Polyurethane synthetic leather cleaning production process based on direct coating method

Abstract

The invention provides a polyurethane synthetic leather cleaning production process based on a direct coating method. The process comprises the steps of firstly spraying mixed double-component solvent-free polyurethane a nonwoven fabric or a knitted fabric through a reciprocating way of a spraying head by utilizing a double-spraying head material feeding machine, scrapping through a double-cutter scrapping machine so as to form a film, then drying and ageing the film through an oven, and ironing through a passing type roller ironing machine, thus forming a bottom layer having a plurality of holes and a flat surface on the nonwoven fabric or the knitted fabric; then coating waterborne polyurethane size on the upper face of the polyurethane bottom layer in a rolling coating way by utilizing a rolling coating machine, wherein the waterborne polyurethane size contains waterborne polyurethane, thickener and flatting agent; then drying through an oven so as to form a flat and smooth waterborne polyurethane surface layer; and finally embossing the upper face of the coating through a passing type roller type embossing machine, and levelly coating aqueous surface treating agent through a rotating type coating machine, thus obtaining the finished product of synthetic leather.

Description

technical field [0001] The invention relates to a production process of synthetic leather, in particular to a clean production process of polyurethane synthetic leather based on a direct coating method. Background technique [0002] Synthetic leather is a composite material that simulates the structure and performance of natural leather and can be used as a substitute for natural leather. Usually non-woven fabric is used to simulate the mesh layer, and microporous polyurethane coating is used to simulate the grain layer. The front and back of the obtained synthetic leather are very similar to leather, and have a certain degree of air permeability, which is closer to natural leather than ordinary artificial leather. Widely used in making shoes, boots, bags and ball games. [0003] According to the statistics of the National Bureau of Statistics on the output of 316 artificial leather and synthetic leather enterprises above designated size, the total output of artificial leat...

AI Technical Summary

Problems solved by technology

The implementation of this technology can solve the problem of solvent pollution in the solvent-based production process very well, but there are three main problems at present: one is that this technology can only be used for the bottom layer of foaming, and it is still impossible to realize the dry film transfer of the top layer , so it is impossible to use this system alone to produce finished solvent-free synthetic leather; second, due to the use of solvent-free two-component polyurethane foam material, it is difficult to control the reaction time of the two components during use, and it is prone to nozzle clogging and knife sticking , the whole system has high requirements on the performance of the equipment; third, the current existing technology is difficult to meet the requirements of machine stripping, resulting in reduced production efficiency