Press Laboratory Presses

Product Description

NATIONAL's 1 & 2 Ton Presses feature a unique laboratory press design combined with the same unibody construction and other features common to our Press line. We have redesigned these laboratory presses to maximize the sensitivity of the press for exact reproducibility of applied force. Normally, hydraulic lab presses use a pump to apply pressure to the piston of the hydraulic cylinder. The hydraulic fluid pump found in standard lab press designs increases the pressure of the hydraulic fluid in spurts which causes the force being applied by the press to jump in increments which are difficult to control with precision. In addition, there is some backflow of hydraulic fluid during the pumping process which amplifies the lack of reproducibility of force levels.

Many applications for low pressure laboratory presses such as intrinsic ingredients dissolution analysis require the application of highly reproducible force levels, and 12 ton hydraulic presses are inherently unsuited to these applications. By removing the pump and sealing the hydraulic cylinder, we have created a press which enables application of very small increments of force levels which can be reproduced with a high degree of precision from sample to sample and without pressure drops. The force is applied to the sealed cylinder by turning the lead screw assembly against the platen on which the die is seated, similar to the manner that a wine press operates. Since the force levels are very low, very little effort is required to turn the lead screw. These lab presses are equipped with clamps which allow them to be anchored to any bench top and easily moved to different locations within the lab and they can also be bolted to a lab bench using the fixtures provided with the press. When used with NATIONAL's intrinsic dissolution analysis dies or NATIONAL's Macro-Micro dies, the dies are automatically centered in the press. Note that special short profile Macro-Micro dies are required for this press. The 1 and 2 Ton Press can also be used with NATIONAL's 2mm, 4mm and 7mm die sets and die centering inserts are available for the smaller die sets. Also available in high profile version for applications such as Wood apparatus intrinsic dissolution testing.