![<?echo $_SERVER['SERVER_NAME'];?>](/template/twentyseventeen/skin/images/header.jpg)
Wang Cheng, Lin Jieqi, Qiao Xiaole, Xue Zhiwei, Song Wei (ä¸æ科技股份有é™å…¬å¸, Nanjing 210012)
Abstract: The drying process of glass fiber textile sizing agent was studied. The different natural storage conditions of the raw silk, the temperature and time of hot air drying, the drying process of the glass fiber raw material moisture content, the combustible content, the strength, the filming effect and migration distribution of the sizing agent, and the textile of the untwisted yarn were tested. The influence of physical and chemical indicators such as process conditions and strength and wear resistance.
Key words: glass fiber; textile type sizing agent; drying process CLC number: TQ171.77+4.2 Document code: A
0. Introduction The production process of glass fiber includes glass melting, fiber drawing, and textile processing. The wire drawing process is a high temperature melting glass liquid flowing out through a leaking plate leakage nozzle having a certain temperature, and hundreds to thousands of monofilaments are drawn to form a tow, the tow passes through the wetting tank and is coated with a layer of sizing agent, and then passes through the row. The wire is wound at high speed on the winding drum of the wire drawing machine and arranged according to a certain winding structure [1].
Since glass fiber is a material with smooth surface and brittleness and no friction resistance, it is necessary to apply a certain protective film, that is, sizing agent, to lubricate and bond during the drawing of glass fiber to meet the drawing and the back textile. The need for production, and ultimately meet the process requirements and mechanical properties of the reinforcement material. The sizing agent is an organic system. At present, it is mainly based on water-based type. It is mainly composed of a sizing agent, a lubricant, a coupling agent, an antistatic agent, etc., wherein the sizing agent is also called a film forming agent, and the sizing agent group The largest proportion of the parts, can make hundreds of monofilaments bond into a single strand and form a protective film. Its satisfaction with the process performance and mechanical properties of glass fiber directly affects the quality of glass fiber products.
During use, the sizing agent is evenly coated on the surface of the glass fiber through a lubrication tank or a monofilament oil applicator, and the raw silk is naturally placed or dried during production to achieve water drying of the glass fiber surface sizing agent. And bonding to form a film. The glass fiber drying process is an important process in the production of glass fibers. The moisture content, combustible content and the film formation and distribution of the sizing agent on the surface of the fiber will affect the normal progress of the subsequent textile process and affect the physical and chemical properties of the glass fiber yarn. In this paper, the glass fiber strands coated with sizing agent, the different storage conditions, hot air drying temperature and time, etc., the moisture content, combustible content, strength, sizing migration distribution and de-merging yarn are studied. The influence of textile conditions and physical and chemical indicators such as strength and wear resistance.
1. Test 1.1 Test scheme The diameter of the glass fiber strand is 7 μm. The main component of the sizing agent is water-soluble epoxy, which is brushed by a sputum method and wrapped around a wire. The raw silk after drawing the sizing agent by drawing is naturally stored and dried, and the storage time is tested; the other group is directly stored in a hot air oven without drying, and the drying temperature and drying time are tested. The effects of different processes on the moisture content of the raw silk, the content of combustibles, the strength, the migration distribution of the infiltrant, the process of reducting and twisting, and the physical and chemical properties of the yarn were studied by the raw silk test under the above two different drying conditions.
1.2 Drying process Natural storage time: 0, h, 2, h, 4, h, 6, h, 8, h, 10, h, 12, h, 24, h.
The raw silk is not stored, directly dried, using a hot air oven 80, ° C, 2, h; 95, ° C, 2, h, 4, h; 110, ° C, 2, h.
1.3 Test items Raw silk moisture content, combustible content distribution, strength, retreating process, moisture content of plied yarn, combustible content, strength, yarn grinding times.
1.4 Test Method Description The test methods used are mainly:
(1) GB/T, 9914.1, Test methods for reinforced products, Part 1: Determination of water content (idt, ISO, 3344: 1997).
(2) GB/T, 9914.2 Test methods for reinforced products, Part 2: Determination of flammable content of glass fibres (idt, ISO, 1887: 1995).
(3) GB/T, 7690.3-2001, reinforced materials, yarn testing methods - Part 3: Determination of breaking strength and elongation at break of glass fibres (idt, ISO, 3341:2000).
(4) The test method of raw silk moisture content adopts the whole silk cake drying weight loss method. The raw silk combustible content distribution test sampling points are 500, m, 1,000, m, 1,500, m, 2,000, m, 3,000, m, 4,000, m, 5,000, m, 10,000, m, 20,000, m, 30,000 from the beginning. At m, the original wire of the entire wire cylinder has a fixed length of about 40,000, m.
2. Test Results and Analysis 2.1 Moisture Content of Raw Silk Since the glass fiber-coated sizing agent is an aqueous solution, the moisture content is used to characterize the mass percentage of moisture contained in the raw yarn or yarn. Table 1 lists moisture content data for natural storage of raw silk at different times and drying temperatures. Table 2 lists moisture content data after hot air drying. It can be seen that the raw silk can be substantially completely dried under the conditions of hot air 110, ° C, 2, h, and has a high water content under other process conditions. 
It can be seen from Fig. 1 that the moisture content of the raw silk is naturally stored in the process of water loss and drying. The loss of water in the front 2 and h of the raw silk is faster, 2 to 12, and the water loss rate is lower, showing a linear change, 12 to 24, h is very slow. The hot air drying rate decreases with the increase of the heat drying temperature and the time. 
2.2 Appearance of raw silk During the natural storage or hot air drying process, the sizing agent will migrate from the inner surface of the original silk, so the outermost skin of the silk cake is white, which is a migration enrichment area with high sizing content. It can be seen from Fig. 2 that for the original yarn which is not completely dried, since the original yarn is a slit type cable, after the partial silk is removed, the original yarn can be seen from the outside to the inside in a three-stage phenomenon, and the outermost layer is white. The part with the highest level of sizing agent, the outer layer to the middle layer is brightened as the original silk layer which is dried by the sizing agent, and the inner layer is light white as the raw silk which is not dried and formed into a film, and still has a high water content (wet feeling). For the completely dried raw silk, the outer layer is still the concentrated sizing agent content enrichment zone, but the middle layer and the inner layer are both dry film forming raw filaments, as shown in Fig. 3. 
2.3 Raw silk combustible content distribution Combustible content refers to the solid organic content of the sizing agent which remains on the surface of the fiber after the glass fiber is dried. The distribution of combustible content of the raw silk reflects the migration and distribution of the sizing agent inside the raw silk. The test starts from the beginning of the original yarn and is also sampled at the outer surface. The length of each line is taken once. Since the combustible content of the raw silk tends to be stable, the test sample is cut to 30,000 m. 
From the data in Table 3 and Figure 4, the content of combustibles in the first 1,500, m or the first 3,000, m is significantly higher, and the closer to the beginning of the raw silk (outer layer), the higher the combustible content. This is the result of the migration and evaporation of the organic matter in the sizing agent from the inner surface of the raw silk to the outer surface during the drying process of the raw silk natural storage or hot air drying. Even if the original yarn 0, h, that is, the wire is not stored or dried for immediate detection, there is also the migration of the sizing agent. This is because the sizing agent is caused by the mechanical centrifugation of the wire at the high speed of the wire winding head during the drawing process. There is a migration from the inside out.
As the natural storage time of the raw silk increases, the migration of the raw silk infiltrant is gradually aggravated due to the gradual evaporation of water. For example, the combustible content of the raw silk at 1,000 to 5,000 m is associated with the natural storage time (0 to 24, h). Increased by growth. In the test hot air drying conditions, different drying temperatures and times will affect the effect of water evaporation in the raw silk, thereby affecting the effect of the migration of the infiltrant. It can be seen that the raw silk under the hot air drying condition has a higher range in the first 500 and m than the natural storage condition, indicating that the hot air temperature causes the water evaporation on the surface of the cake to be more intense, and the infiltrant migrates. It will be more intense, but the drying time will be reduced accordingly, and the migration time of the sizing agent will be reduced. Therefore, in the range of 1,000 to 4,000 m of raw silk, the combustible content under hot air drying conditions is between 12 and h. Between 24 and h, the overall sizing agent migration is larger than the natural storage of 12, h, which is smaller than the natural storage of 24, h.
2.4 Raw silk tensile fracture strong glass fiber sizing agent will be coated on the surface of the fiber to form a film, which can isolate and protect the glass fiber, and also bond bundle and wear-resistant to the original yarn. The effect of this has a direct impact on the strength and processability of the glass fiber and the application of the composite material, and the film bundle of the glass fiber sizing agent is directly related to the drying process of the raw silk.
The raw silk can not be completely dried under natural storage conditions, and the water content is high. The sizing agent on the surface of the fiber cannot be dehydrated and dried to form a uniform protective film, and the film forming bundling effect is not good, so the tensile breaking strength is low. Raw silk 80, °C hot air drying helps the infiltrant to quickly dehydrate and dry, and at high temperature (above the film forming temperature of the sizing agent), it is beneficial to spread the organic matter of the sizing agent evenly into the film bundle, so the strength is improved, but The inner raw silk is still not completely dried to form a film, so it is still lower than 110, °C hot air is completely dried to form a bundle of the original strand strength, see Table 4 for the average strand tensile breaking strength data under different drying processes. 
2.5 Raw silk textile decoupling process The important role of glass fiber sizing agent is to meet the requirements of wire drawing and textile processing. The raw silk needs high strength, good lubrication, less hairiness, abrasion resistance and folding resistance during the textile retreating process. By studying the performance of the raw yarn under the different drying process of the glass fiber sizing agent in the textile detaching process, the drying process of the glass fiber sizing agent and the effect of film formation bundling can be visually evaluated. The ambient temperature of the raw silk retreat is 25, °C ± 1, ° C, humidity is 45%, focusing on the condition of the yarn hook, roller and other equipment parts and the yarn hairiness of the plied yarn.
The test results show that the reclaimed silk with a certain range of water content is better. Naturally stored raw silk with high water content will be broken due to low strength. Dry wind drying 80, °C, 2, h, 95, °C, 2, h and 95, °C, 4, h And smooth, the hairiness of the wool is less, and the excessively dry raw silk, such as hot air drying 110, °C, 2, h, the original yarn retracting process produces a significant increase in the number of filaments. The adaptability of the raw silk in the textile unwinding process is obviously related to the moisture content of the raw silk and the protective property of the sizing agent. The too high or too low water content of the raw silk is not suitable for the textile processing of glass fiber, combined with different raw silk specifications. The infiltrant formulation system, the textile process and the overall combination of ambient temperature and humidity can achieve a good effect on the textile processing performance of the glass fiber.
2.6 Ply yarn properties The raw yarns of various drying processes were evaluated by comparing the various physical and chemical properties of the plied yarns by retreating and weaving into plied yarns to evaluate the effects of various drying processes on the properties of the plied yarns. Due to the poor film formation of the glass fiber surface sizing agent under some of the raw silk drying process, the test performed a secondary heat setting of the plied yarn to achieve the complementary film formation and bond bundling of the glass fiber sizing agent. effect. 
It can be seen from the test results in Table 5 that the strength and wear resistance of the yarn after the strands which are not completely dried are not high, and the hot air 110, °C, 2, h completely dry the strands of the strands. High strength and wear resistance. The strength of the plied yarn after secondary heat drying is obviously improved, indicating that the secondary hot bake can perform secondary film formation on the surface of the original unfiled sizing agent, thereby improving the effect of bonding and film forming protection of the glass fiber, thereby Increased strength of the plied yarn. From the point of view of the number of abrasions before and after the secondary heat-bonding of the plied yarn, it is also proved that the effect of drying the film by the glass fiber sizing agent directly affects the strength and wear resistance of the glass fiber plied yarn product. However, in terms of strength and wear resistance, the performance of the plied yarn after secondary heat setting is not much different.
3. Conclusions (1) The arrangement of the glass fiber strands on the winding drum during drawing is very tight, and it is difficult to completely remove the moisture by natural storage for one day or short drying (see the moisture content and appearance of the raw silk). ), the outer layer of the original silk cake is dry, but the inner layer is still wet, which affects the film formation bundling effect of the sizing agent on the original yarn. Only through the harsh drying process can the raw silk be completely dried into a film, such as increasing the temperature and prolonging the time, but usually the yellowing of the sizing agent and the increase of the textile wool.
(2) The migration of the sizing agent in the glass fiber precursor mainly comes from two aspects. First, the mechanical centrifugation of the high-speed rotation of the wire barrel during the wire drawing process causes the sizing agent to migrate to the outer surface of the cake, and the second is the storage of the original yarn. And the water loss in the drying process, the sizing agent is an aqueous solution containing about 5% of organic matter, in the process of moisture migration from the inside of the original cake to the outside, it will also partially carry the hydrophilic organic matter from the inward direction. The external migration finally formed the distribution of the intrinsic combustible content from the outer layer to the inner layer.
The migration of glass fiber sizing agent may bring about two adverse effects. First, the distribution of combustibles in raw silk is uneven. From the data in Table 3, it can be seen that the distribution of combustibles content of 0.9% to 3.5% will seriously affect the original glass fiber. The stability of the combustible content of the yarn and the plied yarn brings great difficulties to the product index and quality control. The strict product may need to remove the excess of the combustible content of the outer layer of the raw silk and cause waste; the second is the sizing agent The film-forming quality on the glass fiber precursor is also inconsistent with the effect of the bond bundling, which affects the physical and chemical properties, the textile properties, and the post-processing properties of the glass fiber.
(3) The textile fiber has high technical requirements. The over-wet or over-dried raw silk is not conducive to retreating and weaving, and it is easy to produce broken yarn or hairiness. The original silk must maintain a certain amount of water content to meet the textile needs. Some experience shows that by adjusting the effect of the dry and wet lubricating components in the sizing formulation system and controlling the temperature and humidity of the textile environment, it is beneficial to improve the textile performance of the glass fiber.
(4) From the tensile strength and wear resistance of the glass fiber strand and the plied yarn, the state of the sizing agent on the surface of the glass fiber precursor directly affects these properties, and the dried raw yarn is stronger than the unbaked The dryness is completely increased by 50% to 60%. The glass fiber plied yarn under the test condition is not well dried to form a film, and the bond bundling effect is not good, so the initial strength is low, and the strength is generally improved after the second heat drying. About 20%, the wear resistance is also significantly improved. It should be noted that the secondary heat drying is not to dry the moisture of the plied yarn (the moisture content of the plied yarn in Table 5 is already low), but the secondary action of the sizing agent can form a film of good condition, thereby The raw silk acts to protect and bond the bundle.
(5) It can be seen that many of the above factors affect each other and contradict each other. The glass fiber sizing agent drying process needs to be different according to the glass fiber composition, the wire drawing process, the raw wire winding density and weight, the sizing agent formulation, the textile, and the like. The process conditions must meet the needs of the raw silk sizing agent to form a film, and also meet the textile needs for the moisture content of the raw silk, and also control the influence of the migration of the raw silk sizing agent on the performance and quality of the glass fiber, and also consider The energy-saving economy of raw silk and sizing dewatering (usually combined with natural storage or hot air drying).
references:
[1] Zhang Yaoming, Li Jubai, Jiang Yuzhong. Glass fiber and mineral cotton book [M]. Beijing: Chemical Industry Press. 2001.
Aluminum Sheet,Solid Aluminum Sheet,Aluminium Roofing Sheet,Aluminium Corrugated Sheet
SHAOXING YOTO IMPORT&EXPORT CO., LTD , https://www.sxyotoes.com