Sewing and inspection of dust filter bags

Under normal circumstances, the material of the sutures of the dust filter bag should be the same as the material of the filter material.
Under special circumstances, when sutures made of materials different from the filter material need to be used, the strength, heat resistance and chemical resistance of the sutures should be better than sutures made of the same material as the filter material.

Number of rows of filter bag stitches:

• The longitudinal seams on the filter bag body must be strong, straight, and must not be less than 3.
• The bottom and mouth of the bag can be sewn with single or double needles according to different requirements.
• The needle density of the filter bag's stitching is related to the material of the filter bag. It ensures the tightness and strength of the stitching without leaking dust, and does not damage the strength of the filter cloth itself.
• The needle density of chemical fiber filter cloth filter bags is within 10cm (255) needles: the needle density of glass fiber filter cloth filter bags cannot be too large.
• The stitching width of the filter bag is related to the material of the filter material, generally 9~12cm.
• The distance between the outermost sewing needle and the edge of the filter cloth: 2~3mm for acupuncture drill and 5~8mm for glass fiber filter material.

After the filter bag is sewn:

Inspections and repairs should be carried out according to design requirements to eliminate creases, oil stains and grease on the surface. For filter bags sewn with film-coated filter cloth, in addition to strict requirements on the needle size, control of needle density and operating procedures, special materials must be used to repair all pinholes.

Filter bag sewing inspection:

1. Filter bag manufacturers should comply with national standards, industry standards, and enterprise standards. The factory quality supervision department selects items and the proportion of random inspections based on batches. Generally, the batch inspection ratio of filter bags is 5% to 20%. For filter bags with higher requirements, the batch inspection ratio should be more than 15%.
2. Ex-factory products should be strictly inspected according to the ordering contract requirements for the filter cloth, sutures and various accessories of the filter bag. If problems are found, they should be rectified before leaving the factory.
3. For dust removal filter bags that are resistant to temperature, acid and alkali corrosion and anti-static, special inspection is required.