PA12 聚酰胺12或尼龍12

典型應用范圍:
水量表和其他商業設備，電纜套，機械凸輪，滑動機構以及軸承等。

注塑模工藝條件:
干燥處理：加工之前應保證濕度在0.1%以下。如果材料是暴露在空氣中儲存，建議要在
85C熱空氣中干燥4~5小時。如果材料是在密閉容器中儲存，那么經過3小時溫度平衡即可
直接使用。
熔化溫度：240~300C；對于普通特性材料不要超過310C，對于有阻燃特性材料不要超過270C。
模具溫度：對于未增強型材料為30~40C，對于薄壁或大面積元件為80~90C，對于增強型材料為
90~100C。增加溫度將增加材料的結晶度。精確地控制模具溫度對PA12來說是很重要的。
注射壓力：最大可到1000bar（建議使用低保壓壓力和高熔化溫度）。
注射速度：高速（對于有玻璃添加劑的材料更好些）。
流道和澆口:
對于未加添加劑的材料，由于材料粘性較低，流道直徑應在30mm左右。對于增強型材料要求
5~8mm的大流道直徑。流道形狀應當全部為圓形。注入口應盡可能的短�？梢允褂枚喾N形式
的澆口。大型塑件不要使用小澆口，這是為了避免對塑件過高的壓力或過大的收縮率。澆口
厚度最好和塑件厚度相等。如果使用潛入式澆口，建議最小的直徑為0.8mm。
熱流道模具很有效，但是要求溫度控制很精確以防止材料在噴嘴處滲漏或凝固。如果
使用熱流道，澆口尺寸應當比冷流道要小一些。

化學和物理特性:
PA12是從丁二烯線性，半結晶-結晶熱塑性材料。它的特性和PA11相似，但晶體結構不同。
PA12是很好的電氣絕緣體并且和其它聚酰胺一樣不會因潮濕影響絕緣性能。它有很好的
抗沖擊性機化學穩定性。PA12有許多在塑化特性和增強特性方面的改良品種。
和PA6及PA66相比，這些材料有較低的熔點和密度，具有非常高的回潮率。PA12對強氧化性
酸無抵抗能力。
PA12的粘性主要取決于濕度、溫度和儲藏時間。它的流動性很好。收縮率在0.5%到2%之間，
這主要取決于材料品種、壁厚及其它工藝條件。

PA 12

Generic Class

PA 12 (Polyamide 12 or Nylon 12)

Typical Applications

Gear wheels for water meters and business machines, cable ties, cams, slides, and bearings.

Injection Molding Processing Conditions

Drying	The moisture content must be below 0.1% prior to processing. If the material is exposed to air, drying in a hot air oven at 85 C (185 F) for 4 -5 hours is recommended (3-4 hours in a desiccant dryer). If the container is unopened, it may be used directly for molding after 3 hours of equilibration to shop floor temperature.
Melt Temperature	230 - 300 C (446 - 580 F); Not to exceed 310 C (590 F) for standard grades and 270 C (518 F) for flame retardant grades
Mold Temperature	30 - 40C (86 - 104 F) for unreinforced grades; for thin walled or large surface area components, 80 -90 C (176 - 194 F) may be used; 90 - 100 C (194 - 212 F) for reinforced grades. Increasing the mold temperature increases the crystallinity level. It is very important to precisely control the mold temperature.
Resin Injection Pressure	Up to 1,000 bar (14, 500 psi) Low hold pressures and high melt temperatures are recommended.
Injection Speed	High (high speeds give better finish on glass-filled grades)

Runners and Gates

Runner diameters for unfilled grades may be as small as 3 - 5 mm because of the material's low viscosity. Reinforced grades require larger diameters (5 - 8 mm). The runner shape should be the full round type. Sprues should be as short as possible.

A variety of gates may be used. Small gates for large parts should be not be used, in order to avoid highly stressed components or excessive shrinkage. The thickness of the gate should preferably be equal to the part thickness. When using submarine gates, the minimum recommended diameter is 0.8 mm.

Hot runner molds may be used effectively but precise temperature control is necessary to prevent material drooling or freezing off at the nozzle. When hot runners are used, the size of the gates may be smaller than in the case of cold runners.

Chemical and Physical Properties

PA 12 is a linear, semicrystalline-crystalline thermoplastic derived from butadiene. It has properties similar to PA 11 but its crystal structure is different. PA 12 is a good electrical insulator and its properties are not as sensitive to humidity as other polyamides. It has good resistance to shock and resistant to many chemicals. It is extensively modified with plasticisers and reinforcements. In comparison to PA 6 and PA 66, these materials have a lower melting point, density, and much lower moisture regain. It is not resistant to strong oxidizing acids.

Viscosity is determined by water content, temperature, and residence time. This material flows easily. Shrinkage is of the order of 0.005 - 0.02 mm/mm (0.5 - 2%). This is dependent on the specific grade, wall thickness, and processing conditions.

Major Manufacturers

Huls (Vestamid), Elf Atochem (A).