Wire drawing: woven industry also known as the short cut fiber, which is the production of plastic basic materials, flat by a particular species of polypropylene, polyethylene resin film by melt extrusion, and then cut into longitudinal, various articles and heated after drawing orientation stereotypes, and ultimately wound into flat yarn spindles for weaving fabric.
Stretching processes include: modification of raw materials, blending, coloring, filling, preparation, aging, anti-degradation issues, the extrusion process the temperature, pressure, flow control and regulate the rheological behavior of the extrusion process, power, yield issues, the drafting process of the traction ratio, Inflation ratio, draw ratio, cooling crystallization, orientation, heat treatment and stereotypes, in the process of forming and winding spindles quality testing and other technical issues.
Stretching process, also known as yarn manufacturing process, which is the production of plastic knitting the first process, a process is the most important.
Flat Wire forming method for the production process methods divided by two, tubular film peace film, by forming divided after the cooling, air cooling, water cooling and cold room, by drawing a hot plate heating, hot rollers, hot air, according to divided winding spindles forming focus cycloid winding, single-spindle torque motor winding, the magnetic moment of winding.
1. Wire drawing technology index is divided into four categories:
1.1 Is the physical and chemical modification of targets, the main modification, mixed ratio, functional additives added ratio, mixing ratio of waste recycled materials.
1.2 Is the rheological properties of indicators, the main draw ratio, blow expansion ratio, draw ratio, shrinkage ratio.
1.3 Is the mechanical performance, the main tensile force, the relative tensile force, elongation at break, line speed, linear density deviation.
1.4 Is the tolerance size indicators, mainly flat yarn thick, flat and wide.
2. Modification of mixing ratio and the percentage of:
Flat Wire forming method for the production process methods divided by two, tubular film peace film, by forming divided after the cooling, air cooling, water cooling and cold room, by drawing a hot plate heating, hot rollers, hot air, according to divided winding spindles forming focus cycloid winding, single-spindle torque motor winding, the magnetic moment of winding. Biansi materials often add some modifier or function of parent materials and waste recycled materials, etc. There are two indicators.
2.1 mixing ratio, a key raw material components and add the weight ratio of said mixture by weight.
2.2 add the percentage to add group accounts for a total weight percentage of each group, said the added weight percentage.
2.3 flow traction ratio, Inflation ratio, draw ratio, retraction ratio:
2.3.1 traction traction ratio is out of film extrusion speed and the speed from the mouth of the ratio of film, not only for the flat membrane, but also for tubular film, by controlling traction than to make a little film in the direction of orientation of the role of traction. traction than out of control is to control the thickness of film cooling only effective means. because of the extruder die of a basic fixed port clearance, adjust the amount of small, under normal circumstances, appropriate traction ratio remained at 4-8.
2.3.2 inflation ratio, blow molding, the tubular film blowing bubble diameter and the diameter of the original model than the mouth, called the blow than inflation. Inflation is clearly not flat film than the problem. In theory, the bigger the ratio Inflation , the role of film is better directed transverse tensile, tensile strength is better, but actually produced in the not too high, so as to avoid swinging snake, even a decline, thickness ranging from wrinkles appear. general Inflation Control to 2.0-3.5 and the maximum should be no more than eight.
2.3.3 draw ratio, flat stretch, the unit length wire partition (billet wire) multiple of the length of the stretch, or described as a distraction (b slight) speed and traction (a pull) the ratio of the speed of draft ratio . drawing ratio is flat yarn production process the most important indicators. draw ratio, also known as draft ratio, draw ratio. Biansi the draft is conducted in the temperature below the melting point of tension, is the orientation of the drawing process process in order to obtain high-strength flat wire and other mechanical properties. In general, drawing 4-7 times than the control, special needs, flat yarn, involving 11 times.
2.3.4 retraction ratio refers to the flat wire pull-out speed and traction speed ratio. from the production process requires point of view, pull-out rate is lower than the traction speed, to the side of a wire back to the second heat-setting shrinkage, the flat wire elimination of internal stress, get a strong pull and excellent elongation. retraction ratio, also known as the shape ratio. In general, between the retraction than 0.96-0.99.
3. The thread density, the relative tensile load, elongation at break:
Flat silk density, is characterized by mass per unit length of linear objects. Line density, the greater the tensile force. In plastic woven in, flat line density is a measure of the overall strength of plastic knitting the basic elements. By GB/T8946 <plastic bags> of the provisions of Appendix A, yarn box to 100M flat yarn length measuring instrument, precision weighing 0.1 grams.
Relative tensile load, also known as the relative tensile force, is the tex of each pull-off force of flat wire, flat wire for each, because of its different density and thickness, tensile force and thus different. But the relative tensile Basically, the size of the load tends to close. because of the relatively flat yarn tensile load is independent of width and thickness of the indicators of physical strength. It depends on the temperature of raw materials, draw ratio, shape, cooling, crystallization and other factors. stipulated in national standard Breaking force of greater than or equal relative 0.32N/tex.
Elongation refers to the flat wire marking part of the effective tension (between the two jig) to increase the amount of pull-off length and the initial effective marking part (between the two jig) the length of the percentage of elongation is a measure of flat silk toughness (flexible) indicators. have greater elongation at break, have a certain impact characterization of flat yarn of elongation of the single, not immediately brittle. thus breaking elongation, tensile force in the same conditions , the number of drop test may be more. GB requested the elongation at break was 15-30%.
4. Width and thickness:
4.1 the width, is split after the width of the wire through the draft, which determines the fabric weave density. For plastic and composite plastic woven bags, the national standards recommended by the three commonly used weave density (diameter weft density * secret), that is, 36 * 36,40 * 40,48 * 48 / 10cm. This also applies to the other three weave density fabrics, woven by these three densities, flat width of the theoretical calculation is: 2.78mm, 2.5mm , 2.08mm. in the production process of flat wire according to customer requirements the width of flat yarn weaving density control.
4.2 the thickness is the thickness of partition after the wire drawing. Thickness determines the woven per unit area. Also, if the flat wire width have been identified, flat is flat thread the thickness of the determinants of the density.
Woven polypropylene bags producing process: