Magic eraser, melamine foam. Outstanding advantages, dry cleaning can effectively remove stubborn stains. Immersed in water or liquid, the cleaning effect is excellent, leaving no obvious wiping marks. Its material is melamine formaldehyde resin foam (melamine resin foam)
There are many applications, and they are produced and processed all over the world. The most famous is BASF (Germany) brand name "Basotect", which has been used for insulation pipes and sound insulation materials in recording studios for more than 20 years. It has the characteristics of low smoke and flame retardant, so it is also a recommended fireproof material for fire protection. Melamine-formaldehyde foam used for cleaning has a porous three-dimensional network structure, "cells" are all open-cell structures, each "cell" has at least 3 holes or 2 failure surfaces, and most cell edges have at least 3 structural units. This clean foam has the following physical properties: the density is 5-50kg/m3, the tensile strength is 0.6- 1.6 kg/m2, the elongation at break is 8-20%, and the number of holes is 80-300 holes /25 mm. In addition, it has such a surface that particles on the wiped surface will fall off due to friction.
The first consideration is monomer residue. Formaldehyde, melamine and sodium bisulfite may remain under the condition of incomplete polymerization. Because the cost of formaldehyde is the lowest, the molar ratio of formaldehyde to melamine is generally 2: 1~3: 1, or even higher, that is, formaldehyde generally exceeds the standard. We judged that formaldehyde was more prone to monomer residue, so Dad Wei decided to test formaldehyde first! Wei's father sent the magic eraser at home to the laboratory for testing.
At present, there is no specific national standard for its physical and chemical indicators. Considering that the function of the magic dishwasher is almost the same as that of a rag (belonging to textiles), we refer to the test method specified in the commonly used international textile standard EnISO14184-1:2011to test formaldehyde, and the judgment standard is GB180/.
Colorimetric method and laboratory spectrophotometer method were used for detection and determination respectively. According to en 71-9: 2005a1:2007, the formaldehyde content was determined by the test method of en iso14184-1:2001. Seeing this result, Wei Dad patted his thigh: "Sure enough, there is formaldehyde!" Textiles that are in direct contact with human skin require a formaldehyde limit of 75mg/kg, and jackets that are not in direct contact with human skin require a formaldehyde limit of 300mg/kg.
However, formaldehyde is soluble in water. Will there be no formaldehyde after washing? Wei Dad's team continued to dig deep.
It is generally believed that formaldehyde in textiles can be removed by washing, so can formaldehyde in magic wipes really be significantly reduced after washing? Wei's father instructed the laboratory to wash hands manually for five times, and then detected the formaldehyde in the magic towel. The results showed that the formaldehyde content was 700mg/kg. Formaldehyde still exists!
When cleaning tableware, the magic brush comes into contact with grease or acidic conditions, as well as additives used in it, such as foaming agents and dyes. Moreover, monomers with insufficient polymerization are easy to migrate and remain on tableware or fruits, which may damage the function of organs for a long time. According to the reaction raw materials of melamine formaldehyde resin, there may be a certain amount of unreacted melamine monomer and formaldehyde monomer in melamine formaldehyde resin.