Applications Comparison of PA66 GF15, PA66 GF30 and PA66 GF33.

1. Basic Parameter Differences

Material Grade	Glass Fiber Content	Rigidity & Strength	Shrinkage & Dimensional Stability	Flowability	Weight & Cost
PA66 GF15	15% GF	Medium, optimal toughness	Relatively high shrinkage, slight warpage tendency	Best, suitable for thin-wall injection molding	Lightest, lowest cost
PA66 GF30	30% GF	High, balanced strength and rigidity	Low shrinkage, excellent dimensional stability	Medium	Medium weight and cost
PA66 GF33	33% GF	Highest among the three, superior creep resistance	Minimum shrinkage, resistant to long-term high-temperature deformation	Poor, more suitable for thick-wall molding	Heaviest, slightly higher cost than GF30

2. Typical Automotive Application Scenarios for Each Grade

(1) PA66 GF15 (15% glass fiber reinforced PA66)

Suitable for low-load exterior trim and lightly loaded structural parts requiring high toughness, good surface appearance and excellent molding flowability:

1. Automotive grille hinges, small exterior fasteners and decorative covers
2. Low-pressure pipe joints and lightweight small brackets
3. Housings operating at moderate temperatures without long-term high pressure

Advantages: Excellent low-temperature toughness and glossy part surface; smooth mold filling during production. Disadvantages: Prone to creep deformation under long-term high-temperature load; not applicable to pressure-bearing and heat-resistant components such as intercooler end tanks and valve covers.

(2) PA66 GF30 (30% glass fiber reinforced PA66, including Low Odor grade)

The most versatile balanced modified polyamide for complete vehicles, covering interior & exterior trims and powertrain structural parts:

1. Exterior parts: Grille bases, rearview mirror bases and headlamp brackets
2. Powertrain parts: Valve covers, plastic intercooler end tanks and turbocharger rigid connecting pipes
3. Chassis & electrical components: Motor housings, wiring connector shells and water pump brackets

The Low Odor GF30 variant is specially developed for cabin surroundings and new energy engine bays with low VOC emission, complying with automotive interior environmental standards. It delivers a balanced combination of strength, heat resistance, moldability and cost, making it the first choice for mass-produced vehicles.

(3) PA66 GF33 (33% glass fiber reinforced PA66)

Specially designed for high-load, high-temperature and high-pressure working conditions, focusing on dimensional stability and creep resistance:

1. Turbocharged intercooler end tanks and high-pressure air intake chambers
2. Valve covers for large-displacement and hybrid engines, high-pressure cooling circuit housings
3. Heavy-duty fixed brackets and pump structural parts subjected to long-term high temperature and vibration

It performs reliably under sustained temperatures of 150~170°C and cyclic air/oil pressure, resisting bulging, air leakage and oil seepage at high temperatures. Disadvantages: Poor flowability which may cause short shots on thin-wall parts, and more severe glass fiber blooming on product surfaces compared with GF15 and GF30.

3. Material Selection Summary

1. Lightweight decorative parts under low load → PA66 GF15
2. General-purpose powertrain & interior/exterior components, demand for balanced overall performance and low odor → PA66 GF30 Low Odor
3. High-boost, high-temperature & high-pressure structural parts requiring long-term creep resistance → PA66 GF33