HOW WE ADD VALUE TO ALUMINIUM

Hulamin, as the leading semi-fabricator in Southern Africa, plays a key role in the local aluminium industry by unlocking and enhancing the extraordinary properties of aluminium for use in a broad and growing set of product applications on which society is dependent.

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PRIMARY ALUMINIUM


 

REMELT AND CASTING OPERATIONS

Bought-in scrap and scrap from Hulamin’s manufacturing processes are melted together with primary aluminium and alloying elements such as magnesium, manganese, zinc, silicon and copper in Hulamin’s remelt operation.

The molten metal is then treated, filtered and skimmed before being cast into rolling slab and extrusion billet, the feedstock for the rolling and extruding processes.

ADDING VALUE

By adding small amounts of other elements to pure aluminium, strong alloys are produced which can be further conditioned in the heating, rolling, extruding and finishing processes to create products with the appropriate properties that our customers require.

Since aluminium is an infinitely recyclable product, all scrap produced in Hulamin’s manufacturing processes, as well as scrap recovered from our local fabrication customers and post-consumer scrap, is remelted and reused.

 

THE ROLLING PROCESS

The rolling process must produce plate, coil or sheet with not only accurate dimensions, but such other attributes as flatness, edge quality and correct thickness profile, specified physical properties and freedom from surface defects.

In the hot rolling process, slab is heated and then processed through the reversing hot roughing mill (where the thickness of the rolling slab is reduced by up to 95% and the length increased by up to 24 times) before being transferred to the hot finishing mill to ensure that it is rolled to a tight tolerance intermediate thickness.

In the cold rolling process, hot rolled coils are further rolled, at ambient temperature, to achieve the required tight gauge tolerances and mechanical properties required. Foil rolling is a specific cold rolling process designed for very thin products and certain alloys. Hulamin’s stand-alone foil mills can reduce cold rolled products to gauges as low as six microns.

ADDING VALUE

Hot rolling increases density, strength and ductility and cold rolling is used to further harden and strengthen the product, balancing between strength and ductility as required. Further finishing processes deliver the appropriate properties and qualities required for each specific product application, and include:

ANNEALING

A re-heating process performed to regulate the mechanical properties or permit further reductions in thickness during cold rolling.

COATING

The application of paint and lacquer to clean and pre-treated aluminium coil, followed by oven curing, is required for certain applications such as beverage can-ends.

PROCESSING

Further processing is often required to obtain the appropriate widths, lengths or coil sizes, flatness and metal surface cleanliness required by customers. This is achieved through further processing through precision slitters, cut-to-length lines, shears, tension levellers, embossing rolls and degreasing lines.

 

THE EXTRUSION PROCESS

Extrusion billet is heated and passed through an extrusion press, a powerful hydraulic device in which a ram pushes the softened metal through a unique die to produce the desired profile.

The completed extrusion is cut off the die, cooled, mechanically treated and aged to give it the required mechanical strength properties, and may be further coated, anodised and/or fabricated to provide the final specification required by the customer.

ADDING VALUE

The extrusion process supports unlimited possibilities for design. With the appropriate alloy and controlled thermal treatment, extrusions offer a wide range of application opportunities.
 

The production of semi-fabricated aluminium products, with the wide range of precise dimensions, properties and other characteristics required for each particular product application and customer, requires a comprehensive set of complex and technologically-advanced processes.

primary markets and applications for our products

 

 

 

COIL

TYPICAL ALLOYS:

1XXX, 3XXX,
4XXX, 5XXX,
7XXX, 8XXX, 9XXX

AUTOMOTIVE AND TRANSPORTATION

KEY PROPERTIES

Lightweight, corrosion resistant, recyclable, strong and ductile

AUTOMOTIVE CLAD TUBE STOCK AND FINSTOCK

Used in the manufacture of automotive heat exchangers such as radiators, charge aircoolers, condensers and evaporators

PLATE AND HEAT-TREATED PLATE

Used in the production of aerospace components, truck bodies, trailers, tankers, boats and train wagons

HEATSHIELD PRODUCTS

Used for containing heat within engine compartments

 

 

 

 

 

EXTRUSIONS

TYPICAL ALLOYS:

6XXX

GENERAL ENGINEERING AND DURABLE CONSUMER GOODS

KEY PROPERTIES

Corrosion resistant, excellent heat and electricity conductor, strong and ductile and aesthetically pleasing

GENERAL ENGINEERING COIL AND SHEET PRODUCTS

Used in items such as electronics, computers, office products and durable consumer goods

PLATE AND HEAT-TREATED PLATE

Used in vacuum chambers for the manufacture of computer chips, plasma displays, distribution boards and numerous other applications

FINSTOCK PRODUCTS

Used in the manufacture of domestic and industrial airconditioning systems

EXTRUSIONS

Numerous applications and developing opportunities such as solar components

 

 

PLATE

TYPICAL ALLOYS:

1XXX, 5XXX, 6XXX

BUILDING AND CONSTRUCTION

KEY PROPERTIES

Lightweight, corrosion resistant, good reflective qualities, strong and long life

PAINTED AND MILL FINISH BUILDING COIL AND SHEET

Used in a wide range of applications including roofing, cladding, ceilings, gutters and downpipes

EXTRUSIONS

Used in the manufacture of various household frames and other industrial applications

 

SHEET

TYPICAL ALLOYS:

1XXX, 3XXX, 4XXX,
5XXX, 7XXX, 9XXX

PACKAGING

KEY PROPERTIES

Lightweight, corrosion resistant, impermeable, odourless and recyclable

CAN BODY AND COATED CAN-END AND TAB STOCK

Used in the manufacture of cans for the beverage industry

CONVERTER FOIL

Used in the production of laminated cartons and confectionary packets for the food and beverage market. Household foil, rigid container foil, laminated foil, closure sheet For use in the manufacture of bottle caps