Food packaging bags , as the name suggests, use appropriate packaging materials, packaging containers and advanced packaging technology to wrap food, so that the food maintains its value and original state during transportation and storage, and ultimately achieves the effect of ensuring food safety . Â Â Food packaging bags play an important role in the modern commodity society and are inseparable from people's lives. As for the meaning of food packaging, it was initially thought that it was just an appliance to hold items and protect flexible packaging products. Later, it added functions for easy transportation and use, and then increased the role of publicity and promotion of product sales. At the end of the twentieth century, the environment for environmental protection in the world was increasing day by day, so food packaging bags were endowed with pollution-free and easy-to-handle environmental protection features. Then the twenty-first century, China has proposed to build a conservation-oriented society and economy of building a socialist harmonious society, so the "green food packaging bag" appeared, it mainly low consumption, low emission, high efficiency as the core. With the continuous development of science and technology and the continuous improvement of people's living standards, people have higher and higher requirements for food packaging bags . What will the future food packaging look like, let us wait and see!
Although there are many types of tapping screws, they all have the following similarities: Round head Tapping screw,hex tapping screw,flat head tapping screw,pan head tapping screw,truss head tapping screw Shenzhen Lanejoy Technology Co.,LTD , https://www.szsmallcompressionspring.com
(1) are generally made of carbonized carbon steel (accounting for 99% of total production). It can also be made of stainless steel or non-ferrous metals.
(2) The product must be heat treated. Carbon steel tapping screws must be carbonized and stainless steel tapping screws must be solution hardened. In order to make tapping screws to meet the requirements of the standard of mechanical properties and performance.
(3) The product surface hardness is high, the core toughness is good. That is, "soft inside strong outside". This is a major feature of tapping Screw performance requirements. If the surface hardness is low, it can not be screwed into the matrix; If the core toughness is poor, a twist will break, can not be used. So "inside soft outside steel" is self-tapping screw to meet the use of performance, very important requirements.
(4) The surface of the product needs surface protection treatment, generally electroplating treatment. Some product surface must be treated by phosphate (photostatting), such as wall panel self - tapping screws for photostatting.
(5) Production by cold heading process. It is recommended to use high-speed cold heading machine and high-speed wire rolling machine or high-speed planetary wire rolling machine. High speed is emphasized here to ensure product quality. Only the head of tapping screw produced by high-speed machine is well formed and the thread quality is high.