TABLE 2.

Mutual friction results of paper samples.

Mutual friction/times	Weight changes rate/%
	0 BL	4 BL	8 BL	12 BL	16 BL	20 BL
0	100	100	100	100	100	100
50	100	100	100	100	100	100
100	100	100	100	100	100	100
200	100	100	100	100	99.8	99.7
300	100	100	100	100	99.7	99.6
400	100	100	100	100	99.6	99.5
500	100	100	100	100	99.4	99.3