Pouring molding process for thermoplastic elastomer foam particles

Abstract

The invention relates to a pouring molding process for thermoplastic elastomer foam particles. Thermoplastic elastomer foam particles with closed pore structures in composition with open pore structures extending to the epidermis are taken as a raw material; then the thermoplastic elastomer foam particle raw material is loaded into a molding mold, reactive polyurethane adhesive is injected, hot pressing, cooling molding are carried out, and a molding product is obtained. Compared with the prior art, according to the pouring molding process for the thermoplastic elastomer foam particles, through production process innovation of the bead-shaped thermoplastic elastomer foam particles, appropriate foam hole structures are designed, at the same time, functional groups or polar groups are contained, in addition, further through the unique foam particle surface treatment process, the particles obtained by foaming of various thermoplastic elastomers can be directly poured and bonded with polyurethane elastomers or can be directly poured and bonded with foamed polyurethane elastomers to form sole materials with the unique physical property and the unique appearance and other foaming products.

Description

technical field [0001] The invention belongs to the technical field of foam material product preparation, and relates to a thermoplastic elastomer foam particle pouring molding process. Background technique [0002] At present, foamed thermoplastic elastomer particles are widely used as the midsole of shoe materials in shoe materials and other fields. This kind of midsole finished product can realize light weight, effective rebound feedback, and realize cost and material saving. However, the preparation process of the above-mentioned foamed product is basically a particle mold heat-sealing process, and the heating medium for heat-sealing is low-pressure steam, and the steam is usually 1.2-3.5kg / cm2, 120-240°C. [0003] Due to the performance defects of some thermoplastic elastomer foamed particles (such as polyether ester TPEE, polyamide PA), the melting temperature of the outer skin is high, but when the outer skin is melted, the melt strength of the cell wall inside the fo...

AI Technical Summary

Problems solved by technology

[0003] Due to the performance defects of some thermoplastic elastomer foamed particles (such as polyether ester TPEE, polyamide PA), the melting temperature of the outer skin is high, but when the outer skin is melted, the melt strength of the cell wall inside the foamed particle is very low, making heat sealing During the process, when the heat sealing temperature is low, the outer skin of the foamed particles is not softened or melted, so that they cannot be effectively bonded together, and the bonding strength is low. It also melts away and the cells collapse or the cells burn through, which cannot be shaped and has defects in appearance

In this way, the demand for foamed particles to be glued into foamed products began to arise, but the existing glue mostly uses solvent glue, which is strictly restricted by the national environmental protection requirements.

Reactive gluing is widely sought after due to its environmental protection characteristics, but the adhesive strength of reactive gluing and foamed particles is affected by factors such as the functional group properties of the material itself, initial adhesion, and open time, which seriously affects its scope of application. For example, nylon foam particles, TPEE foam particles, polypropylene and other foam particles are difficult to bond directly with reactive polyurethane adhesives due to their continuous and smooth surface. In addition, due to insufficient compatibility between foam particles and reactive polyurethane adhesives , Inconsistency in crystallization shrinkage and other reasons, even if it is cast, it is easy to have insufficient peel strength, which leads to the fact that many low-polarity, low-surface-energy smooth-surface thermoplastic elastomer foamed particles cannot be directly bonded with reactive polyurethane adhesives Strong, not to mention the use of foamed polyurethane sole stock solution to directly bond many of the above types of low polarity, low surface energy smooth surface thermoplastic elastomer foamed particles