US 12,409,587 B2
Producing method of foam sheet for shoe with recycled PU scrap powder
Heedae Park, Busan (KR)
Assigned to SAM BU FINE CHEMICAL CO., LTD., Gimhae-si (KR); and Heedae Park, Busan (KR)
Filed by SAM BU FINE CHEMICAL CO., LTD., Gimhae-si (KR); and Heedae Park, Busan (KR)
Filed on Aug. 27, 2024, as Appl. No. 18/817,192.
Claims priority of application No. 10-2023-0112726 (KR), filed on Aug. 28, 2023.
Prior Publication US 2025/0083365 A1, Mar. 13, 2025
Int. Cl. B29C 44/08 (2006.01); B29C 44/34 (2006.01); B29C 59/02 (2006.01); B29K 75/00 (2006.01); B29L 31/50 (2006.01)
CPC B29C 44/08 (2013.01) [B29C 44/3442 (2013.01); B29C 59/02 (2013.01); B29K 2075/00 (2013.01); B29L 2031/504 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method of producing foam sheet containing recycling polyurethane (PU) scrap powder for shoes using a polyurethane foam composition comprising: as raw materials polyol, isocyanate, a chain extender, and water as a foaming agent in a ratio of 0.1 to 2 wt %, the method comprising:
a step of mixing in a ratio of 10-20 wt % recycled PU scrap powder based on the total weight of the polyurethane foam composition with the polyol to form a polyol mixture;
a mixing step of the isocyanate, the chain extender, and in a range of 0.1 to 2 wt % of water as a foaming agent based on the total weight of the polyurethane foam composition to the polyol mixture to form the polyurethane foam composition;
a step of preparing a polyurethane block foam by adding the recycled PU scrap powder in a ratio of 10-40 wt % based on the total weight of the polyurethane foam composition to the polyurethane foam composition through a side feeder;
a step of cutting the polyurethane block foam to a predetermined thickness to form a polyurethane foam sheet;
a step of combining the polyurethane foam sheet cut to the predetermined thickness with a fabric; and
a step of cutting the polyurethane foam sheet combined with the fabric into a predetermined shape of product, or placing it in a mold and molding and cutting it into a predetermined shape of product by using heat pressing.