55kw XJP-120 Model Rubber Hot Feed Extruder Can Be Used For Tire
Tread Rubber Extrusion And Rubber Inner Tube Manufacturing
Detailed explanation of inner tube hot feed extruder
The inner tube hot feed extruder is a rubber extrusion equipment specially used for producing tire
inner tubes. It adopts hot feeding process (preheating of rubber
compound is required) and forms continuous inner tube blanks
through screw extrusion. The following are its key features,
working principle and application analysis:
1. Main structure and composition
The hot feed extruder is usually composed of the following core
components:
Feeding system:
Hot feed port: Receives rubber compound preheated by open rubber
mixer or hot mixer (temperature is usually 60~80℃).
Forced feeding roller: Assists rubber compound to enter the screw evenly to prevent
slipping.
Extrusion system:
Screw: Single screw structure, small length-to-diameter ratio (L/D)
(usually 4~6:1), low compression ratio (about 1:1.2~1.4), adapted
to the soft characteristics of hot rubber compound.
Barrel: Built-in heating/cooling channel to maintain stable
temperature (about 80~100℃).
Die head and die type:
Annular die: extrude inner tube tubular blank, the diameter can be
adjusted to suit inner tubes of different specifications.
Punching device (optional): punch air holes on the tube blank to
facilitate subsequent shaping.
Auxiliary equipment:
Cooling water tank: preliminarily cool the tube blank.
Traction device: control extrusion speed and tension.
Fixed-length cutting machine: cut the tube blank into a
predetermined length.
2. Working principle
Rubber preheating: the rubber is first heat-mixed in an open rubber
mixer to reach a soft and plastic state.
Forced feeding: the hot rubber is evenly fed into the screw through
the feeding roller.
Extrusion molding: the screw rotates to push the rubber forward,
and the tubular blank is extruded through the annular die of the
die head.
Cooling and shaping: the tube blank is cooled by the water tank to
prevent deformation.
Cutting and collection: cut to a fixed length for subsequent
vulcanization.
3. Application characteristics
Applicable products
Automobile/motorcycle inner tubes (mainly butyl rubber and natural
rubber).
Bicycle inner tubes (lightweight thin-walled tube blanks).
Other inflatable rubber products (such as airbags, lifebuoys,
etc.).
Technical advantages
High stability: The hot feeding process avoids pressure
fluctuations during the extrusion of cold rubber, which is suitable
for high-precision inner tube production.
Strong adaptability: It can process a variety of rubbers (such as
natural rubber, butyl rubber, styrene-butadiene rubber, etc.).
High production efficiency: Continuous extrusion, combined with
automatic cutting equipment to increase production.
Limitations
Depends on the previous hot refining: It needs to be equipped with
an open mixer or internal mixer, which increases energy
consumption.
Low flexibility: The die and process parameters need to be adjusted
when changing the rubber specifications.
4. Comparison Between Hot Feed and Cold Feed Extruders
| Comparison Item | Hot Feed Extruder | Cold Feed Extruder |
|---|
| Material State | Pre-heated (60–80°C) | Fed directly at room temperature |
| Screw Design | Short screw, low compression ratio | Long screw, high compression ratio (1:1.5–2.0) |
| Energy Consumption | Higher (requires pre-heating) | Lower |
| Applicable Materials | Natural rubber, butyl rubber, etc. | Better for synthetic rubber (e.g., EPDM) |
| Application Scenarios | Inner tubes, thick-walled products | Sealing strips, wire & cable (complex profiles) |
