Recycling of LCP

When molded under appropriate molding conditions, SUMIKASUPER LCP exhibits excellent thermal stability and has excellent retention of physical properties even when recycled and reused repeatedly. Since SUMIKASUPER LCP's strength and other properties are expressed through orientation, its electrical properties, flammability, chemical resistance, etc. do not change significantly when recycled and reused.
We evaluated the retention of physical properties by changing the recycle ratio for a representative grade of SUMIKASUPER LCP. At 30% recycling, a slight decrease in strength was observed in the early stages, but there was almost no change after the third recycling. At this time, the strength retention rate was over 90%, and almost no change in shrinkage rate was observed.

Property retention rate of representative grades when regenerated

The physical property retention rate of the representative grade recycled material is shown below when the recycled ratio is changed and the material is repeatedly molded. When using recycled materials, be sure to strictly manage the recycled material and determine the recycled material ratio after fully considering the needs and required quality of the product.

Figure 4-4-1 Relationship between number of recycling cycles and tensile strength retention

Figure 4-4-2 Relationship between number of recycles and molding shrinkage rate

Table 4-4-1 Property retention rate of major grades of SUMIKASUPER LCP when recycled to 50% of virgin materials

(Unit: Retention rate (%))

		Measuring method	E6007LHF		E6807LHF
			50% 3 passes	50% 7 passes	50% 3 passes	50% 7 passes
Tensile strength		ASTM D638	99	99	94	96
Tensile elongation			97	97	97	99
Bending strength		ASTM D790	99	98	98	99
Flexural modulus			99	99	100	99
Izod impact strength unnotched		ASTM D256	99	99	100	96
Deflection Temperature under Load	1.82MPa	ASTM D648	98	98	99	99

		Measuring method	E6808UHF		SZ6505HF
			50% 3 passes	50% 7 passes	50% 3 passes	50% 7 passes
Tensile strength		ASTM D638	100	98	91	95
Tensile elongation			100	94	88	92
Bending strength		ASTM D790	97	99	99	99
Flexural modulus			98	99	99	99
Izod impact strength unnotched		ASTM D256	96	89	100	100
Deflection Temperature under Load	1.82MPa	ASTM D648	98	99	99	100

Property retention rate of representative grade (SV6808THF) when changing the recycled material ratio

According to UL regulations, SV6808THF can be regrind up to 70%. Table 4-4-2 shows the property retention rate when the recycled material ratio of SV6808THF is changed. The allowable recycled material ratio varies depending on the product design level, UL standards, automotive standards, etc. Understanding the characteristics of recycled materials and deciding on the recycled material ratio before using them will lead to lower costs and reduced environmental impact.

Evaluation conditions
Injection molding conditions: resin temperature 350℃, mold temperature 130℃
Recycling method: The molded product is crushed in a crusher to produce recycled material.
Recycled material ratio: 25, 50, 70, 80, 100% uniformly mixed with virgin material
Number of views: 1 to 3

Table 4-4-2 Property retention rate when changing the recycle ratio of SV6808THF

Unit: Retention rate (%)

		Test method	Virgin Material	25% once	25% 3 times	50% once	50% 3 times	70% once	70% 3 times
Specific gravity		ASTM D792	100	100	100	100	100	100	100
Mold shrinkage rate (※)	MD TD	Sumitomo Chemical Method	0.22 0.56	0.22 0.56	0.22 0.56	0.22 0.58	0.21 0.57	0.22 0.58	0.21 0.58
Tensile	Strength stretch	ASTM D638	100 100	98 102	100 103	96 99	96 96	96 97	95 96
bending	Strength Elasticity	ASTM D790	100 100	100 101	102 101	99 102	99 101	100 100	96 101
Izod impact strength	No notch	ASTM D256	100	101	98	96	94	95	81
Deflection Temperature under Load	1.82MPa 0.45MPa	ASTM D648	100 100	99 99	99 100	98 99	99 99	97 99	98 98
Solder temperature resistance		Sumitomo Chemical Method	100	100	104	104	104	104	100
Thin wall flow length 100MPa	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	100 100 100	100 99 100	104 101 105	104 104 108	104 106 110	105 104 108	113 111 117
150MPa	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	100 100 100	103 100 102	102 102 103	106 103 105	102 106 106	108 102 104	111 107 110
Thin-walled bending strength	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	100 100 100	96 101 98	95 99 101	99 98 107	101 96 104	99 97 103	95 93 100

		Test method	80% once	80% 3 times	100% once	100% 3 times
Specific gravity		ASTM D792	100	100	100	100
Mold shrinkage rate (※)	MD TD	Sumitomo Chemical Method	0.22 0.58	0.21 0.58	0.21 0.59	0.21 0.59
Tensile	Strength stretch	ASTM D638	93 94	88 94	92 96	85 82
bending	Strength Elasticity	ASTM D790	96 101	91 101	96 101	88 100
Izod impact strength	No notch	ASTM D256	90	77	95	63
Deflection Temperature under Load	1.82MPa 0.45MPa	ASTM D648	98 99	97 97	97 98	96 96
Solder temperature resistance		Sumitomo Chemical Method	100	100	100	100
Thin wall flow length 100MPa	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	102 105 108	111 114 124	109 109 111	118 122 133
150MPa	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	107 104 106	107 111 112	109 106 108	113 120 118
Thin-walled bending strength	0.1mm 0.2mm 0.3mm	Sumitomo Chemical Method	98 98 102	99 93 95	94 95 100	97 89 82

*Mold shrinkage is the measured value for a flat test piece of 64mm x 64mm x 3mm.