Invention of two piece aluminium cans by Coors Brewery

The 1950s was the era of tuna casseroles and tinned soup; cooking dinner for the family form canned and packaged food was a hallmark of the suburban lifestyle, and a can opener was an essential tool in the modern kitchen.

The first canned beer was sold in Richmond, Virginia, in January 1935 when G. Krueger Brewing Company of Newark, New Jersey and American Can cooperatively released the new 12 fluid ounce package.

When Coors Brewery of Golden Colorado made the first two-piece aluminium can, nearly all beverage cans, as well as many similar types of food containers, are manufactured through the operation known as drawing and ironing, sometimes referred to as D&I process. It was first marketed by Coors Brewing in 1959 via an association with ‘Primo’ a Hawaiian brewery.

Beverage cans for soft drinks and beer are called ‘two piece’ cans because the complete container actually consists of two separate portions. Coors company was founded in Colorado by Adolph Coors, a German immigrant who left the Old World in hopes of one day owning his own brewery.

The Coors Company, held the rights to the production of this new liquid container, but rather than produced cans for the entire market’s demand, Coors Container Co. sold the patent to other packaging production companies including Continental Can Co. and American Can Co.

Then Coors Brewing Company attracted a cult following by selling beer in seven-ounce aluminium cans, instead of conventional twelve ounce settee cans.
Invention of two piece aluminium cans by Coors Brewery

Draw and iron can

The draw-iron can was developed to compete with aluminum alloys for pressurized beverages containers, which have become the highest growth market for cans, due to their popularity for dispensing drinks. In the draw and iron technique, the can is made in two steps.

A disc is blanked from sheet stock, and drawn into a cup. The can is lengthened or deepened by ironing the sides in a stretching operation that reduces wall thickness to about one third of its original gauge.

The drawn and ironed can is then washed clean of lubricant lithographed, interior spray-coated, necked-in and flanged. A two-piece cup-like can ready to receive contents and a double seam end is the resulting product.
Draw and iron can

Two piece cans

Two piece cans is manufactured by press punching cups from sheets or coils of aluminum or steel. During this cupping operation, a blank is produced from the coil stock and in the same punch stroke, s formed into a shallow cup.

The cups are then forced though a series of rings to iron out and form a full-length can and to form the bottom dome.

Subsequent operations include trimming the can to a specified length, washing to remove drawing lubricants, decorating the exterior of the can with the desired brand level and applying coating to prevent contact of the food or beverage product with the metal substrate.

The product at this stage is a container with sides and a bottom representing one of the pieces of a two-piece can. The lid, secured and sealed after filling, is the second piece.

Since 1970, through the conversion of three to two piece cans and subsequent lightweighting, the weight of a 350 mL tinplate soft drink can has been reduced by 50% to 30g, and that of the inherently lighter two-piece aluminum can by 39% to 13 g.

It is evident that two-piece steel can would eliminate the long seam and one double seam and thus preclude two sources of potential leakage.

Steel is a cheaper metal than aluminum, but it is far more difficult to form. A two –piece steel can could offer the advantages of a two piece aluminum can, but at a lower price.

The two piece can has no side seam and only one double seam, which is more easily formed and controlled because of the absence of a side seam lap juncture.

Seaming by the filler at the top end is considerably easier owing to the absence of a junction of the side seam and the end seam.
Two piece cans