Shanghai Daoqin Plastics Co., Ltd.

nylon property can make its in automotive, electronics electrical equipment, machine structure, sports equipment, textile and other 方面 to application. automotive small type 化, electronics electrical equipment high property can 化, machine equipment light amount 化 进程 add fast, for nylon demand and property can requirements add large. nylon modified 便显 尤 is important.

1, material temperature degree setting

（1）因 nylon is crystallization type polymer, therefore melting point obvious, nylon type resin in injection molding selection material temperature degree resin property can, equipment, products factors has 关.

（2） high material temperature easy make parts color 变, and silver streaks, low material temperature make material very hard can can loss mold and screw.

（3） generally PA6 melt temperature degree most low is 220℃, PA66 is 250℃. due to nylon heat stabilized property relatively 差, therefore high temperature long time in material in 停留, 以免引起 material material color 发黄, meanwhile due to nylon flow property relatively good, temperature degree ultra- its melting point rear flow speed.

2, mold temperature degree setting

（1） mold temperature degree for crystallization degree and molding shrinkage has effect/influence, mold temperature scope/range in 80-120℃.

selection high mold temperature, crystallization degree high, wear resistance, hardness, elastic property modulus increase, water property decline, products molding shrinkage increase, combined thick products;

selection low mold temperature, crystallization degree low, tough property good, elongation relatively high, shrinkage rate decline, combined transparent property good thin products.

（2） if thick large 于3mm, use 20~40℃ low temperature mold. for/regarding reinforcement material mold temperature degree large 于80℃.

（3） products thin difficult molding or requirements crystallization degree high mold add temperature control, requirements products has flexibility property generally using/adopting cold water temperature.

3, products thick

nylon long ratio is 150-200 between, nylon products thick low 于0.8mm, generally in 1~3.2mm between selection, but also products shrinkage and products thick has 关, thick thick shrinkage large.

4, gas

nylon resin value is 0.03mm left right, therefore gas 孔槽应 control in 0.025 below/following.

5, runner and gate

gate 孔径不 need small 于0.5*t（t is parts thick degree ）. use 潜入式 gate, gate most small 直径应当 is 0.75mm.

6, glass fiber (GF) filling amount scope/range

nylon molding process in, reduce mold temperature degree, add large injection pressure, reduce material temperature in 一定程 degree upper decrease small nylon shrinkage rate, make products internal stress add large easy deformation. 例如PA66 shrinkage rate in 1.5-2% between, PA6 shrinkage rate in 1% to 1.5% between, in add glass fiber additives rear can make shrinkage rate reduce to 0.3% left right.

实践 experience 告诉我们, glass fiber (GF) add amount more, nylon resin molding shrinkage small. is glass fiber (GF) add more formed surface fiber exposure, versus property and other rear 果, generally add 30%效果 versus for relatively good. lower table/sheet is experience to “ glass fiber (GF) - molding shrinkage ” table/sheet.

7, recycled material use

most good ultra- 三次, 以免引起 products color or machine physical properties decline, application amount control in 25% below/following, more 会引起 process conditions 波动, recycled material and new material mixed combined must drying.

8, safety must 知

nylon type resin machine 时应首先开启 nozzle temperature degree, rear in to material add temperature, nozzle retardant 塞时, 切忌面 for 喷孔, anti material inner solvent pressure poly 集而突然释放, 发生危险.

9, demolding agent use

use a small amount of demolding agent has for bubbles and other defect has improvement and remove function. nylon products demolding agent can selection hard acid zinc and and other, can mixed combined formed use, use must amount less uniform, 以免造 formed products surface defects.

in machine need screw, anti lower production 时, screw.

10, rear 处理

（1） products molding rear need hot 处理

commonly used methods in material 油, 甘油, liquid wax and other high liquid in, hot temperature degree high use temperature degree 10-20℃, time products thick 而异, thick degree in 3mm below/following is 10-15 separation 钟, thick degree is 3-6mm time is 15-30 separation 钟, hot products attention/notes slow cooling room temperature, anti cold products in force heavy new formed.

（2） products molding rear need 进行调 wet 处理

调 wet main/primary is for use ring wet degree relatively large products 而进行, its method has types: water wet method; acid water solvent liquid wet method （醋 acid and water ratio/proportion is 1.25:1, 沸点121℃）.

沸 water wet method 简便, need will products in wet degree is 65% ring lower, make its to balanced wet amount can, time relatively long, acid water solvent liquid wet method temperature degree is 80-100醋 acid water solvent liquid wet method, time main/primary products thick, thick is: 1.5mm时约2 small 时, 3mm时约8 small 时, 6mm时约16-18 small 时.

1, glass fiber reinforcement PA

in PA add 入30% glass fiber, PA force property can, dimensional stability, heat resistant property, resistant aging property can has obvious improve/increase, resistant fatigue strong/high degree is reinforcement 2.5倍. glass fiber reinforcement PA molding process and reinforcement large same, flow relatively reinforcement front 差, therefore injection pressure and injection speed degree need improve/increase, machine temperature degree improve/increase 10-40℃.

due to glass fiber (GF) in injection molding process in flow direction orientation, force property can and shrinkage rate in orientation direction upper reinforcement, products deformation warpage, therefore, mold design 时, gate 位置, need combined 理, process upper can improve/increase mold temperature degree, products rear hot water in let its slow cooling. another, add glass fiber (GF) ratio/proportion large, its for injection molding machine 塑化元 parts abrasion loss large, most good is using/adopting di metal screw, machine 筒.

2, flame retardant PA

due to in PA in add flame retardant, large separation flame retardant in high temperature lower easy separation understanding, 释放出 acid property material 质, for metal tool has function, therefore, 塑化元 parts (screw, 胶头, 胶圈, gasket, method and other)需镀 hard 鉻处理. process 方面, amount control machine temperature degree can high, injection speed degree can fast, 以避免因胶 material temperature degree high separation understanding products color and force property can decline.

3, transparent PA

tool has good tensile strength, resistant impact strong/high degree, rigid property, wear resistance, chemical resistance, surface hardness and other property can, light transmittance high, and optical versus 近, processing temperature degree is 300--315℃, molding processing 时, 需严格 control machine temperature degree, melt temperature degree high degradation 而导致 products color, temperature degree low 会因塑化 defect effect/influence products transparent degree. mold temperature degree amount low, mold temperature degree high crystallization make products transparent degree reduce.

4, weather resistant PA

in PA in add carbon and other absorption outer additives, this for PA lubricated property and for metal abrasion loss large large reinforcement, molding processing effect/influence lower material and abrasion loss machine parts.

therefore, need using/adopting material can force strong/high and wear resistance high screw, machine 筒, 胶头, 胶圈, gasket combined.