The basic straight-root design (Figures 1-4) is formed when the lines of the inside diameter are parallel to the shaft.
In the common form of this design, thread height is gradually increased to the outside diameter to create a smooth container infeed. Variations on this and other screw designs, numbers and placement, enable timing screws to divide and merge containers. They can accelerate, decelerate or even stop the motion of containers for special packaging operations.
Inverse-taper-infeed
: This configuration accepts randomly fed containers more readily than the straight-root design and is also more effective in separating square containers, a design in which the initial pocket of the screw is formed at the maximum outside diameter, then it tapers gradually to the root diameter.
Transfer (Figure 1): Particularly useful on high speed lines, this screw accepts containers at the discharge end of one machine and positively controls the container to the infeed of the next machine. This prevents container contact, thus eliminating scratching and spillage of the contents. The pitch of the screw can remain the same of be varied as called for by the machine pitch requirements. Figure 1. Transfer
180-degree discharge (Figure 2): Known as the dual-flight, or double-lead screw, this design will maximize container output by means of two threads cut into the screw. These threads discharge containers every 180° of rotation instead of the normal 360° standard. This effectively doubles the output. Use for this screw is limited, however, since not all packaging machines are capable of functioning with this timing arrangement. Figure 2. 180 Degree Discharge
Multiple dwell (Figure 3): This screw design, known as stop-position, can stop a container one or more times to perform different functions. The screw has a vertical section in the screw pitch that momentarily halts the container in its forward motion. It is useful for such actions as banding, sleeving, labeling, cottoning, leaflet placement, in-line filling, closing, plugging operations.
Screw design can vary the number of dwells and the degree of dwell time over wide limits to suit packaging requirements. Figure 3. Multiple Dwell
Grouping (Figure 4): When multiple containers must be collated into a grouping, this design performs the operation smoothly by picking up two or more containers in a single pocket and then spacing the collation by a full pitch from the next group. This group of containers can them be discharged closely spaced to enable banding or overwrapping of needed.
The basic straight-root design (Figures 1-4) is formed when the lines of the inside diameter are parallel to the shaft.
In the common form of this design, thread height is gradually increased to the outside diameter to create a smooth container infeed. Variations on this and other screw designs, numbers and placement, enable timing screws to divide and merge containers. They can accelerate, decelerate or even stop the motion of containers for special packaging operations.
Inverse-taper-infeed: This configuration accepts randomly fed containers more readily than the straight-root design and is also more effective in separating square containers, a design in which the initial pocket of the screw is formed at the maximum outside diameter, then it tapers gradually to the root diameter.
Transfer (Figure 1): Particularly useful on high speed lines, this screw accepts containers at the discharge end of one machine and positively controls the container to the infeed of the next machine. This prevents container contact, thus eliminating scratching and spillage of the contents. The pitch of the screw can remain the same of be varied as called for by the machine pitch requirements.
Figure 1. Transfer
180-degree discharge (Figure 2): Known as the dual-flight, or double-lead screw, this design will maximize container output by means of two threads cut into the screw. These threads discharge containers every 180° of rotation instead of the normal 360° standard. This effectively doubles the output. Use for this screw is limited, however, since not all packaging machines are capable of functioning with this timing arrangement.
Figure 2. 180 Degree Discharge
Multiple dwell (Figure 3): This screw design, known as stop-position, can stop a container one or more times to perform different functions. The screw has a vertical section in the screw pitch that momentarily halts the container in its forward motion. It is useful for such actions as banding, sleeving, labeling, cottoning, leaflet placement, in-line filling, closing, plugging operations.
Screw design can vary the number of dwells and the degree of dwell time over wide limits to suit packaging requirements.
Figure 3. Multiple Dwell
Grouping (Figure 4): When multiple containers must be collated into a grouping, this design performs the operation smoothly by picking up two or more containers in a single pocket and then spacing the collation by a full pitch from the next group. This group of containers can them be discharged closely spaced to enable banding or overwrapping of needed.
