如何焊接塑料 - 塑料焊接基础

塑料焊接是在加热状态下加入两片热塑性塑料的过程，并且由于它们的聚合物的交联而在压力下。工作件与填充材料一起融合在一起。当零件在玻璃化转变温度（变象聚合物）低于或低于熔化温度（用于结晶聚合物）时，关节形式。固化条件下的热固性剂（热固性源性）不能焊接，因为它们的分子交联完成。

塑料焊接工艺：

• 热气焊
• 热板焊接
• Ultrasonic Welding
• 旋焊
• 振动焊接

如何使用热气焊法塑料焊接方法

热气体焊接是一个塑料焊接过程,尿路感染lizing heat of hot gas stream. The gas (usually air) is heated by electric heating elements mounted within the welding gun. The torch (welding gun) directs the heated gas toward the work piece surfaces and a rod of filler material. The edges of the joined parts and the filler rod material are fused together and pressed. The polymer molecules are cross-linked when the work pieces cool down, forming a strong joint. Hot Gas Welding is manually operated process requiring high level of the operator skill. Some polymers (e.g. Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE)) oxidize at incresed temperature therefore they are welded by hot Nitrogen.

Applications of Hot Gas Welding:

• 容器;
• 储罐化学品;
• 通风管道;
• 管;
• Repair works.

热气体焊接工艺参数

Process parameters Description
·热气体温度
·Gas – Composition of hot gas(air, carbon dioxide, hydrogen, oxygen or nitrogen)
· Angle – Include angle between weldment and rod, angle between gas nozzle and weldment.
·填写焊接的旅行速度 - 速度
·焊接力 - 施加到填充棒的力量
·填充棒 - 填充棒的组成
·间隙远程 - 气体喷嘴与工件之间的距离
·焊接接合接头和双带圆角接头。

热气技术中的焊接程序

The hot air gun is used for hot air welding. The gun consists of a main body which contain heating element. This is anon contact soldering for high requirements. The air mass flow and the temperature can be adjusted in a prescribed range; the basic element of hot air gun is shown in the figure
2. The nozzles can be easily replaced so that each component is soldered by using the suitable nozzle, air and temperature setting.

作为手动过程，焊接质量取决于技能。没有公认的非破坏性技术，这最终显示了可能导致焊缝失效的塑料焊缝中的缺陷。因此，建议收到良好的质量焊机培训，并采用焊工认证。

Ultrasonic Welding
超声波焊接是一种塑料焊接过程，其中由于施加到焊接部件的压力而与高频声学振动（超声波）相结合，因此粘合两个工作件。由金属工具（喇叭，超声波）传递的超声波振动导致振动材料的弯曲和部件之间的摩擦，这导致两个表面之间的近距离接触，具有与接触面积的同时局部加热。塑料在接触面积中熔化，聚合物分子是交联的，形成强关节。超声波焊接周期大约需要1秒。声学振动的频率在20至70kHz（通常为20-40kHz）的范围内。声学振动的放大率约为0.002“（0.05mm）。焊接部件的厚度受超声波发生器的功率的限制。超声波焊接主要用于加工非晶态聚合物（聚酯（PS），丙烯腈 - 丁二烯 - 苯乙烯（ABS）））

超声波焊接的应用：

• Medical equipment (filters, face mask, valves, cardiometry reservoir);
• Automotive components (glove boxes doors, filters, valves, airflow sensors);
• 电器（真空吸尘器，蒸汽熨斗，洗碗机组件）;
• 电气设备（开关，端子块，连接器）;
• 电子和计算机组件;
• 玩具。

Advantages of Ultrasonic Welding:

• 短焊接周期;
• 易于自动化和可控;
• Small amount of flash forms;
• Low energy consumption;

Disadvantages of Ultrasonic Welding:

• Only small and thin parts may be welded;
• Tool design is required.