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发表于 2007-3-30 08:16:27
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来自: 中国台湾
加熱工藝條件設定. J" N1 L% Y5 {, g1 x6 W. G5 c
Heating technique parameter setting" h4 M- w9 m f; L
1.加熱段溫度設定必須按照産品所使用的原料的不同而不同,但却必須遵循一個這樣的規則,即由射口筒到進科段溫度是逐步遞减的.且遞减溫度是以10.度爲單位.
, s3 n# ^1 e& P( l+ IThe proper temperature setting differs depending on type of resin * D% h' F% ?1 Q( q4 d( ^
material, but it must be abide by a rule that temperature setting should
+ U! U+ ?6 r/ c) q; c& |) q" Xdiminish in step 10.C from nozzle to feeding resin material position.
1 h/ e6 ^/ e% [- Z+ v* @5 V2特殊情况下.如料頭抽絲,則射口筒溫度應降低,如果是比較特殊的原料冷凝比較快的.則射口筒溫度則不止比第二節法蘭溫度高10度.比如PPS. 2 ^% e0 y) o0 E6 [& b8 J
尼龍等.0 E5 M# r, Q# c, k3 `
Nozzle temperature setting should low if product line. If resin + k( N+ n# G4 S5 t+ Q5 {
material such as PPS, PA, cool very soon , Nozzle temperature should higher
1 c* ?8 S# V( ?0 S8 {7 zmore 10.C than the second cylinder temperature.' z8 C' n7 T4 ?$ ?% m- j; J+ _
3.機台馬達啓動溫度視乎機台不同而不同,一般出于對機台油路中的油封保護需要,油溫最好能控制在40度-60度,以免油封長期高壓而變化,縮短使用壽命,造成成型不穩定.2 t1 Y, v2 `# Y4 K& k
Pump turning on temperature is different depending on type of injection 1 h9 ?* l1 p) G% @7 o
molding machine. To protect oil seal of machine it set oil temperature # _) \- x( ]' q" ~/ c
第三節注射及熔膠(加料)工藝條件設定% ^! B" y. h& e& d
Injection and plastic Technique parameter setting
& F9 j7 \ B9 Q9 J一.注射2 ~" ~# W2 t t& z
Injection
1 L6 u6 g* P# q6 K+ A2 L注射是把塑料原料經加熱後射進模腔的過程,它一般可分爲第一級,第二級,第三級,第四級及保壓幾段:3 Z' ^+ \+ z2 ]
Injection is a step which inject melt resin material into mold. It
1 g& Q& z" I9 `5 Gconsists of stepl,step2 ,step3,step4 and holding pressure step:
: b7 R( d9 p! L1.第一級注射一般是注射料頭段.具注射量一般可根據料頭的輕重來估計其行程,當然也可以依據公式來計算,如公式:. C2 N% q* j t/ i( g2 y
Step l injects usually tunnel material, Injection Volume can be 5 e1 U# F/ r8 v2 d+ }
estimated according to the weight of course it can be calculated by formula:
* e; x: L/ s! W) H" q( d& Y) tL=Si=Vi/0.785Ds2! y9 Z& ~/ q3 }6 g, L5 F
L:注射行程; Si: 注射行程;
# w+ F& j8 X; h) G/ b3 X; sL: injection stroke Si: injection stroke5 a/ N9 _ O) H6 P: Z2 x
Vi:理論注射容積; Ds:螺杆直徑; ( Y; z4 k0 m/ a) h, }1 `$ l+ G: T" k
Vi: injection volume of theoretical Ds: diameter of screw7 k6 B8 v5 ]# P! l. v8 s
0.785:是Ω/4的值.6 W" F5 s9 L7 O3 o8 l* u
0. 785: value of Ω/4., \- d$ k& @/ }9 O
當然,如果我們在成型時每設定一個參數都要計算一次,要成型出一個産品就要幾個小時才能完成了.
2 Z" Y- A. L9 @0 Z1 R- cBut it cost a lot of time to produce one product if every time molding
: z) h4 @) j" Oparameter is setting by calculation.9 R n* N. e! u4 W
2.第二級是注塑産品約2/3的階段,當然,根據産品特殊需要,也允許成型不到2/3階段,比如避免結合綫問題,這一階段的成型速度及壓力一般是整個成型段的最大值段,如果排的産品與機台基本是相吻合的.模具結構合理,排氣良好,這一段的壓力一般也不會超過80%.速度側視産品需變,可能大到95%也可,自然一般都是在55%-80%間.
( u- v- @2 y0 Y8 e% NStep 2 inject 2/3 of product. It can lower 2/3 of product according to " P/ U1 [3 B' U W5 h
requirement of product. For example to prevent weld line. Molding speed
$ L; W' w+ O( w3 y/ ^8 R: m) Uand pressure on this step is the maximum of whole molding section. If & t2 b& h2 p& [3 f3 j5 r1 x
Mold suit the injection molding machine and mold structure reasonable
) A- d: K! S* q* rand eject air well, pressure of this step should lower 80%. Molding speed 0 X/ k( V. O( m3 `) @8 D8 ~
setting within 55-80% but it may setting 95% for especial product.. U9 R8 Z X" f; N& ^4 N2 ]0 M8 n8 H& V
3.第三段是注射餘下的1/3段,其速度和壓力根據産品的需要,一般是小于第二段,速度和壓力存在于一個往下降的過程.主要是爲了防止産品毛邊的産生,但同時又必須把産品充填飽滿.
0 d- e$ l; Z* z2 xStep3 inject remain 1/3 of product. According to product molding speed
9 ^8 ?8 s- @) n9 Z9 |2 \4 \9 k+ t$ l" xand pressure lower than that of step2 To prevent flash speed and
7 T# b3 H7 e$ Epressure should decrease but it can’t shot short.
5 T P& Z( a$ G# K% O3 N# ?/ `4.第四段:一般有機台還有第五,第六段,這段的成型速度和壓力相同前,都存在兩段一個遞减過程.其作用都是起到一個再次充滿的作用.
- `/ _& N2 M5 L" nStep4 section: Some injection machines have step5,step6 which are same
$ K2 ]: U) K' @% @+ was former molding speed and pressure this step should diminish and & `1 ] f% f. t; _% W3 m
inject once more.1 f. r9 e/ c8 W) j# [/ }
5.保壓段:不論成型什麽産品,都存在一個保壓過程.任何産品都不同程度的存在一個厚薄不一的問題,正常情况下,較厚的部分都可能存在一個收縮凹陷的現象,爲了解决這種現象,就應應用到保壓,保壓一般來講都應用較慢的射速,而壓力的設置則應看縮水的情况如何,小到25%,大到80%都有可能.
4 @% J) @3 s( n( W3 ?9 s' @Holding pressure step: No matter what product there is a holding
) d- z0 c4 V3 x0 M! rpressure step. Any product can’t molding a same thickness. Usually the + E+ x# ~& V2 q. G5 X) J
deeper section may sink mark . To prevent this defect it should set holding
% Y) y' L. p0 x/ G2 Npressure, The injection speed of holding pressure step is slow but
* }2 _/ a9 _1 m6 Mholding pressure setting within 25-80% depending on sink mark: a2 k L2 w6 V* Z9 h. p+ A
: P: m* c& X- n( t9 q M
within 40.C-60.C, If oil seal work on condition that high pressure and 4 r h6 v4 c8 `6 |
damaged It’s work time will be shorter, it can cause molding stable.
) P v7 X: D' O; m二.熔膠段工藝
* X1 V% }6 i: [Plastic Technique
/ L) w, f( s2 r4 Y3 r) r2 h1.再複雜的熔膠旋轉過程最多不會超過三段,因爲熔膠本身就是存在于把膠熔進料筒的過程,如果原料粘度大,熔膠壓力則大,但速度則應取决于原料的分解溫度,熔膠速度越快,原料中的剪切力則會越大,料管溫度則越高,局部原料産生分解的可能性則會越大,故一般熔膠會采用中速爲宜,如45%-75%,熔膠同時會碰到一個比較重要的環節,那就是背壓的使用,産品精度要求越大,背壓的使用則更大,背壓可使原料分子間結構更緊密,成型出的産品則尺寸更穩定,外觀越好.當然,背壓太大,則會産生流涎,所以背壓的使用又應考虙到其它原因.2 v% U, i- K' K" h5 \& u" t: G
Plastic should lower 3 steps, because plastic is a step to add melt
r% n ?$ C0 g8 |% X1 r% [resin material to cyclinder , Higher stick of resin material ,higher screw
. Z L8 [4 k, y, T5 dback pressure. Screw speed differs depending on decomposing temperature
2 r% @- M9 K, ~- Dof resin material ,Higher screw speed ,Higher trim force of resin, 4 V* W/ _: [/ q
higher cyclinder temperature. Some resin material may decomposes so it set - B& T6 f$ U" H3 E0 A2 `; Y( w
screw speed in mid-speed such as 45-75%, In plastic step setting screw
2 P5 T# O Q0 b% W7 s: xback pressure is very important, Higher screw back pressure ,higher
T3 t: a; B* `; N2 r: ~9 S- Wquality of product screw back pressure make resin structure order, Molding ; r8 G( O* [' p) s" h H5 R$ |
product is beautiful and volume stable. But ,it maybe flow if screw
. [7 ~9 D: [. [8 j2 T4 jback pressure too high . So all factors should be considered when using
+ t: r" ?) R( J( R8 _8 i0 z' }screw back pressure. . U5 f3 R6 ~' {0 d& d
2.熔膠過程還有一個比較重要的環節,那就是松退,松退分前松退和後松退,其作用一般是爲了防止流涎和抽絲,設定值速度和壓力都在20%-50%間,設定的行程一般在2-5cm間,太長的行程可能會使料筒裏面貯存空氣,導致下一模出現不期望的氣泡.: ]8 S* \% A" ^7 R, E4 W
In plastic step sucking back is very important too. Sucking back
5 D3 D6 z* q& r; X* s8 ?! Zinclude front sucking back and back sucking back It setting sucking back to + O* |0 ^( ]- C" }
prevent flow and line. It sets sucking back speed and pressure within ) ?& Y) C; S4 C# {
20-50% and distance within 2-5cm. TOO long distance make cyclinder 8 ?( i# {0 f4 y; x# A/ C: Q
reserve air and cause bubble at next molding. |
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