Assertion: blackboard eraser | /r/HasProperty | manufactured in accordance
Facets:
value: with the present invention
type: OTHER
Source sentences:
text: No. 2,249,912, a blackboard eraser manufactured in accordance with the present invention using a block of non-reticulated, flexible, polyester urethane foam having inter-connected cells and from about 70 to about 100 pores per linear inch is capable of repeated use for several days in succession without requiring cleaning, and will continuously absorb chalk dust until the block of polyester urethane foam becomes completely saturated with the chalk dust.