Basic spreading equipment consists of spreading surfaces, spreading machines, fabric control devices, and fabric cutting devices.
Many firms operate productively with manually operated equipment, while other firms find automated, high-tech equipment to be cost-effective. Understanding the parts and complexities of spreading equipment provides insight for troubleshooting problems and allows better preparation for the process.
- Spreading surface
- Spreading Machine
- Fabric Control Device
- End cutting Device
1. Spreading surfaces
The appropriate type of spreading surface is determined by the fabric type, spreading equipment, cutting method, cutting equipment, and quality standards. Spreading requires a flat, smooth surface. If the spreading surface doubles as a cutting surface, it also must be level. Although spreading and cutting may be done on the same surface, automated cutting requires spreading and cutting to be done in adjacent but separate locations. Spreading and cutting surfaces are available in standard widths that correspond to fabric width. Table width cannot be expanded, although narrow fabric can be spread on a wider table. A spreading surface must be about 10 inches wider than the fabric.
There are different types of spreading tables with advanced technology such as;
Tracked table
Spreading tables may have tracks or rails placed along one or both sides of the tabletop or just a few inches off the floor. This track helps guide and control the spreader as it moves up and down the length of the table. With some types of equipment, the table tracks are geared to synchronize the movement of the spreading machine with fabric unrolling to regulate tension.
Pin Table
Spreading tables may also be specialized for certain types of fabric and cutting equipment. Pin tables have rows of pins located below the surface that can be extended through slats to hold fabric in a precise location for accurate matching of pattern repeats.
Vacuum table
Vacuum tables are used to compress the lay-up and prevent shifting or movement during cutting. A spread is covered with a plastic film that forms a seal over the lay-up when a vacuum is applied. A lay-up of quilted fabric can be compressed as much as 75% when the vacuum is used. This allows more plies in the lay-up and restricts the movement of slippery fabrics for more accurate cutting.
Air flotation table
Air flotation tables may used be moved to a lay-up as another lay-up is prepared farther down the table, or fabric can be spread on one surface and then transferred to the cutting surface. Air flotation tables, when activated, allow easy movement of a lay-up onto an adjacent cutting area. A layer of air between the table surface and the bottom layer of paper reduces friction and allows a lay-up to be moved easily without putting stress on the fabric or the operators.
Conveyorized table
Spreading tables with conveyorized surfaces carry the fabric to the cutting machine so that no time is wasted. Ideally, one lay-up can be cut while another is being spread. Conveyors may be used with computerized cutting systems, large die presses, and laser cutters.
2. Spreading machines.
The fundamental purpose of a spreading machine is to superimpose layers of fabric in a smooth, tension-free manner for accurate and efficient cutting. Manually operated spreading machines can be as simple as roll bar mounted on four wheels that is pushed up and down a spreading table by an operator. Manual spreaders travel only as fast as an operator moves them, while some of the faster automated machines can spread 100 to 150 yards per minute. Spreading speed can be utilized only on long spreads with few defects. Spreading speed may affect productivity, quality, and cost of the operation, but it should not be the primary focus for purchase of new equipment. Manual spreading machines may be used by small firms as the primary spreading device and by large firms for short spreads. More sophisticated spreading machines are motor-driven and have fabric control devices included to increase productivity, decrease variability, and make spreading more cost-efficient
3. Fabric control devices.
Fabric control devices are mechanisms that control fabric as it is carried up and down the table and unrolled by the spreading machine. It may be used when higher rates of travel is difficult for an operator to monitor more than one aspect of the operation; therefore, edge-sensing devices, lap counters, width monitors, and out-of-cloth sensors simplify the operation so the operator’s primary concern is the fabric being spread. These devices include tensioning mechanisms, positioning devices, and end treatment systems.
Tensioning device
Tensioning involves synchronizing the rate of spreading with the rate fabric is unrolled. A positive feed system utilizes a covered roller that is driven and timed to the movement of the machine. It prevents the momentum of a large roll from continuing to unwind when the machine slows down or stops. It also reduces the tension placed on a fabric as it is laid out. This is particularly important for spreading knits and other stretch fabrics. Roller covers of different materials may be used to give better gripping power for different types and weights of fabric.
Positioning devices
Positioning devices and sensors monitor position and control fabric placement during spreading. These devices improve the quality of a spread. Electronic edge sensors monitor selvages as the fabric is spread. A deviation from the proposed alignment triggers a motor that shifts the roll to the correct position. Alignment can be held to a 1/8-inch tolerance with these devices.
Width indicators
Width indicators may sound an alarm to alert the operator whenever the fabric becomes narrower than the established width. Width variations are analyzed to determine where in the marker they fall, whether the fabric will still fit the marker, or whether the variation should be treated as a defect and removed.
End treatment devices
End treatment devices are used with spreaders but are separate and placed at the end of the spread. The specific end treatment equipment such as end catcher, folding blade, and knife box may be needed depending on spreading modes whether the spreading mode is F/F or F/O/W.
- F/F spread utilizes an end catcher and folding blade that work together. These are mechanical parts mounted at opposite ends of the marker to catch and hold the fabric as the blade shapes and creases the fold. An overfeed device may be built into the spreading unit, which automatically feeds extra material when a fold is to be made.
- For F/O/W spreads, a knife box is needed along with an end catcher. A knife box contains a cutting unit (usually a small rotary knife) that operates in a track and cuts across the fabric width when engaged. With face-one-way spreads, each ply must be cut from the roll at the end of the marker. The catcher simply holds the fabric end in place for cutting.
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