JPS63202408A - Production equipment of reclaimed pellet of waste pet resin film or the like - Google Patents

Abstract

PURPOSE:To eliminate the need of long-time drying process and make it possible to easily melt extrude fluff with an extruder by a method wherein the bore of a heating cylinder at a feed zone is specified and a single or double flighted screw is employed in the feed zone ranging to a melt starting means, and a triple shallow flighted screw is employed in the feed zone, in the region back of which material melts. CONSTITUTION:The bore D1phi of a heating cylinder 1 at a feed zone is D1=(0.5-1.5)h+d in which (h) is the channel depth of a screw 5 and dphi is the screw outer diameter, so as to increase the bite of material and conveying capacity in cooperation with the screw 5, and thus the throughput with respect to the bore of an extruder is made as large as possible. A single or double flighted screw having large feeding capacity is employed in the zone A ranging to this side of the kneading block 6, which is the melt starting point, of the screw 5. In the zone B, a triple flighted screw is employed so as to increase the shearing heat buildup due to shallow flight effect and the cuts and surface renewal effect of the material due to the increase of number of flight at vent port 1. In addition, an operation to reduce pressure to 10Torr or less is done at a first vent port 2. As a result, a long-time drying process become unnecessary and reclaimed pellets, the lowering percentage of intrinsic viscosity of which is 5% or less, are easily manufactured with melt extruding fluff having a bulk specific gravity of 0.04-0.18.

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field to which the Invention Pertains> The present invention relates to an apparatus for producing Pj13T resin, and more particularly to an apparatus for producing recycled pellets from pulverized products (fluff) of film or sheet waste with low specific gravity.

Conventionally, this type of recycled pellets has been produced by drying fluff with hot air and granulating it by bath-melt extrusion with a moisture content of 50 ppm or less.

Therefore, in order to dry the material to a moisture content of 50 ppm or less, a long drying process is required, and non-quality PE
In T, temperature control during drying also costs 3.

It was extremely time-consuming work.

PnT granulation without this drying step has a lower intrinsic viscosity (hereinafter referred to as IV) due to hydrolysis and a lower molecular weight, making the Nyu product unusable.

Inventor Temple conducted various studies in order to propose a manufacturing device for producing recycled fluff pellets that does not require the long drying time required in conventional methods and does not lower the IV.

(1) Minimize the time that raw materials in a water-containing state are exposed to high temperatures.

(2) Rapidly remove water immediately after melting to minimize the drop in IV.

(3) In order to minimize the time of exposure to high temperatures, that is, to minimize the residence time of the material in the extruder, etc., the throughput should be made as large as possible relative to the extrusion port diameter.

In order to increase the throughput as much as possible, the inventors considered that the larger the inner diameter of the cylinder, the greater the throughput.
A test was conducted to confirm the injection limit of the feed section of the extruder.

Next, the test results are shown below.

Screw groove depth: h = 9.5 mm Screw rotation speed: 300 m 400 * 48 r, p0m Cylinder inner diameter: Dφ Gap between screw and cylinder inner diameter: , = D s 7 = N , h = 9.5 N (N
: coefficient).

The relationship between the rate of increase in feed amount α) and the gap (1) between the screw and the inner diameter of the cylinder is as shown in the graph shown in Figure 4, and as can be understood from this graph, the rate of increase in feed amount is approximately 50 cm. is the limit, and even if the inner diameter (gap t) is increased further, it will reach a plateau, and the coefficient N is about 1.5.If the lower limit is 0 or more, an increase can be expected, but it is actually better to set it to 0.5 or more. After all, N is preferably about 0.5 to 1.5.

We came to the conclusion that it would be better to use a twin-screw extrusion machine, which can achieve uniform melting and can handle a large amount of extrusion in a short period of time.

This led to the present invention.

Means for Solving the Problems〉 In order to eliminate the above-mentioned drawbacks, the present invention provides a co-rotating, meshing type screw having a kneading disk or kneading block, etc. that provides a strong mixing and kneading action to the materials. PET resin film or film, etc. is pulverized using a block-type heating cylinder combining multiple short / s, I-rels, and a twin-screw press having at least two vents φ, with a specific gravity of 0.04. When melting and extruding fluff of ~0.18 to produce recovered pellets with an intrinsic viscosity reduction rate of 5 cm or less, the feed section up to the melting initiation means such as the inside diameter of the heating cylinder in the hood section is connected to a single or double screw electric wire. After the material melts, a shallow groove 3-thread thread is used, and the first vent hole reduces the pressure to 10 Torr or less. By adopting the above-mentioned invention, a long drying process is not required as in the conventional method. Fluff can be easily melt-extruded using an extruder without having to do so.

Embodiment> Next, one embodiment of the present invention will be explained with reference to Fig. g1 and Fig. 2. 1 is a heating cylinder and a barrel la.

It is a block system that combines multiple lbs, ICs, etc., with different inner diameters, or one with a vent, or one with a material supply port, depending on the operating conditions. Corresponds to a variety of different situations.

The length, etc. of the heating cylinder can be adjusted by changing the order, adding, or removing a plurality of barrels.

2 is the material supply 0.3 and 4 are each ml, the second pen mouth. The vent holes 3 and 4 are two vent holes so that the moisture of the material can be rapidly dehydrated into a 9-hole corner.

The feeding part of the heating cylinder 1 has an inner diameter, ρ♂ is the groove depth of the screw, and the outer diameter of the screw is dk3, then 1) = (0.5 to 1.5) h + d.

Coupled with the screw described below, this increases the material injection and transfer capacity, and increases the extrusion port diameter of the extruder.

We are increasing the amount of processing as much as possible. 5 is a two-axis screw, and as shown in Fig. 2, 58 and 5b mesh with each other and rotate in the same direction.The self-screw 5 has a kneading mechanism that gives strong mixing and acombination effects to the materials. A block 6 is provided, and this kneading block 6 is made up of a plurality of oval or polygonal disks having no threads on their outer peripheral surfaces and stacked one on top of the other in the axial direction with different phases. The screw 5 has a large feed capacity in the section up to the kneading block 6, which is the melting start point (section A in the figure). It is threaded.

Effect> Test results using the recycled pellet manufacturing apparatus according to the present invention, which has the above-mentioned configuration, are shown below.

Chi 15 [↓bi #2”c>) *jQxg i 7
tourJ6fllfiJv(tte1)1ri2
94°C, 72) 211 JOJ'C/O
; o, f; As can be understood from the above test results, the recycled pellet manufacturing apparatus of the present invention does not require the long drying process conventionally performed, and can regenerate with an IV decrease rate of 5 cm or less. Pellets are easily produced.

[Brief explanation of the drawing]

FIG. 1 is a diagram of an apparatus showing one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II in FIG. 1...Heating cylinder, 2...Material supply port, 3゜4...Vent hole, 5...Screw, 6...Kneading block.

Claims (1)

[Claims] Co-rotating machines having kneading disks or kneading blocks that give strong mixing and kneading effects to materials;
The heating cylinder is a block-type heating cylinder consisting of a plurality of short barrels, and has an intermeshing screw, and at least two
When producing recovered pellets with an intrinsic viscosity reduction rate of 5% or less by melt-extruding fluff with a bulk specific gravity of 0.04 to 0.18, which is obtained by pulverizing a PET resin film, etc., using a twin-screw extruder with vent ports at several locations, the feed The inner diameter of the heating cylinder of the screw is set to the outer diameter of the screw + (0.5 to 1.5) h [h: screw groove depth], and the feed section of the screw to the melting start means such as a kneading disk is set to one or two threads. 1. A recycled pellet manufacturing device characterized by having a thread thread and a shallow groove three thread thread after melting the material, and performing a pressure reduction operation of 10 Torr or less at a first vent port to remove debris such as a PET resin film.