[plastic woven bag flat silk production process technical index]
1-1. The production process technical indexes of flat silk are mainly divided into four categories:
1-1-1. It is an objectified modification index, which mainly includes mixture modification, mixing ratio, functional auxiliaries and mixing ratio of waste materials and raw materials.
1-1-2. It is the property rheological index, which mainly has the draft ratio, inflating ratio, drafting ratio, and retraction ratio.
1-1-3. Mechanical performance indicators, mainly tensile force, relative tensile force, breaking elongation, linear velocity, linear density deviation.
1-1-4. Is the tolerance dimension index, mainly has flat silk thickness, flat silk width, etc.
1. Ratio and percentage of modified mixture:
Flat wire production process there are two points by a film forming method, membrane tube membrane peace, according to the film cooling after points a, air cooling and water cooling and cold, according to the draft of heating with hot plate, hot roll, hot air, according to some winding molding have, concentrated cycloid winding, single spindle torque motor winding, magnetic torque winding. Flat wire materials often add some modifier or function of the mother and old reworked material and so on, can use two kinds of indexes.
1-1-1. Mixing ratio, the weight ratio of the added component and the main raw material is called the mixing weight ratio.
1-1-2. Adding percentage, the weight percentage of each group is added, and weight percentage is added.
1-1-2. Variable traction ratio, inflating ratio, draft ratio:
The 1-1-2-1. Traction than is from film extrusion film pulling speed and extrusion speed ratio of the mouth, it is not only used to film, also used for tube membrane, by controlling the traction ratio, make the membrane on the traction direction slightly orientation. Traction than control is to control the extrusion of the thickness of the film cooling after the only effective means. Because an extruder die clearance basic fixed, adjust the quantity is small, in general, it is advisable to traction than stay in the 4 to 8.
The 1-1-2-2. Blowing ratio, blow molding, tube film blown film bubble diameter and the original die diameter ratio, blowing ratio. Flat membrane is apparently not blowing ratio problems. Theoretically, the blowing ratio, the greater the directional role, the better the thin film of transverse tensile, tensile strength, the better, but in fact during can't is too high, lest cause truck hunting, uniformity, film thickness, appear wrinkles, etc. Usually blowing ratio control between 2.0 3.5, no more than eight largest advisable.
1-1-2-3. Draft ratio, flat wire drawing, wire per unit length segmentation (grey silk) the length of the draft ratio, or described as draft (2) the ratio of speed and traction (a guy) to draft ratio. Draft ratio is one of the most important process in the production of flat silk. Draft ratio, also known as the draft draw ratio. The flat wire drawing is at the temperature below the melting point of uniaxial tensile, tensile process is a process orientation, so that the flat wire for high strength and other physical and mechanical properties. In general, draft ratio control in 4 to 7 times, special needs of flat wire, involve than kodak 11 times.
The 1-1-2-4. Retraction than "refers to a flat wire leads to the ratio of speed and haulage speed. Look from the production process needs, pull out rate is lower than drawing speed, shape edge silk secondary heating a shrank back, make flat wire to eliminate internal stress, strong tensile and elongation. Retraction ratio, also called shape ratio. Under normal circumstances, the retraction than between 0.96 to 0.99
1-1-3. Flat silk thread density, relative tensile load, breaking elongation:
The 1-1-3-1. The flat yarn density, is the quality of the characterization of linear objects per unit length. The linear density, the greater the tensile force is larger. In the weaving, yarn linear density is measured plastic knitting of the basic elements of the overall strength. According to GB/T8946 < > plastic sacks in the provisions of annex A yarn length measuring instrument box to 100 m flat wire, weighing accurate to 0.1 grams.
1-1-3-2. Relative to the tensile load, also called relative tensile force, refers to the flat wire tensile force of each Tex, for each flat wire, because of its density and thickness are different, thus different tensile force. But the relative tensile load essentially similar. Because tensile load is nothing to do with flat wire width and thickness of the physical strength index. It depends on the size of the raw material of the temperature, draw ratio, finalize the design, cooling, crystallization and other factors. The relative national standard stipulated in the tensile force is greater than or equal to 0.32 N/Tex.
The 1-1-3-3. The elongation at break, it is the point at which the flat wire drawing the line part () between the two clamping tensile length increase with initial marking part () between the two clamping length, percentage of elongation at break is measured flat silk toughness index (elastic). A larger elongation at break, characterization of flat wire shock sometimes unisexual elongation, not brittle fracture immediately. Thus elongation at break, under the condition of equal tensile force, the number of drop test may be more. In the national standard requirement for elongation at break of 15-30%.
1-1-4. Flat silk width and thickness:
The 1-1-4-1. The width of the flat wire, refers to the width of the split wire after drafting, it determines the knitting weave density. For composite plastic woven bag, plastic woven bag and national standard recommends three kinds of commonly used in weaving density (diameter dense * weft density), namely, 36 * 36, 40 * 40 * 48 root / 10 13 cm. This also apply to other three kinds of knitting density basketwork, according to the three weaving density, theoretical calculation of the width of flat wire to: 2.78 mm, 2.5 mm and 2.08 mm. According to customer's requirement in the process of production of flat silk weaving density control the width of the flat wire.
The 1-1-4-2. The thickness of the flat wire, refers to the thickness. After the split wire drawing thickness determines the woven fabric weight per unit area. At the same time, if the width of the flat wire have determined that the thickness of a flat wire is flat linear density of the deciding factor.