Advantages and disadvantages of PPA materials
PPA (Polyphthalamide) PPA plastic Chinese name: high temperature nylon, the advantages of the material include:
Excellent high temperature performance: thermal deformation temperature of more than 300°C, continuous use temperature
of up to 170°C, can maintain good performance in high temperature environment, and has high heat resistance, can show
excellent welding resistance.
Good mechanical properties: It has the characteristics of high tensile strength, high bending modulus and high hardness,
can withstand long-term tensile creep, and can still maintain a fairly high modulus at high temperature, such as 55% of the
modulus at 23°C when the modulus is 120°C; Its mechanical properties are better than some nylon materials, such as the
bending modulus of ppa is 20% higher than nylon, the tensile strength is 20% higher than nylon 6, and it is also higher than
nylon 66. After carbon fiber, glass fiber reinforced or modified PPA, strength, modulus and other properties can be further improved.
Good dimensional stability: water absorption is much lower than nylon 6 or nylon 66, the size change is small, and it can
maintain good dimensional stability in a humid environment; It has low warping and low shrinkage.
Strong chemical resistance: It can resist acid, alkali, organic solvents and other corrosive substances, and has excellent resistance
to gasoline, diesel, oil, mineral oil, transformer oil and other oils, even at 150°C high temperature; Usually to aliphatic hydrocarbons,
aromatic hydrocarbons, chlorinated hydrocarbons, esters, ketones, alcohols and most aqueous solutions also show excellent
solubility, but can not withstand the action of extremely strong acids and strong oxidants. Soluble in phenol and cresol.
Excellent weather resistance: in extreme weather conditions such as high ultraviolet radiation, high humidity, high temperature,
it is also suitable for long-term outdoor use, and the physical property is reduced less.
Other properties: with good melting flow, easy to be processed by injection molding, but also has excellent thin wall formability,
suitable for the processing of small parts; Has a certain cost advantage; Environmental performance can reach the US FDA level;
Good weldability; Good electrical properties, such as flame-retardant PPA has excellent electrical insulation, high HDT (thermal
deformation temperature) value, high temperature bending modulus, etc.
The main limitations of PPA materials are:
Limited UV resistance: Compared with some other high-performance engineering plastics, PPA has weak UV resistance and may
age when exposed to sunlight for a long time.
High injection molding temperature: the melting temperature during injection molding is in the range of 615-650 °C, which has
high requirements for the processing technology.
Higher cost: As a high-performance engineering plastic, the cost of PPA can be relatively high, which may affect its use in some
cost-sensitive applications.
To sum up, PPA materials are widely used in many fields because of their excellent properties, such as high strength, heat resistance,
chemical resistance and electrical insulation, despite the shortcomings of high cost and insufficient ductility, but its overall
advantages make it the preferred material for many high-performance applications.