Refurbishing

[ 01 ]

Cost saving

Refurbishing can generate 30% or more cost saving against new parts.

[ 02 ]

Shorter delivery time

Repair is typically faster than new, so in critical situations reduce downtime of the machine if something is broken and not available on stock

[ 03 ]

Choice of different welding materials

Material weld can be adjusted to current needs.

Cylinder Repair through larger a larger inner diameter

A worn cylinder, bimetallic or nitrided, can be repaired by honing the inner diameter to a larger diameter. In case of nitrided cylinders, a new nitriding treatment shall be made with a depth of 0,4 ÷ 0,5 mm to ensure the necessary hardness. A honing operation must follow so that all dimensions are within the new oversized tolerances. In the case of a bimetallic cylinder, only the boring needs to be honed. No renitriding and honing is necessary. Of course, the outer diameter of the screw, valve, and eventually the end cap inner diameter must be adjusted to the new (larger) dimension of the cylinder. This is a cheap but effective solution, but has one disadvantage: the repaired cylinder and screw become non-standard equipment, and dedicated spare components shall be stored.

Repair with bushing

In special cases, injection cylinders can be repaired by relining the worn area with a liner that shall be longer than the screw stroke (5D) so the valve operates at the original nominal diameter. The liner can be made of nitrided steel, hardened steel, or bimetallic alloy.

Repair old worn screws by welding the flights

For screws with diameters larger than 60 mm, depending on the type of wear, they can be repaired by welding new material onto the top of the worn flights. This procedure can be applied only if there is no wear on the screw core or front-back flight radius, Important to mention is that a repaired screw will not last as long a new one. For further information about the welding alloys, please refer to the table below.

Welding materials for the screw flights

For larger screw sizes, we often use nitrided materials with the flight tips welded with different materials options. This creates wear/corrosion protection or improves friction/lubrication.

MM CODE

FLIGHT ARMORING

TECHNOLOGY

ABRASIVE WEAR RESISTANCE

CORROSIVE WEAR RESISTANCE
MM120

Cobalt Base Alloy

PTA

+++

+++
MM50

Iron Base Alloy

TIG

++++

++
MM560

Nickel Base Alloy

PTA

++++

++++
MM570

Nickel Base Alloy

PTA

++++++

+++++
MM830

Nickel Base Alloy

PTA

+++++

+++++
MM4900

Molybdenum

HVOF

+++++

++++
MM6000

Tungsten Carbide

HVOF

++++++

++++++

MM120

MM CODE

MM120
FLIGHT ARMORING

Cobalt Base Alloy
TECHNOLOGY

PTA
ABRASIVE WEAR RESISTANCE

+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+

MM50

MM CODE

MM50
FLIGHT ARMORING

Iron Base Alloy
TECHNOLOGY

TIG
ABRASIVE WEAR RESISTANCE

+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+

MM560

MM CODE

MM560
FLIGHT ARMORING

Nickel Base Alloy
TECHNOLOGY

PTA
ABRASIVE WEAR RESISTANCE

+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+
+

MM570

MM CODE

MM570
FLIGHT ARMORING

Nickel Base Alloy
TECHNOLOGY

PTA
ABRASIVE WEAR RESISTANCE

+
+
+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+
+
+

MM830

MM CODE

MM830
FLIGHT ARMORING

Nickel Base Alloy
TECHNOLOGY

PTA
ABRASIVE WEAR RESISTANCE

+
+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+
+
+

MM4900

MM CODE

MM4900
FLIGHT ARMORING

Molybdenum
TECHNOLOGY

HVOF
ABRASIVE WEAR RESISTANCE

+
+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+
+

MM6000

MM CODE

MM6000
FLIGHT ARMORING

Tungsten Carbide
TECHNOLOGY

HVOF
ABRASIVE WEAR RESISTANCE

+
+
+
+
+
+
CORROSIVE WEAR RESISTANCE

+
+
+
+
+
+

Repair old worn twin cylinders

Partial reline of single screw cylinders is mostly not cost-effective, in contrast to twin cylinders, which, based on the added value for the customer, related to costs, is an interesting service.