In rubber plastic open mixing mill processing, stab temperature control is one of the most critical factors to compound quality and production efficiency , affecting mixing quality, production efficiency, and machine lifespan.
Heating tubes , as one electric heating elements, it is a core component responsible for heating the rolls or heating medium ,the mixing equipment place important role components in a rubber open mixing mill. They provide stable and uniform heating to the rolls, which ensure proper plasticization and mixing of rubber compounds. The heating tube inside a rubber open mixing mill ,also named as two-roll mill , it is an critical maintenance task that directly affects temperature stability, rubber mixing quality, energy consumption, and operational safety. Over time, heating tubes may fail due to aging, scaling, overheating, or electrical issues. When the heating tube fails or degrades, it can cause some effect effect , such as uneven mixing, scorching, or reduced output etc.
In this blog, let us explore together how to correctly replace the heating tube in a rubber open mixing mill, and how it directly impacts rubber processing performance. This blog explains when, why, and how heating tube replacement should be carried out, which help operators to understand the importance and best practices that heating Tube Replacement for a Rubber Open Mixing Mill machine .
Role of the Heating Tube in an Open Mixing Mill
Rubber compounds are highly sensitive to temperature. A well-functioning heating tube of open mixing mill heating tube directly impacts mixing efficiency and compound quality, it can ensure:
* Uniform roll surface temperature
* Controlled plasticization of rubber
* Stable viscosity during mixing
* Maintaining stable roll temperature
* Supporting proper rubber plasticization
* Preventing temperature fluctuation during mixing
Replacement of heating tube should always be carried out carefully to avoid damage to rolls or threads.
Why Heating Tube Replacement Is Necessary
* Heating tubes are consumable parts. With long-term operation, they may suffer from:
* Insulation aging
* Scaling or carbon buildup
* Overheating and power loss
* Electrical resistance drift
Once performance declines, problems such as uneven heating, slow temperature rise, or frequent alarms will occur. Timely replacement prevents further damage and production loss.
Understand the Heating System Structure
Before replacement, it is important to understand where the heating tube is installed. Depending on the mill design, heating tubes may be located:
* Inside the part of electrically heated roller
* Inside oil-heated roller which is used to heat thermal oil
* In heating manifolds which is connected to the rolls
Safety Preparation
Safety is always the first priority when replacing a heating tube of open mixing mill equipment. You need to make sure the machine under environment as follows:
1.Shut down the open mixing mill completely
2.Power off the main power supply
3.Apply lockout / tagout (LOTO) procedures
4.Remove the faulty heating tube
5.Clean the installation bore
6.Allow rolls to cool down to room temperature
7.Install the new heating tube correctly
8.Reconnect wiring and grounding
9.Perform testing and commissioning
Wear PPE: insulated gloves, safety glasses, protective clothing
How To Replace Heating Tube Properly :
1. Identify the Location of Heating Tube
For most rubber open mixing mills, heating tubes are installed:
Inside the roll body (oil-heated or electric-heated rolls)
Or inside the heating chamber / platen depending on the design
2. Disconnect Electrical Connections
* Open the electrical junction box connected to the heating system.
* Loosen terminal screws and then disconnect the power cables from the heating tube.
* Check insulation condition , replace it if is damaged.
3. Remove the Faulty Heating Tube
Unscrew the fixing bolts and fix the heating tube in place.
Carefully pull the heating tube out to in case damage the bore.
4. Install the New Heating Tube
To replace the new heating tube , make sure the specifications match the original ,include these parts as follows:
* Voltage
* Power (kW)
* Length and diameter
*Thread or flange type
* Insert the new heating tube slowly and straight into position.
* Tighten fixing bolts evenly to ensure proper seating.
5. Reconnect Electrical Wiring
1. Tighten terminals correctly and securely.
2. Ensure the wire cable connect grounding (earthing) properly.
3. Check that cables are not touching hot or moving parts.
If temperature is stable and uniform, the replacement is successful.
⚠️ Never attempt replacement while the machine is hot or energized.
In conclusion , replacing a heating tube in a rubber open mixing mill machine is a routine but an essential maintenance task that directly affects mixing performance and product quality. When performed correctly, it restores stable roll temperature, improves rubber mixing consistency, and extends the service life of the two roll mixing machine.
For laboratory and large-size industrial open mixing mills (3 inch and above), or oil-heated roll structures, it is strongly recommended that replacement is carried out by trained technicians or under manufacturer guidance.
Heating Tubes Are Easy to Wear Parts
Heating tubes are consumable components. Over time, they are affected by:
* High operating temperatures
* Repeated heating and cooling cycles
* Oil contamination or scaling
* Electrical aging
When Should You Replace a Heating Tube?
When there are signs as follows , you need to consider replace heating tube:
* Slow or uneven heating
* Frequent temperature alarms
* Abnormal current readings
* Visible damage or insulation aging
* Failed resistance test
About Simptek Machine
Simptek Machine specializes in laboratory and industrial rubber mixing equipment, including:
* Open mixing mills (new & refurbished)
* Two-roll mills with bearing or bush design
* Heating and cooling roll systems
* Spare parts: heating tubes, temperature sensors, seals, bearings
With extensive experience in used and refurbished rubber mixing machinery, Simptek provides reliable after-sales technical support, commissioning guidance, and replacement parts worldwide.
For heating tube selection, replacement parts, or technical support for rubber open mixing mills, consult your equipment supplier or professional service team.
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