The fabric density of canvas is calculated in metrics and refers to the number of warp and weft yarns arranged in one square inch. The density directly affects the appearance, feel, thickness, strength, folding resistance, breathability, wear resistance and thermal insulation properties of the fabric, and it also relates to the cost and productivity of the product.
There are two methods for measuring the warp and weft density of canvas:
Direct measurement method
Direct measurement is done by means of a mirror or fabric density analysis mirror. The fabric density analysis mirror has a scale length of 5cm. Under the analysis lens, a long strip of glass is engraved with a red line. When analyzing the density of the fabric, move the lens to align the red line on the glass sheet with the red line on the scale. Between the root yarns, use this as a starting point, and move the number of yarns on the side of the lens until the 5cm mark is used. The number of yarns output is multiplied by 2, which is the density value of the 10 cm fabric.
When counting the number of yarns, the center between the two yarns is used as the starting point. If the number reaches the end point, it exceeds 0.5, and if less than one, it should be calculated as 0.75; if less than 0.5, then Calculated by 0.25. The fabric density should generally be measured from 3-4 data, and then the arithmetic mean is taken as the measurement result.
2. Indirect test method
This method is suitable for fabrics of a regular structure with a high density and a small number of yarns. First, the number of warp yarns in the woven fabric and its tissues (the number of tissue loops) is multiplied, and then multiplied by the number of tissue loops in 10 cm. The resulting product is the warp (weft) yarn density.
What are the types of canvas?
Canvas is usually divided into two categories: coarse canvas and fine canvas. In addition, there are rubber canvas, shield canvas for fire and radiation protection, and canvas for paper machine.
1. Coarse canvas, also known as tarpaulin, is usually woven with No. 58 (10 lbs) 4 to 7 strands. The fabric is strong and resistant to folding and has good waterproof performance. It is used for car transport and covering in open storage and in the wild. tent.
2. Fine canvas warp and weft yarns are generally 2 strands 58 to 6 strands 28 (10 inches / 2 to 21 inches / 6), used to make labor protection clothing and supplies. It can also be used as a shoe, travel bag, backpack, etc. after dyeing.