Types of tape applicators, purpose, line composition, and technological recommendations
Types of tape application equipments:
- Central. The tape roller is positioned in a plane perpendicular to the axis of the wrapped product. The axes of the roller and the product coincide.
They are manufactured in both vertical designs (for wrapping diameters of up to 8 mm) and horizontal designs (for wrapping diameters of up to 80 mm). The advantage of this winder is its high wrapping speed, while the drawback is that when the wrapping material runs out, the workpiece needs to be cut, resulting in the wrapped workpiece being of non-uniform length.
- Eccentric (inclined, flat, tangential, semi-tangential).
- Inclined tape winders. The tape is wound onto the insulated product, unwinding from a roller positioned at an angle to the product.
- Flat tape winders. The roller with the tape is positioned in a plane perpendicular to the axis of the product.
The advantage of inclined and flat tape winders is the ease of maintenance and operation, as well as the ability to replace the wrapping material without disrupting the integrity of the product's length. The disadvantage is the change in the winding angle with variations in the roller diameter, uneven tension on the tape edges, and poor winding density. The maximum wrapped diameter of the workpiece is up to 80 mm.
- Tangential tape winders. The roller with the tape is positioned in a plane parallel to the axis of the product. In the vertical position of the roller, the vertical plane passing through its center of gravity touches the surface of the insulated product
The advantage of this tape winder is the constant tension on the edges, as the central line serves as the axis of rotation. Additionally, the wrapping material can be replaced without disrupting the integrity of the product's length. The maximum wrapped diameter of the workpiece is up to 100 mm.
- Semi-tangential tape winders. The roller with the tape is positioned in a plane parallel to the axis of the product. In the vertical position of the roller, the vertical plane passing through its center of gravity does not touch the surface of the insulated product.
The advantage of semi-tangential tape winders is the equal tension of the tape across its width, as well as the ability to replace the wrapping material without disrupting the integrity of the product's length. The maximum wrapped diameter of the workpiece is up to 120 mm.
Uniform tension of the tape is ensured by braking the roller with the wrapping material. Types of braking systems:
- Braking of the roller with plates (the roller with the wrapping material is positioned between two stationary plates, and a pressing force is applied to the pressing plate), meaning that braking occurs due to frictional force. The drawback of this system is that as the diameter of the roller with the wrapping material decreases, the pressing force must be reduced (requiring constant tension control by the line operator), which can lead to crumpling of the tape edges.
- Braking of the roller with a tape brake (the roller with the wrapping material is mounted on a movable (rotating) plate and pressed against a stationary plate, with braking of the movable plate occurring due to friction between the rotating plate and the brake tape. The friction force is regulated by adjusting the tension of the brake tape). The drawback of this system is that as the diameter of the roller with the wrapping material decreases, the tension of the brake tape must be reduced (requiring constant tension control by the line operator);
- Braking of the roller using an electromagnetic clutch (the principle of operation is as follows: in the cavity between the rotor and stator of the device, there is magnetic powder, which, when an electrical signal is applied, aligns and fills the gap in such a way that friction occurs between the rotor and stator, thus creating a braking force. Electromagnetic powder clutches are controlled by tension controllers).
- To create a dielectric barrier between conductors in the event of a fire, mica-containing tapes are applied to the conductive core (for example, in the production of fire-resistant cables with reduced smoke and gas emissions (FRLS index), fire-resistant cables that do not release corrosive, gas-phase products during combustion and smoldering (FRHF index), or fire-resistant cables with low smoke and gas emissions and low toxicity of combustion products (FRLSLTx index));
- For the production of wires (insulating materials such as cable paper, fluoroplastic film, polyimide-fluoroplastic film, etc., are applied to copper or aluminum conductors);
- For applying a shield made of copper tape or a composite flexible material based on aluminum foil (alumoflex) in communication cables, signal-blocking, multi-frequency, power, and control cables (the designation of the cable or conductor product includes "S"
- For applying an electroconductive layer, water-blocking tape, aluminopolymer tape, polyethylene terephthalate (PET) film, etc.
- For applying aluminum, steel, or galvanized steel tapes (armoring, where the designation of the cable or conductor product includes "A"
Tape winding equipment is widely used in the production of cable and conductor products, for example:
The composition of the winding line, depending on its purpose, includes the following elements:
- Pay-off device (pintle, axial, column, or portal type);
- Rectifying device (leveling units);
- Winding unit (tape winding heads);
- Control and measuring equipment (meter counter, diameter gauge);
- Tensioning device (crawler or wheeled type);
- Take-up device (pintle, axial, column, or portal type).
Tape winders are enclosed in a sealed casing to reduce air resistance and ensure safety in the work area, as the rotation speeds of the heads are very high.
Calculation of the technological process of tape winding.
Depending on the requirements specified in the technical specifications, the tapes are applied as follows: butt joint (the edges of adjacent tape turns are placed tightly against each other, see Fig. a), with a gap (the edges of adjacent tape turns are spaced apart, see Fig. b), with overlap (the edges of adjacent tape turns overlap each other, see Fig. c).
The following data is required to calculate the technological parameters of the winding process:
- diameter of the item to be wound;
- thickness of the tape used;
- width of the tape used;
- required percentage of overlap (or gap)
- equipment specifications (range of winding pitch and tape application angle).
The winding angle should be selected within the range of 40° to 60°
To perform the following calculation
Check the value of the overlap (gap) of the tape. When the tape is applied butt joint, the value of e should be equal to 0.
e=b-h·cosα , - overlap, e=h·cosα-b – gap Where:𝑏 is the width of the tape in mm, ℎ is the winding pitch in mm, 𝛼 is the winding angle of the tape.
α=arctg(h )/(π·(d+δ)), Where:𝑑 is the diameter of the workpiece to be wound in mm, 𝛿 is the radial thickness of the winding in mm. If 𝑒 exceeds the allowable limits, a different winding pitch ℎ or tape width 𝑏 should be selected.