Quality control is crucial in the non-woven composite process. Without it, you may end up with inferior products and wasting valuable materials and resources. In this fiercely competitive era of the industry (2019, global non-woven fabric consumption exceeded 11 million tons, worth $46.8 billion), you will face the risk of losing market share.
In the production of non-woven composite materials, it is crucial to have a deep understanding of the control process and convert it into advantages in order to achieve and maintain the required quality control. Let’s take a look.
How to ensure the highest quality control of composite processes?
The processes that truly determine the quality of non-woven composite materials are only a few and must be strictly controlled, mainly including tension, temperature, line pressure, and the application of adhesives.
tension control.
Fabric tension is the force (MD) applied in the mechanical direction on the fabric. Tension is extremely important throughout the entire composite process. When handling the fabric appropriately, the fabric must always be pulled by the roller, and the tension it receives cannot be too large or too small.
Tension control is crucial at all stages of fabric processing. Generally speaking, post-processing is divided into three different tension zones:
● Unroll
● Processing
● rewinding
Each tension zone must be independently controlled, but must work in coordination with other zones. The tension applied in each area varies depending on the torque of the rollers. The torque must change with the unwinding or unwinding of the fabric roll to maintain appropriate tension.
Temperature control
The temperature setting of non-woven fabric composites is crucial for obtaining top-quality products.
In the process of hot melt adhesive compounding, precise control of the adhesive layer temperature is required, and the composite material needs to be cooled to avoid changing its properties.
The thermal composite process requires high temperatures to utilize the thermoplasticity of one or more synthetic layers in the composite material. High temperature and pressure can cause the synthetic fiber layer to melt, enough to bond with the non-woven fiber layer. However, the temperature setting must be precise. If the temperature is too low, it will not be able to bond and will not last. On the contrary, if the temperature is too high, it will cause degradation of the material in the fabric layer, thereby affecting the structural integrity of the composite material.
Line voltage control
The pressure line is the gap between two rollers along the composite line. When the fabric passes through the pressure line, apply pressure to flatten the fabric and ensure even distribution of the adhesive. When the fabric passes through the pressure line, the amount of pressure applied in the composite process can change the rules of the game.
The key to controlling line pressure is to make it as small as possible: too much pressure can compress the fabric too tightly, even tearing it apart. In addition, line pressure helps to control the tension of the fabric. It is equally important to understand how the fabric affects the mutual relationship between the two rollers when passing through the pressure line. If the positioning or torque of the composite roller is abnormal, defects such as cutting and wrinkling may occur.
Quality of adhesive
Controlling the use of adhesive is the key to quality control. If there is too little adhesive, the bonding may not be strong enough, and some parts may not be bonded at all. If there is too much adhesive, thick and hard areas will appear inside the composite material. No matter which gluing method is used, the control of gluing is related. The gluing method includes:
● Coating head – suitable for contact coating of the entire substrate surface
● spray type – non-contact type, providing various modes, such as bead, melt spray or sine
It is crucial to control the use of adhesive to maintain consistency with the speed of fabric movement. The faster the fabric moves, the faster the glue needs to be applied. To obtain the optimal coating weight for the final product, these settings must be precise.
The role of Industry 4.0 in quality control
The measurement of various parameters of non-woven composite equipment is relatively complicated, and human errors are inevitable when manually adjusting parameters. However, Industry 4.0 has changed the game rules of quality control.
Industry 4.0 is considered the next stage of the technological revolution, transforming the computerization of tasks into complete automation through technologies such as cloud computing and the Internet of Things (IoT).
The non-woven composite equipment designed based on Industry 4.0 includes:
●Sensors distributed throughout the entire production line
●Cloud connection between the device and the main software platform
● Easy to operate control panel, providing complete visibility and real-time control of production processes
Sensors located on the device can measure settings such as temperature, pressure, and torque, and can detect defects in the product. Due to the real-time transmission of these data, adjustments can be made during the production process. With the help of artificial intelligence (AI), these adjustments can be implemented through software to maintain optimal production speed and settings at any time.
Dongguan Liansheng Non woven Technology Co., Ltd. was established in May 2020. It is a large-scale non-woven fabric production enterprise integrating research and development, production, and sales. It can produce various colors of PP spunbond non-woven fabrics with a width of less than 3.2 meters from 9 grams to 300 grams.
Post time: Nov-16-2024