Texin® 990AR - SOLIAO

About

Product Description
Supplier	Covestro
Material Status	Commercial: Negative
Features	Good wear resistance,Food contact compliance,Good flexibility,Hydrolysis stability,High impact resistance
Availabilitys	North America
Process Methods	Injection Molding,Extrusion

Technical Data
PHYSICAL	Nominal value	Unit	Test method
Density	1.13	g/cm³	ASTM D792
Density	1.13	g/cm³	ISO 1183
Shrinkage rate			ISO 2577
TD：2.54 mm	0.80	%	ASTM D955
MD：2.54 mm	0.80	%	ASTM D955
TD：2.54 mm	0.80	%	ISO 2577
MD：2.54 mm	0.80	%	ISO 2577

MECHANICAL	Nominal value	Unit	Test method
Shore hardness
Shaw’s A	90		ASTM D2240
Shaw’s A	90		ISO 868
Bending modulus
23℃	41.4	MPa	ASTM D790
23℃	41.4	MPa	ISO 178
Taber abraser
1000 cycles, 1000 g, H-18 wheels	25.0	mg	ISO 4649
1000 cycles, 1000 g, H-18 wheels	25.0	mg	ASTM D1044

elastic body	Nominal value	Unit	Test method
tensile strength
yield	41.4	MPa	ASTM D412
yield	41.4	MPa	ISO 37
300% strain	14.5	MPa	ISO 37
300% strain	14.5	MPa	ASTM D412
100% strain	7.60	MPa	ISO 37
100% strain	7.60	MPa	ASTM D412
50% strain	6.90	MPa	ISO 37
50% strain	6.90	MPa	ASTM D412
Tensile strain
fracture	520	%	ISO 37
fracture	520	%	ASTM D412
tear strength	96.3	kN/m	ASTM D624
tear strength	96	kN/m	ISO 34-1
Compression deformation			ASTM D395B
23℃，22 hr	15	%	ASTM D395B
23℃，22 hr	20	%	ASTM D395B
70℃，22 hr	35	%	ASTM D395B
70℃，22 hr	75	%	ASTM D395B
Compression deformation			ISO 815
23℃，22 hr	15	%	ISO 815
23℃，22 hr	20	%	ISO 815
70℃，22 hr	75	%	ISO 815
70℃，22 hr	35	%	ISO 815
Basho’s elasticity	40	%	ASTM D2632

THERMAL	Nominal value	Unit	Test method
Embrittlement temperature	< -68.0	℃	ASTM D746
Embrittlement temperature	< -68.0	℃	ISO 974
Glass transition temperature	-44.0	℃	DMA
Vicat Softening Temp	106	℃	ASTM D1525 4
Vicat Softening Temp	106	℃	ISO 306/50

Aging performance	Nominal value	Unit	Test method
The rate of change in tensile strength in air			ASTM D573
100℃，70 hr	16	%	ASTM D573
100% Strain，100℃，70 hr	5.0	%	ASTM D573
300% Strain，100℃，70 hr	3.0	%	ASTM D573
100℃，168 hr	24	%	ASTM D573
100% Strain，100℃，168 hr	6.0	%	ASTM D573
300% Strain，100℃，168 hr	1.0	%	ASTM D573
100℃，336 hr	27	%	ASTM D573
100% Strain，100℃，336 hr	7.0	%	ASTM D573
300% Strain，100℃，336 hr	-9.0	%	ASTM D573
100℃，504 hr	-9.0	%	ASTM D573
100% Strain，100℃，504 hr	-3.0	%	ASTM D573
300% Strain，100℃，504 hr	-24	%	ASTM D573
The rate of change in tensile strength in air			ISO 216
100℃，70 hr	16	%	ISO 216
100% Strain 100℃，70 hr	5.0	%	ISO 216
300% Strain 100℃，70 hr	3.0	%	ISO 216
100℃，168 hr	24	%	ISO 216
100% Strain 100℃，168 hr	6.0	%	ISO 216
300% Strain 100℃，168 hr	1.0	%	ISO 216
100℃，336 hr	27	%	ISO 216
100% Strain 100℃，336 hr	7.0	%	ISO 216
300% Strain 100℃，336 hr	-9.0	%	ISO 216
100℃，504 hr	-9.0	%	ISO 216
100% Strain 100℃，504 hr	-3.0	%	ISO 216
300% Strain 100℃，504 hr	-24	%	ISO 216
The rate of change in ultimate elongation in air			ASTM D573
100℃，70 hr	16	%	ASTM D573
100℃，168 hr	20	%	ASTM D573
100℃，336 hr	36	%	ASTM D573
100℃，504 hr	68	%	ASTM D573
Changes in tensile stress during fracture in air			ISO 216
100℃，70 hr	16	%	ISO 216
100℃，168 hr	20	%	ISO 216
100℃，336 hr	36	%	ISO 216
100℃，504 hr	68	%	ISO 216
The rate of change in hardness of a hardness tester in the air			ASTM D573
Shore D, 100 ℃, 70 hr	2.0		ASTM D573
Shore D, 100 ℃, 168 hr	1.0		ASTM D573
Shore D, 100 ℃, 336 hr	0.0		ASTM D573
Shore D, 100 ℃, 504 hr	0.0		ASTM D573
The rate of change of Shore hardness in air			ISO 216
Shore D, 100 ℃, 70 hr	2.0		ISO 216
Shore D, 100 ℃, 168 hr	1.0		ISO 216
Shore D, 100 ℃, 336 hr	0.0		ISO 216
Shore D, 100 ℃, 504 hr	0.0		ISO 216
The rate of change in tensile strength			ASTM D471
23℃，70 hr，in Reference Fuel A（Isooctane）	12	%	ASTM D471
100% Strain，23℃，70 hr，in Reference Fuel A（Isooctane）	-5.0	%	ASTM D471
300% Strain，23℃，70 hr，in Reference Fuel A（Isooctane）	-6.0	%	ASTM D471
23 ℃, 70 hr, methanol	-28	%	ASTM D471
100% Strain，23℃，70 hr，in Reference Fuel C	-23	%	ASTM D471
300% Strain，23℃，70 hr，in Reference Fuel C	-22	%	ASTM D471
23℃，168 hr，in Reference Fuel A（Isooctane）	12	%	ASTM D471
100% Strain，23℃，168 hr，in Reference Fuel A（Isooctane）	-1.0	%	ASTM D471
300% Strain，23℃，168 hr，in Reference Fuel A（Isooctane）	-6.0	%	ASTM D471
23 ℃, 168 hr, methanol	-25	%	ASTM D471
100% Strain，23℃，168 hr，in Reference Fuel C	-20	%	ASTM D471
300% Strain，23℃，168 hr，in Reference Fuel C	-19	%	ASTM D471
23℃，336 hr，in Reference Fuel A（Isooctane）	7.0	%	ASTM D471
100% Strain，23℃，336 hr，in Reference Fuel A（Isooctane）	-4.0	%	ASTM D471
300% Strain，23℃，336 hr，in Reference Fuel A（Isooctane）	-10	%	ASTM D471
23℃，336 hr，in Reference Fuel C	-27	%	ASTM D471
100% Strain，23℃，336 hr，in Reference Fuel C	-19	%	ASTM D471
300% Strain，23℃，336 hr，in Reference Fuel C	-19	%	ASTM D471
23℃，504 hr，in Reference Fuel A（Isooctane）	19	%	ASTM D471
100% Strain，23℃，504 hr，in Reference Fuel A（Isooctane）	-1.0	%	ASTM D471
300% Strain，23℃，504 hr，in Reference Fuel A（Isooctane）	-3.0	%	ASTM D471
23℃，504 hr，in Reference Fuel C	-28	%	ASTM D471
100% Strain，23℃，504 hr，in Reference Fuel C	-16	%	ASTM D471
300% Strain，23℃，504 hr，in Reference Fuel C	-18	%	ASTM D471
100 ℃, 70 hr, in ASTM # 1 oil	15	%	ASTM D471
100% Strain，100℃，70 hr，in ASTM #1 Oil	2.0	%	ASTM D471
300% Strain，100℃，70 hr，in ASTM #1 Oil	-1.0	%	ASTM D471
100 ℃, 70 hr, in ASTM # 3 oil	22	%	ASTM D471
100% Strain，100℃，70 hr，in ASTM #3 Oil	2.0	%	ASTM D471
300% Strain，100℃，70 hr，in ASTM #3 Oil	-1.0	%	ASTM D471
100℃，168 hr，in ASTM #1 Oil	-10	%	ASTM D471
100% Strain，100℃，168 hr，in ASTM #1 Oil	4.0	%	ASTM D471
300% Strain，100℃，168 hr，in ASTM #1 Oil	14	%	ASTM D471
100℃，168 hr，in ASTM #3 Oil	15	%	ASTM D471
100% Strain，100℃，168 hr，in ASTM #3 Oil	4.0	%	ASTM D471
300% Strain，100℃，168 hr，in ASTM #3 Oil	14	%	ASTM D471
100℃，336 hr，in ASTM #1 Oil	-4.0	%	ASTM D471
100% Strain，100℃，336 hr，in ASTM #1 Oil	8.0	%	ASTM D471
300% Strain，100℃，336 hr，in ASTM #1 Oil	1.0	%	ASTM D471
100℃，336 hr，in ASTM #3 Oil	5.0	%	ASTM D471
100% Strain，100℃，336 hr，in ASTM #3 Oil	8.0	%	ASTM D471
300% Strain，100℃，336 hr，in ASTM #3 Oil	1.0	%	ASTM D471
100℃，504 hr，in ASTM #1 Oil	-12	%	ASTM D471
100% Strain，100℃，504 hr，in ASTM #1 Oil	6.0	%	ASTM D471
300% Strain，100℃，504 hr，in ASTM #1 Oil	3.0	%	ASTM D471
100℃，504 hr，in ASTM #3 Oil	-2.0	%	ASTM D471
100% Strain，100℃，504 hr，in ASTM #3 Oil	6.0	%	ASTM D471
300% Strain，100℃，504 hr，in ASTM #3 Oil	3.0	%	ASTM D471
The rate of change in tensile strength			ISO 175
23℃，70 hr，in Reference Fuel A（Isooctane）	12	%	ISO 175
100% Strain，23℃，70 hr，in Reference Fuel A（Isooctane）	-5.0	%	ISO 175
300% Strain，23℃，70 hr，in Reference Fuel A（Isooctane）	-6.0	%	ISO 175
23 ℃, 70 hr, methanol	-28	%	ISO 175
100% Strain，23℃，70 hr，in Reference Fuel C	-23	%	ISO 175
300% Strain，23℃，70 hr，in Reference Fuel C	-22	%	ISO 175
23℃，168 hr，in Reference Fuel A（Isooctane）	12	%	ISO 175
100% Strain，23℃，168 hr，in Reference Fuel A（Isooctane）	-1.0	%	ISO 175
300% Strain，23℃，168 hr，in Reference Fuel A（Isooctane）	-6.0	%	ISO 175
23 ℃, 168 hr, methanol	-25	%	ISO 175
100% Strain，23℃，168 hr，in Reference Fuel C	-20	%	ISO 175
300% Strain，23℃，168 hr，in Reference Fuel C	-19	%	ISO 175
23℃，336 hr，in Reference Fuel A（Isooctane）	7.0	%	ISO 175
100% Strain，23℃，336 hr，in Reference Fuel A（Isooctane）	-4.0	%	ISO 175
300% Strain，23℃，336 hr，in Reference Fuel A（Isooctane）	-10	%	ISO 175
23℃，336 hr，in Reference Fuel C	-27	%	ISO 175
100% Strain，23℃，336 hr，in Reference Fuel C	-19	%	ISO 175
300% Strain，23℃，336 hr，in Reference Fuel C	-19	%	ISO 175
23℃，504 hr，in Reference Fuel A（Isooctane）	19	%	ISO 175
100% Strain，23℃，504 hr，in Reference Fuel A（Isooctane）	-1.0	%	ISO 175
300% Strain，23℃，504 hr，in Reference Fuel A（Isooctane）	-3.0	%	ISO 175
23℃，504 hr，in Reference Fuel C	-28	%	ISO 175
100% Strain，23℃，504 hr，in Reference Fuel C	-16	%	ISO 175
300% Strain，23℃，504 hr，in Reference Fuel C	-18	%	ISO 175
100 ℃, 70 hr, in ASTM # 1 oil	15	%	ISO 175
100% Strain，100℃，70 hr，in ASTM #1 Oil	2.0	%	ISO 175
300% Strain，100℃，70 hr，in ASTM #1 Oil	-1.0	%	ISO 175
100 ℃, 70 hr, in ASTM # 3 oil	22	%	ISO 175
100% Strain，100℃，70 hr，in ASTM #3 Oil	2.0	%	ISO 175
300% Strain，100℃，70 hr，in ASTM #3 Oil	-1.0	%	ISO 175
100℃，168 hr，in ASTM #1 Oil	-10	%	ISO 175
100% Strain，100℃，168 hr，in ASTM #1 Oil	4.0	%	ISO 175
300% Strain，100℃，168 hr，in ASTM #1 Oil	14	%	ISO 175
100℃，168 hr，in ASTM #3 Oil	15	%	ISO 175
100% Strain，100℃，168 hr，in ASTM #3 Oil	4.0	%	ISO 175
300% Strain，100℃，168 hr，in ASTM #3 Oil	14	%	ISO 175
100℃，336 hr，in ASTM #1 Oil	-4.0	%	ISO 175
100% Strain，100℃，336 hr，in ASTM #1 Oil	8.0	%	ISO 175
300% Strain，100℃，336 hr，in ASTM #1 Oil	1.0	%	ISO 175
100℃，336 hr，in ASTM #3 Oil	5.0	%	ISO 175
100% Strain，100℃，336 hr，in ASTM #3 Oil	8.0	%	ISO 175
300% Strain，100℃，336 hr，in ASTM #3 Oil	1.0	%	ISO 175
100℃，504 hr，in ASTM #1 Oil	-12	%	ISO 175
100% Strain，100℃，504 hr，in ASTM #1 Oil	6.0	%	ISO 175
300% Strain，100℃，504 hr，in ASTM #1 Oil	3.0	%	ISO 175
100℃，504 hr，in ASTM #3 Oil	-2.0	%	ISO 175
100% Strain，100℃，504 hr，in ASTM #3 Oil	6.0	%	ISO 175
300% Strain，100℃，504 hr，in ASTM #3 Oil	3.0	%	ISO 175
Change rate of ultimate elongation			ASTM D471
23℃，70 hr，in Reference Fuel A（Isooctane）	11	%	ASTM D471
23 ℃, 70 hr, methanol	4.0	%	ASTM D471
23℃，168 hr，in Reference Fuel A（Isooctane）	0.0	%	ASTM D471
23 ℃, 168 hr, methanol	3.0	%	ASTM D471
23℃，336 hr，in Reference Fuel A（Isooctane）	15	%	ASTM D471
23℃，336 hr，in Reference Fuel C	5.0	%	ASTM D471
23℃，504 hr，in Reference Fuel A（Isooctane）	7.0	%	ASTM D471
23℃，504 hr，in Reference Fuel C	3.0	%	ASTM D471
100 ℃, 70 hr, in ASTM # 1 oil	28	%	ASTM D471
100 ℃, 70 hr, in ASTM # 3 oil	28	%	ASTM D471
100℃，168 hr，in ASTM #1 Oil	30	%	ASTM D471
100℃，168 hr，in ASTM #3 Oil	30	%	ASTM D471
100℃，336 hr，in ASTM #1 Oil	31	%	ASTM D471
100℃，336 hr，in ASTM #3 Oil	31	%	ASTM D471
100℃，504 hr，in ASTM #1 Oil	33	%	ASTM D471
100℃，504 hr，in ASTM #3 Oil	33	%	ASTM D471
Changes in tensile stress during fracture			ISO 175
23℃，70 hr，in Reference Fuel A（Isooctane）	11	%	ISO 175
23 ℃, 70 hr, methanol	4.0	%	ISO 175
23℃，168 hr，in Reference Fuel A（Isooctane）	0.0	%	ISO 175
23 ℃, 168 hr, methanol	3.0	%	ISO 175
23℃，336 hr，in Reference Fuel A（Isooctane）	15	%	ISO 175
23℃，336 hr，in Reference Fuel C	5.0	%	ISO 175
23℃，504 hr，in Reference Fuel A（Isooctane）	7.0	%	ISO 175
23℃，504 hr，in Reference Fuel C	3.0	%	ISO 175
100 ℃, 70 hr, in ASTM # 1 oil	28	%	ISO 175
100 ℃, 70 hr, in ASTM # 3 oil	28	%	ISO 175
100℃，168 hr，in ASTM #1 Oil	30	%	ISO 175
100℃，168 hr，in ASTM #3 Oil	30	%	ISO 175
100℃，336 hr，in ASTM #1 Oil	31	%	ISO 175
100℃，336 hr，in ASTM #3 Oil	31	%	ISO 175
100℃，504 hr，in ASTM #1 Oil	33	%	ISO 175
100℃，504 hr，in ASTM #3 Oil	33	%	ISO 175
The rate of change in Shore hardness			ASTM D471
Shore D, 23 ℃, 70 hr, in reference fuel A (isooctane)	1.0		ASTM D471
	-4.0		ASTM D471
Shore D, 23 ℃, 168 hr, in reference fuel A (isooctane)	0.0		ASTM D471
Shore D, 23 ℃, 168 hr, in reference fuel	-4.0		ASTM D471
Shore D, 23 ℃, 336 hr, in reference fuel A (isooctane)	2.0		ASTM D471
Shore D, 23 ℃, 336 hr, in reference fuel C	-4.0		ASTM D471
Shore D, 23 ℃, 504 hr, in reference fuel A (isooctane)	0.0		ASTM D471
Shore D, 23 ℃, 504 hr, in reference fuel C	-3.0		ASTM D471
	-5.0		ASTM D471
Shore D, 100 ℃, 70 hr, in ASTM # 3 oil	-5.0		ASTM D471
	-4.0		ASTM D471
Shore D, 100 ℃, 168 hr, in ASTM # 3 oil	-4.0		ASTM D471
Shore D, 100 ℃, 336 hr, in ASTM # 1 oil	-3.0		ASTM D471
Shore D, 100 ℃, 336 hr, in ASTM # 3 oil	-3.0		ASTM D471
Shore D, 100 ℃, 504 hr, in ASTM # 1 oil	-2.0		ASTM D471
Shore D, 100 ℃, 504 hr, in ASTM # 3 oil	-2.0		ASTM D471
The rate of change in Shore hardness			ISO 175
Shore D, 23 ℃, 70 hr, in reference fuel A (isooctane)	1.0		ISO 175
	-4.0		ISO 175
Shore D, 23 ℃, 168 hr, in reference fuel A (isooctane)	0.0		ISO 175
Shore D, 23 ℃, 168 hr, in reference fuel	-4.0		ISO 175
Shore D, 23 ℃, 336 hr, in reference fuel A (isooctane)	2.0		ISO 175
Shore D, 23 ℃, 336 hr, in reference fuel C	-4.0		ISO 175
Shore D, 23 ℃, 504 hr, in reference fuel A (isooctane)	0.0		ISO 175
Shore D, 23 ℃, 504 hr, in reference fuel C	-3.0		ISO 175
	-5.0		ISO 175
Shore D, 100 ℃, 70 hr, in ASTM # 3 oil	-5.0		ISO 175
	-4.0		ISO 175
Shore D, 100 ℃, 168 hr, in ASTM # 3 oil	-4.0		ISO 175
Shore D, 100 ℃, 336 hr, in ASTM # 1 oil	-3.0		ISO 175
Shore D, 100 ℃, 336 hr, in ASTM # 3 oil	-3.0		ISO 175
Shore D, 100 ℃, 504 hr, in ASTM # 1 oil	-2.0		ISO 175
Shore D, 100 ℃, 504 hr, in ASTM # 3 oil	-2.0		ISO 175
Volume change			ASTM D471
23℃，70 hr，in Reference Fuel A	2.0	%	ASTM D471
23 ℃, 70 hr, methanol	35	%	ASTM D471
23℃，168 hr，in Reference Fuel A	3.0	%	ASTM D471
23 ℃, 168 hr, methanol	35	%	ASTM D471
23℃，336 hr，in Reference Fuel A	4.0	%	ASTM D471
23℃，336 hr，in Reference Fuel C	36	%	ASTM D471
23℃，504 hr，in Reference Fuel A	4.0	%	ASTM D471
23℃，504 hr，in Reference Fuel C	36	%	ASTM D471
100 ℃, 70 hr, in ASTM # 1 oil	0.0	%	ASTM D471
100 ℃, 70 hr, in ASTM # 3 oil	0.0	%	ASTM D471
100℃，168 hr，in ASTM #1 Oil	0.0	%	ASTM D471
100℃，168 hr，in ASTM #3 Oil	0.0	%	ASTM D471
100℃，336 hr，in ASTM #1 Oil	1.0	%	ASTM D471
100℃，336 hr，in ASTM #3 Oil	1.0	%	ASTM D471
100℃，504 hr，in ASTM #1 Oil	1.0	%	ASTM D471
100℃，504 hr，in ASTM #3 Oil	1.0	%	ASTM D471
Volume change			ISO 175
23℃，70 hr，in Reference Fuel A	2.0	%	ISO 175
23 ℃, 70 hr, methanol	35	%	ISO 175
23℃，168 hr，in Reference Fuel A	3.0	%	ISO 175
23 ℃, 168 hr, methanol	35	%	ISO 175
23℃，336 hr，in Reference Fuel A	4.0	%	ISO 175
23℃，336 hr，in Reference Fuel C	36	%	ISO 175
23℃，504 hr，in Reference Fuel A	4.0	%	ISO 175
23℃，504 hr，in Reference Fuel C	36	%	ISO 175
100 ℃, 70 hr, in ASTM # 1 oil	0.0	%	ISO 175
100 ℃, 70 hr, in ASTM # 3 oil	0.0	%	ISO 175
100℃，168 hr，in ASTM #1 Oil	0.0	%	ISO 175
100℃，168 hr，in ASTM #3 Oil	0.0	%	ISO 175
100℃，336 hr，in ASTM #1 Oil	1.0	%	ISO 175
100℃，336 hr，in ASTM #3 Oil	1.0	%	ISO 175
100℃，504 hr，in ASTM #1 Oil	1.0	%	ISO 175
100℃，504 hr，in ASTM #3 Oil	1.0	%	ISO 175

Supplementary information	Nominal value	Unit	Test method
Compression load			ASTM D575
10% deflection	3.10	MPa	ASTM D575
15% deflection	4.48	MPa	ASTM D575
2% deflection	0.689	MPa	ASTM D575
20% deflection	5.86	MPa	ASTM D575
25% deflection	7.24	MPa	ASTM D575
5% deflection	1.72	MPa	ASTM D575
50% deflection	19.3	MPa	ASTM D575

Process Conditions
Injection	Nominal value	Unit	Test method
extrusion	Nominal value	Unit	Test method
Drying temperature – hot air dryer	93 to 104	°C	null
Drying time – hot air dryer	2.0	hr	null
Recommended maximum moisture content	< 0.030	%	null
Suggested injection volume	40 to 80	%	null
Suggested maximum proportion of recycled materials	20	%	null
Temperature at the rear of the barrel	182 to 199	°C	null
Temperature in the middle of the barrel	182 to 204	°C	null
Front temperature of material barrel	182 to 210	°C	null
Nozzle temperature	188 to 213	°C	null
Processing (melt) temperature	202	°C	null
Mold temperature	16 to 43	°C	null
Injection pressure	41.4 to 96.5	MPa	null
Locking force	4.1 to 6.9	kN/cm²	null
Screw length to diameter ratio	20.0:1.0		null
Screw compression ratio	2.5:1.0 to 3.0:1.0		null
drying temperature	93 to 104	°C	null
Drying time	2.0	hr	null
Temperature of material cylinder zone 1	182 to 199	°C	null
Temperature of material cylinder zone 2	193 to 210	°C	null
Temperature of material cylinder zone 3	193 to 216	°C	null
Melt Temperature	202	°C	null
Mouth temperature	193 to 216	°C	null

Notes
【 Disclaimer 】 Guangzhou Soliao Information Technology Co., Ltd. reserves all rights. The information in this data table was obtained from the manufacturer of the material on soliao.com. Soliao.com makes every effort to ensure the accuracy of this data. However, the search company does not assume any responsibility for the uncertainty and consequences caused to users by these data values and suggestions, and strongly recommends verifying the data values with the material supplier before the final selection of materials.

Notes

【 Disclaimer 】
Guangzhou Soliao Information Technology Co., Ltd. reserves all rights. The information in this data table was obtained from the manufacturer of the material on soliao.com. Soliao.com makes every effort to ensure the accuracy of this data. However, the search company does not assume any responsibility for the uncertainty and consequences caused to users by these data values and suggestions, and strongly recommends verifying the data values with the material supplier before the final selection of materials.