With the development of material science, plastics are applied more and more widely, and the problem of plastic connection has been brought. Plastic welding has many difficulties due to its special properties. The application of various advanced welding methods makes it difficult to solve.

中国塑料加产业有着巨大的发展潜力，随着产业生产的迅速发展，塑料以其密度小、重量轻、比强度高、抗冲击性好、加工性能好、设计自由度大、耐化学腐蚀性强以及可回收再利用等优点广泛用于国民经济和人民生活的各个领域。

China plastic processing industry has great potential for development, with the rapid development of industrial production, plastic with its small density, light weight, high strength, good impact resistance, good processing performance, design freedom, strong corrosive and can be recycled and reused is widely used in various fields of national economy and people's life.

由于塑料的加工工艺等方面的原因，很多结构复杂的产品不能一次加工成型，需要把多个零部件无缝连接到一起。连接方法有两种：粘接和焊接。一般粘接工艺生产效率低、质量安全需要保障，并且胶粘剂都有一定的毒性，轻易引起环境污染，危害生产职员健康。塑料焊接工艺得到了越来越广泛的应用，能够被激光焊接的塑料均属于热塑性塑料，在实际生产过程中，只有分子结构相同或相近的热塑性塑料才能进行焊接，在焊接面上是分子间的化学结合，所以母材越相近，焊接效果越好，焊接质量也就越高。

Due to the processing technology of plastics, many complex products cannot be processed at one time, and multiple parts need to be seamlessly linked. There are two kinds of connection methods: bonding and welding. The general bonding process is inefficient, quality and safety need to be guaranteed, and the adhesive has certain toxicity, which can easily cause environmental pollution and harm the health of the production staff. Plastic welding technology has been more and more widely used, can be laser welding of plastics are thermoplastic, in the actual production process, only the molecular structure of the same or similar thermoplastics can be welded to the welded surface is chemical bonding between the parent material, so the more similar the welding effect the better, the welding quality is also higher.

目前应用较多的塑焊方法有激光焊接、超声波焊接、高频焊接、摩擦焊、红外线、热板焊接和热风焊接。

At present, the most applied plastic welding methods are laser welding, ultrasonic welding, high frequency welding, friction welding, infrared, hot plate welding and hot air welding.

激光焊接技术

Laser welding technology

20世纪70年代，激光开始被应用到塑料焊接上。其原理是两种塑料在低压力下被夹紧在一起，将激光器产生的光束（通常存在于电磁光谱红外线区的集束强辐射波）通过反射镜、透镜或光纤组成的光路系统，聚焦于待焊接区域，穿过一个制品，然后被另外一个制品吸收。吸收激光能量的制品形成热作用区，在热作用区中将光能转化为热能，塑料的接触面软化、熔化，形成一个焊接区，在随后的凝固过程中，已融化的材料形成接头，待焊接的部件即被连接起来。

In 1970s, the laser began to be applied to plastic welding. The principle is that two kinds of plastics under low pressure are clamped together, the beam will be laser produced (usually found in the infrared electromagnetic spectrum cluster radiation wave) optical system with the reflector, lens or optical components, focusing on the area to be welded, through a product, and is also a product absorption. Product formation thermal effect absorption of laser energy into heat energy in the region, the heated region will contact the plastic softening and melting, forming a weld zone, in the subsequent solidification process, the melted material forming the joint, the welding parts are connected.

尽大多数本色的塑料和很多有色的半透明塑料都能被激光焊接，例如聚苯乙烯（PS）、聚氯乙烯（PVC）和聚苯烯（PP）等材料，也通常在热作用区添加碳黑等吸收剂增强吸热效果。

Most of the natural plastic and many colored translucent plastics can be laser welded, such as polystyrene (PS), polyvinyl chloride (PVC) and polyphenylene (PP) and other materials. Usually, in the thermal zone, carbon black and other absorbers are added to enhance the endothermic effect.

与传统的塑料焊接技术相比，激光焊接塑料技术主要有以下几方面的优点：焊接缝尺寸精密、牢固、不透气及不漏水，部件表面能够严密地连接起来；在焊接过程中树脂降解少、产生碎屑少；与其他熔接方法比较，大幅减少制品的振动应力和热应力；能够将多种不同塑料焊接起来（其他焊接方法有较大限制）；擅长焊接具有复杂外形（甚至是三维）的制品；能够焊接其他方法不易达到的区域，易于控制，具有良好的适应性；

Compared with the traditional plastic welding technology, laser welding plastics technology mainly has the advantages as follows: welding seam size precision, firmness, breathable and not Water Leakage closely connected parts of the surface, can rise; in the process of welding, resin degradation debris is produced less; compared with other welding methods, greatly reduce the product vibration and thermal stress; welding can be a variety of different plastics (up other welding methods have great limitations); good at welding has a complex shape (or three-dimensional) of the products; to other welding method is not easy to reach the area, easy to control, and has good adaptability;

塑料激光焊接还具有焊接速度快、精度高、自动化、精密数控轻易实现、本钱相对较低等优点，因此塑料激光焊接技术在汽车、医疗器械、含有线路板的塑料制品、包装等领域得到了比较广泛的应用，也特别吸引了那些寻求更清洁的方式来熔接复杂部件的加工商。

Plastic laser welding has high welding speed, high precision, automation, precision CNC easily, cost is relatively low, so the laser welding technology of plastics in the automotive, medical equipment, circuit board containing plastic products, packaging and other fields has been widely used, especially attractive to those who seek more ways to clean welding complex parts manufacturer.

超声波焊接

Ultrasonic welding

超声波焊接就是使用高频机械能软化或熔化接缝处的热塑性塑料。被连接部分在压力作用下固定在一起，然后再经过频率通常为20或40kHz的超声波振动，换能器把大功率振动信号，转换为相应的机械能，施加于所需焊接的塑料件的接触界面，但超声波被引向待焊的塑料表面时，塑料质点就会被超声激发而作快速的振动，从而产生机械功，再转为热能，热塑性塑料的温度就会上升以至熔化。非焊接表面处的塑料，其温度是不会上升的。机械功的形式是塑料质点因振动引起的连续交替的受压和解压以及被焊表面之间因振动引起的摩擦。焊件接合处剧烈摩擦瞬间产生高热量，使分子交替熔合，从而达到焊接效果。

Ultrasonic welding is a thermoplastic that uses high frequency machinery to soften or melt the joints. By connecting part under pressure are fixed together, and then through the ultrasonic vibration frequency is usually 20 or 40kHz, the high power transducer vibration signal is converted to the corresponding mechanical energy, applying plastic contact interface to the required welding, ultrasonic plastic but surface to be welded, plastic particles will be as fast excited ultrasonic vibration, resulting in mechanical work, then turned into heat, thermoplastics and melting temperature will rise. The temperature of the plastic on the non - welded surface will not rise. The form of mechanical work is the continuous alternating compression and decompression of the plastic particles caused by the vibration and the friction caused by the vibration between the welded surfaces. High heat is generated at the moment of intense friction between the joints of the welding parts, and the molecules are fused alternately so as to achieve the welding effect.

超声波焊接的特点是，发热只集中在焊接部分，焊缝牢固而美观，不管塑料的极性大小，几乎所有加热熔融的塑料薄膜都可以采用超声波焊接，尤其适合于焊接刚性较大的薄膜材料。超声波焊接不受待焊表面污染的限制，焊接过程很快，焊接时间不到1s，并且很轻易实现自动化，可通过计算机程序控制来实施对大件和不规则工件的焊接，如汽车保险杠、前后门、内饰件、滤清器、刹车灯、灯具等，同时反光片及反光材料也越来越多的采用超声波焊接。

The characteristic of ultrasonic welding is that heating is concentrated only in the welding part, and the weld is firm and beautiful. Almost all heating and melting plastic films can be welded by ultrasonic, no matter the polarity of the plastic, especially for welding rigid rigid film materials. Not to be welded surface pollution limits of ultrasonic welding, the welding process is very fast, the welding time is less than 1s, and easy to realize automation, can be implemented for welding large and irregular workpiece by computer program control, such as car bumpers, front and rear doors, interior parts, filter, brake lights, lamps, etc., at the same time reflective film and reflective material is widely used in ultrasonic welding.

高频焊接

High frequency welding

高频焊接又称高频热合，是利用电磁感应原理高频感应加热技术，穿透塑料制品对埋躲于塑料件内部的感应体或磁性塑料产生感应加热，被焊塑料在快速交变电场中可以产生热量而使需焊接部位迅速软化熔融，继而填充接口间隙，并以完善的机械装置辅助以达到完美焊接。简单地说，它是利用电子管自励振荡器所产生的高频电场，使

High frequency welding also called high-frequency heat sealing, is using the principle of electromagnetic induction of high frequency induction heating technology, through plastic products have induction heating of buried in plastic internal inductor or magnetic plastic, plastic welding can produce heat and make the welding site rapid softening and melting fast in alternating electric field, and then fill the gap in the interface. To assist in the development of the mechanical device to achieve the perfect welding. Simply speaking, it is the high frequency electric field generated by electron tube self-excited oscillator, the