CS258205B1 - Spdsob and equipment for waste recovery from thermoplastic production - Google Patents

Abstract

Method and device enabling the use of waste from the production and processing of thermoplastics, especially in the mass of colored thermoplastics, into full-fledged products of defined coloration using color additives in the waste thermoplastic by dosing the waste thermoplastic in the form of an agglomerate into the empty cavity of the screw of the melting-mixing member and filling the unfilled space of the screw cavity with the base polymer. The amount of dosed waste thermoplastic depends on the current performance of the device, which consists of a waste thermoplastic dispenser, which flows into the melting-mixing member before the outlet of the feed of the processed base polymer. The drive of the waste thermoplastic dispenser is adjustable together with the drive of the screw of the melting-mixing member.

Description

258205

The present invention provides a method of treating waste from the production of thermoplastics, especially fibers and foils treated with pulp, granulate or powder, and equipment for such waste treatment.

Secondary raw materials arising from the production and processing of thermoplastics are processed in a variety of ways into profiled products of lower quality, as long as I cannot return directly to production at the time of production. Most often they are crushed, chopped, ground, agglomerated, and processed into more sophisticated products again, melted and regranulated, and can be treated qualitatively with the addition of stabilizers or other impurities and de-impurities, e.g. by trapping metal particles with magnets, melt filtration, and the like. Such treated wastes are mixed with granulate, grit and the like. with a handle prior to feeding it to the melter.

The most effective processing is usually their incorporation into the product, the production of which they were produced, especially if they are high-value products. For example, in the production of synthetic fibers, these wastes are typically incinerated and, until recently, they have been processed by polymerization, application to adhesives, or molding into various plastic products, usually of lower value. All of these processes are energy-intensive or do not sufficiently recover waste, especially when it comes to waste. The use of pigments and dyes requires the incorporation of the same color tones, hampering the long-term storage problems of individual shades. The time depends on how quickly an amount of waste can be recovered economically. In chemical processing processes, pigments and colorants which are substantially more expensive than the polymer itself are destroyed. There are known systems for dispensing two components with two hoppers in succession into one excerpt such as NSH 3 107 214, United Kingdom 1 590 381, 2 028 218, USA 4 252 755 and others and their systems are not able to respect their exact ratio, which is in demanding production, especially the production of a wider assortment of, for example, fibers dyed in the mass to different shades by the decisive factor.

In an irregular manner, the material from the first hopper passes into the second hopper and the uneven production process. Therefore, this problem is already solved by the multi-threaded spindle of the extruder, whereby the individual threads take the material from the individual pins. These solutions are particularly suitable where high melt homogeneity of the two components is not required, such as in the marble structure of products, laminates and the like.

More preferably, these wastes can be returned to production according to the present invention, the principle being that the waste thermoplastic in the form of agglomerates, optionally with additives, is continuously fed into the empty recess of the screw of the melting screw and the unfilled spaces are filled with the base polymer in a certain ratio so that the technological process and ultimately the properties of the fibers were not affected.

The process according to the invention is carried out in an apparatus according to the invention in which the waste thermoplastic dispenser drive from the screw of the melter-mixing member is capable of changing the proportions of the dispensed waste thermoplastic to the base polymer being processed. In this case, the waste polymer dispenser discharges into the melter-mixing member by pre-dispensing the feed of the processed base polymer in the direction of material displacement.

In the case of fibers dyed in the mass, pigments which are deposited in the waste can also be very advantageous if the waste is sorted according to color shades. Their addition in small amounts rarely affects the resulting color shade. The shade is usually only influenced when one of the pigments needed for tinting the color shade is used in low concentration and its thermostability is low in processing temperatures. In this case, the pigment is added in addition to the waste to be treated or the coloring agent in a suitable form, e.g. a low pigment concentrate.

Various types of volumetric dispensers are suited for dispensing waste, the network of which is derived from 3 258205 from the drive of the worm-reducer screw. This method is also suitable when the screw threads of the melting-down member are controlled in a pressure-dependent manner, whereby variations in the spindle speed, and thus the speed of the dispenser, do not affect the properties and color shade of the molded articles being manufactured.

In the accompanying drawing, there is shown schematically a waste recovery device from the production and processing of thermoplastics according to the present invention, which consists of a melting-down member 100 on a surface 105 and a spindle drive 110 provided with a polymer inlet 102 and a periphery 103 thereof. wherein the waste thermoplastic dispenser 200 is comprised of a spindle 201 of its drive 210, which is derived from the drive 110 of the screw 101a is provided with an inlet 202 of the waste thermoplastic material. Přikladl

Fibrous waste from the production of polypropylene fibers dyed in the mass to a red shade of 0.8% by weight. of pigment RED 144 and 0.3 wt. pigment RED 166 was agglomerated with a Condux agglomeration plant. The agglomerate was added in the production of the fiber of the same color shade by the Spiral Bulk Dispenser to the front of the spinning line of the spinner extruder, separated from the subsequent portion to feed the granulated polypropylene through the baffle. thereby providing 8% agglomerate dosing. 0.8% reduced the dosage of the bleach concentrates of the mentioned pigments by which the fibers were dyed. The fibers thus produced the same color shade and the same physico-mechanical properties as without the agglomerate. Example 2

The fibrous waste as in Example 1 was processed into an agglomerate which was mixed with 0.2% by weight prior to dosing. of a styrenised phenol phosphite heat stabilizer. The modified agglomerate was metered in the production of fibers of the same shade by a two-helical dispenser into the front of the spinner extruder hopper as in Example 1. The speed of the dispenser was firmly fixed by an easily variable set of gears allowing to vary the speed ratio of the dispenser and the extruder. With set weight. a ratio of 1: 2.5 to the extruder of 10.2% by weight. agglomerate. The dosage of the concentrate composition of Example 1 was reduced by 10.2% by weight. The fibers had the same properties as without the addition of agglomerate. In addition, the aging resistance of the fibers increased by 10%. Example 2

Fibrous waste from fiber production dyed to a golden yellow shade of 0.8% by weight. PigmentYellow 83 0.05 wt. % Red pigment and 0.03 wt. The pigment Black was treated similarly to Example "2" to an agglomerate that was melted on the extruder. The melt is extruded on strings which, after cooling in water, are cut into granules. The granulated concentrate was added to the base polymer with a single-screw dispenser as in Example 1.

The speed of the dispenser was mechanically stable with the speed of the extruder spinning device with a 2-outlet - for the dispenser and the extruder with the possibility of setting different ratios.

At a speed ratio of 1: 3, 8 wt. regranulate. Since the red pigment dispensed at low concentration was destroyed by multiple remelting, its content in the concentrate concentrates of the mentioned pigments increased by 8% by weight. and dispensing this fiber staining composition by 8% by weight. In the fibers, the same color shade and properties were obtained as due to the production without the granulate.

Legend: 100 - melting-off member 101 - screw 102 - primary polymer inlet 103 - processed polymer discharge

Claims (2)

258205 Legend: 105 - heating of melting-down member 110 - drive of screw * 200 - dispenser of waste thermoplastic 201 - spindle of dispenser 202 - inlet of waste plastic material210 - spindle drive A method of utilizing waste from the production and processing of thermoplastics by mixing the waste treated to the agglomerate with the added additives with the fresh thermoplastic in the screw and mixer, and re-forming the articles characterized in that the agglomerate wastes are added to the empty voids, and the unfilled spaces are filled with fresh thermoplastic, the performance of the dispenser and additive being dependent on the performance of the melting mixer. 2. Installations for the utilization of waste from the production and processing of thermoplastics by the method of floor 1, consisting of a melting element and a waste thermoplastic dispenser, characterized in that the drive (210) of the waste thermoplastic dispenser (200) is adjustable with a screw drive (110) the melter-mixing member (100), wherein the waste-plastic waste dispenser (200) opens into the melter-mixing member (100) prior to the inlet (102) of the base polymer being processed. 1 drawing