Description

STATIONARY OR MOBILE BITUMINOUS MODIFIED PLANT

Technical Field

The present invention includes an integrated and/or complicated plant, which enables to obtain and/or apply the modifier materials containing polymer and/or rubber and/or chemical components mixed into the bituminous material used in asphalt and/or directly into asphalt as admixtures in the best way and consists of five chapters totally as two main chapters.

Prior Art

There are many inventions, which enable the asphalt obtained by using polymer and/or rubber admixtures in the world to become much more durable, flexible, quieter and long-lasting, and the application techniques obtained as a result of these inventions.

Much more efficient and useful ones and more usable ones than these techniques are rubber-based admixtures. However, mixture of this admixture into asphalt requires special machinery and equipment.

There are many general purpose plants in the world that have been developed in this regard and have been actively involved in the asphalt applications for years. There are a rare number of plants globally for use and/or application of the polymer or rubber admixtures as the bituminous and/or asphalt admixtures, and the present invitation includes a complicated plant incorporating al of the procedures and methods of manufacture of both polymer and/or rubber-based raw materials and use and/or application of these raw materials as the bituminous and/or asphalt modified admixtures.

The complicated plant subject to the present invitation incorporates the customized bench, machine and equipment, which are subject to another patent, and have the vulcanized powder rubber-based bitumen and bituminous binder properties, and enable to obtain a developed surface consisting the interconnected particles having a grain size of 50m for the modifying admixture added to the bituminous mixture in the conglomerates having a grain size of 800m and a rubber bituminous mixture with an NR-SBR-BR mixture obtained from the powder vulcanized rubber having a bulk density of 350Kg.m ³ . Again, the complicated plant subject to the present patent provides the bituminous and/or asphalt applications of the vulcanized rubber admixture obtained in the scope of the patent directly or indirectly.

The styrene butadiene rubber (SBR) structure contains approximately 75% butadiene (CH2=CH-CH=CH2) and 25% styrene (CH2=CHC6Hs) raw materials.

Description of the Invention

The plant subject to the invention consists of two main divisions:

1. Polymer Bitumen asphalt admixture

1.1.0. RAW MATERIAL MIXTURE STOCK DIVISION

1.2.0. MODIFIED MILL

Capacity : 20 tons/hour (and more and less)

Mill Feeder Pump : 4" Ultra Pump (15kW, 1000 rpm)

1.3.0. VERTICAL/HORIZONTAL MIXING TANK (2 sets)

1.3.1. Casing-Main Unit

a. It has a vertical, rectangular/cylindrical/ellipsoidal section.

b. It has a volume of not less than 8m ³ and/or more.

c. The casing is made of 5mm St 37.2 A1 grade sheet.

d. It has the breakwater plates against return to ensure that bitumen is mixed homogenously with the polymer admixture in the internal wall surfaces of the tank according to the capacity.

e. The lower cambers have a suitable depth to prevent any dead zones.

f. The suitable electrodes and methods are used in the welded joints.

g. It has 2x 7.5kw 105 rpm reducer/motor-drive mixer levers.

h. There are 1x 3" DN80, PN16, DIN2633 bitumen filling pipe, and 2x 3" DN150, PN16, DIN2633 and 3" DN80, PN16, DIN2633 discharge pipes.

i. 1 SBS filling pipe has a diameter of 6".

j. The inspection door is 500x500mm. 1.3.2. Heating

a. The dia-thermal hot oil (12m ² ) shall be heated on the external wall.

b. The external wall is made of 4mm St 37.2 A1 grade sheet.

c. The wall pitches that provide circulation of the oil are 100mm.

d. The top sides of the wall have the annual bleed outlets.

e. The oil inlet and outlet pipes are 2" and have DN50, PN16, DIN2633 properties. f. The impermeability test is conducted at 6 bar for 12 hours.

1.3.3. Isolation

a. 50mm rubitz stranded rock wool is suitable for TSE standards

b. Its external surface shall made of trapezoidal sheet coated by RAL 9002 dye and/or coated by isolate and/or similar special insulation material and built in the container.

1.3.4. Mixing System

a. 2x 11 kW, 60 rpm mixing systems.

b. The drive sprocket coupling is used.

c. Impermeability is provided in the bearings.

d. SKF or FAG is used in the bearings.

e. There are a rotating spindle and spiral blades on it. Thus, accumulation of material is prevented

f. The fixed blades are mounted on the outer walls, thus increasing the dispersion and providing a more homogeneous structure. The fixed blades are distributed equally between the movable blades and 8 units are used

1.3.5. Weighing System

4 load cells having a capacity of 5000Kg are used.

1.4.0. SPIRAL

Size : 0 168 x 6000mm (from axis to axis)

Quantity : 1 set

Engine : 3kW 100 rpm reducer type

There are 2 inspection covers as one at the top and one at the bottom. 1.5.0. COMPRESSOR

Operating Pressure : 6 bar

Air Tank : 1x 200L

1.6.0. INSTALLATION EQUIPMENT

1.6.1. Pipes

a. The steel drawn pipe shall be DIN171175 (DN200, DN150, DN100, DN80, DN65, DN25).

b. The mill line shall built with 3" internal pipes and 4" external pipes coated by jackets and/or isolate and/or similar special insulation and/or anti-corrosion and/or fire protection material.

c. The jacketed pipes must be welded in TSE standards.

d. The bypass pipes shall be 1" and mounted in any proper places.

1.6.2. Compensators

a. 2x DN 50, PN16, 400°C

b. 2x DN 80, PN16, 400°C

1.6.3. Heating Type 3-Way and 2-Way Valves

a. It is suitable for TSE standards.

b. It is pneumatic controlled type.

c. It provides any conditions, when it can operate at high pressure (16 bar) and temperature (230°C).

1.6.4. Hot Oil Valves

a. DN25 PN16: 6 ones are in suitable size and standards.

b. DN65 PN16: 4 ones are in suitable size and standards.

c. DN50 PN16: 2 ones are in suitable size and standards.

1.6.5. Filter

a. It has 3mm wire and an internal reservoir, and may be cleaned frequently and easily.

b. It has 3" flanged inlet and outlet pipes. 1.7.0. CONTROL CABIN AND CONTROL SYSTEM

a. The system has a PLC control.

b. The industrial and rack type computer/operator panel and desktop computer are used in the system.

c. There are the switchgear and control panels in the system.

d. There is a board, which conforms to the IC standards.

e. Mixing time and temperature are controlled automatically.

f. After mixing, P.M.B. (Polymer material) is passed and its supply to the other mixing tank is controlled automatically.

g. P.M.B. prepared in the system is supplied automatically to the stock tank.

h. All the valves used in the system during all processs are controlled on the operator panel via the pneumatic actuators.

2. Rubber Bitumen asphalt admixture division

2.1.0. RAW MATERIAL MIXTURE STOCK DIVISION

2.2.0. MODIFIED MILL

Capacity : 5 to 40 tons/hour (and more and less)

Mill Feeder Pump : 4" Ultra Pump (15kW, 1000 rpm)

2.3.0. VERTICAL/HORIZONTAL MIXING TANK (1 set)

2.3.1. Container Type Frame

a. The profile has a square/rectangular/cylindrical/conical section.

2.3.2. Casing-Main Unit

a. It has a vertical, rectangular/cylindrical/ellipsoidal section.

b. It has a volume of 12m ³ .

c. The casing is made of 5mm St 37.2 A1 grade sheet.

d. It has 2” tubular spray nozzles.

e. It has 2x 7.5kw 105 rpm reducer/motor-drive mixer levers..

f. The suitable electrodes and methods are used in the welded joints.

g. The bitumen filling pipe: 1x 3" DN80, PN16, DIN2633 bitumen filling pipe.

h. The discharge pipe: 2x 3" DN150, PN16, DIN2633 and 3" DN80, PN16, DIN2633 discharge pipes.

i. The inspection door is 500x500mm. 2.3.3. Heating

a. The dia-thermal hot oil (12m ² ) shall be heated on the external wall.

b. The external wall is made of 4mm St 37.2 A1 grade sheet.

c. The wall pitches that provide circulation of the oil are 100mm.

d. The top sides of the wall have the annual bleed outlets.

e. The oil inlet and outlet pipes are 2" and have DN50, PN16, DIN2633 properties.

f. The impermeability test is conducted at 6 bar for 12 hours.

2.3.4. Isolation

a. 50mm rubitz stranded rock wool is suitable for TSE standards

b. Its external surface shall made of trapezoidal sheet coated by RAL 9002 dye and/or coated by isolate and/or similar special insulation material and built in the container.

2.3.5. Mixing System

a. 1x 7.5kW, 114 rpm mixing system.

b. The drive sprocket coupling is used.

c. Impermeability is provided in the bearings.

d. SKF or FAG is used in the bearings.

e. There are a rotating spindle and spiral blades on it. Thus, accumulation of material is prevented

f. The fixed blades are mounted on the outer walls, thus increasing the dispersion and providing a more homogeneous structure. The fixed blades are distributed equally between the movable blades and 8 units are used

2.3.6. Weighing System

4 load cells having a capacity of 5000Kg are used. 2.4.0. DOSSING SPIRAL

Size : 0 173 x 6500mm (from axis to axis)

Quantity : 1 set

Engine : 4kW 98.5 rpm reducer type 2.5.0. FEEDING SPIRAL Size 0 173 x 8000mm (from axis to axis)

Quantity 1 set

Engine 7.5kW 124.4 rpm reducer type 2.6.0. RAW MATERIAL SHREDDING MIXER

Drive : Cylindrical from the casing

Quantity : 1 set

Engine : 4kW 58 rpm reducer ' 2.8.0. COMPRESSOR

Operating Pressure : 6 bar

Air Tank : 1x 200L

2.8.0. INSTALLATION EQUIPMENT

2.8.1. Pipes

a. The steel drawn pipe shall be DIN171175 (DN200, DN150, DN100, DN80, DN65, DN25).

b. The mill line shall built with 3" internal pipes and 4" external pipes coated by jackets and/or isolate and/or similar special insulation and/or anti-corrosion and/or fire protection material.

c. The jacketed pipes must be welded in TSE standards.

d. The bypass pipes shall be 1" and mounted in any proper places.

2.8.2. Compensators

a. 2x DN 50, PN16, 400°C

b. 2x DN 80, PN16, 400°C

2.8.3. Heating Type 3-Way and 2-Way Valves

a. It is suitable for TSE standards.

b. It is pneumatic controlled type.

c. It provides any conditions, when it can operate at high pressure (25 bar) and temperature (230°C). 2.8.4. Hot Oil Valves

a. DN 15 PN 16, DN 20 PN 16, DN25 PN16 and/or DN65 PN16, DN50 PN16, DN 80 PN 16 are in suitable size and standards. A different number of them are used sufficiently.

2.8.5. Filter

a. It has 3mm wire and an internal reservoir, and may be cleaned frequently and easily.

b. It has 3" flanged inlet and outlet pipes.

2.8.6. Circulation Pump

3" / 4" ultra / helical / internal eccentrically pumps.

2.8.7. Filling Pump

3" / 4" ultra / helical / internal eccentrically pumps.

2.9.0. CONTROL PANEL

a. The system has a switchgear and a control panel.

b. It conforms to the 1C standards.

Description of the Figures That Shall Help to Understand the Present Invention

Figure 1 ; a representative view of the general embodiment of the plant subject to the invention.

Figure-2; a representative view of the manufacture division, where the polymer-based admixture material is added to bitumen at the plant subject to the invention (Single Line).

Figure-3; a representative view of the rubber-based raw material manufacture division at the plant subject to the invention.

Figure-4; a representative view of the manufacture division, where the rubber and/or chemical modifier-based admixture material is added to bitumen at the plant subject to the invention (Single Line). Figure-5; It is a representative view of the dual-function manufacture division which enables the plant subject to the invention to add rubber or polymer-based admixture material as a bituminous admixture, provided it is not at the same time.

Part Numbers

(1 ) - Polymer-based raw material procurement and storage division

(2) - Rubber-based raw material production department

(3) - The division that makes the polymer-based raw material ready for application

(4) - The division that makes the rubber and/or chemical-based raw material ready for application

(5) - Polymer-based raw material product storage

(6) - Rubber-based raw material product storage

(7) - The division that makes polymer and rubber-based raw materials ready for application.

(8) - Polymer and rubber-based raw material product storage

(9) - Polymer application division, Chasing main unit (including the frame)

(10) - Polymer application division, Modified mill

(1 1 ) - Polymer application division, Material Vertical-heating type weighing and mixing tank

(12) - Polymer application division, Spiral

(13) - Polymer application division, Compressor

(14) - Polymer application division, Heating and Transfer Installation Equipment (Pipes, Compensators, Heating type two- and/or three-way valves, Hot oil valves, Filters, etc.)

(15) - Polymer application division, control cabinet and control system

(16) - Rubber-based raw material manufacture division, Crushing process

(17) - Rubber-based raw material manufacture division - Extrusion (Granulation)

(18) - Rubber Vulcanization Process (including carbon blasting)

(19) - Rubber-based raw material manufacture division - Powdering

(20) - Rubber-based raw material manufacture division, Packaging or direct transfer to the application

(21 ) - Rubber application division, Casing main unit (including the frame)

(22) - Rubber application division, Modified mill

(23) - Rubber application division, Material Vertical-heating type weighing and mixing tank

(24) - Rubber application division, Spiral (25) - Rubber Raw Material Dispenser

(26) - Rubber Raw Material Feed Spiral

(27) - Rubber application division, Compressor

(28) - Rubber application division, Heating and Transfer Installation Equipment (Pipes, Compensators, Heating type two- and/or three-way valves, Hot oil valves, Filters, etc.)

(29) - Rubber application division, Control cabinet and control system

(30) - Rubber and/or polymer-based application division, Casing main unit (including the frame)

(31 ) - Rubber and/or polymer based application division, Modified mill

(32) - Rubber and/or polymer-based application division, Material Vertical-heating type weighing and mixing tank

(33) - Rubber and/or polymer-based application division, Spiral

(34) - Rubber and/or polymer-based Raw Material Dispenser

(35) - Rubber and/or polymer-based Raw Material Feeding Spiral

(36) - Rubber and/or polymer-based application division, Compressor

(37) - Rubber and/or polymer-based application division, Heating and Transfer Installation Equipment (Pipes, Compensators, Heating type two- and/or three-way valves, Hot oil valves, Filters, etc.)

(38) - Rubber and/or Polymer-based application division, Control cabinet and control system

Description of the Invention

The invention consists of two main divisions:

1. The Polymer Bitumen asphalt admixture division;

It consists of two sub-divisions:

a. The polymer-based raw material storage division.

b. The division, which makes the raw material ready for application.

2. The Rubber Bitumen asphalt admixture division;

It consists of two sub-divisions.

a. The rubber-based raw material storage division.

b. The division, which makes the raw material ready for application. The plant subject to the invention has four functional divisions. These divisions may ensure installation and function completely fixed or partially fixed/mobile or completely mobile.

Detailed Description of the Invention

1. Polymer Bitumen asphalt admixture division;

a. The polymer based raw material storage division.

b. The division, which makes the polymer raw material for application.

i. Load cell feed silo.

ii. Quick Mixer.

iii. Static mixer.

iv. Mill.

1. Disintegrator (at least 20m3/h).

2. Hydraulic and manual adjustment of grinding discs with two different mechanisms.

3. Air Conditioner type Control Cabinet.

v. Continuous (continuous system).

vi. It has a system that automatically adjusts the disk space depending on the manufacture capacity.

2. Rubber Bitumen asphalt additive section; a. Rubber-based raw material manufacture division.

In 1839, Mr. Charles Goodyear observed that there were very important changes in its physical properties, exposing the rubber wares to sulfur vapor over the melting point. In the same dates, Hancock conducted any similar works in UK. They discovered the vulcanization together. In 1898, Dunlop succeeded to open new drill sites for rubber by making the first bicycle tire that was inflated by air.

The formula of natural rubber was found by Faraday in 1826. The chemical name of the natural rubber is cis 1-4 poly-isoprene. Of course, because the rubber has a highly regular and 99% cis structure, it has a high degree of crystallization. Namely, it hardens very easily.

Because of its high degree of crystallization, the movement of carbon atoms is limited. Therefore, the rubber molecules must be degraded mechanically and chemically.

Due to the double bonds and methyl groups contained in its molecular structure, the molecule is highly active. The active double bonds have a very high ability to enter the reaction. For example, it is vulcanized easily by sulfur. Mr. Charles Goodyear first time discovered the vulcanization as mentioned before. When he mixed and heated the natural rubber and sulfur, he observed that there were any improvements happened in many physical and chemical properties of the natural rubber. In case of vulcanization conducted with sulfur, an 8-atom ring-shaped sulfur molecule appears. The sulfur atoms interconnect the poly-isoprene chains and the crosslinking happens.

Whether natural or synthetic, all rubbers are part of the general polymer class of elastomers. Therefore, the elastomer concept must be known primarily.

Elastomer: The polymeric materials (macromolecules) which can be extended up to at least double its original length at room temperature and which can be restored almost to its original condition when the force providing this extension is eliminated is called as elastomer. The elastomers have binary bonds that provide flexibility. When the elastomers are in the raw state, that is, before they are subject to any chemical treatment or cooking, their properties are not suitable for commercial use. Therefore, in general, the elastomers are cooked by using various chemicals, namely vulcanized. Thus, the undesirable properties of the elastomers are eliminated and they are made very suitable materials for commercial use. Vulcanization, namely cooking event is called as a chemical crosslinking. The rubbers are elastomers that can be shaped and baked. The rubbers are divided into two among them: Natural rubbers and synthetic rubbers.

Although its raw material is rubber, tire is a material obtained by the combination of rubber, which is generated in a natural state from milky juice (latex) of some tropical plants, with petroleum and alcohol. The rubber, which was discovered by French scientists in South America in 1736 and which was vulcanized by Mr. Charles Goodyear in the early 1840s, has taken its place in the industry since then and has gained commercial importance.

This method of Mr. Goodyear has been developed over time with the addition of certain chemical substances which accelerate the sulfurization process and enhance the resistance of the rubber against breakage. First, the tire was obtained as "sulfur + rubber" and then the improvement was made by adding foreign substances into the tire for purpose of gaining importance. Furthermore, the dye material was added and the production of tires and plastics were started in different colors.

Phenols, amines and also some salts have been added to the rubber to become long lasting against the effect of the air, and to increase the strength of the tire, amorphous carbon and steric acid have been added to the tire in order to increase its strength. Today, any versatile special tires are manufactured and various parts are manufactured from them in line with the developing technology due to different raw materials.

Rubber, which is the most basic raw material of rubber dough, is never used alone. Generally, rubber dough contains 50% rubber by weight.

The natural rubber is manufactured from a milky fluid which is composed of the rubber tree called“Hevea brasiliensis.” The natural rubber consists of:

• 30 to 40% tire (cis-1 ,4 poly-isoprene);

• 2% resin and 60 to 65% water; and

• 2 to 5% lipid and protein. Raw Materials Used In Rubber dough

I. Peptizers

II. Elastomers

a. Natural Rubbers

b. Synthetic Rubbers

c. Reclaimed Rubbers III. Vulcanizing substances a. Sulfur

b. Sulfurous Substances c. Others

IV. Accelerators

a. ZnO

b. MgO

V. Activators

a. Organic

b. Inorganic VI. Preservatives

a. Anti-oxidants b. Anti-ozonants c. Physical preservatives VII. Softeners

a. Oils

b. Bitumen

c. Tars

d. Resins

VIII. Fillers

a. Booster

i. Carbon black

ii. Others

b. Attenuators

IX. Specific Components a. Colorants

b. Retardants c. Hardeners Materials used in typical rubber dough:

Ingredients Amount (phr) Function

NR 100.0 Natural rubber

Sulfur 1.0 Volcanizer

MBT 1.0 Accelerator, primary

TMT 0.1 Accelerator, secondary

ZnO 5.0 Activator, inorganic

Stearic acid 1.5 Activator, organic

Carbon black 40.0 Boaster carbon black

Mineral oil 1.5 Softener

PBN 2.0 Antioxidant

TOTAL 152.1 This formula is prepared according to 100 parts of rubber and abbreviated as PHR (Parts Per Hundred Rubber). In this formula, the weight of the mixture and contents is not important.

The mixture ratio is determined according to the raw rubber to be used. The formula containing the weight percentages of the components is more useful, because such formulas cause some confusion in calculating the weight of the rubber dough to be prepared. Thus, the composition weights required for the mixture to be prepared can be calculated easily. The formula prepared according to PHR is given below by weight percentages:

Component %

NR 65.746

Sulfur 0.657

MBT 0.657

TMT 0.066

ZnO 3.288

Stearic acid 0.986

Thermal black 26.300 Mineral oil 0.986

PBN 13.14

Total 100.00

(The example rubber dough by above weight percentages)

Most of the components have dual functions. For example, the accelerator MBT also behaves as a peptizer. In some raw materials they behave differently in synthetic and natural rubber. For example, ZnO can be used as an activator and a boaster filler for neoprene and for volcanic and natural rubber.

Of course, these formulas will not be enough to form rubber dough. Besides, the materials used in the dough recipe are not mixed at the same time. For this, the instructions given in the rubber dough are predetermined. A sample instruction is as follows:

(Instruction on rubber dough)

Another rubber formula and instruction

A recipe used in manufacture of car tires;

ingredients Amount (phr) Function

SMR 20 25 Elastomer (natural rubber)

SBR 1712 Kralex 62 Elastomer (SBR)

BR Nipol 1220 30 Elastomer (BR)

N-1 15 (carbon black) 65 Filler

ZnO 4,0 Activator

Stearic acid 2,0 Activator

6PPD 2,0 Antidegradant

TMQ 1 ,0 Antidegradant

Ceresine 1 ,5 Antidegradant Oil Nysolvex 830 21 ,0 Softener

CBS 1.0 Vulcanization accelerator

DPG 0,2 Vulcanization accelerator

Sulfur 1.9 Vulcanization chemical

(Rubber dough instruction)

Sulfur Use In the Rubber Industry (manufacture);

Sulfur is found in the category of cookers in the rubber chemicals. Powder and oily sulfur are used in rubber dough. Liquid sulfur is not used, because it is not pure.

Raw rubber consists of long-chain polymer chains that are not interconnected. A polymer chain is obtained by combination of a large number of small molecule chemical substances called “monomer” and measured as one hundred thousand of ones. Polymer chemistry is a science that deals with manufacture of polymers with various properties, starting from monomers. Because the polymer chains forming the raw rubber have an independent structure, they can slide over each other if a force is applied. This leads to the fact that the mechanical properties of the raw rubber such as tensile, tear, abrasion, etc. are very low. Therefore, raw rubber is not a convenient material for direct use. In 1839, Mr. Charles Goodyear discovered that these polymer chains, which could slide over each other, could be interconnected by the sulfur bonds. These bonds, which are formed between the polymer chains by sulfur, are then referred to crosslinks. The process of forming the crosslinks is called“vulcanization.” CROSSLINK DENSITY;

Because the resulting structure is more robust as the number of crosslinks connecting the polymer chains increases, the values such as hardness, breaking, tear, etc. rapidly increase. Thus, number of crosslinks in unit mass or unit volume (1 cc) is the most important parameter that determines stability of the tire. This parameter is called “crosslink density.”

As the crosslink density increases, the rubber hardens, but loses its flexibility, the extension reduces, and the modulus increases. A tire with highly increasing crosslink density losses its elasticity and is vulcanized. Therefore, the rubber products are referred to the products which are bonded with rare crosslinks. The crosslinks formed by vulcanization should not be so less as to create a weakness or not so much as to lose flexibility.

MONO VE POLY-SULPHIDIC STRUCTURE; Moore Parameter

Crosslinks can form in the mono-sulphidic or poly-sulphidic structure. The MONO structure defines a bond consisting of only one sulfur atom and the POLI structure defines a bond consisting of more sulfur atoms. The sulfur molecule is in the form of a ring with 8 atoms (S 8).

The accelerators turn on and activate this ring and allow this molecule to be transferred onto the chains of the rubber polymer. Most of the sulfur transferred to the rubber polymer crosslink the polymer chains to each other, forming the polyatomic sulfur bridges. However, some of them are connected merely to the polymer chains without forming a bridge. This last situation is called “sulfurization.” Sulfurization is nonfunctional for vulcanization. Moreover, it is also harmful because it causes oxidation easily. As the number of sulfurs increases in a sulfur bridge, the stability of the bridge decreases. Therefore, it is important to form the sulfur bridges in mono structure through the various formulation techniques. However, since the sulfur molecule has 8 atoms, the poly-structure is dominant in general. This particularly accelerates aging and reversion.

Moore Parameter: An important parameter that determines the average number of sulfur atoms used per crosslink. CROSSLINKING (VULCANIZATION) CONDITIONS;

The materials referred to accelerator and activator, and temperature and time, more clearly the heat profile and heat history of the vulcanization over time affect the crosslink formation. Without them, it is not possible in practice to form sulphate alone. Only vulcanization with temperature and sulfur can be provided in a very long time (3 to 5 hours).

To ensure that crosslinking takes place efficiently, sulfur must be dispersed very well and to be fine granular. The element that affects the final product properties at the top level is a good homogenous dispersion of sulfur. Sulfur can be used in quantities ranging from 0.5 Phr to 4 Phr in conventional, semi-efficient and efficient vulcanization systems. The recipe dosage of sulfur is an important recipe design that needs to be handled with other parts of the recipe.

SCORCHING OR EARLY SCORCHING;

Scorch means that the sulfur crosslinks begin to form earlier than desired during manufacture. In general, sulfur is added to the rubber dough after all other ingredients. The aim of adding sulfur to the rubber mixture finally is to prevent premature formation (premature cooking) of the crosslinks in the dough due to the heat generated by previous mixing process. Since the rubber dough is loaded with all fillers and other admixtures at the time of sulfur addition, its viscosity in Mooney increases highly and therefore requires a lot of energy. Such high mixing energy increases the dough temperature, and upon the addition of sulfur to the mixture, it enables the dough to cook quickly. The moment of sulfur addition is the most dangerous situation of the dough. All the early cooking and "scorch" events occur with the extension of this position. Therefore, sulfur is required to be added very quickly and the temperature is required to be increased during addition. To ensure that they may happen, it depends on the facts that the used sulfur variety may be dispensed very easily and viscosity of the dough with Mooney viscosity increased highly may be reduced again and cooled down. FUNCTIONAL SULFUR USE;

The task of sulfur vulcanization is a very critical basic function. The functions of all other admixtures such as accelerators and activators are in fact helpful for sulfur to conduct its basic function better. If sulfur, which is forced to react with admixtures more expensive than it by tens of times and identifies nature of the dough more valuable than it by hundreds of times from the foundation is ignored and its cheapest type is used, this is an interesting application encountered frequently in the conventional tire industry. The commodities such as powder sulfur, etc. are inputs used by the tire plants at the "conventional method" only by taking any cheap inputs into consideration. As they adopt the total quality management, and pass to the "customer focusing" and "process improvement" stages as next stages, the plants leave the commodities and direct to the functional chemicals improving the business processes. Art this stage, powder sulfur is left as a commodity, and use of the functional sulfurs (e.g. pre- dispersed granules in rubber) is started. Sulfur, which has a very critical function in the tire industry, must be observed as an input that must be chosen very carefully and accordingly its functions must be designed by taking the business processes of the tire industry into consideration.

Ethylene propylene diene monomer, which is the most correct raw material among the synthetic rubbers, is used, because it has resistance against solar-air oxidation and ozone cracks, a shore hardness range of 30 to 95 at temperatures between +1300°C and -400°C, and necessary permanent deformation values for impermeability in the system under extreme wind pressure.

When the explanations made so far are considered, this division of the plant is built as a functional building that may obtain the modifying admixture added to the bituminous mixture in the form of vulcanized powder rubber-based bitumen and bituminous bonders as a mixture of natural rubber (NR), styrene butadiene rubber (SBR) and butadiene rubber (BR) obtained from the powder vulcanized tire having its improved surface consisting of 50m interconnected particles in the conglomerates with a grain size of 800m having a bulk density less than 350Kg.m ³ .

The styrene butadiene rubber (SBR) structure contains about 75% butadiene (CH ₂ =CH-CH=CH ₂ ) and 25% styrene (CH ₂ =CHC ₆ H ₅ ). b. The division, which makes the rubber raw materials ready for application.

The equipment stated here enters a heavy machine class. First, the mixture is prepared, and then formed, and finally volcanized (cooked). The resulting product is subject to any processes such as deburring or surface polishing, and packaged depending on the type and construction of the product.

The mixing process is the most important step in terms of homogeneous feed of raw materials to the elastomer. The well-mixed dough will manifest itself with its physical values during subsequent processes, i.e. calendaring, extruding and molding, or after it is volcanized. At the same time, high quality and cost effective production is only possible with homogeneous distribution of the fillers and chemicals in elastomer.

In the mixing process, the following goals are expected primarily:

• To ensure that the fillers and admixtures are distributed sufficiently;

• To achieve a very good distribution of the materials that constitute the mixture and to reach a situation where the physical values such as hardness, breaking elongation, etc. remain unchanged partially in the mixture; and

• To achieve the same perfectly similar dispersion and viscosity in successive mixtures.

Selection of the materials is made as required by the technical specifications of the product to be obtained. The properties are kept in the formula and economy is provided.

Mixers

They are the machines which mix raw materials to constitute a tire having a desired property homogenously. These machines are classified as follows:

• Open mixers;

• Intermix;

• Permanent mixers;

• Closed mixers;

• Dough machines; and

• Banbury machines Open Dough Machines

Although the closed mixers are used today, mixing in the two-cylinder dough machines in the world and in our country still continues. Although it is very difficult to make the dough in large cylinders, large machines are operated to crush the mixture from the closed mixers, to reduce its heat and to make it thin and make a plate, or to crush the stored mixture again and heat it up to prepare it for calendar and extruder.

The structure of the dough machines is as follows: Two cylinders made of hard casting rotate parallel to each toward other in the bearings. High-speed of the drive engine is reduced to any desired speed via the gear box and large gear. The bearings are connected between the feet, and all the elements are connected on the frame.

The frame is usually made of steel construction, embedded in concrete and bonded by the studs. The feet are usually made of pig iron to minimize resilience. Therefore, they are thick, heavy and robust. The bearings are mostly made of yellow casting.

The most important components are the cylinders. The cylinders must have hardness that they shall not be worn and must be hollow for cooling. Cooling is important in rubber processing. But, in some cases, pre-heating may also be necessary. The opening in the cylinder should be removed evenly from the cast mold for equal cooling, and cleaned out of any undesired parts thoroughly.

Softened water and preferably water containing chemical admixture should be used to avoid lime build-up. In the other better method, cooling is made through the perforated holes in the circumferential periphery close to the surface. The two heads of the cylinders rotate in the red bearings. The bearings must be lubricated and cooled down constantly. Otherwise, the red bearings are worn out very quickly.

The rotation speeds of the two cylinders are different. This speed difference is adjusted by the numbers of the head gears. The difference is called “FRICTION.” Friction is between 1 : 1.05 and 1 : 1.25. The fast rotating side is the rear cylinder. Large (flywheel) gears move in the rear cylinder. On the front roller side driven by the head gears, there are the adjusting levers or engines. It adjusts the thickness by increasing and decreasing the distance between the cylinders. The friction ratio between the fast roll and the slow roll creates a shear action and allows the rubber to be crushed well and thus shortens the mixing time. The crush action is performed until rubber is wrapped into the roll. The fillers having the same softness are mixed later and more difficult.

The dough machines perform the following processs:

Mastication and breakdown: The polymer chains forming the mixed structure in the natural rubber are broken. This process is called“mastication.”

Dough making - mixture preparation: The rubber dough or yeast (masterbatch) is prepared by adding other admixtures to the rubber.

Feeding: The cold dough taken from the warehouse is heated to feed the processing machines such as calendars and extruders.

Furthermore, some different models of the dough machines are operated for the processs such as shredding, washing, grinding, crushing, etc.

The following properties must be considered in identifying and selecting the dough machines:

• Roll diameter and roll length (mm);

• Speed of the front roll or rear roll (m/s);

• Speed ratios of the rolls;

· Dough capacity, kg;

• Engine power, KW

• Dimension of the machine, mm (width x length x height); and

• Weight of the machine, kg. Permanent Mixing Systems:

MVX farrel mixers: In this patented system, all raw materials are collected in the premixer at the room temperature. Thus, all chemicals are distributed thoroughly before mastication. Because the temperature control can be done very well and the rubber is masticated both in the mixer and in the extruder, the same distribution is obtained continuously. The premix is pushed by air pressure piston to the main mixer with the triangular rotors. If the mixer is full, the piston speed is adjusted accordingly. The other spiral end of the rotors keeps the mixture and pushes it to the lower extruder. The mixing reservoir is designed for the gases emerged until it operated at the load from 60% to 80%.

The rotors and the extruder shaft are powered by separate engines and their revolutions are adjusted as desired. Here, because the heat control and pressurized water cooling are important, thermocouples are installed and controlled in various places. The company states that the power consumption for the mixtures is 28% less than the other mixers. EVK Werner&Pfleiderer mixers: It is made entirely in the form of extruder, but it is shaped suitable for decomposition by mixing and rubbing with the spiral. The materials of the spiral are compressed and decomposed by the obstacles in geometric shapes to the inner surface of the cylinder, and collected and mixed again. Before feeding, the rubbers are made into granules.

Closed Mixers (Intermix):

To increase efficiency in large tire factories, pre-mixes are made by closed mixers for reasons such as saving time and space. When two rotors with indentations and blades rotate towards each other in closed environment, a homogenous mixture is achieved by compressing the mixture between them and by squeezing it on the inside surface. The rotor, which rotates much faster than the two-cylinder open dough machines, makes the uniform mixtures in a short time due to much more crushing and mixing surfaces. The facts that powder does not come out, especially after the mixture made with carbon black, and the risk of occupational accidents can be reduced are known as other advantages.

Intermix machines, which are very similar to the Banbury machines, were designed and developed by“Francis Shaw and Company of Manchester” in 1937. The difference between them is that the mixture in Banbury machine is on the sides and the surface of the reservoir, whereas the mixture in Intermix machine is in the openings in the rotor. In other words, the dough is prepared by transferring the mixture from the rotor rotating in opposite directions to the rotor. The intermeshing rotors are used.

The Intermix closed mixer is the Farrel mark 5 series mixer, and its properties are as follows:

• It has an effective cooling system.

• Its maintenance is easy.

• By means of its rotors, it mixes and kneads the dough easier.

• The feeding and mixture discharge times are very short.

• By means of the water cooling system, it has a homogeneous heat dissipation.

As you see, it has almost all of the features found in Banbury machine.

The difference is only the rotor design and mixing between the intermix rotors.

Banbury Closed Mixers:

The first mixtures were made in a two-cylinder open machine. In the 1820s, Hankcock made a single rotor mixer. In 1865, two-rotor closed mixers began to emerge. But it's doubtful that it making a good mixing, because they have not enough strong structure. In late 1870, Mr. Paul Pfleiderer shaped a double rotor machine similar to a z-knife to make a rubber mixture, and obtained its patent. The Gummi-Kneter (GK) mixer was patented in 1913 upon further improvement of this design. Mr. Fernley H. Banbury, who worked at Werner and Pfleiderer in those years, designed the rotors that will further improve the insufficient performance of the GK mixers. Saginaw left the company, because he couldn’t receive the support of the plant located in Michigan, and received a patent on its behalf in 1915. Birminigham Iran Fundry, which merged with the Farrel company later, owned this design and the machine is still manufactured by the Farrel company under the Banbury patent.

Based on the process principles of the dough machine, machines that do the mixing work in closed environment were developed as a result of the end of the works on machines that will scatter less dust into the environment and make the dough faster. In 1915, these machines, known as "Banbury", took the job of making dough through dough machines because of their high productivity, reliability and low pollution of the environment. Due to their high efficiency, work reliability and low environmemtal pollutant, these machines called "banbury" in the name of the inventor in 1915 took over the dough making work.

Banbury is now referred to as a general name, but it is better to call it a closed (internal) mixer. Today, many companies in many countries manufacture similar machines and make them more efficient by taking advantage of rapid development of the computers.

Banbury consists of two or sometimes spiral and blade type four rotors, fed by two motors rotating in different directions at a slightly different speed in a closed reservoir. For quick and good mixing, crushing process is also done by the rotor blades. The temperature of the machine should be kept under control. This control is performed with cooling water in the frame and in some areas.

Mixing process is performed several times. Then, the dough coming from the Banbury machine is taken into the sheet by the meskolator. Rubber is processed here and brought to the plastic and adhesive consistency. It is transferred to the drying units.

In addition to the mixers equipped with two or four blade type rotor rotating at different speeds, there are also the types of mixers operating with the rotors, which rotate at the same speed and engage each other and crush the material. In this system, although they rotate at the same speed, they form friction (friction) between themselves because the rotor diameters are different. This increases the efficiency of the mixer.

The Banbury mixers basically consist of 5 parts:

Ram cylinder: The ram consists of a ram head (piston) and a cylinder on the ram. It is the place where the mixture is fed into the mixer housing by closing the opening and applying a certain pressure on the mixture. The ram pressure is applied via the ram cylinder and by the pneumatic power. Mixer housing: The reservoir where the mixing process takes place is called“mixer housing.” It has two rotors. The mixing process is performed between the rotors and the inner wall of the housing. The mixer housing consists of channels with heating and cooling system in the walls.

Rotors: The main element that performs the mixing process in the Banbury mixer includes two rotors, which have a very small speed difference between them and rotate counter-clockwise inward. They are the elements with spiral flaps on the rotors. Because the speeds of the rotors are different, the positions of the blade tips are not always the same.

Two types of rotor are used in the Banbury mixers:

1. Intermeshing rotors; and

2. Tangential rotors.

Interminging rotors have the ability to mix by crushing the mixture. In particular, the fibers are separated easier by this method in use of the natural rubber. This type of rotors are used mostly in the intermix mixers.

The tangential rotors have the ability to mix by hitting the mixture to the left and right. They are more efficient than the intermeshing rotors. However, they are not as good as intermeshing rotors in terms of homogenous heat dissipation in the reservoir.

Feeding inlet: The feeding cover is a box where the materials to be mixed are fed into the mixer. The opening and closing movements of the box are performed by the pneumatic system.

Discharge cover: The discharge cover is mounted on the shaft rotating in parallel with the rotor. This balanced hinge-like system allows the cover to swing down and move away from the underbody cover opening, thus allowing the blend with its mixing process completed to fall down.

The shaft called“rotor” and rotated by the hydraulic power turns the lower cover on and off. When the lower cover is turned off completely, a limit reducer attached on the end of the rotor activates the solenoid valve. This valve movement runs the lower cover pin. Other than these components, some of the equipment connected to the Banbury mixer may be listed as follows:

• Control panel;

• Carbon black weighing and feeding system;

• Oil weighing and feeding system;

• Engine;

• Reducer;

• Thermocouple;

• Dust trap

• Lubrication discharge opening; and

• Heating and cooling units.

There is a platform built so that the upper part of the opening drilled in the feeding inlet area will align with the stomach of the Banbury operator, and the ingredients that will enter the mixture are retained in turn in the appropriate containers previously to weigh and pour or discharge it into the inlet. When the inlet cover is turned on, rubber and other materials are put into the feeding inlet of the banbury machine in accordance with the dough making conditions and order. The materials fill into the mixing reservoir, which is closed on the tilted inlet, and in which the rotor rotates in the opposite direction. The blades especially made on the rotor, retain and knead again the mixture and the materials falling onto the bottom of the reservoir. In the meantime, the knob installed on two rotors and pushed the top piston pushes the incoming materials between the rotors and thus the mixture is provided.

The materials and rubber dough fed according to the determined schedule falls into the dough machine installed under the Banbury machine again according to the determined schedule after the determined time is over and the discharge cover is turned on.

Loading of Raw Materials into Dough Machines:

The materials are thrown into the mixer according to the desired rubber formula. For this, they have to pass through the weighing scales at first to determine the accurate amounts. The synthetic or natural rubber that will enter the mixer comes packaged in standard weights. Therefore, rubber raw materials do not need to be weighed. However, in the case of the open or closed dough machines, the polymer to be loaded at the feeding end passes through the manual or computer control. If a special non-standard mixture is considered, the natural rubber rolls may be cut by the cutters called“guillotine” in the desired weight and dimensions. The guillotines are used mostly at the small rubber plants.

In addition, some of the raw materials that will enter into the mixture in the dough machines and in the closed mixers may be passed from the stock or the spiral mixer. This is used mostly in dough machines. With the rotation movement driven by the engine at the top of this type of blenders, the spiral in the reservoir rotates and makes the mixture homogeneous. After mixing for 4-5 minutes, the dough is poured between the rolls of the machine in a controlled manner.

Any matters that must be known on the dough machines, when the raw materials are loaded into the machine:

• The Peptizers may be used in the dough machines. The peptizer reduces fluidity (viscosity) and reduces energy use. If the peptizer is not used, it is necessary to give a plenty of water to keep the rolls warm. Through use of a peptizer, it is advantageous to use the high temperature cylinders.

• Because the synthetic rubber is already in a normal condition in terms of viscosity and a mastic application is limited, they do not require a special preliminary study.

It is recommended that the opening between the cylinders must be 6 to 7mm at the stage before applying the fillers. If the peptizer is used, this opening may be 8 to 10mm.

• The particles that have fallen in the pan are picked up with the shovel and then added until the band that is wrapped in the roll is obtained and the rubber is laid to the right and left, and displaced and mixed by throwing the blade many times. Meanwhile, the rubber temperature may increase above 100°C.

• This process is continued until the rubber trims will not remain. If the rubber trims are not crushed and broken well, any difficulties are encountered in shaping the next calendar or extruder. • Excess mastication is undesirable. Extreme mastication is suitable only allow the gases swell easier in sponge manufacture. However, aging and physical properties are affected adversely. The duration of the mastication varies according to the temperature and the petizers involved. It is important that the process must always be conducted at the same temperature and at the same time to keep a mixture all time in the same quality. On the other hand, activation of the profiles to be volcanized in autoclave requires keeping the duration of the mastication short. The excessively masticated elastomer loses its vitality.

• After the band is obtained, the setting of the rollers is turned on. If the adjustment screw is motorized, the work is easy. Otherwise, the rubber band is cut down and the manual setting is turned on. The setting should be turned on until there is no horizontal rubber accumulation between the two rolls at the top. In other words, the front plug should be provided to wrap the whole rubber. The rubber must remain in a thin horizontal line between the two rolls rotating properly at each side.

• The rubber crushed previously and rested is wrapped in cylinders heated at 40 to 50° C and the same process is continued.

• In general applications, a less amount of chemicals that difficult to disperse may be given. For example, antioxidants, dyes, accelerators, etc.

But, the thing to be considered is to select ones not containing sulfur in their structure.

Thiuram (TMTDS) or DM (MBTS) contains sulfur and is at risk. Then, the homogenizing chemicals (STRUKTOL 40 MSF), chemicals that prevent aging and oxidation, resins, asphalt, factice and regenerated rubber are given.

The softening oils start to be added even after the whole carbon black is fed. Giving the oils first extends the mixing period, because the band wrapped around the machine makes the process difficult, and due to the displacement feature, the cutting process caused by the friction is reduced and mixing of the other fillers is delayed. If the oil content is high, it is recommended to mix it with some fillers beforehand in the mixer. If very little oil is to be given, it is given finally together with dust that has been spilled on the pan and collected by a shovel.

The total mixing time lasts 20-35 minutes. Sometimes there may be applications that require more time. It is necessary to cut the band completely on the cylinder until all the materials are fed in the mixing process. However, short cuts can be made to transfer the goods to left and right. In the meantime, if the band wrapped on the roller shall be loose, the adhesion enhancing resins (Koretack 5193 or in case of EPDM, Struktol TS 50) must be added and wrapped, or if they are adhesive excessively for metals, special sliders are added (Struktol EM16).

Before giving sulfur, the setting is turned on and the sulfur is evenly distributed to the surface until a thin horizontal line between the two cylinders is achieved. It is necessary to distribute all the chemicals which are already in small quantities in this way. After the mixture is finished, the setting is reduced and the goods cut and rolled on the knife are fed several times by the operator (dough operator) so that all sides are equal and a homogeneous mixture is obtained, and the process is finished.

The processed front roll warms up greatly and the obtained mixture endeavors to wrap toward the rear roll, which rotates quickly and is respectively cool.

It may be necessary to increase the amount of water of the front roll. In some cases, it is more suitable to perform the homogenization processes, and to take the goods out from the machine and to complete the process. But, it is difficult to perform this process properly by human power. Such a process requires a different method in the large machines which manufacture the goods over 30 to 35Kg.

For example, it is possible to make 70 to 90Kg dough on a machine with cylinder dimensions of 560mm x L 1500mm. As described above, after a mixture is made, approximately half of the goods are taken out in rolls and put in a pan or on a table. The setting is turned off, and the other half of them is tilted to right and left until a homogenous distribution is achieved. The goods are delivered in rolls and vertically. The operator continues to mix by using the machine's power without any effort. Then he cuts the pieces out in plates and transfers them to the cooling system. He transfers a last piece onto the goods wrapped on the roller and repeats the process. Although this method takes time, it is worth to get a very good mixture.

The amount of rubber mixture that may be prepared by the operator in the dough machines is about three grams per square centimeter of the front cylinder perimeter of the machine. This amount corresponds to a rubber mixture layer of about 2.5mm in thickness evenly coated on the surface of the front cylinder.

Accordingly, the amount of rubber mixture which may be prepared in a batch is:

3 x 3.14 x D x L/1000 = . Kg mixture

or

0.0094 x D x L = . Kg mixture

D= Diameter of the front roller, cm

L= Length of the front roller, cm

Method and Order of Loading the Materials in the Closed Mixers:

The mixing process takes place most efficiently upon addition of hard materials at the beginning and addition of softeners later. Therefore, it is necessary to put the softening agents as late as possible and then to wait.

If the mixture becomes harder, it is necessary to add the softening agents earlier and increase the amount.

The polymer to be used in the closed mixers comes in standard weight. But, it is transferred by the computer control from the banbury machine to the mixing room.

There are the control rooms, power panels, computer tables and peripherals in the control rooms, which are usually located in the large tire plants. All systems used in tire manufacturing are controlled and intervened via a computer. Furthermore, the other computers used in the control system can be interconnected. The entire system is installed on the PLC base.

The dough or raw materials is or are weighed by the automatic devices. In general, two types of weighing scales: Conveyor type permanent weighing scales or fixed weighing scales. In the conveyor-type weighing scales, the raw materials are weighed and loaded into the mixer under control of the operator while they pass over the band. In the fixed weighing scales, the raw material will fill into the weighing chamber. When the weighing scale reaches the desired value, the filling operation is stopped automatically. These weighing systems are digital completely and consist of the hydraulic or pneumatic systems. There are also very different weighing systems that weigh the raw materials or dough.

The process oils are usually liquid. These are then transferred by the dosing pumps into the mixture. After the oils are weighed in various containers in the small businesses, they are added into the mixture.

The carbon blacks are taken out from the bags and weighed, this always causes pollution. In the modern businesses, the carbon blacks are taken out by the pneumatic means from the warehouses, weighed automatically, and then transferred intact to the banbury mixers.

In another feeding method of carbon blacks, they are weighed full or semi- automatically by using the cover spirals or conveyor systems. Other admixture materials are weighed by using the scales or weighbridges in PE bags or buckets according to the amount to be used in the small businesses.

Some of the large businesses still have automatic weighing and feeding methods. Computer controlled weighing scales on the most commonly used carrier rails or bands weigh the raw material and discharge it to the vessels on the carrier. The vessels also transfer the materials into the mixer at the desired time.

In the closed mixer, it is very important that the rotor speed is variable. The variable rotor speed allows you to control mixing time and mixing temperature. The high rotor speed increases the mixing temperature and reduces the proper mixing time for quality. To solve high temperature problems during sudden rise in rotor speed, the following operations are performed:

^• To change the process order;

• To reduce weight of the load; and

• To reduce pressure of the press piston. Some points to be considered during the installation of the Banbury benches:

• The measured temperature of the machine at the beginning of the mixing is the most important temperature control. Before each mixing process, the temperature of the machine must be the same.

• The mixing periods should be controlled by a timer, and the timings should be adjusted carefully by heat indicator and ammeter. The processes must be performed only by looking at the timer.

• The upper press of the closed mixer should be the same.

• The coolant temperature, flow rate and pressure must the same (in night and day, summer and winter).

• The rotor blade ends of the closed mixer and the inner wall of the reservoir must be filled with cold welding yearly and the opening must be minimized. Thus, it is ensured that the mixture is always the same (the intermediate opening is worn 1 to 1.5mm yearly).

• The oil to be mixed in the closed mixer must be heated.

• When it is operated over time, it must be operated within a tolerance of ±5 seconds.

• A system that weighs any materials, which are not weighed automatically, very well and quickly and a feed conveyor must installed behind the mixer and.

• Operation of ventilation hoods should be checked especially at the small workplaces.

• The hand-weighed materials should be fed to the banbury machine in the polyethylene bags melted at the low temperatures, and their mouths should not be knotted.

• The Raw materials in the same dimensions and shapes must be fed to the machine. If the raw materials are fed in sometimes large or sometimes small pieces, different distributions are obtained.

• Sulfur and accelerants are fed not in powder, paste or granules, but in a masterbatch form.

• The mixing volume (V) of the banbury machine is based on calculation of the amount of rubber mixture that the mixers may prepare in a batch. The specific weight of the rubber mixture is accepted averagely as 1.2g/cm ³ . If the specific weight of the mixture is very different from this, it is considered. Amount of mixture processed at once

Volume x Specific Weight = . Kg

V x 1.2 = . Kg

Taking the Mixture Out From the Mixer

The dough that falls in large pieces and without any shape from the mixer is mixed and made in a band form in the cooler environment. This process is called “first stage manufacture of the rubber dough.” After mixing, it is desirable that the mixture is in the form of a strip or layer. This is achieved in various ways.

By passing through the calendar's rolls: The dough that falls in large pieces and without any shape from the mixer is mixed and made in a layer form in the cooler environment. In the meantime, the cooling process can be accelerated by supplying air by the fans to the mixture which is in the form of curtain and falls between the two cylinders. Sulfur and other accelerating chemicals can also be added here. Dough is obtained without pre-cooking.

By pressing through the extruder: Here, no further chemicals are fed, but the dough is prepared with less workmanship. Special spirals are used to make the mixture more homogeneous. The mixture, which falls in large pieces from the internal mixer, is rounded into the hopper and then it is pushed by the air pressure cylinder into the extruder and the timing is adjusted to obtain the continuous band. The mixture, which comes out in a tubular form from the head, is cut by the upper fixed cutter and takes the shape of a band.

Cooling is also very important in this system and cold water is circulated through spaces in the spiral if necessary. The extruders used in mixing machines can be one- screw or conical twin screw type which is often used in recent times.

Dough Storage: The rubber dough is stored in a clean and suitable warehouse for next operations after it is taken or from the dough making room. There are rules that must be observed when storing this mixture, which is not cross-linked yet naturally. It is said by the employees working in the businesses that the use of rubber dough after one day of use will increase the quality of the product. It is not clear that it is based on a scientific basis, but anything that people say must never be ignored.

Since the main material of the dough is rubber, the rules applied in rubber storage also apply to the dough. The dough is stored in the folded forms, cut sheets or thick strips. It is stored in the steel pallets, steel containers or special hangers to prevent contamination of any undesired materials from the ground. The dough warehouse must be cool.

In any seriously operating businesses, any samples taken from the dough warehouse are subjected to tests in the laboratory and green dyes are applied to the edges of the approved dough. In the subsequent works, only the dough applied by green dye is used. The term "green", which is often mentioned in tire properties, is derived from this.

The Modified Bitumen Specification must be prepared and contain the following properties:

PENETRATION, MIN. : 40°C

SOFTENING POINT, MIN. : 60 to 70°C

FLASH POINT, MIN. : 200°C

SPECIFIC WEIGHT: 1.0 to 1.1

DUCTILITY, MIN. : 80°C

ELASTIC RECOVERY, MIN. : 50°C

At the modified asphalt plants, the mixing process must be performed at 180°C (degrees) min.

The application temperature on the road must be between 170°C and 180°C (degrees). The number of the tandem cylinders must be doubled.

The Pneumatic (rubber wheeled) cylinders should not be used.

The compaction process should have been finished before the mixing temperature falls below 135°C to 145°C (degrees).

When the points described so far are considered, the raw materials obtained from recycling of the rubber or waste tires used in tire coating will be modified by bitumen and/or asphalt by means of chemicals and different physical applications in accordance with the points described above after they pass through many processes and after the mechanical separation and granulation processes are performed. Bitumen and/or asphalt are/is modified at our plants specified above, and the modified rubber asphalt material turned into a product:

1- Increases the physical strength of the asphalt;

2- Increases elasticity of the asphalt;

3- Ensures that the asphalt is laid on the road under the adverse weathers;

4- Ensures that the asphalt is communicated to longer kilometers under the adverse weathers;

5- Extends the lifespan of the asphalt;

6- Reduces the costs significantly, while the asphalt is modified; and

7- Ensures that an energy lower than the existing modified asphalt products by 60% is consumed during the modified manufacture.