Polyethylene Plastic（PE）

Polyethylene is the most commonly used plastic polymer in the aquaculture nets with annual consumption rates exceeding 50 billion pounds per year. Over 70 percent of Porex products use porous polyethylene.

With a linear molecular structure of repeating –CH2-CH2-units, PE is a semi-crystalline polymer that elongates before breaking, enhancing its toughness. In general, porous PE is considered a strong, lightweight thermoplastic with strong chemical resistance. Products made from standard polyethylene grades typically have pore size diameters ranging from 7 to 150 micrometers, but these nominal values can be increased to 300 micrometers with special blends.

KEY BENEFITS

• most commonly used plastic in the world
• strong,lightweight thermoplastic with strong chemical resistance

High-Density Polyethylene (HDPE)

Porex high-density polyethylene (HDPE) is available in sheets, rods, tubes and molded shapes. HDPE can be used in continuous service at temperatures up to 180°F (82°C) and intermittently at 240°F (116°C). If not stressed, it is stable at 212°F (100°C) in continuous service.

KEY BENEFITS

• most commonly used plastic in the world
• strong, lightweight, tough
• resistant to concentrated acids, alkalis, many organic solvents
• suitable for use in continuous service at temperatures up to 180°F (82°C) and intermittently at 240°F (116°C)
• if not stressed, stable at 212°F (100°C) in continuous service

 Polypropylene (PP)

Polypropylene is similar in many respects to high-density polyethylene (HDPE). However, instead of forming a long polymer chain made up of repeating –CH2 components, the porous polypropylene molecule has a series of CH3 groups that hang off the main carbon backbone. Porex porous PP is isotactic — that is, the CH3 groups are oriented on one side of the carbon backbone. This orientation creates a greater degree of crystallinity, making PP stiffer and more resistant to creep (the tendency to flow under stress) as compared to polyethylene (PE).

KEY BENEFITS

• resilient and resistant to fatigue
• highly resistant to most acids and alkalis
• resistant to most organic solvents below 176°F (80°C)
• can be subjected to steam sterilization

Nylon（PA）

Nylon is commonly referred to using the chemical designation “PA” (e.g. PA 6 or PA 6/66) and is most commonly available in black, white, and it’s natural color (off white or beige). Perhaps the most common variant for engineering applications is Nylon 6/6. Nylon 6/6 can be extruded (melted and forced through a nozzle) and is therefore a good plastic for both injection molding and 3D printing. It has a high melting temperature making it a wonderful substitute for metals in high temperature environments (e.g. under the hood in a vehicle). The material’s downside is that it has relatively low impact strength (even when compared to other plastics, see the chart below). The following diagram shows the relative impact strength of Nylon when compared to the impact strength of other commonly used plastics such as ABS, Polystyrene (PS), or Polycarbonate (PC). Of note, the impact strength of Nylon can actually be improved by a process called “conditioning.” For this reason as well as the ease with which Nylon can be combined with other materials to improve its strength, it is important to check the material properties of the specific Nylon composite you are using.

KEY BENEFITS

• low-friction properties
• highly performance in mechanical/chemical/thermal properties
• high melting temperature
• many different variants