EDS: Extrusion Die Stretcher
The Extrusion Die Stretching Machine (figure 1) performs hot die draw-down of plastic tubing used in catheter production. Three different models are available, 3×26, 3×68, and 3×80, letting you maximize your workspace based on the tube extrusion requirements. The process enhances material strength and improves O.D. tolerances. The machine can process up to three tubes in parallel. The typical applications include tubing neck down, balloon tubing pre-stretching, and sheathed balloon heat setting on completed catheters. Model EDS-3X26 can also be used to jacket hypotubes and other applications requiring stretching tubes.
Key Features
- 26”, 68” or 80” maximum draw-down length
- 6-digit LCD display for draw speed and draw distance readout
- Chain Drive with air-activated engage/disengage clutch
- Optical limit switches
- Quick release mechanism for fast exchange of the extrusion dies
- Air clamps with polyurethane soft jaws or stainless steel serrated jaws available
Operation
Thinned-down tubing ends are inserted through the hot extrusion die (figure 2). An air clamp with serrated hard jaws (figure 3) or optional urethane soft jaws grip the tubing. The draw slide travels on a precision ball-bearing carriage along a central guide rail.Adjustable home switch and end of draw switch slide along the central rail and their position can be set against the S.S. ruler graduated in centimeters. A microprocessor-based control unit provides function sequencing, timing, and safety interlocks. The machine can perform one-step or two-step pulls. During the two-step pull the 4 tubing tail is first drawn through the die a short distance of 0.5 or 1.0 inches. Secondly, the jaws release, reposition themselves close to the die, grip the tube again by its thickest section, and perform the final pull.
Specifications
Dimensions (LxWxH) | 3×26: 38” x 17.75” x 10.25” (96.5cm x 45.0cm x 26.0cm) |
Weight | 3×26: 45lbs (20.2Kg) |
Power Requirements | Standard System: 120VAC 50/60 Hz., 520 Watts. |
Air Supply | 80-120 PSI (0.7 MPa) Shop Air, Dry, Filtered |
Capacity | 3 tubes, side by side, .020 inch to .187 inch |
Max Stretch Distance | 3×26: 26 inches (66cm) |
Minimum Stretch Speed | 3.0 mm/sec |
Temperature Range | Ambient to 450°F (232°C) |
Summary of Featured Photos
Figure 2: Detail view of the heater block showing three 3 dies side-by-side. The dies are easily removed by loosening two 2 retaining screws at the upper rim of the dies.
Figure 3: A small fan adjacent to the heater block cools the tubing as it leaves the hot die. A detail of open jaws of the air clamp is shown.
Figure 4: Examples of finished parisons.
Figure 5: A row of four switches at the front edge of the machineis used during each cycle for loading/unloading the tubing and starting the cycle. The controls on the panel in the top half of the picture are used for setting the process parameters.
Figure 6: Detail of the guideblock with tension roller lifted 45 degrees. This mechanism allows simultaneous loading of three 3 tubes in parallel while the roller maintains tension on the tubing during the process. The tension level is adjustable.
Heater Jaw Options
Tubing Support Slide Assembly 502222
Extrusion Dies are sold separately. They are fabricated from 440C stainless steel, heat treated to RC 62, and diamond polished to a mirror finish. The dies are available in sizes 0.014 to 0.126 in 0.001 inch increments.
