A Complete Overview of Polyamide (PA) Hot Melt Adhesives

What Are Polyamide (PA) Hot Melt Adhesives?

Polyamides are linear thermoplastic polymers formed by the reaction of carboxylic acids with amines, featuring repeating amide structural units (—CONH—) within their main chains.

Polyamide has the characteristics of easy crystallization, high melting point, and poor solubility due to its regularity, symmetry, low steric hindrance, and polarity of amide groups. 

The advantage of polyamide hot melt adhesive is that it has a narrow softening point range, solidifies immediately at temperatures slightly below the melting point, and has good oil and drug resistance. Due to the presence of amide groups and a small amount of unreacted polar groups such as amino and carboxyl groups in the molecule, it has good adhesive strength to polar materials and is therefore widely used in the industrial field.

Composition of PA Hot Melt Adhesive

PA hot melt adhesive is divided into two categories: one is polymer polyamide hot melt adhesive (nylon type), mainly used in industries such as clothing and spinning; Another type is low molecular weight polyamide hot melt adhesive (dimer acid type), which is formed by the condensation of dimer acid with diamine or polyamine. The preparation of polyamide hot melt adhesive generally does not add tackifying resin, and a small amount of plasticizer and paraffin can be added to improve the melt flowability.

In recent years, researchers worldwide have conducted physical and chemical modification studies to enhance the performance and expand the application scope of dimer acid-based polyamide hot melt adhesives.

The selection of comonomers has also become more diversified: acids used include dimer acid, sebacic acid, adipic acid, etc.; amines used include ethylenediamine, hexamethylenediamine, dimer amine, piperazine, and polyamines.

Based on copolymerization, further blending modification with acrylate rubber, polyethylene (PE) wax, tackifying resins, and other components can significantly improve the flexibility and adhesive performance of the hot melt adhesives.

5 Typical Formulations of Polyamide (PA) Hot Melt Adhesives

1.Formulation of Polyamide Hot Melt Adhesives for Apparel

Main Components:See Table 32-8. Additionally, it contains appropriate amounts of molecular capping agents, antioxidants, anti-aging agents, fluorescent whitening agents, coagulants, and water.

Application: Polyamide hot melt adhesive for clothing is the main raw material for producing clothing adhesive lining fabric, and has become one of the important types of adhesive used for clothing adhesive lining fabric. Polyamide hot melt adhesive used in clothing is made of multicomponent copolymer nylon, which reduces the regularity of macromolecules and increases the disorder of intermolecular arrangement through copolymerization, thereby reducing the melting point of the polymer and increasing the melt index.

2.Dimer Fatty Acid Polyamide

Main Components:Dimeric fatty acid polyamide

Characteristics and Applications:Film has high peel strength against flame treated or non flame treated polyethylene, and is non corrosive to metals such as steel and aluminum. It maintains good adhesion to communication cables and has good gas retention during the alternating process of -40~60 ℃. It can be

 repeatedly heated and melted to meet the needs of wrapping communication cable joints with strong fiber pressure maintenance type heat shrinkable sleeves.

Construction Process:100 parts of dimer fatty acid polyamide, 30 parts of acid modified polyethylene, 10 parts of terpene, 1 part of ethylene propylene elastomer, and 1 part of antioxidant 1010 are mixed in a mixer. The oil bath in the reaction kettle is stirred at 200 ℃, and various specifications of films are made by a rolling

Antioxidant 1010 CAS 6683-19-8

High-purity Silica Matting Powder

 mill.

3.Four-Component Nylon Hot Melt Adhesive

1.Main Components:Nylon 1010 salt, nylon 610 salt, nylon 66 salt, and caprolactam co polymerization reactants.

2.Characteristics and Applications:This type of hot-melt adhesive features strong bonding strength, resistance to both water washing and dry cleaning, low application weight, and a balance of softness and crispness. Consequently, it is widely utilized in the processing of garment waistbands, collars, and similar components, and is suitable for use as an adhesive interlining in mid-to-high-end apparel; furthermore, it is available at a relatively low cost.

3.Construction Process:Add a mixture of quaternary nylon monomer, regulator sebacic acid or glacial acetic acid, antioxidant 1010, stabilizer hypophosphite, and matting agent into a stainless steel high-pressure reactor, fill with N ₂ or CO ₂, maintain at 15MPa and 230 ℃ for 2 hours, dehydrate at atmospheric pressure for 1 hour, discharge, cut into pellets in a cold water tank, freeze (-196 ℃), crush, screen, and package.

4.Nylon Hot Melt Adhesive Powder

Main Components:Nylon 6, Nylon 66, and Nylon MXD10, etc

Characteristics and Applications:

• Operating temperature range: -20 ～ 60 °C
• Pollution-free, fast bonding, flexible and high strength.
• Mainly used for bonding various interlinings, collar linings (including non-woven fabrics), plastics, paper, metals and bookbinding. Also applied in the shoe manufacturing industry and canning industry.

5.CP-Type Polyamide Hot Melt Adhesive

Characteristics and Applications:High softening point, narrow melting range, moderate viscosity, excellent electrical properties, good toughness, heat resistance, and flame retardancy. Used for bonding and fixing the deflection coil of color TVs.

Construction Process:A polyamide (011 resin) is obtained through the reaction of dimerized linoleic acid and ethylenediamine; this is then grafted with a C₁₃ dibasic acid and subsequently reacted with a modifier to undergo cross-linking, yielding the final polyamide.

Reliable Polyamide & Hot Melt Adhesive Raw Materials Manufacturer| Kerton Industry

Looking for high-quality polyamide (PA) hot melt adhesives raw materials?Kerton Industry provides stable supply, professional technical support and customized solutions for global manufacturers in textile, automotive, packaging, construction and other industries.

Visit our official website to learn more about our full product range and get professional support:https://www.kerton-industry.com