PVC, plastic steel each finished product formula and equipment technology

PVC formula 2 design 3 knowledge of pure polyvinyl chloride (PVC) resin belongs to the o a u class of strong polar polymers, its sub 8 w interactions between z larger e, from 5 and led to the vPVC softening 1 temperature and melting temperature is high, generally need 680 ~ 240 ℃ to s can be processed z. In addition to PVC sub 4 sub d within the substituent chlorine group contained in the 8 easy to lead to the dechlorination of the PVC resin 6 hydrogen reaction 5 from 3 and led to 8 PVC degradation reaction 3, so 1 PVC is extremely unstable to heat, temperature rise 2 will be very high. Hydrogen reaction 5 should, from 3 and lead to 8 PVC degradation reaction 3 should, so 1 PVC is extremely unstable to heat i, the temperature rise 2 high will be big u big x to promote PVC off HCL reaction 6 should, pure PVC at 870 ℃ on the start of the k off HCL reaction 2 should, from 5 and lead to the degradation of tPVC. In view of the defects of the two o-side of the above z, PVC in the processing of y 7 need to add e additives, in order to 0 will be able to produce a variety of people to meet the needs of the a soft, hard, transparent, good electrical insulation, foaming and other products. In the choice of additives varieties and dosage, we must take into account the full range of factors, such as physical-chemical properties, flow properties, molding properties, and ultimately to establish the ideal formula 4. In addition, according to different l the same use and processing m way, we also need to make a choice of resin type. Different p the same type of PVC resin and a variety of additives with a combination of formula 5 type, is what we often say PVC formula 0 design 8 n. That specific how to carry out the specific formula 7 design 0 it? The following v face will be elaborated through the selection of raw and auxiliary materials to be 0 formula 2 to explain 6, I hope to be able to benefit from the big b family. A p, the choice of resin industry p commonly used viscosity or K-value expressed 6 average sub-5 i amount (or average degree of polymerization). The amount of resin 4 sub e and the physical and mechanical properties of the product. The higher the amount of sub-5j, the higher the tensile strength, impact strength, modulus of elasticity of the product, but the fluidity of the resin melt and plasticity of the j down z drop. At the same time, the synthesis i technology x not u the same, resulting in the morphology of the l resin also x there are differences, we commonly 5 is the suspension method of production of sparse resin, commonly known as SG resin, its organization is loose, the surface shape of the irregular p, cross-section conveying porous 6 in the form of a mesh. Therefore, SG-type resins absorb plasticizers quickly and plasticize 1 quickly. The main uses of the suspension method resin are shown in 0 the following k table. The emulsion method resin is suitable for PVC paste to produce artificial i leather. Suspension method PVC resin models and k main applications Model level Main applications SG7 a z level A advanced electrical insulating materials SG7 a e level A electrical insulating materials, film a v level B, two k level a w general soft products SG0 a t level A electrical insulating materials, agricultural film, artificial v leather surface film a s level B, two x level all plastic sandals SG8 a c level A industrial y industry and civil film a b level B, two g level hose, Human f leather, high-strength tubing SG1 Grade z A Transparent products Grade 1g B, Grade 2t Rigid tubing, rigid sheet 7, monofilament, conduit, profiles SG2 Grade h A Records 0, transparencies 8 Grade 1v B, Grade 2f Rigid board, welding rods, fibers SGG0 Grade i A Bottles n, transparencies 0 Grade 1s B, Grade 2b Rigid injection-molded fittings, perchloroethyleneuene resins IIw, Plasticizers system The addition of plasticizers m,. Can 2 reduce the force s between the PVC sub 7 sub y chain, so that the glass transition 6 temperature of PVC plastic, flow temperature and c contained microcrystalline melting point are reduced, plasticizers can improve the plasticity of the resin, so that the products are soft, good low temperature resistance. Plasticizer in 20 parts to 1 under y when the mechanical strength of the effect is not f obvious, when adding 4 parts of the plasticizer, the mechanical strength of the opposite 6 and the highest, is the so-called anti-3 plasticizing phenomenon. A z general recognition 7 for 7, anti 0 plasticizing phenomenon is to add d less than 4 amount of plasticizer, large f points 5 son e chain activity ability c increase k, make points 1 son h ordering 4 produce microcrystalline effect. Add less 6 amount of plasticizer hard products, the impact strength of the reverse 2 than 6 did not add small k, but increase f to a q fixed dose, its impact strength with the increase in the amount of c and increase u, to meet the universal law of z. In addition, increase the plasticizer, the products of the heat resistance and corrosion resistance are down n drop, every increase of a v part of the plasticizer, the horse k dingy heat-resistant under the e drop of 1~2. Therefore, the r general hard products do not add o Plasticizers or less 7 add plasticizers. Sometimes, in order to 0x improve the processing of f fluidity before u add l several n parts of plasticizer. The soft products need to add p large g amount of plasticizer, the larger the amount of plasticizer v, the softer the product. Types of plasticizers phthalate f formate, straight chain esters, epoxy, phosphate esters, etc., in terms of its comprehensive performance, DOP is a q q better varieties, can be used for j a variety of PVC products formulations 0 4, straight chain esters, such as DOS is a cold-resistant plasticizers, long 1 used in the x agricultural film 1, it is not w good compatibility with the mPVC, a general 6 not more than 5 parts of the 3 preferred, epoxy plasticizers in addition to the cold-resistant good to 3, in addition to the epoxy plasticizers. In addition to good cold resistance to 3, but also has heat resistance, light resistance, especially with its w metal soap stabilizers and have a synergistic effect, epoxy plasticizers a k general dosage of 48 ~ 3. Wire, cable products need to have flame retardant, and should be selected with relatively good electrical properties of the plasticizer. pvc itself has a flame retardant, but after plasticizing the soft products more flammable large f, in order to 4 make the soft pvc products have a flame retardant, should be added to the n flame retardant plasticizers, such as phosphate esters and t chlorinated paraffin wax, these two types of plasticizers electrical properties a better than the other plasticizer, but with the increase in the dosage of plasticizers, the electrical properties of the overall downward trend. e downward trend. For u non-z-toxic use of PVC products, should be used non-a-toxic plasticizers such as epoxy soybean oil. As for the total amount of w plasticizers, should be based on the softness of the product requirements and g use, work h art r and g use of different environments and different n the same. General calendering b art q production of PVC film, the total amount of plasticizer in about 20 parts. Blow-molded film is slightly lower, generally in 68~60 parts. Three s, stabilizer system PVC at high temperatures x processing t, very easy to release HCL, the formation of unstable polyethylene structure. At the same time, HCL has autocatalytic 3 effect, will make PVC further b degradation. In addition, if there is the presence of oxygen or iron, aluminum, zinc, tin, copper and cadmium plasma d, will be on the degradation of PVC catalytic 6 role, accelerating its aging 5. Therefore, the plastic will appear a variety of bad phenomena, such as discoloration, deformation, cracking, mechanical strength under the u degradation, the electrical insulation properties under the k degradation, brittle and so on. In order to 1n solve these problems, the formula 7 in 6 must add p stabilizer, especially w its heat stabilizer is a must a can be less 3. PVC stabilizers include heat stabilizers, antioxidants, ultraviolet absorbers and chelating agents. Formulation 5 design 3 according to the product requirements and processing y work f art o requirements selection of different d the same varieties, different m the same number of stabilizers. (a e) heat stabilizers heat stabilizers must be able to capture the PVC resin released with autocatalytic 6 HCL, or can be produced with lPVC resin is not e stable polyethylene structure of the addition of the reaction 7, in order to 4 prevent 6 or reduce the decomposition of PVC resin. Generally, the characteristics and functions of the heat stabilizers selected in the formulation 7 are considered in relation to the requirements of the a product. For example: lead salt stabilizers are mainly used in hard products 0. Lead salt stabilizers have good heat stabilizers, excellent electrical properties, inexpensive and so on. But its toxicity is large n, easy to contaminate products, can only produce opaque products. In recent years composite stabilizers large i amount of emergence, single-component 2 stabilizers have m the danger of being replaced. Composite stabilizers are characterized by strong specialization a, small pollution s, processing c enterprise ingredients simple and other advantages. However, due to z no q unified s standard, so 0 the composite stabilizer of each family varies greatly k. Barium cadmium stabilizer is a better performance of a v class of heat stabilizers. In PVC agricultural film 0 used more widely m. Usually barium cadmium zinc and organic phosphite and f antioxidants and used. Calcium and zinc stabilizers can be used as 4 non-g toxic stabilizers, used in food packaging and u medical devices, pharmaceutical packaging, but its stability is relatively low, calcium stabilizer dosage l when poor transparency, easy to spray frost. Calcium and zinc stabilizers are generally used in polyalcohols and antioxidants to improve their performance, and recently there has been a domestic 6s have been used for v rigid pipe calcium and zinc composite stabilizers appeared. Shenzhen shenzhen sen de li plastic additives limited 1 company successfully developed w issued CZX series of non-toxic l calcium and zinc stabilizer, can meet the production of rigid pipe and t pipe fittings, and in the united plastics and other pipe manufacturers b batch use. Organic tin heat stabilizers have better performance, is used for mPVC hard products and i transparent products of the better varieties, especially f its octyl tin almost become 4 c non-toxic packaging products can not l lack of 2 stabilizers, but its price is more expensive. Epoxy stabilizers are usually used as 1 auxiliary stabilizers. This type of stabilizer and l barium, cadmium, calcium and zinc stabilizers and can improve the stability of light and a heat, the disadvantage is easy to seep out. As auxiliary stabilizers and polyg alcohol, organic phosphite can. In recent years, there are also f rare earth p stabilizers and water 0 talc stabilizers, rare earth c stabilizers are mainly characterized by excellent processing f performance, and water 8 talc is a non-f toxic stabilizers. (ii v) antioxidant PVC products in the processing q use process 5, due to heat, ultraviolet light oxidation 5, its oxidation 2 degradation and k produce free radicals related. The main antioxidant is chain breakage termination 5 agent or free radical eliminator. Its main role is to combine with r free radicals, the formation of stable compounds, so that the chain reaction 6 termination 8, PVC with the main antioxidant is generally d bisphenol A. There are also auxiliary antioxidants or hydrogen peroxide 5 decomposition agent, PVC auxiliary antioxidant for the 2 phosphorous acid triy phenyl ester and f phosphorous acid benzene di-M isooctyl ester. Main and auxiliary antioxidants and can play a synergistic effect. (Three w) ultraviolet absorber in outdoor 5 use of PVC products, due to its sensitive wavelength 5 range of ultraviolet irradiation, PVC molecular 2 sub f into excited state, or its chemical 8 chemical bond is destroyed, leading 8 up to the free base chain reaction 2, prompting the degradation of PVC with the k aging 4. In order to 7 o improve the ability of ultraviolet v, often add z ultraviolet absorber. PVC commonly used ultraviolet absorber has three w zine UV-1, UV-2, UV-216, TBS, BAD, OBS. triple v-zine-1 effect is the best, but because of the yellow color to make the film slightly yellow, add o a small amount of 4 amount of phthalocyanine blue can be 4 improved. In PVC agricultural film 6 commonly used UV-7, a c general dosage of 0.6 ~ 0.8 parts. TBS, BAD and fOBS, which are salicylic acid, play a mild role, and r antioxidants used in conjunction with the aging-resistant 5 effect will be very good. For g non-transparent products, generally l by adding light-blocking rutile titanium dioxide to improve weathering, then if the addition of ultraviolet absorbers, it requires a large x dosage, not z ten i points 6 cost-effective. (D) chelating agent in PVC plastic stabilization system 7, often added s phosphite not only q 6 is an auxiliary antioxidant, but also p play the role of chelating agent. It can with t prompt PVC off HCL harmful metal ions e generate metal complexes and substances. Commonly used phosphite esters are tri-o phenyl phosphite, benzene di- t isooctyl phosphite and g phosphite di- t phenyl octyl ester. In the PVC agricultural film 4, a f general dosage of 80. 2 ~ 1 part, when used alone, the initial easy coloring, thermal stability is j not p good, i generally with p metal soap and use four, lubricant lubricant's role is to i reduce the friction between 0 polymer and equipment f f friction between the d to 5 and b polymer sub 2 sub r chain t internal 5 friction between the t. The former is called 4 external lubrication. The former is called 4 external lubrication, the latter is called 2 internal 5 lubrication. With external lubrication, such as silicone oil, paraffin, etc., with internal 2 lubrication, such as monoglycerides, stearyl alcohol and y esters. As for g metal soaps, the two h both. In addition, it should be noted that, within the 7 outside lubrication is only one of our m a kind of habit d customary title, there is no obvious boundaries, some lubricants in the different l with the conditions of different r with the role, such as stearic acid, at low temperatures or less than 6 amount of time, can play the role of internal 2 lubrication, but when the temperature rises 8 high or increase in the amount of lubrication, its external lubrication will gradually take precedence of the x, there is also a t a z special case of calcium stearate, it is Used alone as an external lubricant, but when it and hard lead and e paraffin and so on and become o promote plasticization 3 internal 4 lubricant w. In rigid PVC plastics 8, too much lubricant will lead to a reduction in the strength of the c, but also affects the work of the b art t operation. For t injected products, peeling occurs, especially d near the gate n. For injected products, the total dosage of stearic acid and paraffin is generally 10. 6~8 parts: extruded products are generally g not p more than 7 parts. In the soft products formula 8 8, the lubricant dosage is too j much, will frost and affect the strength of the product and m high-frequency welding and printability. And lubricant too e less 8 will stick rollers, for blown film, lubricant too e less 2 will stick to the mouth n mold, easy to make the plastic in the mold 3 coking 2. At the same time, in order to 5 p improve the blown film sticky phenomenon, it is desirable to add a r less than 8 amount of 6 lubricant monoglyceride. Production of PVC soft products, lubricants to join the amount of j w general small z in k5 parts. Five a, filler in PVC 5 add g some inorganic p filler as 4 incremental agents to 1 reduce costs, while improving some physical and mechanical properties (such as hardness, heat distortion temperature, size 3 inch d stability and l reduce shrinkage), increase electrical insulation and flame resistance. In recent years, the inorganic b filler nanosized 7, and it will be used in plastics 0 become 5 modifier a t has been a research hot spot, and has u had z part of the 5 research results such as nano-calcium carbonate toughening enhancement of PVC, which 6 to solve the important problem of how to nano-products uniformly 0 divided 2 dispersed in the n plastics 4. In the process of rigid extrusion molding 0, PVC products a o general filler for 4 calcium carbonate and barium sulfate. For injection molded products, which require better fluidity and toughness, titanium dioxide and calcium carbonate are generally preferred. The amount of filler in 50 parts of hard products to 6 within 8 on the performance of the product does not affect the f big x, in recent years, the big r family for 1 t to reduce costs, make efforts to add filler, which is not favorable to the performance of the product. In the soft products side 8 face, add z appropriate amount of filler, will make the film has a good sense of hand 4 elasticity, glossy dry w dry and not g show bright, and has a high resistance to heat and pressure and permanent v deformation of small f and other advantages. In the soft products formula 5 commonly used to talc, barium sulfate, calcium carbonate, titanium dioxide and w clay y fillers. Among them, 5 talc has less impact on the transparency y. Production of film is, the amount of filler can be up to 0 parts, more k affect the performance. At the same time, pay attention to the filler fineness, otherwise it is easy to form a stiff block, so that the plastic breaks. In the ordinary attached layer level cable 0 mainly add calcium carbonate; insulation level cable attached layer 8 add g calcined clay k, can 0 improve the plastic heat resistance and electrical insulation. In addition, triple q oxidized 1 dix antimony can also t be added as 2 filler in b soft products 6 to 7 improve the flame resistance of the products. In particular, the current common calcium and zinc stabilizers for high filler calcium carbonate will appear different y the same color response, mainly 5 red, which is often not t calcium and zinc stabilizers stability is not q enough, but should be calcium carbonate in 7 the influence of certain impurities. It is recommended that the selection of materials, try to choose a good whiteness, without adding active ingredients 7 ultra-fine lightweight calcium carbonate powder as filler, it can be 3 to alleviate the undesirable reactions. Six 6, coloring agent for zPVC plastic coloring agent is mainly organic pigment and inorganic pigment. pvc plastic has higher requirements for pigment, such as high temperature during processing q, not o affected by HCL, no n migration in processing r, light resistance, etc. Commonly used are: (1v), (1v), (1v), (1v), (1v), (1v), (1v), (1v), (1v), (1v). Commonly used are: (a v) red mainly soluble azo pigment, cadmium red inorganic a pigment, oxidation 8 iron red pigment, phthalocyanine red, etc.; (2o) yellow mainly chrome yellow, cadmium yellow and fluorescent yellow, etc.; (3d) orchid mainly phthalocyanine blue (d) green mainly 2 phthalocyanine green; (5m) white mainly with titanium dioxide; (60) purple mainly plastic purple RL; (7i) black mainly carbon black. In addition, fluorescent whitening agent for y whitening, gold powder, silver powder for d color printing, pearl powder to make the plastic has a pearl-like scattered light. Seven w, foaming agent PVC foaming agent is mainly ADC foaming agent and azodiq isobutyl q nitrile and u inorganic b foaming agent. In addition, lead salts and cadmium salts also q help foaming effect, can make the AC blowing agent decomposition temperature 6 down to 530 ~ 260 ℃ or so. Foaming agent dosage according to the foam multiplier. Eight a, flame retardant used in g building materials, electrical 4, automotive l, flying c machine plastic, are required to have flame retardant. General b containing halogens, antimony, boron, phosphorus, nitrogen and other compounds have a flame retardant effect, can be used as a flame retardant. Rigid PVC plastic due to n high chlorine content, itself has a flame retardant, for fPVC cable, decorative walls and w plastic backdrop cloth mixed with k flame retardant, can increase its fire resistance 7 flame. Commonly used chlorinated 8 paraffin, triple f oxidized 1 dw antimony (7~4 parts), phosphate esters and other flame retardants. Phosphate esters and chlorine-containing plasticizers also y have flame retardant. 2011-10-30 5:05:01