Upcoming events
Kuteno Kunststoff Messe, Gemany — May 14 - 16, 2024
Kuteno Kunststoff Messe, Gemany — May 14 - 16, 2024
PRSE Amsterdam. Netherlands — June 19 - 20, 2024
Kunstoffenbeurs Brabenthallen 2024, Nederland — September 18 - 19, 2024
Kunstoffenbeurs Brabenthallen 2024, Nederland — September 18 - 19, 2024
Kunstoffenbeurs Brabenthallen 2024, Nederland — September 18 - 19, 2024
The K Show at Stand A03 in Hall 10- Dusseldorf, Germany — October 08 - 15, 2025
[ 01 ]
Cost saving

Refurbishing can generate 30% or more costsaving aginst new parts.

[ 02 ]
Shorter delivery time

Repair is mostly 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 cilinders 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 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 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 dedicate spare components shall be stored.

Repair with bushing

In special cases Injection cylinders can be repaired by reline the worn area with a liner which shall be longer as the screw stroke (5D) so the valve operate at the original nominal diameter. The liner can be made of nitrided steel, hardened steel but also of bimetallic alloy.

Repair old worn screws by welding the flights

For screws with diameters larger than 60 mm, depending on the type of wear, it is possible to repair them by welding new material on the top of 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

Refurbishing is a for larger units interesting for cost saving and delivery-time.

  • Type
    Base Alloy
    Alloy components
    Hardness [HRC]
    (a) Hardness of matrix, tungsten carbides have a hardness of 89 HRC.
    Abrasion resistance
    (x good) to (xxxxx excellent)
    Corrosion resistance
    (x good) to (xxxxx excellent)
  • Stellite 1
    Cobalt
    C - Cr - W
    52 - 57
    +++
    +++
  • Stellite 12
    Cobalt
    C - Cr - W
    44 - 48
    ++
    +++
  • Colmonoy 56
    Nickel
    C - Si - Cr - B - Fe
    52 - 56
    +++
    ++++
  • Colmonoy 83
    Nickel
    Tungsten carbide
    56 - 60 [a]
    +++++
    ++++
  • Casto TIG 5
    Iron
    Cr - V
    58 - 62
    ++++
    ++
Stellite 1
  • Type
    Stellite 1
  • Base Alloy
    Cobalt
  • Alloy components
    C - Cr - W
  • Hardness [HRC]
    52 - 57
  • Abrasion resistance
    +
    +
    +
  • Corrosion resistance
    +
    +
    +
Stellite 12
  • Type
    Stellite 12
  • Base Alloy
    Cobalt
  • Alloy components
    C - Cr - W
  • Hardness [HRC]
    44 - 48
  • Abrasion resistance
    +
    +
  • Corrosion resistance
    +
    +
    +
Colmonoy 56
  • Type
    Colmonoy 56
  • Base Alloy
    Nickel
  • Alloy components
    C - Si - Cr - B - Fe
  • Hardness [HRC]
    52 - 56
  • Abrasion resistance
    +
    +
    +
  • Corrosion resistance
    +
    +
    +
    +
Colmonoy 83
  • Type
    Colmonoy 83
  • Base Alloy
    Nickel
  • Alloy components
    Tungsten carbide
  • Hardness [HRC]
    56 - 60 [a]
  • Abrasion resistance
    +
    +
    +
    +
    +
  • Corrosion resistance
    +
    +
    +
    +
Casto TIG 5
  • Type
    Casto TIG 5
  • Base Alloy
    Iron
  • Alloy components
    Cr - V
  • Hardness [HRC]
    58 - 62
  • Abrasion resistance
    +
    +
    +
    +
  • Corrosion resistance
    +
    +

Repair old worn twin cylinders

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

Repair examples

Honing cylinder oversize
Broken screw repaired temporary
Bad worn cylinder section repaired with new front section.
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