Common quality defects and causes of melamine impregnated paper
Physical properties of melamine impregnated paper:
- Low hot pressing temperature or short hot pressing time, incomplete resin curing, easy adhesion of dust on the surface of the panel during use, difficult to clean, and the formation of dirty surfaces.
- If the hot pressing temperature is too high, uneven template temperature or uneven substrate density can easily form surface cracks (commonly known as cracks).
- The resin content is too low, resulting in low surface splitting strength of the substrate.
- The unit pressure is too high, the density of the board is uneven, the structure is asymmetric, and the hot pressing temperature is too high, resulting in warping of the veneer.
- The moisture content of the board is too high, and the substrate density is too low. During compression, the core layer generates significant steam pressure, causing it to bubble into layers.
Uneven surface gloss of melamine impregnated paper:
- The impregnation amount of impregnated paper is uneven, the moisture content of the board is too high, and local bubbles appear on the board surface during pressing, resulting in uneven glossiness of the board surface.
- The surface of the template is contaminated, dirty, or the buffer pad is damaged, the temperature of the bottom plate is uneven, and the demolding is poor.
- The moisture content of the board is too high, the hot pressing temperature is too low, or the hot pressing time is short, resulting in water marks on the board surface and uneven gloss.
- Impregnated paper has low hot pressing pressure or long storage time, high resin toughness, and poor resin fluidity during hot pressing, resulting in poor gloss of the cardboard.
- During embryonic formation, there may be dirt, fingerprints, paper scraps, etc.
melamine impregnated paper
Dry pattern on the surface of melamine impregnated paper:
- There is a pre cured layer on the surface of the substrate, which leads to low density of the board, high resin absorption, and poor resin fluidity on the surface of the board.
- The concave surface of the substrate is affected by insufficient internal pressure during hot pressing, which affects resin flow.
- The hot pressing temperature is too high, the hot pressing pressure is too low, or there are pollutants on the surface of the template.
- Local damage or prolonged use of the buffer pad can cause excessive temperature in the pressing plate, uneven pressure on the surface, and dry flowers.
- The prolonged storage time, high toughness, poor resin flowability, or excessive resin impregnation of impregnated paper can cause blistering and drying of the board surface during pressing.
Wet spots on the surface of melamine impregnated paper:
- The high moisture content of the substrate leads to excessive foaming during pressing.
- Excessive volatilization of impregnated paper or dirt on the surface of the template.
- Low hot pressing temperature or short hot pressing time.
Adhesive template of melamine impregnated paper (i.e. poor demolding):
- Excessive resin impregnation or dirt on the surface of the template.
- The hot pressing temperature is low, the time is short, and the resin is not fully cured.
- The buffer pad is locally damaged, resulting in uneven surface temperature and low local temperature of the template.
- The high moisture content of the board affects resin curing and poor demolding.
To produce high-quality products, it is necessary to choose excellent impregnated paper and substrates, and adopt reasonable processing techniques; In addition, operators and inspectors should work together to control product quality, promptly identify causes, and solve problems in order to ensure product quality.
