What is the melt index of TPE material?
Source：德創化工Time：2020-03-12Hits：2554
What is the melt index of TPE material? TPE/TPR is not a rubber and plastic material with fixed physical properties. Its physical properties can be adjusted according to different applications. For example, hardness, specific gravity, stretching, melt index, abrasion resistance, etc. The melt index of TPE material is between 0 and 90. The melt index of each formula is different. The specific design should be based on application and physical properties. What are the influences on the melt index of TPE materials?
Molecular Weight of Substrate in TPE Formulation System
TPE Materials We TPE manufacturers all choose SBS or SEBS. The molecular weight is inversely proportional to the melt index. The higher the molecular weight of the substrate, the lower the melt index.
Molecular Chain Structure of Substrate in TPE Formulation System
Under the condition equivalent to other parameters, the higher the branching degree of molecular chain, the lower the melt index of TPE blending system, and the melt index of TPE material with star structure as the substrate is lower than that of TPE material with linear structure as the substrate.
Additives for Substrate in TPE Formulation System
Due to various performance requirements, various additives will be added to TPE formula to be used together. Some additives have an effect on the melt index, for example, flame retardant, the melt index will decrease with the addition of flame retardant in the formula, and the melt index will also decrease with the increase of the addition ratio.
TPE material manufacturers also have corresponding standards and conditions for melt index testing: weight and melt temperature. Temperature conditions (150℃, 190℃, 210℃), weight (1.2kg, 2.16kg, 5kg). Generally, it is tested at 190℃ with a melt index of 0-150 at 2.16kg. Usually, if the fluidity is lower than 0, the condition test will be changed, for example, 5kg, 190℃ or 2.16kg, 210℃ and above 100, the condition test will be 1.2kg, 190℃ or 2.16kg, 150℃.
