Hydrostatic Pressing
Hydrostatic (cold isostatic molding) is the use of high pressure pump to press the liquid medium into the high pressure steel body closed container, the static pressure of high pressure fluid directly acts on the powder in the elastic mold sleeve, so that the powder body at the same time in all directions of the balanced pressure to obtain uniform density distribution and high strength of the billet.
In metal die forming, complex shape or cylindrical and other simple shape object forming, the thickness of the pressure direction is larger than the pressure fracture area, forming density is not uniform, in sintering will produce deformation problems. This is because when the metal mold is shaped, the friction between the mold wall and the powder occurs, and the pressure conduction cannot uniformly reach the whole system. And with hydrostatic forming, because through rubber and other elastomers should be formed on the powder with hydrostatic pressure, so that the metal mold forming powder flow and prevent its flow of the wall friction resistance problem through the use of rubber and powder similar shrinkage elastomers and solved.
Although hydrostatic pressing was proposed 70 years ago, it has not been used commercially because of the long period of non-development of ultra-high pressure technology. In the past 20 years, with the progress of ultra high pressure technology, it has become an industrial forming method. From spark plug, ball mill and other small products, to continuous casting immersion nozzle, have been used in industry. It is developing to large-scale production for the purpose of forming large and large quantities of products at the same time. In the large equipment, the high pressure vessel inside the size of the appropriate diameter of 1.5m, 3.5m high super large machines have also appeared.
Hydrostatic process is one of the methods of powder forming which can obtain uniform density pressed parts. The essence of this method is that the powder is placed in an elastic mold and subjected to hydrostatic pressure in all directions. The process is carried out in a sealed chamber which contains the liquid for the work - oil, water, glycerin, etc. The hydrostatic pressure is usually 202~404MPa or higher.
Hydrostatic elastic die is generally made of rubber, plastic, etc. When the powder is packed into the mold, the uniformity of the powder has a certain effect on the density and shape of the product, so the powder is usually filled evenly in the mold by vibration method. A sleeve with a hole should be tightly set outside the sealed elastic die, and then pressed.
Hydrostatic pressing is characterized by the absence of external friction in this case. The powder particles move towards the center of the press under hydrostatic action. Hydrostatic pressing of various shapes (cylinder, sphere, rectangular blank bar), found only spherical and cylindrical pressing, its outer edge to the center of the density has a small reduction (1% ~ 2%). This phenomenon may be caused by the arch bridge effect. The rectangles have the same density and hardness everywhere.
Jiangsu High Industry on the research and development and production of high-performance polyurethane isostatic pressing molds. Through in-depth cooperation with many isostatic pressing equipment manufacturers and in-depth study of the industry, the developed isostatic pressing polyurethane mold series products have the characteristics of long service life, high precision, small deformation, easy demoulding, etc., and are widely used in ceramics, etc. Static pressing mould, cemented carbide isostatic pressing mould, rare earth permanent magnet material isostatic pressing mould, graphite isostatic pressing mould, etc
We support all kinds of customization, if you need it, please contact us.
Phone/whatsapp:+86 18234744811
Email:sales@highindustryco.com
Polyurethane Products Pu Products Rubber Mold Plastic Mold
