Shanghai Daoqin Plastics Co., Ltd.

in for use polymer 螺母 导 screw plant/unit positive design and type 时, pressure speed degree (PV) is key/critical design parameters. although large more engineering polymer 都列出 PV parameters, in 考虑螺母 negative 荷额定 value 时, this parameters generally by 忽略, more more by used for toward sleeve/set and sliding application. PV parameters through and screw between pressure and speed degree 乘积 定义导 screw plant/unit property can scope/range. plastics tool has solid has PV 额定限 value, in certain conditions lower system PV can 计算出. simple 说, add to screw upper negative large, must will it 转动 越 slow, 以避免 ultra- 螺母 PV value. 反之亦然, speed degree large, negative amount small. plastics PV value is 由特定 product material composite/compounding 人员赋予. Common composite/compounding plastics has DuPont company Delrin AF, Quadrant company Torlon and GE Plastics company LNP Lubriloy. material composite/compounding negative for resin and additives formulation design. additives commonly used improve/increase structure and scratch property can. material composite/compounding usually use material in 一 钢 surface upper 进行PV testing. through sample negative and speed degree, can abrasion loss 拐点, 因而测出材 material PV value. although resin tool has 一 特定PV value, through add lubricant and other composite/compounding material, can will 该额定 value large large improve/increase. this is design provide very large active property, can for application 取 适宜 PV scope/range. attention/notes is, company testing methods has different, therefore in selection types material 时, most good need for mono material composite/compounding different plastics comparison. will to, can through 改变导 screw parts 几何形状 改变 system PV value. 令人吃惊 is, large more design in design system 时, is simple 考虑螺母 negative 荷额定 value, 而忽略 speed degree effect/influence, this 会导致迅 speed 而突然 失效. screw main/primary 失效模式 is abrasion loss and PV. scratch generate hot amount to ultra- 螺母 most high use temperature degree 时, 会导致PV失效. in relatively low PV value lower, abrasion loss speed degree increase, from shrink short use lifespan. through in PV value scope/range inner design, can make is abrasion loss 而发生. abrasion loss is types relatively slow and property degree relatively large type type, can in design in add 以考虑. to material PV value can in PV upper table/sheet 示（见图1）. this is through will pressure and speed degree 乘积设置 is material PV value achieve （见 and other 式1）. pressure by is add to upper toward force remove it bearings 面积 结果, speed degree by is surface between sliding speed degree. through understanding pressure （ or speed degree ）, can made 出 需 speed degree （ or pressure ） scope/range inner 曲线. is anti 止失效, must will system PV value maintain in material PV lower 面. is 确定材 material PV value how to and screw plant/unit system PV value related, need for it 几何形状进行 analysis. through obtain 螺旋线 long degree 计算螺母 and screw between 投影接 combined 面积（见 and other 式5）. this is in 发生理论螺纹接 combined 节圆直径 upper 沿螺纹行进 一 strip/profile false 想线. through will 螺纹 螺旋线展开, can through 一 三角形 for it analysis, its in, 直角三角形 斜边代 table/sheet 螺纹旋转一圈 螺旋线 long degree （见 and other 式4）. 节圆直径 and 螺纹导程 is 直角三角形 底 and high. for 斜边进行求 understanding, 并乘以螺母 in 螺纹圈数 and 螺纹线数, to 螺旋线总 long degree. will 螺旋线 long degree 乘以螺母 and screw between 螺纹接 combined deep degree, can 计算出二者 between 接触面积（见 and other 式2）. surface speed degree can through will 每圈 螺旋线 long degree 乘以旋转 speed degree 计算（见 and other 式3）. 实际操 as in generate complex factors. due to use polymer material solid has rigid degree, in and between 会发生偏转（见图2 ）. this type of can 导致螺母 螺纹发生像梁 bending in that type of 旋转, make and screw between 接触面 reduce. this type of 接触面 reduce 发生, 接触面进一步 toward 导杆螺纹 牙侧 upper 方移动, to large separation negative by add to large 径附近（见图3）. this type of will for to negative lower 两 部 parts between pressure generate negative effect/influence. upper, very difficult 计算出 this type of decrease/reduce has more large. is, 面积会随 negative increase reduce, this add heavy and PV has 关 失效 trend, from maintain in property can scope/range inner 显示十 separation important. need solution this issues, need will 一 校 positive 因子(Cf) used for 投影面积. negative from light negative increase to 满额定 negative amount, 此因子 usually in large 约0.75 至0.25 scope/range inner. through 计算螺旋线 long degree, pressure will pressure surface speed degree, can 计算出一 system PV value. ensure mono is psi ft/min or MPa m/s, this can will and material PV value comparison. use safety 因子2. already attention/notes to, system pressure ultra- PV value separation 之一时, abrasion loss accelerated. therefore, although 不会发生突然失效, system abrasion loss lifespan will shrink short. another, also can made negative for RPM or 螺母线 property speed degree 曲线图. through will pressure remove positive rear 接触面积, can made strip/profile for negative PV 曲线, and can for RPM 进行求 understanding （见 and other 式3）, can will surface speed degree table/sheet is speed degree. its 结果就 is, can for 特定导 screw system made 出一 允许 negative and speed degree 便利图形关系曲线. 当位于曲线 lower 面区域 in 时, screw plant/unit 失效形式 main/primary is abrasion loss 失效. control PV scope/range methods main/primary has below/following types: polymer composite/compounding material or resin can 导致PV value increase, this can has will PV in PV upper toward upper and toward right 移动, from improve/increase system property can （图1）; reduce parts between scratch can 导致PV value increase, drop low friction methods will lubricant composite/compounding to plastics in, toward screw in add lubricated and use dry film lubricant; 改变螺母 几何 dimensions can reduce to negative and speed degree lower system PV value, 例如, relatively long will reduce upper pressure, in long degree is screw 直径4 倍 螺母周围 certain upper, 会发生回程 decrease small. due to in 计算导 screw system PV value tool has certain types degree solid has complex property, therefore 结果总存 in certain 不确定 property. is, if for versus 互关系 and versus function add understanding, will non has 助于进行 combined design. another, screw injection molding parts processing also provide application 支持. this or is for PV value 进行验证 most good methods, is 他们拥 has most can 靠 材 material and system PV 信息. in this type of 信息 情况 lower, 请参考 below/following experience: false more product catalog negative 荷额定 value in large 约500 rpm speed lower is 准确, high value speed can can need as negative versus reduce. if in application in need ultra- PV value relatively a large amount of, will negative 荷系数 maintain in 10％ or 20%.