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Polyurethane and Rubber product projects

Shot peening masks

The most common method of masking is moulded masking, the main attractions of this method are that it is quick, reusable and offers repeatability.
Initially to determine whether a moulded mask is practical it is necessary to ascertain that the job will be on going and there is sufficient part volume.

Speed and repeatability come automatically with moulded masking for when the tooling is well engineered the component fit can be accurate and tight. It is advisable to work with a company that understands shot peening and gas turbine engines as this will ensure the correct material selection is made and your time input is not wasted whilst away from production. Most shot peening applications that call for moulded masking are blades and vanes. There is also another significant benefit in that with an interface the mask acts both as a mask and fixture. Machine position repeatability reduces set-up times and time wasted repositioning nozzles.

Walther Trowal reline of an AV 600 Through Finisher

Lima Envec have recently won the order to reline a Walther Trowal AV 600 Through Finisher with a cast polyurethane liner.

This machine was relined in 10 working days.

In the 10 day period we produced all the necessary mould tooling and carried out the relining work. Future relining of this machine will typically take 5 working days now that we have suitable mould tooling.

The cost to carry out the re-lining work was approximately for this order was 50% of the OEM price.

This Walther Trowal AV 600 through finisher was relined in November 2014. The cost of a Lima lining is typically 50% of a OEM lining

This Walther Trowal AV 600 through finisher was relined in November 2014. The cost of a Lima lining is typically 50% of a OEM lining

Recovering of rollers with polyurethane

Bonding roller

Bonding roller

Pouring Polyurethane

Pouring Polyurethane

Machining of the roller.

Machining of the roller.

Rollers ready for dispatch

Rollers ready for dispatch

Bonding agent is applied to steel roller prior to the moulding process being carried out. Brush or spray application. Polyurethane is dispensed, placed under a vacuum to remove any enveloped air and poured into the mould cavity.
Excess polyurethane is faced of the roller on a lathe. This is part of the trimming operation.
Rollers are palletised and inspected ready for dispatch to the customer.

Skip Wheels Coated in Polyurethane

Lima envec supply polyurethane coated wheels which are fitted to skips where the ground requires protection from damage. The Pu coating is ideally suited to the situation and is a cost effective way of protecting the yard from damage

 Batch of wheels ready for coating.

Coated wheel with spanner for scale.

Industrial valves coated with spray polyurethane

Dart valve 1

 

Dart valve 2

 

Dart valve 3

 

Dart valve 4

 

Spray polyurethane.

Dart valves coated with  4mm thick spray applied polyester polyurethane.

The mild steel  dart valve is grit blasted and a bonding is applied prior to coating.

The mild steel dart valve is mounted on a manipulator to aid coating.

The valve is coated to a thickness of 4 mm with tough spray applied polyurethane.

Polyurethane masks for turbine blades.

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks

Polyurethane masks.

Compressor blades and turbine blades are routinely shot peened to impart strength.

The shape of the root and aerofoil differ from blade to blade creating a requirement for custom moulded protection masks.

Polyurethane masks can be moulded in various colours for easy identification.

This slide highlights the moulded process. The blade root securely held by the polyurethane mask.

Walther Trowal reline in Polyurethane

 

 

 

 

This post describes the relining of a Walther Trowel mass finishing vibratory bowl in polyurethane. The old worn out lining is removed and the steel shell is heat treated and then grit blasted back to the original steel. A new steel mould tool is fabricated by our team of specialist fabricaters. The tool is designed to mould a 25 mm thick lining A moulded lining ensures correct fitting of doors, drains, and dam flaps. This is not possible to achieve with rubber or spray poly linings .A moulded lining  will outperform spray poly or rubber linings. A reline typical takes 7 working days.

 

 

Rosler Reline in polyurethane

                                                                                                                                                  

 

A Rosler barrel arrives for a new polyurethane liner. The fabrication weighs 3.7 ton.

The customer required the machine back within 1 working week. The old rubber lining is worn out and detached from the work tub. The old rubber lining is removed

and the steel fabrication is grit blasted. Both internally and externally to ensure good adhesion for both polyurethane and paint. A new mould tool is manufactured to suit the internal dimensions of the vibratory trough. This work is carried out in house by our own team of specialist fabricators. The mould is lowered into the fabrication and positioned centrally. A nominal 35 mm gap is created between the work tub and the 

mould, and the unit is ready to be filled with polyurethane. Polyurethane is dispensed via our special machine and decanted into pails prior to pouring the new lining.275 kg of polyurethane was required to reline this machine. The lining is cured in an oven at 80 deg c for 16 hours.The mould is removed and the outside of the tub is painted.The works were completed in 5 working days.