Here is an excellent video showing testing procedures with this screw press: PINEAPPLE LEAVES – https://youtu.be/ydiKmiOuK6Y
First introduced in 1994, the little Model CP-4 screw press has proven a steady seller. The largest single market is laboratories, although most sales fall in a wide range of miscellaneous applications. Until the advent of the Model KP-6, the press was a popular choice in the plastics recycling industry for dewatering wash tank sludge. Recent applications include pressing cranberries, egg shells, nutraceuticals, crumb rubber, sludge from sidehill screens, biofuel samples, alfalfa, and orange juice pulp. Not long ago the “hottest” application was to squeeze aqueous alcohol solution from hemp in the production of CBD and THC.
With each production run, a review is made for possible improvements. We are now in our 68th production release! Looking back, we see that the press has gradually become more powerful, safer, and more reliable. Just like automobiles.
The CP-4 is extremely handy to use because it can be plugged into a 110-volt or 220-volt single phase wall outlet. Also, the capacity is such that it can be conveniently fed from 5-gallon pails. We have thirty-four of these in our rental fleet today, so there is almost always something available.
The 4″ screw of the press is driven by a hollow bore gearbox. Motors ranging from 0.5 to 7.5 hp can be supplied, although 1-1/2 hp is the most common. The most common screen is wedgewire with available slots ranging from 0.006” to 0.016″ (150 to 400 microns) wide, with perforated screen optional.
To regulate the moisture content of the press cake, an air cylinder actuator is used to position the discharge cone. A recent change has been to mount the air cylinder in-line with the screw shaft.
Another recent change is to offer the Model CP-4L model with an inlet hopper twice as large as that of the standard model. All CP-4 presses continue to have four stages of compression.
The latest CP-4 looks quite different from predecessors. The press liquor collection pan is now, for easy cleaning, made in an inverted pyramid configuration. And the brass discharge cone has been switched to plastic. (There were concerns of food grade ingredients coming in contact with lead in the bronze alloy.)
The inlet hopper features a vertical wall on one side and a sloped wall on the other. The vertical wall is used to minimize bridging of material in the inlet hopper, while the sloped wall is employed to maximize hopper capacity.
Units are frequently customized. Stands with wheels are available. VFD’s which accept single phase power are included to allow variable speed operation. Gearboxes can be changed for different screw speeds. Various screw options, including continuous flighted, hardsurfaced, notched, and step-shaft, are offered. On occasion the press is made vapor-tight, with an explosion proof motor.
Originally published January 16, 2002
Updated June 2010
Updated July 2018
Updated October 2026
ISSUE #124
