Background

 

The long-term use of polypropylene composites at elevated temperatures is important for many applications. The polypropylene resin in Twintex® is heat stabilized and is well suited for elevated temperature applications. Twintex® test specimens were subject to a 140°C oven for 1,000 hours. Tensile tests were performed on exposed specimens to confirm that polymer degradation did not occur.

 

Experimental

 

> Material

 

 

Material	Product	Color	% Glass	Thickness
Twintex®	T PP 60 1485	Black	60%	4 mm

 

> Sample Preparation

 

Twintex® samples were prepared by molding two layers of Twintex® 2mm consolidated sheet. The consolidated sheet was placed between two, thin stainless-steel platens and heated in a 210°C press at pressure of 5 Bars. When the middle of the material reached 200°C, the molten material was transferred to a cold press and cooled to room temperature under 15 Bars pressure.

 

> Test Specifications

 

A set of test plates was placed vertically in a Blue M circulating air oven at 140°C. After aging for 1,000 hours, the plates were removed from the oven. Tensile bars were cut from the panels subjected to the thermal aging and from virgin panels. The material was tested in both primary directions. Tensile tests were performed in accordance with ASTM D639-96 at an A2LA-certified laboratory.

 

> Results

 

A set of test plates was placed vertically in a Blue M circulating air oven at 140°C. After aging for 1,000 hours, the plates were removed from the oven. Tensile bars were cut from the panels subjected to the thermal aging and from virgin panels. The material was tested in both primary directions. Tensile tests were performed in accordance with ASTM D639-96 at an A2LA-certified laboratory.

 

 

 

Tensile Properties of Virgin Twintex® Panels vs. Panels Aged for 1,000 Hours at 140°C
	Tensile Strength		Tensile Modulus		Tensile Elongation
Test Direction	Warp (MPa)	Weft (MPa)	Warp (MPa)	Weft (MPa)	Warp (MPa)	Weft (MPa)
Virgin Panel	318	316	12200	13300	2.89	2.97
Aged Panel	314	300	13800	13000	2.56	2.89
% Change	99%	95%	113%	98%	89%	97%

 

 

> Conclusion

 

Subjecting Twintex® to 140°C for 1,000 hours does not significantly change the tensile properties of Twintex® in either direction.