Drawing and folding wire is a large bag of plastic flat warp. In the process of drawing, the blank wire is regularly folded in two or three layers through a special folding device. The folded flat wire is mainly used to produce high weight and complete heat setting. draft. Plastic woven base fabric, especially for high-demand plastic woven products such as flexible container bags, carpet base fabrics, tent fabrics, artificial turf base fabrics, and geotextiles.
As the thickness of the plastic flat wire reaches a certain size, the flat wire will become brittle and hard, and will bring difficulties in the subsequent processes of weaving, cutting, sewing, and packaging, which greatly increases the cost of raw materials and manufacturing costs.
As early as the end of the 1980s, some developed countries invested a lot of manpower and material resources to research high-strength plastic woven products, and developed wide and thin plastic flat yarns instead of single narrow and thick yarns. Through weaving When beating up and squeezing the wire, the width of the flat wire is narrowed during weaving, which not only improves the absolute strength of the woven fabric, but also improves the relative strength and softness of the woven fabric to a certain extent. However, because it is during the weaving process that the beating-up and squeezing methods turn the wide filaments into extruded narrow filaments, it will inevitably lead to the increase in the beating-up force and friction in the weaving process, and the resulting wefts, The warp yarn is raised, split or even broken, which affects the normal weaving production, and the surface of the woven cloth is rough and the wool is all over. For some materials with cleanliness requirements, such as medicine, chemical industry, and food, it cannot meet the packaging. And the relative strength of woven products is greatly reduced. During this period, the wide and thin flat yarns were drawn into fibrillated yarns by needle punching to make the flat yarns softer and easier to squeeze the wefts. However, it still cannot solve the problem of woven fabrics. Fuzzy surface and low relative strength defects.
Nearly 20 years ago, plastic machinery manufacturers began to try to use wide and thin flat yarns. Before weaving, they folded them into shapes, mainly folded into an "e" shape, which is now commonly known as three-folded yarn. , And then use it in the weaving process, which greatly improves the performance of the woven product, and its superiority is mainly reflected in the following aspects.
1. The relative strength is greatly improved, and the absolute strength of the woven fabric with the same unit weight is increased by 15% to 30%. The absolute strength is improved, which is equivalent to greatly reducing the weight per unit area and saving the cost of raw and auxiliary materials by 15% to 30%.
2. The woven fabric is soft and flat, with a smooth, flat surface, no wool, and good hand feeling.
3. Improve the subsequent manufacturing process, especially greatly improve the efficiency of the weaving process, reduce the force and friction of squeezing weft, and reduce the rate of wire breakage.
However, due to the deviation of the design of the folding equipment at the time, it could not meet the continuous industrial production requirements. Especially around 1992, a world-renowned company tried to provide a large domestic woven bag factory with a set of this equipment, and it was modified many times. , Service, because the three-folding device could not normally produce qualified three-folded flat wire, in the final negotiation, the equipment manufacturer paid hundreds of thousands of dollars in compensation. The incident caused a sensation in the industry, and as a result, it is impossible to buy professional folding wire machines in the world.
Around 2000, some FIBC buyers in Japan and Korea were willing to purchase woven bags made of folded silk at high prices. Individual woven bag manufacturers in Shandong, relying on their own production experience and creative wisdom, are forced to design and manufacture folding silk devices by themselves. Although the efficiency is low and there are many defects, they can still produce three-folded silk to meet user requirements.
Many years ago, the most famous domestic plastic woven machinery and equipment manufacturing company began to develop a three-folding device under the strong request of users. As a global problem of plastic weaving equipment, under the background of a large number of unsuccessful investments and many test failures, the technical director of the company and many colleagues have brainstormed and developed a unique way, from mold design, production, mold repair, to the formal test of the unit , With perseverance, a lot of practice and trial and error, and finally successfully developed the first-generation three-folding device that can be used for industrialization. At that time, although the three-folding device still had technical defects, it was already in the leading position of international originality.
It goes without saying that China's plastic machinery was developed on the basis of digesting and absorbing similar foreign equipment. It can also be said to be a history of imitation. However, the development of the plastic flat wire three-folding device is completely domestic independent intellectual property rights, which is also a pride in the development history of plastic weaving equipment.
At present, the three-folding devices that are being pushed on the market have roughly the same general idea, with big differences in structure, and, more importantly, the specific effects are worlds apart. As a result, our plastic woven manufacturers have very different understanding of the use of folded yarn. We must respect intellectual property rights and prevent infringement of patented technologies: we agree with differentiated competition, hierarchical development, and encourage and promote the development and improvement of industry technology; at the same time, we should be true to the convenience of using equipment for users, to the greatest extent Improve the quality of plastic weaving and plastic weaving enterprises to increase market competitiveness to make contributions.
Plastic woven companies have different understandings on the use of three-folded yarns. Most companies have realized the advantages of using three-folded flat yarns in container bags, geotextiles, and tarpaulins, and continue to expand the use of three-folded flat yarns. Scope, such as the weft yarn, warp yarn, sling yarn, rope cable yarn, etc. of container bags, geotextiles, tarpaulins, etc. However, there are still a considerable number of plastic woven enterprises that do not know, even the understanding of = folded yarn. Bias, the focus is on:
①It is believed that the product uses brand-new raw materials, and the strength meets the requirements of national standards under the premise of ensuring the weight. It is not necessary to use three-folded wire;
②Thinking: The production of three-folded flat wire is troublesome and has a high rate of wire breakage, making it impossible to achieve high-speed production;
③Think that: using part of recycled materials and a larger amount of calcium fillers, the flat yarn itself is soft and unnecessary. In view of these points of view, it is necessary to do some analysis from the physical form of the three-folded yarn, the principle of flat yarn drafting, the weaving process and the current state of the equipment on the market in order to have a new understanding of the use of folded yarn