Monday, October 30, 2006

Unscrewing device helps moulder unwind

A medical care equipment component with a long internal thread recently necessitated the use of an innovative 'unscrewing' device (the first in the UK) from DMS-Diemould.

A medical care equipment component with a long internal thread recently necessitated the use of an innovative 'unscrewing' device (the first in the UK) from DMS-Diemould to help the moulder achieve the required result in a simple, compact, rapid, cost effective and successful manner - a feat that could not be achieved using other systems. RA Labone has built a formidable reputation based on the moulding and pressing work it produces for the automotive sector. Manufacturing automotive parts such as screen connectors for heated front and rear screens, mounting studs and clips for car windows, rear lamp backplates, lampholders and interior light fittings today represents 50-60 per cent of business at the Ilkeston-based company.

The company's success in the automotive industry is mirrored in other sectors, such as home security, cash dispensing and medical care equipment (medicare).

A current medicare project at RA Labone centres around a component with a long, fine pitched, internal thread, a feature that has caused the company some concern, as Engineering Director Richard Goldthorpe explains.

'To manufacture these moulded medicare parts we need to extract and 'draw out' the component before it is fully ejected,' he says.

'Conventionally this kind of task will involve the use of a rack and pinion device.

However, a rack and pinion demands either an exceptionally large press or plenty of headroom to fit it to the tool.

In this case it simply wasn't practical, on top of which it didn't give us the desired level of control during the unscrewing process.' Manufactured from acetal , the medicare part will suffer damage in the form of melting by friction if the unscrewing action occurs too quickly, meaning that precise control is required.

Undeterred the company then specified the tool be fitted with an AC motor featuring an inverter drive.

However, this also proved unsuccessful, largely due to interface problems between the drive, motor and machine.

At the point of exasperation, the company had the fortune to read a short article about hydraulic unscrewing devices from DMS-Diemould, citing a long list of benefits.

'The EXAflow unscrewing device sounded ideal for our application,' says Mr Goldthorpe.

'The first thing we noticed was its ease-of-use - it's simply a direct bolt-on replacement for an inverter motor.

Secondly it is so compact - it required no alterations to our guarding and we didn't have to consider running a larger machine.

Thirdly, there is no need to de-mount the tool from the machine, which would have been the case using a rack and pinion device.

And lastly, the hydraulic control means there is no electronic interfacing required - the hoses and built-in proximity sensor connect directly to the machine.

EXAflow unscrewing devices (supplied as either single or twin drive units) are exclusively distributed in the UK by DMS.

The devices provide time and cost gains in mouldmaking while reducing production costs for the injection molder by giving reliable, trouble-free service.

The secret behind the precision of the EXAflow unscrewing device lies in the fixed stop of the core holder.

The core holder must run against a fixed stop with its entire front surface area.

This can even ensure a precise thread start position, for example, in the case of triangular caps for shampoo bottles, which need to be aligned with bottle geometry.

With 120 employees on site at Ilkeston and associated operations in the Czech Republic and Germany, it is clear that RA Labone is set for a bright future.

'We like to work closely with both our customers and suppliers to promote quality at all stages of the process,' concludes Mr Goldthorpe.

'Today's product designs are increasingly complex and innovative solutions are required to overcome the challenges we face.

The EXAflow unscrewing device is the perfect example of how this ethos can be applied with great success.'