45results about How to "Small thickness tolerance" patented technology

The invention relates to a preparation method of a large planar polyphenylene sulfide board, in particular to a preparation method of a polyphenylene sulfide board, which aims at solving the problem existing in the prior art that the large planar polyphenylene sulfide board with good mechanical property is not easy to be prepared. The method comprises the following steps: a polyphenylene sulfide composite material is put into a hot-air drying oven at the temperature of 100-150 DEG C and kept for 4 to 8 hours; the polyphenylene sulfide composite material is fused at the temperature of 280-320 DEG C, mixed together and squeezed out, and the fused mass thereof is squeezed into a compacting die heated to the temperature of 280-320 DEG C; the initial states under the identical die stamping pressure and die stamping height are maintained at the temperature of 280-320 DEG C; when the temperature of the fused mass is reduced to 260-280 DEG C, pressure is applied, and pressure complementing isstopped when the temperature is reduced to 230-250 DEG C; the gradient type annealing treatment is carried out when the temperature of the fused mass is reduced between 150 and 250 DEG C; and then, natural temperature reducing and pressure maintaining are performed, stripping is carried out by pressure releasing when the ambient temperature is reached, and then the finished product is obtained. The method can be widely applied to special tool boards, working tabletops, and the like.

The invention discloses a method of forming high-precision bright flat steel by carrying out cold rolling on a wire. The method is characterized in that the method sequentially comprises the following steps: selection of wire coiling steel is carried out; the wire coiling steel is subjected to acid cleaning with a hydrochloric acid solution; alkaline liquor is used for neutralizing; high pressure water is used for flushing, presetting and cleaning are carried out; a first five-stand tandem rolling mill, a second five-stand tandem rolling mill, a third five-stand tandem rolling mill, a fourth five-stand tandem rolling mill and a fifth five-stand tandem rolling mill are used for primary rolling; a polished rod reciprocating winding displacement and winding machine is used for winding displacement and winding; a first three-stand tandem finishing mill, a second three-stand tandem finishing mill and a third three-stand tandem finishing mill are used to roll semifinished flat steel, and the finished flat steel with the width tolerance being less than 0.08mm, the thickness tolerance being less than 0.05mm and the surface smoothness Ra being 0.08-0.13 is formed, wherein width control mechanisms are arranged at inlets of the first three-stand tandem finishing mill, the second three-stand tandem finishing mill and the third three-stand tandem finishing mill and on-line grinding roll devices are arranged on rolls of the first three-stand tandem finishing mill, the second three-stand tandem finishing mill and the third three-stand tandem finishing mill. With the adoption of the method, the width tolerance of the rolled flat steel can be reduced, the surface smoothness of the rolled flat steel can be improved, the equipment investment can be reduced and the production efficiency can be improved.

The invention discloses a low-water vapor transmission rate type polyester film for an acrylic acid type coating. The low-water vapor transmission rate polyester film is characterized by consisting of a double-direction stretching polyester film prepared from polyethylene terephthalate or poly-2,6-ethylene naphthalate and acrylic acid type glue coatings, wherein the both sides of the film are coated with the acrylic acid type glue coatings; the thickness of the polyester film is 150-250 microns; the thickness of the acrylic acid type glue coatings is 0.08-0.32 microns; acrylic acid type glue consists of a water-based acrylic emulsion, a nanometer silicon sol, a surfactant, a flatting agent, a de-foaming agent, a curing agent and de-ionized water; after a polyester chip is cast to form a casting piece through an extruder and forms a film through vertical stretching, the both surfaces of the film are coated with the acrylic acid type glue in an online coating manner; the low-water vapor transmission rate type polyester film for the acrylic acid type coating is prepared by transverse stretching, drying, cross-linking, curing and thermal shaping. The film provided by the invention can be used for manufacturing a backboard film for a solar battery or other products in need of the low-water vapor transmission rate polyester film.

The invention provides a sapphire crystal brick polishing method. According to the sapphire crystal brick polishing method, firstly, polishing is conducted at a low pressure, low rotating speed and large flow in the first polishing step, so that sharp parts on the surface of a crystal brick are removed, and broken edges of the crystal brick and scratches of a polishing disc are reduced; secondly,removal polishing is conducted at a high pressure, medium rotating speed and properly-lowered flow in the second polishing step, so that the probability of incomplete polishing is lowered, and accordingly the surface of the sapphire crystal brick polished in the first step is smoother; and finally, the third polishing step is conducted at a low pressure and high rotating speed, and thus the smoothness of the polished surface of the crystal brick is ensured. Through the sapphire crystal brick polishing method, the surface of the sapphire crystal brick can be made transparent and has the effectof a mirror surface, a platform is provided for defect detection of the crystal brick, and the machining cost of the subsequent section is reduced; and defective material flow is effectively preventedcirculating to the subsequent procedure, and waste of machines, labor and auxiliary materials is reduced. In addition, in the polishing process, scratches, broken edges and cracks of the polishing disc are avoided; and the polishing method is also suitable for polishing nonmetal bricks made of aluminum oxide, zirconium oxide ceramic and the like.