InjectionMoldingDesignGuidelines

1、injection molding design guidelinesmuch has been written regarding design guidelines for injection molding. yet, the design guidelines can be summed up in just a few design rules.1use uniform wall thicknesses throughout the part. this will minimize sinking, warping, residual stresses, and improve mo

2、ld fill and cycle times. wall section considerations voids and shrinkage warpage2use generous radius at all corners. the inside corner radius should be a minimum of one material thickness. radius limitations3use the least thickness compliant with the process, material, or product design requirements

3、. using the least wall thickness for the process ensures rapid cooling, short cycle times, and minimum shot weight. all these result in the least possible part cost.4design parts to facilitate easy withdrawal from the mold by providing draft (taper) in the direction of mold opening or closing. draft

4、 and texture5use ribs or gussets to improve part stiffness in bending. this avoids the use of thick section to achieve the same, thereby saving on part weight, material costs, and cycle time costs. rib designuniform walls parts should be designed with a minimum wall thickness consistent with part fu

5、nction and mold filling considerations. the thinner the wall the faster the part cools, and the cycle times are short, resulting in the lowest possible part costs. also, thinner parts weight less, which results in smaller amounts of the plastic used per part which also results in lower part costs.零件

6、的設(shè)計(jì)應(yīng)以最小壁厚符合部分功能和充填型腔的考慮。越快越細(xì)越墻的部分,于是循環(huán)冷卻的時(shí)間很短,導(dǎo)致零件成本最低。同時(shí),較薄的部分,它的結(jié)果必然是重量更少的塑料使用少量的每部分也導(dǎo)致了較低的部份成本。the wall thicknesses of an injection-molded part generally range from 2 mm to 4 mm (0.080 inch to 0.160 inch). thin wall injection molding can produce walls as thin as 0.5 mm (0.020 inch).墻的厚度一般范圍從2”塑料部

7、分毫米(0.080英寸到0.160英寸)。薄壁注塑模具可以生產(chǎn)墻壁薄如0.5毫米(0.020英寸)。the need for uniform walls需要統(tǒng)一的壁厚 thick sections cool slower than thin sections. the thin section first solidifies, and the thick section is still not fully solidified. as the thick section cools, it shrinks and the material for the shrinkage comes o

8、nly from the unsolidified areas, which are connected, to the already solidified thin section. 酷慢于厚壁處薄片。第一次的凝固薄片,濃烈的部分還沒有完全凝固。為厚段冷卻后,它收縮和材料的收縮是只能從unsolidified區(qū)域是相連的,已經(jīng)凝固薄片。 this builds stresses near the boundary of the thin section to thick section. since the thin section does not yield because it is

9、 solid, the thick section (which is still liquid) must yield. often this leads to warping or twisting. if this is severe enough, the part could even crack. 這個(gè)建立在邊境附近應(yīng)力的薄壁厚的部分。由于薄壁不屈服,因?yàn)樗枪腆w,厚的部分(這仍然是流動(dòng)的)必須屈服。這常常會(huì)導(dǎo)致扭曲或扭曲。如果這是嚴(yán)重的足夠的,部分甚至開裂。uniform wall thicknesses reduce/eliminate this problem. 均勻的壁厚度

10、的減少或消除這一問題。 uniform walled parts are easier to fill in the mold cavity, since the molten plastic does not face varying restrictions as it fills.堅(jiān)固的部分是容易制服填寫模具型腔,因?yàn)槿刍苣z沒有面臨不同的限制其填充。what if you cannot have uniform walls, (due to design limitations) ?如果你不能擁有統(tǒng)一的墻壁,(由于設(shè)計(jì)的局限性)? when uniform walls are not

11、possible, then the change in section should be as gradual as possible. 當(dāng)統(tǒng)一的墻壁是不可能的,那么改變部分應(yīng)該是作為逐漸越好。 coring can help in making the wall sections uniform, and eliminate the problems associated with non-uniform walls. 取心能幫助使墻面部分統(tǒng)一和消除非均勻壁相關(guān)的問題。 warping problems can be reduced by building supporting feat

12、ures such as gussets.翹曲的問題可以減少建筑配套功能,如gussets。voids and shrinkage孔洞及收縮shrinkage is caused by intersecting walls of non-uniform wall thickness. examples of these are ribs, bosses, and other projections of the nominal wall. if these projections have greater wall thicknesses, they will solidify slower.

13、 the region where they are attached to the nominal wall will shrink along with the projection, resulting in a sink in the nominal wall. 摘要縮松缺陷是引起非均勻壁厚壁的相交。其中一個(gè)例子是肋骨,老板,和其他預(yù)測(cè)的命名的墻。如果這些預(yù)測(cè)有更大的墻厚度不同,他們就會(huì)凝固速度較慢。他們的地方被納入名義墻會(huì)收縮隨著投影,導(dǎo)致在一個(gè)沉名義墻。 shrink can be minimized by maintaining rib thicknesses to 50 to

14、60% of the walls they are attached to. 收縮可以最小化維持肋厚度的60%至,在墻上。 bosses located at corners can result in very thick walls causing sinks. bosses can be isolated using the techniques illustrated. 位于角落老板會(huì)導(dǎo)致很厚壁造成下沉。老板會(huì)被孤立使用技術(shù)做了說明。warpage翹曲thick sections cool slower than thin sections. the thin section firs

15、t solidifies, and the thick section is still not fully solidified. as the thick section cools, it shrinks and the material for the shrinkage comes only from the unsolidified areas, which are connected, to the already solidified thin section. 酷慢于厚壁處薄片。第一次的凝固薄片,濃烈的部分還沒有完全凝固。為厚段冷卻后,它收縮和材料的收縮是只能從unsolid

16、ified區(qū)域是相連的,已經(jīng)凝固薄片。this builds stresses near the boundary of the thin section to thick section. since the thin section does not yield because it is solid, the thick section (which is still liquid) must yield. often this leads to warping or twisting. if this is severe enough, the part could even crac

17、k.這個(gè)建立在邊境附近應(yīng)力的薄壁厚的部分。由于薄壁不屈服,因?yàn)樗枪腆w,厚的部分(這仍然是流動(dòng)的)必須屈服。這常常會(huì)導(dǎo)致扭曲或扭曲。如果這是嚴(yán)重的足夠的,部分甚至開裂。other causes:其他原因: warping can also be caused due to non-uniform mold temperatures or cooling rates. 翹曲也可以引起模具溫度不均勻或冷卻率。 non-uniform packing or pressure in the mold. 包裝或非壓力模具。 alignment of polymer molecules and fiber

18、 reinforcing strands during the mold fill results in preferential properties in the part. 校準(zhǔn)及纖維增強(qiáng)聚合物分子在模具填充股優(yōu)惠的性能結(jié)果的部分。 molding process conditions-too high a injection pressure or temperature or improper temperature and cooling of the mold cavity. generally, it is best to follow the resin manufactur

19、ers guidelines on process conditions and only vary conditions within the limits of the guidelines. 成型工藝條件太高的注射壓力或溫度或不當(dāng)?shù)哪＞邷囟群屠鋮s腔。通常,最好遵循樹脂生產(chǎn)廠家的指南只不同工藝條件和條件的范圍內(nèi)的指導(dǎo)方針。it is not good practice to go beyond the pressure and temperature recommendations to compensate for other defects in the mold. if runner

20、s need to be sized differently to allow for a proper fill, or gate sizes that need to be changed, then those changes need to happen.這并不是一個(gè)好實(shí)踐,超越了壓力和溫度補(bǔ)償其他缺陷,建議在模具。如果選手需要大小不同的允許一個(gè)恰到好處的填補(bǔ),或門大小需要改變以后,這些變化一定會(huì)發(fā)生。otherwise the finished parts will have too much built in stresses, could crack in service or

21、warp-leading to more severe problems such as customer returns or field service issues.否則制件將有太多可以建在應(yīng)力、裂縫或warp-leading服務(wù)更多的嚴(yán)重問題,例如客戶回報(bào)或現(xiàn)場(chǎng)服務(wù)的問題。radius半徑 sharp corners greatly increase the stress concentration. this high amount of stress concentration can often lead to failure of plastic parts. 急轉(zhuǎn)彎大大增加的

22、應(yīng)力集中。這種高數(shù)量的應(yīng)力集中會(huì)導(dǎo)致失敗的塑料部件。sharp corners can come about in non-obvious places. examples of this are a boss attached to a surface, or a strengthening rib. these corners need to be radiused just like all other corners. the stress concentration factor varies with radius, for a given thickness.在棱角能來non-o

23、bvious的地方。 這樣的例子是一個(gè)老板在一個(gè)表面上,或加強(qiáng)肋。這些角落需要就像所有其他各類的角落。應(yīng)力集中系數(shù)隨半徑,對(duì)于一個(gè)給定的厚度。as can be seen from the above chart, the stress concentration factor is quite high for r/t values lesss than 0.5. for values of r/t over 0.5 the stress concentration factor gets lower. 可以看出,從上面的圖表的應(yīng)力集中系數(shù)比較高,lesss和r / t值達(dá)0.5以上。和r

24、/ t為價(jià)值超過0.5的應(yīng)力集中系數(shù)得低。the stress concentration factor is a multiplier factor, it increases the stress.actual stress = stress concentration factor k x stress calculatedthis is why it is recommended that inside radiuses be a minimum of 1 x thickness.應(yīng)力集中系數(shù)是一個(gè)乘數(shù)因素,它增加了壓力。實(shí)際應(yīng)力=應(yīng)力集中系數(shù)k應(yīng)力計(jì)算這就是為什么在各類建議至少1厚度

25、。 in addition to reducing stresses, fillet radiuses provide streamlined flow paths for the molten plastic resulting in easier fills. 除了能減少應(yīng)力、魚片各類流線形途徑提供容易熔化塑膠導(dǎo)致填充。typically, at corners, the inside radius is 0.5 x material thickness and the outside radius is 1.5 x material thickness. a bigger radius

26、should be used if part design will allow it. 通常,在街角,里面半徑0.5倍的材料厚度和外半徑的材料厚度為1.5倍。一個(gè)更大的半徑應(yīng)使用部分設(shè)計(jì)將允許它。the reason for draft草案的原因 drafts (or taper) in a mold, facilitates part removal from the mold. the amount of draft angle depends on the depth of the part in the mold, and its required end use function.

27、 drafts (or taper) in a mold, facilitates part removal from the mold. the amount of draft angle depends on the depth of the part in the mold, and its required end use function. the draft is in the offset angle in a direction parallel to the mold opening and closing. 草案在偏置角與邊線平行的方向模具開啟和關(guān)閉。 it is best

28、 to allow for as much draft as possible for easy release from the mold. as a nominal recommendation, it is best to allow 1 to 2 degrees of draft, with an additional 1.5 min. per 0.025 mm (0.001 inch) depth of texture. see below. 最好是讓盡可能多的草案易釋放從模具。作為一個(gè)命名建議,最好是讓1至2度的草案,另外有1.5min.每0.025毫米(0.001英寸)的深度的紋

29、理。見下文。 the mold parting line can be relocated to split the draft in order to minimize it. if no draft is acceptable due to design considerations, then a side-action mold (cam-actuated) may be required at a greater expense in tooling.模具分型線可以分裂的草案被安置在為了避免它。如果沒有草案由于設(shè)計(jì)上考慮是可以接受的,那么side-action模具(cam-actua

30、ted)都需要在一個(gè)更大的消費(fèi)在工具。the reason for texture紋理的原因textures and letteringcan be molded on the surfaces, as an aesthetic aid or for incorporating identifying information, either for end users or factory. texturing also helps hide surface defects such as knit lines, and other surface imperfections. the dep

31、th of texture or letters is somewhat limited, and extra draft needs to be provided to allow for mold withdrawal without marring the surface. 紋理和letteringcan被塑造的表面,作為審美援助或合并身份識(shí)別信息,無(wú)論是為最終用戶或工廠。材質(zhì)也有助于隱藏表面缺陷如接合線,和其他表面缺陷。深度的紋理或字母是有點(diǎn)有限,需要提供額外的草案,以便模具表面沒有嫁給撤軍。 draft for texturing is somewhat dependant on t

32、he mold design and the specific mold texture. guidelines are readily available from the mold texture suppliers or mold builders. 匯票要貼圖是有點(diǎn)依賴于模具設(shè)計(jì)和具體的模具結(jié)構(gòu)。方針是現(xiàn)成的從模具結(jié)構(gòu)供應(yīng)商或模具建設(shè)者。 as a general guideline, 1.5 min. per 0.025mm (0.001 inch) depth of texture needs to be allowed for in addition to the normal

33、draft. usually for general office equipment such as lap-top computers a texture depth of 0.025 mm (0.001 inch) is used and the min. draft recommended is 1.5 . more may be needed for heavier textures surfaces such as leather texture (with a depth of 0.125 mm/0.005 inch) that requires a min. draft of

34、7.5.作為一個(gè)通用的方法,min. 1.5每0.025毫米(0.001英寸)的深度的紋理需要允許除了正常的匯票。通常一般辦公設(shè)備如手提電腦一個(gè)紋理深度0.025毫米(0.001英寸),是用來和min. 1.5推薦草案。更可能需要重表面如皮革紋理貼圖(深度0.125毫米(0.005英寸),要求min. 7.5草案。the use of ribs使用肋骨 ribs increase the bending stiffness of a part. without ribs, the thickness has to be increased to increase the bending sti

35、ffness. adding ribs increases the moment of inertia, which increases the bending stiffness. bending stiffness = e (youngs modulus) x i (moment of inertia) 肋骨提高梁的抗彎剛度的一員。無(wú)肋,厚度增加而增加抗彎剛度。加肋增加慣性矩的抗彎剛度,增加了。彎曲剛度= e(楊氏模數(shù))i(慣性矩的)the rib thickness should be less than the wall thickness-to keep sinking to a m

36、inimum. the thickness ranges from 40 to 60 % of the material thickness. in addition, the rib should be attached to the base with generous radiusing at the corners. 肋厚度應(yīng)小于墻thickness-to保持下沉降到最低。厚度范圍從60%到的材料厚度。此外,應(yīng)重視肋慷慨的radiusing底座的四角。 at rib intersections, the resulting thickness will be more than the

37、 thickness of each individual rib. coring or some other means of removing material should be used to thin down the walls to avoid excessive sinking on the opposite side. 在十字路口,產(chǎn)生肋厚度會(huì)超過每一個(gè)個(gè)體的厚度骨刺。取心或其他方式去除材料應(yīng)沿著墻壁用來稀釋來避免過多的下沉的一側(cè)。the height of the rib should be limited to less than 3 x thickness. it is

38、 better to have multiple ribs to increase the bending stiffness than one high rib. 肋骨的高度應(yīng)限于厚度小于3倍。最好是有多個(gè)肋骨增加抗彎剛度比一個(gè)高肋骨。 the rib orientation is based on providing maximum bending stiffness. depending on orientation of the bending load, with respect to the part geometry, ribs oriented one way increase

39、 stiffness. if oriented the wrong way there is no increase in stiffness. 肋定位是基于最大彎曲剛度提供。根據(jù)彎曲載荷的定位,就部分幾何方法之一,肋骨導(dǎo)向增加剛性。如果導(dǎo)向錯(cuò)誤的方式有不增加結(jié)構(gòu)剛度。 draft angles for ribs should be minimum of 0.25 to 0.5 degree of draft per side. if the surface is textured, additional 1.0 degree draft per 0.025 mm (0.001 inch) d

40、epth of texture should be provided.草案肋骨應(yīng)該最小角度0.25至0.5度的每邊草案。如果表面是粗糙的,另外1.0度每0.025毫米(草案)深度0.001英寸的質(zhì)地應(yīng)提供。plastic part designto insure a quality final product, it is necessary to start out with quality components. injection molded parts can be molded to a high quality standard by focusing on these area

41、s of plastic technology:以確保最終產(chǎn)品質(zhì)量,有必要對(duì)質(zhì)量與部件出發(fā)。注塑件可以被塑造到高質(zhì)量的標(biāo)準(zhǔn),將研究集中在這些領(lǐng)域的塑料技術(shù):1) correct part design1)正確的零件設(shè)計(jì)2) accurate selection of material2)準(zhǔn)確選擇材料3) processing plastic processing3)加工塑料加工only by drawing on expertise from these three areas of plastic technology can a product designer create qualit

42、y molded parts that maximize performance and are cost effective. the purpose of this design guide deals with the first of these three issues - part design.只有借鑒從這三個(gè)領(lǐng)域的專業(yè)塑料技術(shù)的產(chǎn)品設(shè)計(jì)師能制造出質(zhì)量塑件的性能和成本,最大限度地有效。的目的,這城市設(shè)計(jì)導(dǎo)則的第一處理這三個(gè)問題部分的設(shè)計(jì)。correct part design guidelines正確的部分設(shè)計(jì)準(zhǔn)則if there was only one rule for th

43、e injection molding process it would have to beto maintain uniform wall thickness. here are some examples of problems associatedwith part designs that feature non-uniform wall thicknesses.如果只有一個(gè)規(guī)律,它將注塑工藝保持均勻的壁厚。以下是一些例子有關(guān)的問題這些特點(diǎn)的原料,當(dāng)與零部件設(shè)計(jì)非均勻壁厚度。sink marks due touneven shrinkage凹痕由于不均勻收縮sink marks re

44、sult from a wall yielding to the still shrinking interior mass.凹痕造成一個(gè)墻還是屈服于室內(nèi)腫塊。收縮stress due touneven shrinkage導(dǎo)致心理壓力不均勻收縮a part with non-uniform wall thickness will cool unevenly, resulting in high molded-in stress.與非均勻壁厚部分就會(huì)使不均,導(dǎo)致高注入壓力。voids due to unevenshrinkage由于空隙的不均勻收縮the already cooled secti

45、on will not yield to the shrinking action of the cooling interior mass causing voids in the thick portion of the part.已經(jīng)冷卻部分將不能屈服于收縮引起的內(nèi)部質(zhì)量的作用導(dǎo)致冷卻在茂密的空隙部分的部分。warpage due touneven shrinkage里面由于不均勻收縮concentrated stress at the junction of high & low shrinkage area may cause a part to warp.在應(yīng)力集中交界的高、低收縮

46、可能會(huì)導(dǎo)致部分區(qū)域移動(dòng)。draft 拔模錐度plastic parts are always designed with a taper or draft in the direction of mold movement to allow part ejection or removal from the mold. since plastics shrink when cooled, it is common for parts to shrink (or grip tightly) to cores. a good definition for draft would be: the d

47、egree of taper of a side wall or rib needed to allow the molded plastic part to be removed from the metal mold. without proper draft, plastic parts may be difficult to remove from the mold. a draft angle of 1/2 degrees is regarded as minimum for most applications. draft angles of 1 1/2 to 2 degrees

48、per side are considered normal for plastic injection molding.塑料件總是圓錐或草案設(shè)計(jì)模具運(yùn)動(dòng)的方向,讓產(chǎn)品頂出或脫除模具。當(dāng)冷卻,自塑料收縮是常見的收縮(或控制部分緊)核心。一個(gè)好的的定義是:草案的錐度的程度一側(cè)墻或肋骨需要允許注塑塑料零件,除去金屬模具。沒有適當(dāng)?shù)牟莅?塑料部件可能很難被除掉了模具。匯票的1/2度角度被視為最低為大多數(shù)應(yīng)用程序。匯票的角度1又1/2至2度被認(rèn)為是正常的每邊塑料注射成型工藝。top of pageribs肋骨many times the stiffness of a part must increas

49、e because of the load applied to the part design. one of the easiest ways to cure this problem is change the part geometry by adding ribs. the use of ribs is a practical way and economical means of increasing the structural strength of a part. but there are guidelines that govern adding ribs without

50、 causing sink marks or surface blemishes to your parts.多次剛度的一部分必須增加由于荷載的部分的設(shè)計(jì)。一個(gè)最簡(jiǎn)單的方法來治療這種改變部分幾何問題是通過增加肋骨。使用一個(gè)實(shí)際的方法和肋經(jīng)濟(jì)的方法增加結(jié)構(gòu)強(qiáng)度的一個(gè)部分。但是有指南添加肋支配沒有造成凹痕或表面磨損到你的部分。1) rib thickness should be less than wall thickness. a rib thickness of 60% to 80% of nominal wall thickness is recommended.2) to increase

51、 stiffness increase the number of ribs or gusset plates, another feature designed to strengthen the plastic part.3) for a given stiffness, it is better to increase the number of ribs, not the height.4) for thick ribs core out the rib from the back. this creates a hollow space underneath the part and

52、 maintains a uniform wall thickness.下面部分并維持均勻的壁厚。height:maximum height of three time nominal wall thickness of part.身高:最大高度第三次名義壁厚的部分。spacing:minimum of two times nominal wall thickness of part between ribs.間距:至少兩次的名義壁厚之間的部分的肋骨。top of pageholes孔holes are easy to produce in molded parts. core pins th

53、at protrude into the mold cavity make the holes when the part is molded. through holes in the molded parts are easier to produce than blind holes, which do not go all the way through a part. blind holes are made by core pins supported on one end only. the pins can be deflected and pushed off center

54、by the pressures of the molten plastic material during the molding process. a good rule of thumb: the depth of the blind hole should be about twice the diameter of core pins up to 3/16, and up to four times the diameter of core pins over 3/16. the guidelines for blind and through holes are seen belo

55、w.漏洞是容易產(chǎn)生在模具零件。核心針,突出到模腔內(nèi)孔時(shí)的部分是塑造。通孔的模具零件比較容易產(chǎn)生比盲孔,不走這條路通過一個(gè)部分。盲孔都是由核心針支承在一端而已。可以彈針推離中心的,是工作壓力與鑄造的塑膠材料在成型工藝。有一條好經(jīng)驗(yàn):深度的盲孔直徑應(yīng)該會(huì)在大約兩倍的核心銷到3/16 和4次核心針的直徑的超過3/16”。指南為盲人和通過孔如圖。blind hole (shown with draft)盲孔(草案)表現(xiàn)出來l = 2d for diameters less than 3/16 dia. core pinsl = 2 d直徑小于3/16英寸dia.核心針l = 4d for diamet

56、ers more than 3/16 dia. core pinsl = 4 d直徑超過3/16“dia.核心針through hole (shown with draft)l = 4d for diameters less than 3/16 dia. core pinsl = 4 d直徑小于3/16英寸dia.核心針l = 6d for diamters more than 3/16 dia. core pinsl = 6d for diamters more than 3/16 dia. core pinsthere are definite rules for the placemen

57、t of cored holes in a molded part. if these minimum distances shown below are not followed, the holes will be egg shaped or the part will deform in the areas around the holes.有明確的規(guī)則的放置在一個(gè)模芯孔的一部分。如果這些的最小安全距離沒有按照如下圖所示,孔將蛋狀或部分將各地區(qū)的變形的洞。t= wall thickness of part d= diameter of holet =壁厚的部分d =孔直徑as depic

58、ted above, the distance from the edge of a hole to a vertical surface (i.e. rib) or the edge of a part should be twice the part thickness (or more), or at least one diameter of the hole. this same rule applies between holes - at least two part thicknesses or one hole diameter should be specified.作為如上圖所示,距離邊的一個(gè)小洞,一個(gè)垂直的表面(例如肋)或邊緣的部分應(yīng)該成品厚度的兩倍(或更多),直徑至少一個(gè)洞里。這個(gè)規(guī)則同樣適用于在孔間至少兩部分厚度或一個(gè)洞的直徑應(yīng)指定。holes (p