Plastic mesh for packaging
DATE：2021/8/23 8:34:07 / READ： / SOURCE：This station
Plastic mesh for packaging
Plastic mesh for packaging is a kind of packaging material with continuous mesh structure of certain specification, which is made of plastic and woven into a mesh through plastic wire or extruded into a mesh directly by extruder. The earliest mesh materials were made of plastic extrusion spinning, stretching, spinning and weaving. This method has less technical difficulty, easier process control and stable quality, but it has many processes, low output and small mesh change. Using extruder and mesh forming die to extrude mesh at one time has the advantages of fast extrusion speed, few processes, diversified mesh forms due to different die design and low production cost. The key lies in the design and manufacture of mesh forming die. www.handern.com1、 Molding of extruded mesh: the key of mesh molding is the design of machine head. The basic principle of netting is to open a group of circular or semicircular, rectangular, trapezoidal and triangular grooves on the inner and outer die lips of the circular die of the extruder. The die core and die sleeve can rotate separately or in the opposite direction to each other. When the molten material is extruded from the groove, it will separate each material with the die rotation or the upper and lower dies of the T-shaped die to form a network, When the inner and outer molds rotate or the upper and lower molds move back and forth, when the melt flows out of the groove, a mesh is formed, and the continuous extrusion network and mesh become products with mesh structure. The round or flat mesh is extruded from the machine head, cooled and shaped, and then rolled into products. After cooling and shaping, it can also be heated to a high elastic state for unidirectional or bidirectional stretching, and rolled into products after heat setting, which can greatly improve the strength of mesh packaging products. www.handern.com
2、 Selection and molding of raw materials for extruded mesh materials: in fact, all thermoplastics can be used to extrude mesh packaging. At present, the most commonly used are LDPE, HDPE, PP and EPS, or the mixture of PE and PP or the mixture of LLDPE and HDPE can be used to extrude mesh. See table 5-5-1 for its properties. The raw materials and the shape of the machine head can be selected according to the application situation of the mesh material. It can produce non tensile mesh, tensile mesh with high strength, and EPS can also be used to produce foamable polystyrene extrusion mesh. Through a set of specially designed variable speed transmission mechanism, the diameter of the network is alternately changed with the change of a certain speed ratio and duration to form a variable diameter mesh. Mesh material: LDPE, MFR: 2 ~ 4G / 10min; foaming agent: f1224% - 30%; Talc powder: appropriate amount: mesh diameter (thickness), mm: 460803100, foaming ratio: 20 ~ 25: tensile strength: ≥ 120N / cm; Elongation: > 100%; Hygiene: non toxic standard. www.handern.com
3、 Application of extruded mesh: 1. Civilian shopping bags, bags, etc. Main properties: relative density: 0.91-0.92; Tensile strength ≥ 0.8MPa, elongation at break ≥ 180%, breaking diameter 200 ~ 550mm, sheet weight 90 ~ 350g / m. Scope of application: used for fruit and vegetable fittings, market shopping bags, clothing packaging bags and daily carry on bags. 2. Breathable packaging of fruits, vegetables and fresh food.
3 protective packaging of mechanical parts: for example, the outer protective packaging of various rubber rollers. The properties of extruded mesh of such packaging are as follows: relative density 0.91 ~ 0.93, specification: 10 ~ - 100mm, unit length weight 20 ~ 130g / m, tensile strength ≥ 0.8MPa, elongation at break > 150%. Chemistry: resistant to any concentration of acid, alkali and salt, but oxidizing acid can oxidize the mesh. Its function is to prevent parts from being damaged during machining, such as trauma protection of steam pressure pump valve parts, packaging of glassware and packaging and protection of other products with high surface finish. 4 protective buffer packaging for fragile products such as glass, blood and ceramics, especially foamed mesh. 5 winding packaging instead of ordinary winding film. www.handern.com
In addition, it can also be used for bird protection on farmland and orchards, subgrade protection on both sides of roads and railways, fish protection in aquaculture farms, etc. www.handern.com
Author：admin