Лако-красочные материалы — производство

In general two types of adhesives are used for the manufacture of baby diapers, feminine-hygiene, and incontinence products. For simple construction purposes, hot — melt adhesives based on amorphous poly(alpha-olefins) (APAOs) are used. High-quality constructions are produced with adhesives based on styrenic block copolymers. For bonding of elastic materials such as polyurethane foam, lycra and natural rubber strands, and hydrophilic and hydrophobic of nonwovens, pressure-sensitive adhesives (PSAs) based on styrenic block copolymers are used. Hot-melt adhesives are the most common types of adhesive. The most widely used synthetic block copolymers are styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), and styrene-eth­ylene-butadiene-styrene (SEBS) with different styrene contents.

The adhesives are mainly applied intermittently (up to 650 pieces per minute for baby diapers and up to 1000 pieces per minute for feminine-hygiene products) at line speeds of up to 400 m/min. These requirements place high demands on the perform­ance properties of the adhesives.

Construction Adhesives. APAO-based adhesives are mainly applied by slot nozzles on both the polyethylene backsheet and the nonwovens top sheet. Usual application temperatures are 125 -140 °С.

The thermoplastic rubber-based adhesives are applied by application methods such as spiral spraying, fiberization, and melt blowing. Application temperatures are usually in the range of 140 -165 °С.

Elastic Attachment Adhesives. These thermoplastic rubber-based adhesives are usually applied by spraying at 140-165 °С. As different elastic materials are used, different adhesives need to be formulated to give the right adhesion performance for each substrate.

Positioning adhesives for feminine-hygiene products are usually thermoplastic rubber-based, pressure-sensitive, and have low viscosities. The tack level can vary from very low to very high depending on the type of product and customer requirements. The positioning adhesive can be applied by both slot and fiberization applicators. The application temperatures depend on the type of substrate and vary from 120 to 170 °С.