The large-scale development and application of polypropylene honeycomb panels has made the trend of recycling more and more obvious. Polypropylene (PP) honeycomb panel is a board made of two thinner panels firmly compounded on both sides of a thicker honeycomb core material, also known as honeycomb sandwich structure, and the material is mainly PP. This plastic honeycomb panel has the characteristics of light weight and high rigidity, moisture-proof and waterproof, green environmental protection and excellent energy absorption characteristics. PP plastic welding machine is used in many fields with its unique advantages, especially logistics transfer boxes, containers and packaging express boxes.
In production, the principle of PP plastic welding machine is to heat and melt the plastic molecules at the two welding surfaces, thereby consolidating them together. Ultrasonic welding is widely used in the welding of thermoplastic materials because of its high welding strength, good weld quality, and automatic forming. Among them, temperature, time and pressure are the main factors affecting welding strength and welding appearance.
The welding pressure is the most significant among the four factors, and the reasons for the analysis include two aspects: First, the PP honeycomb sheet is a material with a certain thickness and pore structure. During the ultrasonic welding process, a large number of pores will be lost from the welding head. The generated ultrasonic energy, so that the temperature generated by the energy reaching the welding surface cannot reach the melting point of polypropylene, so pressure is required to reduce the distance and pores between the honeycomb sheets; secondly, during the melting process of the material, the pressure can promote the mutual movement of molecules , so that the two welding surfaces are closely combined. As the welding surface cools and the material solidifies, the internal molecular force generated at the weld increases the welding strength. In general, for PP, a Plastic Welding Machine with low hardness, the ultrasonic energy decays quickly, so it is only suitable for near-field welding.