How to prevent the injection mo大樹lding machine head visc刀樂ose

   By changing the angle of the ext做分rusion profiles draw多費n from the die head, the pos慢人ition of the glue on the di分女e head can be changed, there得睡by making it easier to be 街數cleaned. In addition, t訊要he die viscose can費一 also be transferred筆畫 to the product by artificial me話人thods, and then c內喝ompletely removed. For thin舞哥 plate, you can us身拿e automatic scraper scraper scraper不吃.
      However, operato關西rs often need to p子自ay such a high price to stop the remo我為val of viscose. After the cleani做關ng is finished, the mold releas些見e agent or the silicone resin is applie東有d in the die outlet area, which can 多做reduce the forming speed 數化of the viscose 金美and prolong the interva土多l of two cleaning. In addit小現ion, reducing the op黑師erating speed o多計f the device can also reduce the放雪 die viscose, but this will affect 公喝the yield.
      All of these methods are pall來女iatives, the better solu靜黑tion is to find t又吃he cause of the formation of vi頻們scose.
      The die head adhesive is腦綠 related to the stress at the exit of d請線ie head. At the inner surface of th林朋e die, the flow rate of th她筆e molten resin 去也is relatively s對冷low, and then suddenly accel兵算erates at the di船地e exit. This acceleration causes str笑國ess in the melt, 用土and under the ac船男tion of stress, the low molecular他下 weight polymer compo校如nent is separated from the ot車行her components in 也厭the melt, and is deposite空算d at the exit of the die head to form a員雨 viscose. Therefo的路re, the solution to the problem is算林 to reduce the die outlet stres遠務s, or to reduce the tenden花票cy of the separatio上生n of melt components. This體友 may be related to the change of the p河舊rocess material or 暗資die. 1. The format船個ion of a thick and loose mold hea拍冷d may be due to the partia友子l foaming of the me吧知lt the compatibility of the resin or t車愛he excessive stress of the die
      Increasing the temperature of 友學the die and melt 習黑is one of the methods to reduce the exi國工t pressure of the die, but it may lead司相 to additional d市年egradation, which leads to the increa地妹se of low molecular weight comp身關onents. Therefore, it is necessary to 靜姐adjust the temp空區erature of melt and die. But note that,森說 sometimes, the low die temp視友erature, the resin ma銀妹y form a slow v地服elocity of flow in the di筆資e surface layer of cold flow, the main那微 flow layer and the r這匠esin cold from each other, and e雜學ventually lead to the for跳看mation of viscose.
      Through the simulation of the d能秒ie flow to study 科他the resin in the outlet of the die stre市農ss changes, this stress w兵雨ill eventually lead to the generat務吃ion of die viscose (pictures from Com做紅puplast company) to s人喝et the temperature of the die head, fir也上st to determine the true temperatu路國re of the melt. Since司厭 the standard melt這南 thermocouple often pro票這duces errors, it is necessa個謝ry to manually me愛見asure the melt temperature.雜討 Although this app微請roach is difficult, but it is nece些雪ssary to find the cause of the f知線ault. In addition,會水 because the surfa樹長ce temperature at the die ex黃志it is much lower than 跳答the temperature of the die hea器哥d, the surface thermocouple should b如現e used as the exit temperatu也人re.
      The air outlet of the die h照遠ead can reduce and control the鐵樹 generation of viscose, and議吧 can also be used to remo坐土ve various kinds of 好很flue gas and condensable朋銀 gas from the die head. In a體開ddition, the blast 歌商also helps to cool the mold 多就head of viscose, so that it is not ea歌唱sy oxidation black大服. N2 can also be鄉微 used to preven化工t oxidation. It shou鄉答ld be noted, however, 店但that it is not too cold西紙 or too low to red中購uce the die temperature.
      Change die viscose raw materi用拍al may make different 土會forms, some thick女黃 and sticky, some thick loose書制. A thin, sticky adhes雨內ive is formed at t嗎你he exit of the die head河書 and is condensed on th遠花e surface of the die head. Thick and窗男 loose viscose is us來樂ually caused by the partial foami海信ng of the melt, the compatibility司計 problem or the internal press錯吧ure of the die head. Th劇睡erefore, in the extrusion, 開麗the resin should avoi冷風d excessive humidity or degradation,又明 as well as possible melt ruptur話制e or improper ex問資haust.
      There are some suppliers 視鄉of resins that produce more adhesive 懂用than those from other sources, even樂店 if they have exactly the sa個歌me technical specifications開呢. When the head of viscose, try to use 有子other suppliers of similar grades o年要f resin, if the problem has i是計mproved viscose, the in拿雜itial resin may 知業be a problem in performance.
      Resins from diff匠道erent suppliers may have si舊醫milar shear viscosity, but have v你森ery different elongational viscosit報熱y. If there is 子章no difference in performance,地相 it is possible to test the visc船這osity. The higher the vis麗了cosity of the resin may be due to d坐門ie outlet pressure becomes l市鐘arger and more viscose.
      At the same time, the resin 湖到with higher expansion of the mol議空d has a higher rat讀懂e of the formation of t林錢he die head. When the resin has行謝 a narrow molecular we件土ight distribution, the expansion of t校低he mold may be lower, b線藍ut this does not necessarily me員他an that the formation of less v劇可iscose. In general, 有師the resin with n器會arrow molecular we她車ight distribution is difficult to be pr海市ocessed, and the low molecular weigh理明t components may be produced, which eve大熱ntually lead to the formation o火東f the viscose.
      For the regeneration of re對低sin, usually contain民體ing a low molecu中她lar weight due to thermal 線我degradation of the朋長 previous processing. In this 河男regard, additives c市數an be added to inhibit degradation, o朋秒r the use of chain extende靜員r can cause the degradation of 些道components to b城海e re polymerization. If these do not w金慢ork, they will not 西些be suitable for use.
      In some cases, the a大計ddition of lubricants 要看helps to reduce the amoun這窗t of viscose, but too 技厭much lubricant may also inc木窗rease the production of visc商時ose. The chemical compatibility o電小f different components in都熱 the formula is one of th土男e important factors服美 affecting the viscose. F明討or example, when highly音請 incompatible polyme煙師rs melt and mix together, the extrem現制e case of viscose. In this case, 道線the use of compatibilizer will help 請問ease the format又也ion of viscose. In addition, the ad南說dition of a small amount of flu飛照oropolymer processing都弟 aids can also red務為uce the die exit geometr電行y of the die exit strain gauge 3
      For rapid oxidation什木, variable die viscose物暗 type yellow or black, can add antiox姐雪idant in the formula. Although t廠小his does not solve the proble都務m of die adhesive, 會上the adhesive on the product be子白comes invisible.
      Changing the mold head時草 on the surface of the那花 mold coated with fluoropolymer, such a工數s PTFE, to a ce志子rtain extent to preve的門nt the formation of viscose. The m答放ore effective way is to use t見呢he metal coating, 有章so that the fluorine p資到olymer into the 亮坐mold head, to reduce 要弟the stress of the die outle章一t.
      On the other hand, the flow simulation木信 of the die head has been succe上事ssfully applied to solve the problem o煙媽f die adhesive. By simulating 市近the flow state of the resin at the di內高e head, it can be used to算現 study the forming 為得reason of the d能房ie exit stress, and to evaluate the e現水ffect of changing the geometry of 道厭the die exit on the adhesive.
      It is a widely used method to impro上區ve the die exit geometry to reduce stre說去ss. Some die shape has been export prod員公ucers and processor答喝s of resin applied for pa慢請tent protection. It can reduce 美農the improved die outlet die visco輛玩se production include: square, ladder的能 shaped export sharp sharp sharp expo中事rt exports, round export, outward學鐘 stepped exit, inwa玩上rd outward and funnel-shaped outlet.路文
      In addition, by increasing 南呢the length of t司音he die forming section, t月報hereby reducing the r紙鐵esin at the exit of the mol裡高d head changes, but al雪藍so help to reduce the die o村民utlet stress.