Hard Tooth Surface Reducer Water Cooling Two Roller Rubber Mixing
Mill For Manufacturing Rubber Products Factory
What are the sizes of rubber mixing mills?
16-inch mixing mill for rubber mixing equipment. Mixing mills can
be divided into: laboratory 6-inch mixing mill, 10-inch mixing
mill, 12-inch mixing mill, 14-inch mixing mill, 16-inch mixing
mill, 18-inch mixing mill, 22-inch mixing mill, 24-inch mixing
mill, 26-inch mixing mill according to the size of the machine.
Mixing mills can be divided into: automatic rubber turning mixing
mill, hydraulic baffle mixing mill, electric adjustable mixing
mill, hydraulic adjustable mixing mill, variable frequency speed
mixing mill, etc. according to the degree of automation.
The three basic processes of rubber mixing mills:
The rubber mixing mills basically have three processes in the mixing
process: wrapping the rollers/eating powder/turning.
The first process is: wrapping the rollers
During mixing, there may be four situations in which the raw rubber
on the rollers of the mixing mills
The first situation occurs when the roller temperature is too low
or the rubber is hard. The rubber stays at the accumulated rubber
and slides, and cannot enter the roller gap, or can only become
fragments when forced into.
The second situation occurs when the rubber is in a highly elastic
state, with both plastic flow and appropriate highly elastic
deformation. After the rubber passes through the roller gap, it
only wraps on the front roller, which is conducive to mixing
operations and dispersion of compounding agents in the rubber.
The third situation occurs when the temperature is too high, the
fluidity of the rubber increases, the intermolecular force
decreases, and the elasticity and strength decrease. At this time,
the rubber cannot wrap the roller tightly and become a bag-like
shape, and the rollers are removed or broken, and mixing operations
cannot be performed.
The fourth situation occurs when the temperature is higher, the
rubber changes from a highly elastic state to a viscous flow state,
the elasticity and strength almost disappear, and the rubber is
difficult to cut. Therefore, the mixing temperature should be
controlled to keep the rubber in a state that is conducive to
mixing.
The second process is: powder eating
The powder eating stage refers to the process of mixing the
compounding agent into the rubber.
After the rubber is wrapped around the roller, in order to mix the
compounding agent into the rubber as soon as possible, a certain
amount of accumulated rubber should be retained at the upper end of
the roller gap.
When the compounding agent is added, due to the continuous flipping
and replacement of the accumulated rubber, the compounding agent is
brought into the wrinkle groove of the accumulated rubber and then
into the roller gap.
In the process of eating powder, the amount of accumulated rubber
must be moderate. When there is no accumulated rubber or the amount
of accumulated rubber is too small, on the one hand, the
compounding agent can only be rubbed into the rubber by the shear
force between the rear roller and the rubber, and cannot penetrate
into the rubber and affect the dispersion effect; on the other
hand, the powdered compounding agent that is not rubbed into the
rubber will be squeezed into pieces by the rear roller and fall
into the receiving tray. If it is a liquid compounding agent, it
will stick to the rear roller or fall on the receiving tray,
causing mixing difficulties.
If there is too much accumulated rubber, part of the rubber will
rotate and roll at the upper end of the roller gap and cannot enter
the roller gap, making it difficult for the compounding agent to
mix in. The amount of accumulated rubber is often measured by the
contact angle (or bite angle), and the contact angle is generally
taken as 32-45.
The third process is: refining
The third stage of mixing is refining.
Due to the high viscosity of rubber, the rubber only flows
circumferentially along the rotation direction of the open mill
roller during mixing, without axial flow, and the rubber flowing
along the circumferential direction is also laminar. Therefore, the
rubber layer close to the surface of the front roller at about 1/3
of the thickness of the rubber sheet cannot flow and becomes a
"dead layer" or "sluggish layer".
In addition, the accumulated rubber on the upper part of the roller
gap will also form a partial wedge-shaped "reflow zone". The above
reasons all cause uneven dispersion of the compounding agent in the
rubber.
Technical Parameters:
Parameter/model | XK-160 | XK-250 | XK-300 | XK-360 | XK-400 |
Roll diameter(mm) | 160 | 250 | 300 | 360 | 400 |
Roll working length (mm) | 320 | 620 | 750 | 900 | 1000 |
Capacity (kg/batch) | 4 | 15 | 20 | 30 | 40 |
Front roll speed (m/min) | 10 | 16.96 | 15.73 | 16.22 | 18.78 |
Roll speed ratio | 1:1.21 | 1:1.08 | 1:1.17 | 1:1.25 | 1:1.27 |
Motor power (KW) | 5.5 | 18.5 | 22 | 30 | 37 |
Size (mm)
| Length | 1104 | 3230 | 4000 | 4140 | 4578 |
Width | 678 | 1166 | 1600 | 1574 | 1755 |
Height | 1258 | 1590 | 1800 | 1800 | 1805 |
Weight (KG) | 1000 | 3150 | 5000 | 6892 | 8000 |
FAQ
1. What is a rubber mixing mill?
A rubber mixing mill is a machine consisting of two
counter-rotating rolls that are used to mix, knead, and homogenize
rubber compounds. It is commonly used in the rubber industry to
prepare rubber for further processing, such as calendering,
extrusion, or molding.
2. How does a rubber mixing mill work?
The rubber mixing mill works by passing rubber compounds through
two rotating rolls. The rolls rotate at different speeds (friction
ratio), creating shear forces that mix and homogenize the rubber
with additives like fillers, curing agents, and processing aids.
3. What are the main components of a rubber mixing mill?
The main components include:
Rolls: Two counter-rotating rolls made of hardened steel.
Frame: A sturdy structure to support the rolls.
Drive System: Motor and gearbox to power the rolls.
Adjustment System: To control the gap between the rolls.
Cooling System: To regulate the temperature of the rolls.
Safety Devices: Emergency stops and nip guards.
4. What is the friction ratio in a rubber mixing mill?
The friction ratio is the speed difference between the two rolls.
Typically, the front roll rotates slower than the back roll,
creating shear forces that help mix the rubber compound
effectively. Common friction ratios range from 1:1.1 to 1:1.4.
5. What materials can be processed in a rubber mixing mill?
Rubber mixing mills are primarily used for natural rubber,
synthetic rubber, and rubber compounds. They can also process
materials like EPDM, SBR, NBR, and silicone rubber, along with
additives like carbon black, silica, plasticizers, and curing
agents.
6. What are the advantages of using a rubber mixing mill?
Efficient mixing and homogenization of rubber compounds.
Flexibility in processing different rubber types and formulations.
Ability to handle small to medium batch sizes.
Cost-effective for small-scale production.
7. What are the limitations of a rubber mixing mill?
Requires skilled operators for optimal results.
Limited batch size compared to internal mixers.
Longer mixing times for large batches.
Heat generation can affect rubber properties if not controlled.
8. How do you maintain a rubber mixing mill?
Regularly lubricate moving parts.
Check and adjust roll alignment.
Inspect and replace worn-out rolls.
Clean the rolls and machine after each use.
Monitor the cooling system to prevent overheating.
9. What safety precautions should be taken when operating a rubber
mixing mill?
Always use nip guards to prevent hand injuries.
Avoid loose clothing or jewelry that could get caught in the rolls.
Use emergency stop buttons in case of emergencies.
Train operators on proper handling and safety procedures.
10. What is the difference between a rubber mixing mill and an internal
mixer?
Rubber Mixing Mill: Uses two rolls to mix rubber compounds; suitable for small to
medium batches; requires manual feeding and cutting.
Internal Mixer: Uses rotors inside a closed chamber; suitable for large batches;
faster and more automated but less flexible for small-scale
production.
11. How do you choose the right rubber mixing mill?
Consider factors such as:
Roll size and capacity.
Friction ratio.
Power and speed requirements.
Cooling system efficiency.
Material compatibility.
Budget and production needs.
12. What is the typical temperature range for rubber mixing mills?
The temperature of the rolls is usually maintained between 40°C to
70°C (104°F to 158°F), depending on the rubber compound and
processing requirements. Excessive heat can degrade the rubber.
13. Can a rubber mixing mill be automated?
Yes, modern rubber mixing mills can be equipped with automation
features like programmable logic controllers (PLCs), automatic roll
gap adjustment, and feeding systems to improve efficiency and
consistency.
14. What are common problems with rubber mixing mills?
Uneven mixing due to improper roll gap or friction ratio.
Overheating of rubber compounds.
Roll wear and misalignment.
Inconsistent batch quality due to operator error.
15. Where are rubber mixing mills used?
Rubber mixing mills are used in industries such as:
If you have more specific questions about rubber mixing mills, feel
free to ask!
