Manufacturing and Production

Woven Polypropylene Sacks and Raffia Production

Woven sacks carry fertiliser, grain, cement and sugar across the region, and they fail in exactly two ways: the fabric tears or the seam opens, both usually traced to a tape produced outside specification. This course starts at the tape. Delegates work through resin selection, filler and additive use, and the ultraviolet stabilisation that decides how long a sack survives outdoors. Tape extrusion is covered in detail: cast film, slitting, hot stretching and annealing, with the draw ratio that sets tenacity. Tape denier, width and strength testing follow. Winding and bobbin quality are addressed, since a poor bobbin stops a loom. Circular loom operation is covered, including warp and weft tension and the fabric weight that specification demands. Lamination and printing follow. Conversion to sacks is addressed: cutting, stitching, valve construction and seam strength. Testing is covered across fabric weight, tensile, drop and stacking. The course closes on scrap, on regrind limits and on cost per sack.