Considering the production cost or some functional purpose, in addition to polypropylene, which accounts for the largest proportion of the raw materials of pp woven bags, additives such as masterbatch, whitening agent, UV ray retardant and flame retardant are added. In order to increase the chemical stability of polypropylene and reduce the production cost to a certain extent, the addition of masterbatch is an important part of woven bag materials. Manufacturers have been looking for a perfect balance between tensile strength and production cost when producing and designing woven bags, In other words, according to the actual use of customers and the procurement budget to find an optimal balance. Next, let’s learn some details about the addition ratio of woven bag masterbatch,
1. Filling masterbatch is one of the main ingredients in the raw material ratio of woven bag. Its main function is to stabilize the physical properties of wire drawing. At the same time, because the price of filling masterbatch is far lower than that of polypropylene, the addition of masterbatch can reduce the cost
2. With the increase of filling amount of filling masterbatch, the tensile strength of wire drawing will gradually decrease. Because the main component of filling masterbatch is calcium carbonate, there is no tensile strength. A small amount of filler masterbatch dispersed in the gap of polyolefin polymer chain has little effect on the drawing tensile strength, but the drawing stiffness is improved.
3. When the addition amount is more than 20% ~ 25%, the filling masterbatch occupies the position of polymer chain due to excess, which hinders the elastic deformation of polymer chain and makes the polymer chain unable to be fully stretched along the longitudinal external force, thus affecting the tensile orientation effect of polymer chain and reducing the drawing strength.
As a professional pp woven bags manufacturer, it is more suitable to control the amount of filling masterbatch in the range of 8% ~ 12% in order to make the woven bag products achieve better use effect in the actual production process.
Plastic woven bags are widely used in industry and agriculture. The addition of fluorescent brightener can make the recycled plastic woven bag whitener and brighter. Woven bag drawing is an important step in the production process of woven bag. Recycled PP is granulated, drawn and woven into recycled woven bag. Generally, the ash content of recycled PP plastics is relatively large, and the appearance of bopp plastic bags is seriously affected by the dark color. Manufacturers usually add a certain proportion of fluorescent whitening agent before wire drawing and hot melting, so as to increase the whiteness of woven bags. The fluorescent whitening agent absorbs the invisible ultraviolet yellow light and reflects the blue light in the plastic woven bag drawing process, so that the finished product can achieve a whitening and brightening effect through the optical principle. It is generally recommended to add 200 grams of whitening agent to a ton of plastic. The amount of whitening agent used by different manufacturers and brands is different.
