Molecular weight distribution: narrow distribution from the viewpoint of molding processability, a broad molecular weight distribution, better flowability and ease of process control, and a wide molecular weight distribution can be reduced die pressure, reducing parison tendency to melt fracture and improve the processing performance,the extrusion speed can be increased under the same conditions of the wood material.
The presence of relative molecular weight of the low and the upper part of a broad molecular weight distribution products, mechanical properties, thermal stability, and are decreased, when the relative molecular weight of the low part of the proportion is too high, wood-plastic floor and flow process grading effect, and low molecular weight of the polymer more focused to the extrusion of the parison surface, even clarity from the surface, the the parison surface looks sprinkle some small white particles, the inner wall of rough blow molding products, off the white particles are often easy to plug the valve, causing the gas system failure.
Part of a high proportion of plasticizing difficulties, the surface of the parison is not fully plasticized particles relative molecular weight high quality appearance. Alternative unimodal distribution trend of the bimodal distribution of the resin, under the same conditions, has excellent processability and melt strength, and environmental stress cracking resistance is also improved significantly.
(1) WPC processing more - its containing fiber and plastic polymer materials, in addition to sawing, Nails, planing, grip nails than other synthetic materials are generally three times the timber, which is 5 times the particleboard.
(2) WPC is mechanically stronger - fibers mixed with the plastic, so that WPC having a considerable compressive and hardwood, Resistance to bending and other physical and mechanical properties, durability significantly better than the general timber, more surface hardness.
(3) the wood plastic long service life - moisture-proof, water-proof, acid-proof, anti-corrosion, will not be destroyed by insects, so in a variety of Under the conditions of life are far more than the general timber.
(4) wood-plastic scalability good - through the adjustment of the production process, the WPC material can change the wood products strength and density, in order to achieve the anti-aging, anti-static, flame retardant and other special requirements.
(5) wood plastic recycling - scrap plastic sheet can be easily recycled decomposition cycle of reproduction production, use, and recycling processes are completely environmental pollution. wood plastic composite extrusion
(6) WPC beautiful personalized - compared to the general wood, wood-plastic material is Mianqi can mimic the texture of natural wood, and the color is extremely rich meet consumer DIY personality pursuit.
Melt flow rate: melt flow rate to a certain extent reflects the relatively large molecular weight, the smaller the melt flow rate, the relative molecular weight bigger. Relative molecular weight of the more large preform having a good melt strength, can change the sagging parison DeadWeight article tensile strength, impact strength, heat distortion temperature, and other properties are improved, it is advantageous, but the relatively higher the molecular weight the greater the viscosity of worse liquidity difficulties processing parison high "retraction" and there will be a large contraction in before clamping parison. Under the same conditions, the parison unstable flow phenomenon is intensified, even melt fracture. Therefore, considering the equipment processing capacity, and feasibility of the process, almost all 200L plastic drum manufacturers have chosen HMWHDPE resin, melt flow rate is able to meet product quality requirements can, typically about 2.0 (g/10min, 21.6kg).
WPC materials for marine application
没有评论:
发表评论