MACHINERY | PIPE DIES
Right: Guill Tool has
developed a new reciprocat- ing head that automatically alters a tube’s profile
determine how the new crosshead could be incorporated. For instance, as well as being appro- priate for new lines, the 3000A crosshead could replace existing Model 2000 crossheads.
Crosshead selection The 3000A crosshead was showcased at K2019, where Davis- Standard shared a stand with its subsidiary Maillefer – which showed, among other products, its ECH cross- heads.
Maillefer offers a wide range of extrusion heads for pipe and tube manufacturing. These include the VLCH and ECH crossheads, and the TL and ELH longitudinal heads. They can be used in a variety of applications, such as single- or multi-layer, stripe or skin options, co-extrusion or tandem processes, and special connections and tooling configurations. Most of the head designs support multi-layer
co-extrusion. The ECH models boast high flexibility in layer positioning, superior flow distribution and ergonomic qualities, says the company. As an example, it cites the five-layer ECH 5/50. Its indexing feature allows for up to 120 different layer combinations. While the longitudinal TL and ELH families are optimised for single layer or striping extrusion, the larger VLCH crossheads are dedi- cated to the offshore flexible pipe application. While some manufactures favour co-extrusion to unite the polymer flows within a multi-layer head, another option is tandem extrusion configurations. Here, subsequent layers are added further down- stream in a second extrusion step. Specific single- layer TL and dual layer ELH and ECH crossheads respond well in these configurations, says Maillefer. “We see such setups with certain tubes where polymer viscosities are quite different between layers,” said the company. “A longitudinal TL or ELH head produces the inner tube layer(s) and an ECH
one further downstream for the outer layer(s).”
In addition, Maillefer offers its TOA 32, which helps to identify die drool deposits inside the tube – so they can be detected before the product is sent to the customer. Die drool is a common phenomenon that occurs over time and originates on the extrusion die face. Bits of plastic accumulate until they form a deposit that drops off into the product, where it remains hidden. The result is a poor construction – which needs to be separated, due to its sub-standard quality. Maillefer says that its TOA 32 can be used in a
range of applications – such as for making blown fibre ducts.
Double speed Guill Tool has redesigned its high-production rotary dies – both inline and crosshead styles – which it says has doubled production speed. The company says that models running at 1000rpm are now available in its line of patented rotating tip and die designs. By rotating the tooling in relation to material
flow, a rotary head can increase the wall strength of an extrusion – allowing a thinner wall with less mate- rial, and corresponding cost savings for the user. Typical applications for rotary heads include medical and multi-lumen tubing plus various high-end extrusions with interlocking layer or multiple striping requirements.
� DON’T MISS THESE ISSUES OF
CLICK ON THE COVERS TO VIEW
WOOD-PLASTIC COMPOSITES
PIPE CORRUGATORS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50
