注塑工藝手冊

1、工藝注塑手冊injection process handbook一. 基本理念：basic opinion:1. 什么是最佳的流動狀態(tài)：what is the best flow state: 流體流動狀態(tài)應該是噴泉狀的，最佳的流動狀態(tài)是流體前端的流動速度在型腔內(nèi)處處相等。由于流動方向上截面積的不同，在其變化的位置應進行注射速度的調(diào)節(jié)（注意：機床上所能設定的注射速度是指螺桿的前進速度）。 the flow state should be like fountain, and the best is that the speed of the front melt is the same eve

2、rywhere in the cavities. for different areas in the direction that is vertical with the flow way, we must adjust the injection speed.(attention: the injection speed, which we can set on the machine, is the screw forward speed)2. 什么是最佳的壓力,溫度分布狀態(tài)：what is the best pressure and temperature state:最佳的壓力和溫

3、度分布狀態(tài)是壓力和溫度分布在型腔內(nèi)部處處相等，并且隨著熔體地逐步冷卻而下降并使最終產(chǎn)品的內(nèi)應力為零。the best pressure and temperature state should be like this that the pressure and temperature everywhere in cavities are the same, and make the force of the part inside be zero finally as the melt solidified.實際壓力分布狀況是澆口附近最大并隨著距離的增加而降低。（記?。郝輻U頭處的熔體和流動著

4、的熔體前端存在壓力差是使熔體發(fā)生流動的根本原因）the actual pressure around the gate is the highest and as the distance goes its getting lower and lower。(remember: its the pressure in front of the flowing melt is lower than in cylinder that makes the melt flow.) 所以,綜合來講,參數(shù)設定的一般準則:(1) 盡量選用高的注射速度(螺桿前進速度)(2) 盡量選用高的料筒溫度(3) 盡量選用

5、高的模具溫度so the general principles when setting parameters are:(1) as fast injection speed as possible (screw forward speed)(2) as high cylinder temperature as possible(3) as high mold temperature as possible二. 基本概念：basic conception:1. 收縮：shrinkage:（1）收縮的原因：.a.熱脹冷縮；.b.熔體結(jié)晶；(結(jié)晶度越高，熔體收縮越嚴重).c.分子取向；（一般來說，

6、分子總是沿著流動方向取向的。對于未增強型材料，其熔體在流動方向上的收縮總是大于垂直方向；對于增強型材料，正好相反）. d.狀態(tài)變化 the reasons of shrinkage: a. chang from hot to cold; b. crystallization ;( the more crystallization, the more shrinkage)c. molecule orientation; (for non-strengthen material, the shrinkage in the flowing direction is more than that, w

7、hich is vertical with the flowing direction; and for the strengthen material, the result is just reverse,) d. form changing（2）收縮的階段： the stages of shrinkage: 收縮從注射開始就隨著熔體的逐步冷卻而開始 the shrinkage starts from injection to forever. 它包括三個階段：a.從注射開始到保壓結(jié)束；b.從冷卻時 間開始到脫模前；c.脫模后 it contains three stages: a. fr

8、om injection stage to end of holding stage; b. from cooling stage to demold stage; c. after demold.（3）變形： deformation 變形的根本原因時收縮的不均勻。造成收縮不均勻的原因有：the root cause of deformation is inhomogeneous shrinkage. the causes of inhomogeneous shrinkage are as follows:a. 冷卻(即溫度分布)不均勻inhomogeneous coolingb. 壁厚不均勻

9、different wall thicknessc. 壓力分布不均勻not average location of pressure location d. 分子取向molecule orientatione. 脫模受力不均inhomogeneous forces when demolding 2. 結(jié)晶crystallization: （1）什么是結(jié)晶： what is crystallization: 簡單的說，結(jié)晶就是指分子的有序排列 in a short word, it means to make the molecule in order. （2）結(jié)晶的影響因素： factors

10、affecting crystallization: 結(jié)晶的影響因素：冷卻速度。冷卻速度越快，結(jié)晶程度越低。 the cooling speed affects the crystallization. the faster cooling speed the more crystallization （3）結(jié)晶對產(chǎn)品性能的影響： how does crystallization affect the parts: 結(jié)晶度越高：密度越高 收縮越大 光潔度越好 強度越高 韌性變差 the more crystallization: the higher density the more shri

11、nkage the better surface the stronger of the parts 3. 粘度：（1）什么是粘度： what is viscosity: 粘度是流體本身的一種性能，它的大小是流體流動性能的一種衡量。數(shù)值越大，流體的流動性能越差。 viscosity is a character of the flowing material. its value is used to measure the flowing character. the bigger value it is, the worse flowing character it is.（2）粘度的影響

12、因素： what affect the viscosity: a.溫度 temperature b.剪切速度 shear rate c.壓力 pressure 千萬注意：往往粘度是三者共同作用的結(jié)果。不同的材料對溫度，剪切速度和壓力的敏感程度是不同的，并且在不同的注射速度下哪一個起主導作用也是不同的 attention: the three factors affect the viscosity together all the time. different material are differently sensitive to temperature, shear rate and

13、pressure, and which factor will be the main factor in different phase is also different. 通常：（a）對溫度敏感：pa；pc normally: sensitive to temperature: pa, pc 對剪切速度敏感：pom；pp；pe sensitive to shear rate: pom, pp, pe 對壓力敏感：pp；pe sensitive to pressure: pp, pe( b ) 在高速注射的情況下，剪切速度起主導作用(所以,對于薄壁 產(chǎn)品或含薄壁部分的產(chǎn)品宜采用高速注射)。

14、 in high injection speed situation, the shear rate is the main factor. (so use high injection speed for thin wall thickness parts)4. 止回閥:non-return valve:a. 止回閥的功能是什么:function of non-return valve:在注射，保壓時防止熔體倒流，從而給予熔體我們所需的壓力和速度。to prevent the melt flowing back when injection and packing.b. 怎么判斷止回閥或料筒

15、損壞how to recognize the non-return valve is broken:初步判斷：經(jīng)常性的出現(xiàn)料墊不穩(wěn)，或無料墊。recognize presumedly: melt cushion is not stable usually or no cushion.準確判斷：延長保壓時間，如果出現(xiàn)零料墊則說明止回閥損壞或料筒損壞。recognize precisely: prolong the holding time, if there is no melt cushion, the non-return valve is broken or the cylinder is

16、 broken. c. 怎么區(qū)別止回閥損壞還是料筒損壞how to recognize the non-return valve is broken or the cylinder is broken:方法一：換上新的止回閥，延長保壓時間依然沒有料墊，則說明料筒損壞。method 1: change into a new non-return valve; prolong the holding time, if there is still no melt cushion, it means the cylinder is broken.方法二：放大料墊，延長保壓時間依然沒有料墊，則說明止回

17、閥損壞；反之則說明料筒損壞。method 2: make the melt cushion big enough; prolong the holding time. if there is still no melt cushion, it means the non-return valve is broken; if there is melt cushion, it means the cylinder is broken.三.基本參數(shù)： basic parameters:1. 注射速度：injection speed:（1）什么是注射速度： what is injection spe

18、ed: 通常我們所設定的注射速度是指螺桿前進的速度。但是真正重要的是 熔體在型腔里前進的速度，它與流動方向的截面積大小有關(guān)。 the injection speed, which we can set on the machine, is the screw forward speed. but what is very important is the melt forward speed in cavities（2）怎么確定注射速度： how to set the injection speed: 作為原則，注射速度應越快越好。 as a rule, the injection speed

19、 should be the faster the better. 它的確定取決于熔體的冷卻速度和熔體粘度： 冷卻速度快的或粘度高的熔體采用高的注射速度。注意：冷卻速度的快慢取決于材料本身的性能，壁厚以及模具溫度高低。 the injection speed is determined by the cooling speed and the viscosity of melt: to the melt, which cooling speed is very fast and the viscosity is high, we d better use fast injection spee

20、d. attention that the cooling speed is determined by the material character itself, wall thickness and mold temperature（3）注射速度太快：易出現(xiàn)焦斑，飛邊，內(nèi)部氣泡或造成熔體噴射 too fast injection speed: burns, flash, air bubble inside or melt jet. 注射速度太慢：易出現(xiàn)流動痕， 熔接痕，并且造成表面粗糙，無光澤 too slow injection speed: flow line; weld line,

21、 or bad surface.* 注射速度和注射時間設定的一般原則: general principles when setting injection speed or injection time:注射體積injection volume (ccm)注射時間 injection time (s)低粘度low viscosity中粘度mid viscosity高粘度high viscosity1-80.2-0.40.25-0.50.3-0.68-150.4-0.50.5-0.60.6-0.7515-300.5-0.60.6-0.750.75-0.930-500.6-0.80.75-1.00

22、.9-1.250-800.8-1.21.0-1.51.2-1.880-1201.2-1.81.5-2.21.8-2.7120-1801.8-2.62.2-3.22.7-4.0180-2502.6-3.53.2-4.44.0-5.4250-3503.5-4.64.4-6.05.4-7.2350-5504.6-6.56.0-8.07.2-9.5塑料plasticpe, pp, pa6, pa66, pom, pet, pbt, ppspe, pp, pa12, abs, pspc, pmma2. 轉(zhuǎn)壓點：switch point:（1）怎么確定轉(zhuǎn)壓點： how to set switch poin

23、t: 一般來說，轉(zhuǎn)壓點是指在零保壓壓力的情況下把產(chǎn)品打到95滿時， 由注射到保壓的切換點。 normally the switch is the changing point of screw from injection phase to holding phase, when the parts are 95% of their volume. 對于薄壁產(chǎn)品（如：扎帶）：一般打到產(chǎn)品的98 to the thin wall thickness parts (example: cable strap): up to 98% of their volume. 對于非平衡流道：一般為70-80，

24、應視具體情況而定。并建議采 用慢-快-慢多級注射。 to non-balance runners: normally its up to 70% to 80%. it should be determined by the reality. we suggest using step injection speed (slow- fast- slow).（2）轉(zhuǎn)壓點太高：產(chǎn)品充模不足，熔接痕，凹陷，尺寸偏小等 too high switch point: empty part, weld line, sink mark, and small dimension 轉(zhuǎn)壓點太低：飛邊，脫模困難,尺寸

25、偏大等 too low switch: flash, difficult to demold， big dimension.3. 保壓壓力：holding pressure:（1）怎么確定保壓壓力： how to set the holding pressure: 優(yōu)化的保壓壓力一般為最低保壓壓力和最高保壓壓力的中間值。 the optimized holding pressure is in the middle of the maximum and minimum normally. 最低保壓壓力：在準確的轉(zhuǎn)壓點基礎上，給予一定的保壓壓力，當產(chǎn)品剛出現(xiàn)充模不足時的保壓壓力。minimum

26、holding pressure: based on the correct switch point, the pressure when the parts start to be empty . 最高保壓壓力：在準確的轉(zhuǎn)壓點基礎上，給予一定的保壓壓力，當產(chǎn)品剛出 現(xiàn)毛刺時的保壓壓力。minimum holding pressure: based on the correct switch point, the pressure when the parts start to have flash.（從最低和最高保壓壓力我們可以看到產(chǎn)品工藝波動的安全范圍）(from the maximum

27、 holding pressure and minimum holding pressure, we can see the safe extension of the parts when the process is a little bit fluctuate)（2）一般來說： normally: pa保壓壓力=50% 注射壓力 pom 保壓壓力= 80% 注射壓力；對于尺寸要求高的產(chǎn)品可達到 100注射壓力pp/pe 保壓壓力=30-50 注射壓力pa holding pressure = 50% injection pressurepom holding pressure = 80%

28、 injection pressure; 100% injection pressure to high dimension requirement partspp / pe holding pressure = 30-50% injection pressure4. 保壓時間：holding time:（1）怎么確定保壓時間： how to set holding time: 保壓時間的確定以澆口冷凝為依據(jù)。通過產(chǎn)品稱重來確定。 holding time is determined by the solidification time of the gate. we decide it ac

29、cording to the weight.（2）保壓時間太長： 影響周期 too long holding time: waste time 保壓時間太短：重量不足，產(chǎn)品內(nèi)部空洞，尺寸偏小 too short holding time: not enough weight, empty inside, small dimension * 注意：保壓壓力會影響保壓時間的長短。保壓壓力越大保壓時間越長。 attention: the holding pressure will affects the holding time. the higher holding pressure the lo

30、nger holding time.5. 螺桿轉(zhuǎn)速rotation speed:預塑的目標是：獲得均一穩(wěn)定的熔體（即塑化均勻，無冷料，無降解，無過 多氣體）target of plastification: to get homogeneous melt.（1）怎么確定螺桿轉(zhuǎn)速： how to set the rotation speed: 作為原則，螺桿轉(zhuǎn)速的確定必須使螺桿的預塑時間，回吸時間與射臺 的回退時間之和略短于冷卻時間。as a rule, the rotation speed is determined by that the total dosing time, retract

31、 of screw and retract of injection unit must be a little bit shorter than the cooling time.（2）螺桿轉(zhuǎn)速太快：塑化不均（從而造成產(chǎn)品冷料，充模不足和斷裂 等），材料分解（從而造成焦斑，色差，斷裂等） too fast rotation speed: inhomogeneous melt (which cause empty parts, broken), material decomposed (which cause burns, different color, broken etc) 螺桿轉(zhuǎn)速太慢

32、：影響周期 too slow rotation speed: waste time.6. 冷卻時間：cooling time:作為原則，冷卻時間的設定應越短越好，以產(chǎn)品不變形，不粘模，無過深的頂出痕為基本要求。并且：螺桿轉(zhuǎn)速： pa<1.0m/s; pom < 0.7 m/s; pp/pe/ps < 1.3m/s; abs/pc/pmma < 0.6m/sas a rule, the cooling is the shorter the better based on the parts are not deformed, not sticky and without

33、too deep impressed by ejectors. and the rotation speed: pa<1.0m/s; pom< 0.7m/s; pp/pe< 1.3m/s* 推薦的脫模溫度如下:suggested demolding temperature is as follows:塑料 plastics脫模溫度°c demolding temperature低限 mini中間值 mid高限 maxpc60-8585-110110-130pe soft300-4040-5050-65pe rigid40-5050-6060-75pp45-5555-

34、6565-80pa650-7070-9090-110pa6675-9090-120120-150pa1240-6060-8080-100pom60-8080-100100-130ps20-3535-4545-60abs35-5555-7575-90pbt60-7575-9090-120pps120-145145-170170-190pmma50-7070-9090-1107. 背壓：backpressure:（1）什么是背壓： what is backpressure: 背壓是指螺桿預塑時，液壓缸阻止螺桿后退的力，其大小等于螺桿前 端熔體對螺桿的反作用力。 backpressure is th

35、e hydraulic force preventing the screw going back as dosing, the value is equal to the force that the melt in front of the cylinder to the screw.（2）怎么確定背壓： ho to set the backpressure: 背壓的確定取決于不同材料的性能，通常由材料供應商提供。 一般來說：pa: 20-80 bar ; pom : 50-100 bar ; pp/pe : 50-200 bar the backpressure is determine

36、d by the material character and its value is offered by the supplier. normally: pa: 20-80 bar; pom: 50-100 bar; pp/pe: 50-200 bar（2）背壓太高：材料分解；流涎；需要更長的預塑時間 too high backpressure: material decomposed, material escaping from the nozzle; need more dosing time 背壓太低：塑化不均（特別對于含色母料），塑化不實（從而造成產(chǎn) 品氣泡，焦斑等）too l

37、ow backpressure: inhomogeneous melt (especially for material with pigment etc.), not packed enough (which cause air bubbles, burns etc.)8. 回吸量：retract：（1） 如何確定回吸量：how to decide retract:回吸量的確定（結(jié)合背壓的確定）以不流涎為原則the retract is determined by the principle that there is no melt escaping from nozzle.（2） 回吸量

38、太大：氣泡，焦斑, 料墊不穩(wěn)too much retract: air bubble, burns, and unstable melt cushion回吸量太?。?流涎， 料墊不穩(wěn)（由于止回閥關(guān)不?。﹖oo little retract: melt escaping from nozzle, unstable melt cushion (because of the non-return valve not closed)9. 鎖模力：clamping force: （1） 鎖模力的確定：鎖模力的大小取決于型腔投影面積和注射壓力的大小how to decide the clamping fo

39、rce: its determined by the projection acreage of the cavities and the injection pressure （2） 鎖模力太大：排氣不暢（焦斑，充模不足），模具變形 too much clamping force: bad vent(burns, incomplete), mold deformation. 鎖模力太?。猴w邊 too low clamping force: flash10. 熔體溫度：melt temperature:（1）怎么確定熔體溫度： how to set the melt temperature:

40、通常熔體溫度的確定取決于不同材料的性能，由材料供應商提供。（所用材料的熔體溫度及模具溫度見附表）the melt temperature is determined by the material character and its value is offered by the supplier. (see the attached sheet) （2）料筒溫度的設定： how to set cylinder temperature:a. 一次注射量小于總料量的20時： 噴嘴 下料口 when one-shot quantity is less than 20% of maximum ： n

41、ozzle entranceb. 一次注射量在20-70之間時：噴嘴 下料口 when one-shot quantity is between 20% - 70% of maximum: nozzle entrancec. 一次注射量大于70時：噴嘴 下料口 when one-shot quantity is more than 70% of maximum: nozzle entrance （2）熔體溫度太高：材料分解（從而造成產(chǎn)品氣泡，色差，焦斑，斷裂 等） too high melt temperature: material decomposed (which cause air b

42、ubble, different color, burns, broken etc.) 熔體溫度太低：材料塑化不均，熔體內(nèi)含冷料（從而造成充模不足， 冷料，產(chǎn)品斷裂等） too low melt temperature: inhomogeneous melt with cold material inside (which cause empty parts, broken parts etc.)11. 模具溫度：mold temperature:（1）為什么需要模溫： why the mold temperature is needed: 無論模具溫度高低，它的作用始終是為了在穩(wěn)定生產(chǎn)過程中

43、使模具維持一定的溫度，起冷卻作用的。真正重要的模溫是指模具型腔的溫度，而不是模溫機上顯示的溫度。通常，在穩(wěn)定生產(chǎn)過程中型腔溫度會達到一個穩(wěn)定的動態(tài)平衡，并高于顯示溫度10度左右（對于大模具在生產(chǎn)之前必須使模具充分加熱，尤其是薄壁，且流長比 很大的產(chǎn)品模具） whatever the mold temperature is high or low, its function is to keep the cavity temperature on the same level. it is for cooling. what is important is the temperature of

44、the cavities, not the temperature showing on the controller. normally the cavity temperature will come into a stable temperature, which is 10 degrees more than the temperature showing on the controller when the production is stable（ for the big mold, it must be heated enough before start production）

45、 .（2）模具溫度會影響什么 what the mold temperature affect:會影響熔體的流動性和冷卻速度。 affect the melt flow rate and the cooling speed.因為影響流動性，從而影響產(chǎn)品外觀（表面質(zhì)量，毛刺）和注塑壓 力；for affecting the flow rate, the mold temperature affects the appearance of the parts and the injection pressure. 因為影響冷卻速度，從而影響產(chǎn)品結(jié)晶度，進而影響產(chǎn)品收縮率和機 械強度性能. for

46、affecting cooling speed, the mold temperature affects the crystallized rate and then affects the shrinkage and the mechanical strength.（3）模溫高：流動性好；結(jié)晶度高；收縮率大（從而造成尺寸偏?。?；變 形；需要更長的冷卻時間 high mold temperature: good flow character; high-crystallized rate; big shrinkage (which cause small dimension); need more cooling time 模溫低：流動性