Grainger and Worrall works visit
Tuesday, 11 October 2016
Branch President Ian Shergold, Prof. MICME, and branch members were welcomed to Grainger and Worrall foundry by Managing Director, Edward Grainger and Engineering and Technical Director, Keith Denholm.
Prior to the tour of the facilities Edward and Keith spoke of the history of the company and its development into the company it is today. Started some 70 years ago as a wood pattern shop it continued as such until the 1970’s when it expanded into providing castings as well as patterns. At this time the castings were out-sourced and it was not until the 1980’s that casting began in house. Patternmaking continues on site to support Grainger and Worrall’s own requirements which helps ensure complete customer confidentiality. The foundry uses silica and a variety of special synthetic sands for its no-bake moulding lines and for coremaking. The customer base is predominantly automotive but also includes marine, defence and architecture with castings mostly in aluminium. A small specialist ferrous foundry is on site producing a wide range of cast irons and stainless steel.
Grainger and Worrall turnover is divided equally between casting sales and added value items such as finish machined product, consultancy and technical support. Machining facilities are shortly to be extended to meet the increased demand for machined components.
The casting business can be separated into 3 sectors; prototype, series production and motorsport with prototype casting accounting for around 50% of casting production. Each section is separated from the next by a corridor or wall to enforce the need for a different mind-set in the various sectors operators.
Prototyping requires speed to market and right first time products. Demands for ever more efficient engines backed by legislation is a key driver for the 300 to 400 new products ordered each year. Production could be from resin pattern equipment, sand printing or a combination of the two. Sand printing, using both silica sand and a range of synthetic sands, enables ever more intricate and challenging designs to be incorporated whilst being able to give customers greater product assurances and quality and often a quicker turn around.
The series foundry supports customers with pre-production requirements and also the short series runs demanded by the luxury car and sports car market. Moulding is on a loop system and cores may be blown or printed.
Confidentiality is an absolute requirement of motorsport customers and it was no surprise that this area was off limits to the visitors. The very high demands of these customers has helped develop the quality culture now seen throughout the organisation.
A new product begins with simulation of the casting process plus prediction of post casting stresses using Magma software. The in house laboratory monitors and controls metal and sand quality and also works closely with universities to help develop new alloys and processes to keep Grainger and Worrall at the forefront of foundry technology.
A comprehensively equipped facility ensures product compliance. Casting integrity and dimensional compliance is checked by CT scanning and geometric optical scanning and / or using more common methods such as CMM checks and leak testing by water or air leak decay. Full traceability is assured.
Following the tour Chris Mintern gave a vote of thanks to Edward, Keith and their staff for a very interesting, thought provoking and informative visit.