Why does instrument coating resin turn yellow?
As the name suggests, musical instrument coating resin is specially coated on the surface of the musical instrument resin material.Because of their decoration, these instruments are protected from damage to their foundations.But it doesn't prevent them from turning yellow after a while.What is the reason for this?Is there any way to avoid this?In the following content, we will introduce for everybody in detail.
Cause one, the yellow change that musical instrument coating colophony contacts ultraviolet ray and cause, main factor is the benzene that exists in colophony annulus, the reason may be aromatic group compound produces hot oxygen to degrade when high temperature, the electron jump on easy happening PI PI orbit, make colophony presents yellow.
Second, in the process of resin production, raw materials are exposed to oxygen due to poor tightness of the device and other reasons. In the molecular chain of general unsaturated polyester, there are not only ester groups, hydroxyl groups and carboxyl groups, but also double bonds and aromatic rings. Trace oxygen can lead to thermal oxidation and degradation, and the most obvious performance is the yellowing of the resin color.
Three reasons, Musical Instruments in the process of coating resin through esterification, yellowing caused by high temperature thermal aging, unsaturated resin, generally the esterification temperature, is 180 ~ 220 ℃ or higher, under the temperature of resin is easy to become yellow due to thermal aging, affect resin product appearance.
Based on the above three reasons, the surface of the resin coating on the musical instrument turned yellow.So we do not have to panic when the resin turns yellow, the correct solution is more important.
QuanZhou Neweco High Polymer Material Co.,Ltd.
Neweco is one of the leading unsaturated polyester resin manufacturers and suppliers,widely used in automobiles, ships, rail transit, wind power generation, pipe cans, heat and corrosion protection, building materials, stone repair, sanitary ware, artificial stone and other industries. Suitable for hand lay-up, spray, pultrusion, winding, molding, vacuum introduction / RTM, casting and other molding processes. Neweco Resin is committed to excellence and focuses on the application of composite materials to provide customers with comprehensive solutions.