First, in order to meet the safety factor, the base fabric should have a higher strength, but not the higher the base fabric strength, the better. Under the premise of the weight of the specific base fabric, the manufacturer of the container bag is under the general rule that the tensile force and elongation are inversely proportional. The flat yarn for weaving should be in pursuit of absolute strength, while maintaining good elongation at the same time as pulling force. Without good elongation, excessive pursuit of pulling force will be counterproductive, and the aging performance of the product will be greatly reduced. Elongation is one of the main indicators for judging fabric properties without the addition of additives. Once the base fabric strength is determined by design, the sum of the tensile forces of each monofilament can not be equal to the measured strength of the base fabric at a predetermined width, and there is a woven loss of 5%-15%. This is related to the difference in equipment structure, the degree of newness and oldness, and also the raw material melt index (soft and hard material of the material), proportion and process. In addition, the latitudinal direction is relatively larger than the warp strength loss.

Secondly, the production of bulk bags must be resolutely put an end to the addition of recycled materials, as this involves safety issues. We know that although polypropylene materials have good mechanical properties, their ability to resist natural aging is inherently poor. If you want to maintain relatively long-term performance, scientific and reasonable addition of additives is an inevitable choice. If recycled materials are used, first, the composition is difficult to control, and the performance of the finished product is difficult to grasp. Second, the molecular chain is plasticized or even plasticized multiple times, even if the effect of adding an "anti-aging agent" is uncontrollable.

Third, anti-natural aging is an unpopular subject involving multiple theories and complex mechanisms. I am not involved in the deep, but it is about the anti-aging of plastic products, a little understanding, in the "Chinese Plastics" in the seventh issue of 1998, there was a "Preliminary Study on the Anti-natural Ageing of Polypropylene Fabrics" discussed the mechanism and effect. The main points are:

Adding anti-aging agent to the fabric and adding anti-aging agent, the effect is obviously different; 2. There are several famous brands in China, the raw materials are relatively stronger than the general raw materials without adding additives; 3. The means of adding auxiliaries in the raw materials is very important, it is necessary to stir evenly, and it must be ensured that it can enter the barrel; 4. The proportion of auxiliaries should be appropriate, the effect is not obvious, and more is waste; 5. Stabilizer grades must be appropriate. The wavelength to be prevented by the auxiliary agent should be the sensitive wavelength of all raw materials; 6. Determine the appropriate stretching ratio, maintain sufficient elongation and make it consistent under the premise of meeting the strength requirements; 7. Relatively the finished fabric When thicker, the relative loss of performance is smaller; 8. The anti-aging property of the laminating material is better than that of the non- laminating material, and the PE film is better than the PP film; 9. The surface of the product is flatter than the surface of the product has wrinkles; 10. Elongation The rate (appropriate) is better than the elongation; 11. The strength of the fibrillated flat yarn is lower than that of the non-fibrillated; 12. The anti-aging performance of the product is determined according to the climate characteristics of the area in use.