The code specifies the identification of polyethylene plastic extrusion materials for wire and cable so that sellers and buyers can agree on the acceptability of different commercial batches or shipments. Polyethylene plastics are primarily identified based on two characteristics, namely density and flow rate (formerly known as melt index). The former is the criteria for type assignment as follows: Type 0, Тип I, Type II, Type III, and type IV, while the latter is used to specify categories, а саме: Category 1, Category 2, Category 3, Category 4, and Category 5. Other attributes that are important for some applications are covered by three general categories and a minimum number of key characteristics that are too broad or not covered at all by specifying the type, category, and category names by level in more detail. Each of the five types and categories is subdivided into four categories based on composition and use, as follows: Class A, Class B, Class C, and Class D. В додаток, materials can be classified into different grades, namely Grade E1, Grade E2, Grade E3, Grade E4, Grade E5, grade E6, grade E7, grade E8, grade E9 and grade E10. The extruded material for wire and cable should be powder, particle or particle form polyethylene plastic. The extrusion material of wire and cable should be as uniform as possible in composition and size, and pollution-free as can be achieved through good production practices. In order to determine the following physical properties of the extruded material, different tests should be performed: tensile stress, elongation, brittleness temperature, environmental stress cracking, thermal stress cracking without cracking, dissipation factor before and after milling, dielectric constant, volume resistivity, water stability, absorption coefficient, weather resistance of the colored material and carbon content.
ASTM D1248-2016 Standard Specification for Polyethylene Plastic Extruded Materials for Wire and Cable
Radius
1.1 The Code specifies the identification of polyethylene plastic extrusion materials for wire and cable so that sellers and buyers can agree on the acceptability of different commercial batches or shipments. The tests covered in this specification are intended to provide information identifying the material according to the type, клас, category and grade covered. It is not the function of this specification to provide specific engineering data for design purposes.
1.2 This Code does not allow the use of recycled plastics (see note 3).
1.3 Стандартними вважаються значення, виражені в одиницях СІ. The values given in parentheses are mathematical conversions of inch-pound units and are for informational purposes only and are not considered standard.
1.4 The following safety hazard warnings relate only to the Test Methods section of Section 12 цієї специфікації: Цей стандарт не призначений для вирішення всіх питань безпеки (якщо хто-небудь) пов'язані з його використанням. Користувачі цього стандарту несуть відповідальність за встановлення належної техніки безпеки та охорони здоров’я та визначення застосовності нормативних обмежень перед використанням.
Примітка 1: There is no known ISO equivalent to this standard.
Примітка 2: This standard has undergone major revisions since it was reapproved in 1989 and now covers only polyethylene for wire and cable applications. For information on forming and extrusion materials, see Specification D4976. For information on plastic piping materials, see Specification D3350.