CARPET BACKING PROCESS

Please go through the guideline schematic diagram of the process equipment for manufacturing.

PROCESS AND EQUIPMENT FOR:

• (a)

  Moldable automotive carpets with backing

• (b)

  Fusible interlining fabric for garments.

Briefly the process is as follows:-

• (a)

  The roll of uncoated fabric is mounted on a frame with a shaft. The shaft has a cylinder or brake drum on one side over which a leather strap with a weight is hung. This provides the friction required for giving tension to the fabric and prevents free-rolling.

• (b)

  Over the width of the fabric a “Powder Hopper” is mounted which contains the coating powder. Inside the hopper a “Rotary Agitator” is installed to provide easy fluidity or flow to the powder. Sometimes the whole hopper is vibrated with vibrators or oscillated with a cam. The main object is to provide free and uniform flow to the powder. A “ZALI” or wire mesh screen is mounted over the entire length of the hopper so that a uniform and continuous shower of powder takes place over the width of the fabric.

• (c)

  A “Doctor’s Blade” or simple adjustable scraper is mounted across the width of the fabric to smoothen out the powder layer and remove the excess powder.

• (d)

  An “Excess Spill-Off Tray” is mounted under the fabric web to collect the excess powders scraped off by the doctor’s blade. This powder should not be allowed to fall on the floor and periodically it should be emptied out and fed back into the powder hopper for re-use.

• (e)

  The “Oven” should be well designed with good insulation and temperature control.

• (f)

  “Cold Water Plate” is provided inside the oven over which the uncoated side of the fabric slides. This protects the fibres and tuft of the carpet from singeing due to the heat in the oven. The top of the cold plate should be smooth and polished.

• (g)

  “Electric Heaters with Reflectors” and a suitable temperature control Thermostat are mounted on top of the fabric to heat and melt the powder in a controlled manner. Great care should be taken in designing the oven, insulation, heaters, reflectors, temperature control and cold water plate. Apart from the fabric and powder this is the major cost centre and improper operation can lead to rejections and wastage of electricity. The cold water plate can be supplied cold water from a desert cooler which will provide cool air to the workers and cold water to the plate.

• (h)

  To get a smooth and denser coating which looks good, the coated fabric can be passed through “Adjustable Chilled Water Calendaring Rolls” The surface of the rolls is highly polished and chilled water is circulated inside the rolls to solidify the molten polyethylene coating. This also prevents the coating from sticking to the rolls.
  
  The fabric pulling traction can also be applied through these rolls. The advantage being constant speed, independent of the diameter of the unwinding and winding rolls of fabric.

• (i)

  The “Coated Fabric Roll Winding” has a geared drive with a slip clutch or torque motor arrangement to provide uniform tension and speed to the fabric.