LV11943B - Method and device for producing of thermal shrinking adhesive polymeric clutch - Google Patents

Abstract

This method and device are designed for the production of an active cylindrical type polymer thermo-settling cap which at the time of settling shrinks only in a radial direction. The orientation device provides development of no-residue technology using a supply of the production material in non-stop mode. The adhesively active thermo-settling-capping intermediate layer is formed of polymeric mixtures among others. The composition contains inorganic type filling materials.

Description

The patent relates to the processing of polymeric materials and can be used to obtain thermosetting polymeric sleeves (tubular cuts) using dead-end technology and techniques that modify and make the inner surface of adhesive-active sleeves important for the operation of these products.

The method is based on the radiation or chemical treatment of crystallizable polymers (mainly polyolefins) which promote the "crosslinking" of polymer macromolecules.

Radiation treatment uses gamma rays or accelerated electron flow, and chemical treatment uses the presence of crosslinking agents, such as organic peroxides.

The crosslinks between macromolecules resulting from crosslinking form a three-dimensional (mesh) lattice, thus altering the structure of the polymer resulting in a change in the deformation properties of the polymer. At elevated temperatures, such modified polymers do not undergo a viscous flowing deformation (do not melt) and exhibit rubber-like properties.

If the polymeric material is deformed (e.g., stretched to a temperature greater than the melting point of the crystalline phase, then cooled under isometric conditions (deformed), the material acquires a new shape and size according to the orientation and degree of orientation. the phase melts, the deformed intermolecular bonds relax (shrink) and the material regains its original shape uu dimensions, resulting in a so-called "shape memory effect".

Known methods and devices for obtaining thermoset couplings are the radial orientation of cross-linked polymeric tubular products at elevated temperature with subsequent product-oriented cooling. Orientation is accomplished by a variety of techniques: the thin-walled tube is orientated continuously by means of a calibration chamber where the heated tube is blown with compressed air [1], the thick-walled tube is oriented by placing it on a larger diameter nozzle or by other mechanical orientation techniques; which extend the tube [2] with each other, etc.

The closest prototype to the nature of the method and the principle of the device used is the orientation of the radiation-bonded polymer tubular cut (including thick-walled) by blasting and forming an inner interlayer of the same polymer with a slight for the purpose [3],

The disadvantages of the prototype are as follows; the orientation is subjected to separate small tubular cuts, both ends of which are sealed by mechanical shutters, which result in unoriented tube end residues; the applied interlayer does not provide the effectiveness of the increased adhesive bond required for operation; the interlayer material requires mandatory surface heat treatment; the interlayer material is easily meltable (compared to the base material), practically devoid of thermosetting forces, and cannot be used in parallel orientation with the base material in case of elevated orientation temperature (eg if the base material is made of a mixture of polyethylene and polypropylene, etc.).

The purpose of the patent is to obtain thermonuclear sockets that do not produce technological residues during the orientation process; the interlayer material may be oriented simultaneously with the parent material in any temperature range necessary for orientation of the parent material; to obtain thermoset couplings with increased adhesive properties and to heat-treat the inner surface of the interlayer, if necessary to improve the adhesive properties.

The objective can be achieved by simultaneously orienting the base polymer and the adhesive active layer-forming intermediate polymer made of special compositions (polymer blends; polymer containing adhesive bonding inorganic nature fillers; polymer by special chemical, thermal, plasma, etc.) The orientation device consists of bi-directional moving heating and new shape locking (orientation) half shapes, as well as raw material transportation, the necessary pipe end sealing and compressed air supply systems.

The method and device to be patented differ from the prototype; Orientation is accomplished by means of a device that enables the development of outlaw technology; orientation is achieved by long polymer tubes (eg in the form of a roll); the inner interlayer is made of a polymeric composition whose thermal and deformation properties are comparable to those of the parent polymer.

Thus, the method and device to be patented have elements of "novelty". The essential features, other than the prototype, are known in science and technology. Only by embracing these elements in their entirety and interconnected can it be possible to obtain an adhesively active polymeric thermoset coupling having the characteristics required for operation.

Example of method application and device operation.

The radiation modified polymer tube 1 (Fig. 1) is subjected to a radially oriented orientation by means of a device consisting of a feed mechanism 2 (made of profiled rubber rolls), two heating half shapes 3 (reflectors with halogen infrared tube lamps), two orientation half shapes 4, which simultaneously serves for cooling the article (made of stainless steel with the necessary surface forming and treatment), for the internal heating element 5 (halogen infrared lamp enclosed in a copper mesh housing with a perforated fluoroplast on the top) and a polymer tube at the bottom sealing element 6 (profiled fluoroplast lining).

At the start of operation, the end of the raw material (polymer tube) must be designed to be seated on a tapered sealing member 6.

If only the polymer orientation is provided, no further operations are required.

If the parent material and the adhesive-active interlayer material are to be oriented simultaneously, additional operations must be performed in advance to insert the interlayer material into the parent material tube. The interlayer material must be made in the form of a tube. If the tube is a thin wall (may be flattened), it is pulled through the entire length of the base material by various means (eg wire) and blown (if necessary with hot air) to close the inner surface of the base material. If the interlayer polymer tube is thick-walled, it shall be inserted into the base tube in the form of strips during the process steps.

The oriented tube is heated to the required temperature by at least 10 ° C above the melting point of the crystalline phase of the parent material (optimally to a known polymer equilibrium melting point) by means of semi-heating.

The internal heating element 5 is simultaneously used to accelerate the heating of the polymer tube. The temperature of this element may be increased if heat treatment of the inner layer (thermo-oxidative desorption) is required.

After the heating half-shapes are folded around the polymer tube, the orientation half-shapes are folded 4. The half-shapes are formed so that they seal together the lower part of the polymer tube (around the sealing element 6).

By supplying compressed air at a specific pressure of 0.05 ... 0.2 MPa (depending on the deformation properties of the polymeric material and the wall thickness of the tube) towards the upper end of the tube (e.g., the start end of a rolled coil) the dimensions of the orientation shape. The compressed air simultaneously cools the inner surface of the oriented portion of the tube if the sealing member 6 is formed with calibrated air leakage ducts. The time of the isometric cooling process is chosen by experimentally determining the temperature of the outer and inner surface of the tube, which does not cause the thermoset socket to self-dry.

After the orientation half-shapes are retracted, the finished part is cut (eg with a rotating saw) at a location 7 that meets the requirements of the techno logical mode (for laying a new part of the tube on element 6). This requires a slight retraction of the elements 5, 6, followed by a tilt in the head to remove the article.

The method and device used produce thermoset nozzles which, during the deposition process, change their dimensions mainly in the radial direction (axial displacement of not more than 1% of the length of the article).

Tables 1 and 2 show examples of materials needed to make radiation modified thermosets and their properties when oriented with the patented device.

The shrinkage of the thermoset coupling in the radial direction during heating (settling) is provided by the forces determined by the thermo-relaxation voltage (gtr). After settling on a certain diameter body and cooling, etc. The forces of the "envelope" are in turn determined by the residual sedimentation voltage (Jun). These forces depend on the chemical composition of the material subjected to orientation, the amount of dose absorbed by ionizing radiation, the degree of orientation (stretching), the heating temperature and the cooling mode (speed), as well as the thickness of the thermoset socket wall.

The interfacial adhesive activity A * 'was determined after contact with the chemically purified iron sheet. The contact temperature is selected according to the orientation temperature and the pressure is determined according to the force values determined by σ · π <σ-τκ and σ _{Ν on} the tape type samples on the tensomelar stress measuring device in the isometric heating and cooling modes respectively.

'A is determined by the peel resistance value at 20 ° C.

Example 1:

The base material and interlayer material are made of low density polyethylene (LDPE) with a melt index of ki = 1,7 g / 10 min. The basic material is irradiated with gamma radiation up to an absorbed dose D „ _bs = 150 kGy, the interlayer material - D _abs = 15 kGy. The interlayer material is heat treated for 3 miu. at 250 ° C.

Example 2:

The base material is made of ZPPE and irradiated to D _abs = 150 kGy. The interlayer material is made from 50% ZBPE + 50% SKEPT (synthetic rubber of ethylene-propylene copolymer with daily addition) and irradiated to D _abs = 150 kGy.

Example 3:

The base material is made from ZBPE uu irradiated to D _abs = 150 kGy. The interlayer material is made of 5% ZBPE + 95% SKEPT uu irradiated to D _abs = 100 kGy.

Example 4.

The base material is made of high density polyethylene (ΑΒΡΕ) with a melt index kj = 0.53 g / 10 min. and irradiated to D _abs = 150 kGy. The interlayer material is made from a composition of 20% ΑΒΡΕ + 80% SKEPT uu irradiated to D _abs = 150 kGy.

Example 5.

The base material is made of a mixture of polymers 50% ΑΒΡΕ + 50% PP (polypropylene) and irradiated to D _abs = 150 kGy. The interlayer material is made from 50% ΑΒΡΕ + 50% SKEPT and irradiated to D _abs = 150 kGy.

Example 6.

The basic material is made of recycled (secondary raw material) high density polyethylene (HDPE-R) with a melt index k; = 3.9 g / 10 miu. and irradiated to D _abs = 150 kGy. The interlayer material is made from 80% HDPE-R + 20% SKEPT and irradiated to D _abs = 150 kGy.

Example 7.

The base material is made from a composition of secondary raw materials: 90% HDPE-R + 10% kaolin and irradiated to D „bs = 150 kGy. Interlayer material shall not be used.

Example 8.

The base material is made from a composition of recycled raw materials with the addition of rubber SKEPT: 70% ZBPE-R + 20% ABPE-R + 10% PP-R + 5% SKEPT and irradiated to Nature ⁼ 150 kGy. Interlayer material shall not be used.

In all examples, the base material of said thermosetting socket is made of a polymer tube having an outer diameter of 20 mm and a wall thickness of 2 mm; interlayer material made of polymeric tube, external diameter 15 mm, wall thickness 0,5 mm.

Table 1

Example Basic material Orientations degree, ε,% Orientations temperature, T, ° C Thermonuclear forces Adhesion A, kN / m σ ™, MPa σ _Ν , MPa Example 1 (prototype) 100 125 0.2 1.1 1.2 Example 2: 100 125 0.2 1.1 1.2 Example 3: 100 125 0.2 1.1 1.2 Example 4 100 140 0.3 2.0 0.6 Example 5 100 175 0.5 2.4 1.6 Example 6. 100 140 0.1 1.8 1.0 Example 7 100 140 0.2 1.0 3.5 Example 8 100 175 0.18 1.2 2.6

Table 2

Example Interlayer material Orientations degree, ε,% Orientations temperature, T, ° C Thermal fusion forces Adhesion A, kN / m Gtr, MPa Yes, MPa Example 1 (prototype) 100 125 are not are not 1.8 Example 2: 100 125 0.5 0.8 2.64 Example 3: 100 125 0.3 0.3 3.2 Example 4 100 140 0.4 0.5 2.0 Example 5 100 175 0.6 0.9 1.8 Example 6. 100 140 0.2 0.4 2.6 Example 7 no interlayer Example 8 no interlayer

Comparing the patented method and device with the prototype, it can be concluded that: the proposed method and device produce thermosetting sockets without the remnants of the pipe ends; simultaneous orientation of the parent material and interlayer material is possible since the deformation properties of the interlayer in relation to temonosedic forces meet the deformation conditions of the parent material; increases the adhesive properties of the thermoset couplings compared to the prototype.

LITERATURE

1. USSR a / apl. N 513870, m.p. B29 D 23/03, 1976.

2. Japanese Patent N 56-139590, p. B 29 C 17/02, 1983.

3. USSR a / apl. N 1463499, s.kl. B29 D 23/09, 1988.

Claims (3)

PATENT FORMULA 1. A method for producing an adhesively active polymeric thermoset coupling, characterized in that it simultaneously orientates the thermoplastic coupling base material and the inner interlayer having deformable properties and thermosetting forces comparable to the base material. 2. The method of claim 1, wherein the interlayer material is formed from an adhesively active polymer composition. 3. The belt for carrying out the method of claim 1, wherein the orientation assembly comprises two-way movable tubular article exterior surface heating molds, an article interior surface heating element, article oriented positioning mold semiconductor element, end sealing, an orientation assembly area for the compressed air supply mechanism and a cut-off mechanism for creating a new workpiece according to the requirements of the technological cycle.