Abstract: The invention provides a high strength flame-retardant polyester material, which includes a PET resin, a nucleating agent, a flame retardant, an antioxidant, a rod-shaped filling and reinforcing material and a compatibilizer. The PET resin includes virgin pellets or environmentally-friendly recycled pellets, which can meet the demand for the introduction of recycled materials.

Abstract: The disclosure provides a polyester composite board structure and a manufacturing method thereof. The manufacturing method includes extruding a polyester layer into a board using a multi-layer extrusion equipment, and laminating a polyester film by heat using a wheel during an extrusion process.

Abstract: A light leveling device includes a housing having a chamber to rotatably receive a light instrument which may generate a light beam or a reference line out through the housing. One or more batteries may be used to energize the light instrument. The light instrument may be rotated relative to the housing, for allowing the light beam or the reference line to be rotated relative to the wall members. The light instrument includes a knurled surface to be rotated by users. The light instrument includes a projection slidably engaged in a curved passage of the housing, to limit the rotational movement of the light instrument relative to the housing.

Abstract: A light leveling device includes a housing having a chamber to rotatably receive a light instrument which may generate a light beam or a reference line out through the housing. One or more batteries may be used to energize the light instrument. The light instrument may be rotated relative to the housing, for allowing the light beam or the reference line to be rotated relative to the wall members. The light instrument includes a knurled surface to be rotated by users. The light instrument includes a projection slidably engaged in a curved passage of the housing, to limit the rotational movement of the light instrument relative to the housing.