece is mounted with the possibility of longitudinal movement relative to the body. figure 1 SU ,, „1255450