Shanghai Daoqin Plastics Co., Ltd.

 PMMA材 material processing formed plastics products, tool has light transmittance high, chemical resistant product property good, and tool has hardness and strong/high degree. therefore, by a large amount of used for optical products, small type container and type decoration applications, optical 镜头, product bottle, parts and other.

due to material light transmittance high, for comparison 敏感, therefore products in has defect very easy 暴露而 by to. 另一方面, material in melt lower degree relatively large, flow property relatively 差, for processing equipment 提出 一 requirements. 回复“PMMA”, more more related 文章

一, PMMA材 material molding processing attention/notes “十三” issues

1, equipment selection : according to products weight, 形状, cycle and other selection injection amount and clamping force equipment, injection amount large, cycle long effect/influence products quality.

2, screw selection : selection hot small, good screw. processing PMMA材 material requirements screw surface light degree good, plastics melt 流经处没 has and abrasion loss. 例如: for/regarding transparent sheet/slice using/adopting belt/tape 屏障 function structure, can add strong/high 塑化效果. for/regarding color sheet/slice use type screw or type 胶头, add strong/high mixing/compounding 效果.

图: has machine 玻璃PMMA鱼缸

3, selection : using/adopting 开放式 structure, 射嘴孔 versus for relatively large, long degree short long.

4, material drying : using/adopting ring hot drying, due to PMMA粒 material surface easy soft viscous 连, in material lower block, lower material difficult. need attention/notes temperature degree high, amount need 足够.

5, material processing : can in machine in 停留 久, long time 停止操 as, need will machine temperature degree drop 至170 ℃ below/following, melt degradation.

6, water material : water material 取出, 破碎, packaging, 储存, mixed combined and other process need control, 避免杂 color material and mixed 入. new material ratio/proportion products 而定.

7, mold 清理: 定期清理 mold type surface water 垢, products light degree 不够时就 need 清理.

8, mold gate, runner design : combined less 剪切, flow 顺畅 原则. using/adopting relatively large dimensions runner and gate. tool good gas property can, combined 理开设排 gas and gas 槽.

9, mold type demolding degree design : is ensure made parts molding can demolding, design must in demolding direction demolding degree.

图: PMMA products

10, mold or sheet/plate design : for/regarding decoration type products, very less design 顶针, more using/adopting sheet/plate demolding. for/regarding need use 顶针, design must meet/satisfy balanced ejection 原则.

11, 一模 more mold : its cooling water 道 布置应尽 can can balanced, can can very difficult ensure products quality 一致.

12, processing PMMA plastics products : generally need water temperature machine, make processing process mold temperature degree stability control

13, transparent PMMA products very easy 出现熔接纹, 乱流纹, cold material 斑, shrinkage and bubbles and other defect .

二, PMMA材 material 7 large application analysis

1, plastics sheet/slice : sheet/slice has 近视镜 sheet/slice, 老花镜 sheet/slice and cationic sheet/slice and other. using/adopting injection molding methods, one-time property molding 出一定 degree 数 眼镜 sheet/slice, color easy, cost low. generally using/adopting PMMA材 material relatively more, requirements high using/adopting fiber, transparent nylon or PC plastics.  

图: sheet/slice

processing sheet/slice generally selection CJ150M3 and CJ180M3 machine relatively more, and selection small screw, mold cavity generally design is 1×5 or 1×6圆周 for 称排列. 老花镜 sheet/slice and 近视镜 sheet/slice dimensions requirements high, need relatively long holding pressure time, decrease small shrinkage, make products to design dimensions. cationic sheet/slice belongs to light sheet/slice, requirements that high, generally need color, separation method color and method color.

2, plastics light guide sheet/plate : has liquid 晶显示 device need use to plastics light guide sheet/plate. light guide sheet/plate use material, basic upper is transparent degree good PMMA or PC plastics.

use injection molding machine specifications from 50T to 180T. in low product using/adopting liquid pressure machine injection molding machine; in high product using/adopting pressure or electrical liquid composite/compounding injection molding machine; high product use full electrical machine or belt/tape injection pressure shrink function injection molding machine.

light guide sheet/plate is high degree optical products, requirements formed product 网点完整, overall shrinkage deformation; products surface 无黑黄点, 无晶点, 无杂质, overall light degree and light degree good.

基于 above quality requirements, light guide sheet/plate main/primary processing process requirements lower:

1）, injection molding machine clamping force need 足够, sheet/plate degree need high, ensure products flash, thick thin uniform.

2）, requirements equipment injection stability, amount 准确.

3）, equipment injection amount 不必太 large, large easy make melt yellowing color. is anti plastics and generate 黑黄点 issues, for 塑化组 parts light degree requirements relatively high.

4）, requirements equipment injection pressure high, injection speed degree fast. due to PMMA and PC plastics melt flow property relatively 差, especially is processing thin light guide sheet/plate 时, more need large injection pressure and large injection speed degree.

5）, melt viscosity large, requirements screw has large 旋转扭矩. meanwhile requirements screw in structure design upper tool has strong/high resistant property.

6）, mold design upper must meet/satisfy 顺利充填, demolding requirements, mold processing degree need high, has 精确 排 gas 槽.

图: light guide sheet/plate

3, plastics optical sheet/slice : remove 眼镜镜 sheet/slice outer 诸如数码 versus machine sheet/slice, machine sheet/slice, and its it optical 透镜. material generally use PMMA plastics.

generally use 50T to 120T injection molding machine. optical sheet/slice generally thick degree relatively large, products requirements appearance saturated 满, key/critical control products shrinkage, meanwhile requirements products 不泛黄, 无晶点, black spots, overall light degree and light degree good. optical sheet/slice main/primary process features lower:

1）, requirements injection molding machine clamping force need 足够. processing optical sheet/slice requirements injection molding machine has fast speed injection speed degree, requirements machine can provide stability slow speed speed degree, can provide high injection pressure and stability holding pressure pressure.

2）, processing cycle relatively long is its features 之一. therefore generally 配备变 amount or use full electrical machine.

3）, mold must deep degree 0.03mm below/following gas 槽, 以排走 mold cavity in gas and melt 挥发出 gas 体, anti products gas effect/influence transparent degree.

图: optical sheet/slice

4, process decoration 球（￠40 left right ）: equipment generally selection 80T or 120T, ensure has injection pressure. material using/adopting PMMA plastics （ if material is GPPS, easy processing more ）. mold generally design is 1×1 or 1×2, can using/adopting hot sheet/plate 模, can using/adopting large water sheet/plate 模. due to products thick degree especially large, products shrinkage, internal bubbles and surface issues control difficult degree versus for large more.

图: force 球

5, transparent thick 壁化妆 product box/case （PMMA材 material ）: according to parts dimensions, generally selection 80T to 150T injection molding machine, small screw. mold generally design is 1×2, can using/adopting hot sheet/plate 模, can using/adopting fine water sheet/plate 模, processing process methods has different. products belongs to transparent thick products, due to thick degree large, its processing process requirements and methods and decoration versus 似.

6, thick degree sheet/plate type parts （PMMA材 material ）: micro front 门, can use 250T injection molding machine. mold using/adopting sheet/plate 偏心模 or using/adopting sheet/plate 模. type parts main/primary is material must drying, focus/key point control products deformation issues.

图: micro front 门

7, thick long strip/profile type parts （PMMA）: type parts relatively heavy, generally according to parts large small selection injection molding machine. mold generally design is large water sheet/plate 侧进胶（ parts long degree in ）; has fine water large water 口 三 sheet/plate 模（ parts long degree very long ）. this category of parts main/primary issues is material need separation drying, focus/key point is control deformation issues.  

above 列出 几 type products, tool color, has same 方, has different 点. processing in, for/regarding effect/influence factors 都应认 true analysis, issues 点, can solution issues.