How to improve the appearance of wood pencil gloss prevent light loss?

The production history of wooden pencils in our country has been nearly 80 years. The annual production of pencils is the highest in the world. It is a veritable pencil manufacturing power. However, the quality of pencils is in the middle reaches of the world. In particular, the appearance of pencils (coating and appearance of coatings) is still quite different from that of foreign developed countries. Compared with the international brand name pencil, the appearance of bright light, looks like a plastic coating, China's pencil appearance in the short term glossiness and fullness can still be, but a few months later lost light, the pencil appearance no longer has the original light and fullness Now. In order to improve the luster and plumpness of wooden pencils and prevent the occurrence of loss of light, the author discusses solutions to these problems from the point of pencil paint. 1. Sealing paint Wood contains a certain amount of water, and it can absorb and evaporate water as the environment changes. Although the wood of pencil pencils was subjected to a denaturing treatment and a paint coating on the face, the instinct of the moisture of the wood was not lost. The pencil manufacturing process stipulates that the pencil rod must be coated with paint for a certain period of time, otherwise quality problems will occur. Although the pencils have been painted, the current pencil primer (formulations and materials) is not tightly closed. As the moisture evacuates, the wood fiber shrinks, the surface gap increases, the paint film subsides with the gap, and the paint film subsides. After that, the surface was uneven. As a result, the gloss is decreased and the fullness is decreased. Therefore, a resin having a large molecular weight, a small shrinkage, a good sealability, and a better resistance to moisture penetration is selected. This prevents the gloss and fullness of the wooden pencil from decreasing. 2. Primer The primer is generally a type of paint with a relatively large amount of filler. Its role is to increase the fullness of the paint film on the one hand, and to fill the gaps on the surface of the wood, on the other hand to increase the thickness of the paint film and improve the smoothness of the surface. Degree, reducing the number of finishes. The pigment filler of the primer also requires a certain degree of fineness. When the surface area of ​​the pigment filler reaches a certain value, the shrinkage of the surface of the paint film after the paint is dried can be reduced, and the flatness of the surface of the sheath can be ensured. 3. Topcoat The topcoat is the key material in the pencil painting of wooden pencils. The topcoat not only provides colorful pencils for wooden pencils, but also provides the user with a beautiful enjoyment. Therefore, the following requirements are put forward for topcoats: (a) The resins used in the topcoat should have good intermiscibility with each other, and the solvent chosen in the formulation should be balanced: solvent balance and volatility balance, so as to reduce the film dry The shrinkage rate ensures the smoothness of the paint film surface. (b) The pigment used in the topcoat must be ground to a certain fineness standard, and a system in which the pigment particles are dispersed and stabilized (stability during storage and workability during application) should be obtained. If the pigment particles are dispersed and unstable, the pigment particles will appear to be thickened with time, which will destroy the construction performance of the paint and the smoothness of the surface of the shaft, which will directly lead to a decrease in gloss. It should be pointed out that even if the varnish is overlaid on the surface of the paint film, it generally cannot make up for the loss of glossiness, and there may also be floating phenomenon. (c) Use as little or no filler as possible in the finish coat, as the filler will have a certain extinction effect on the paint, (it only acts as a cost reduction in the paint), so that although the film forming material in the top coat increases, However, there is a certain loss of gloss on the surface of the paint film. 4. Light paint Light paint is the most important paint in determining the appearance of wooden pencils. On the one hand, it provides a glossy, mirror-like film on the surface of the barrel, and on the other hand provides a certain hardness for the paint film. The degree of abrasion resistance and scratch resistance of the varnish is also a factor affecting the gloss. The gloss of the varnish is related to the flatness of the varnish, and is related to the structural properties of the varnish molecules. For this purpose, the following requirements are imposed on the varnish: (a) The resins used in the varnish should have good mutual compatibility with each other and provide some hardness and transparency for the varnish. (b) The solvent used in the varnish must be balanced in two phases: the equilibrium of dissolution and the equilibrium of volatilization, so that all the resins used are in a stable state of dissolution, and in the process of solvent volatilization, the mixture of solvents always makes the resin In a stable system of dissolution, all the resins can level out smoothly until the final solvent has evaporated. In this way, it can be ensured that the light paint is always in a good and stable state from the wet paint film to the dry film, and that the gloss of the paint film does not drop due to the precipitation of a certain kind of resin in the light paint. (c) Select suitable additives to increase the feel of the varnish film, but at the same time, other processes after polishing should also be taken into consideration, in particular, the recoatability of the varnish film should not be affected. (Author: Wang Shixiong Ni Rende) Source: Internet AD: [Office Solution Center] OfficeMate Office Partner Mall