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60 February 2008 • The Manufacturing Confectioner

The vast majority of candy and formedfood bars in the world are manufac-

tured by pressureless extrusion. This typeof extrusion uses forming drums to create aslab or ropes which are then cut to shape.This paper will cover the basic concepts ofbar forming, concentrating on pressurelessforming of multilayer candy bars includingnougat and caramel layers; granola andcereal bars; dough-type nutritional bars; andfruit-based bars and ropes.

There are various ways of configuring theforming drums, depending upon the actualbar to be formed. Examples of many of thepossibilities will be discussed and illustratedin this paper. Process parameters such asdrum surface temperature, product pre-

conditioning, use of scrapers, etc., will all bediscussed in detail.

The advantages of pressureless extrusionfor bar forming will be illustrated withexamples such as constant product weightover the complete belt width and preser-vation of the integrity of fragile ingredients.

Pressureless extrusion technology allowsthe product to be cooled while it is beingformed, unlike pressure extrusion. The con-cept of this type of forming technologyresults in open drums or forming cylinders,which are accessible and easily cleaned.

OVERVIEW

Pressureless drum-based continuous bar-forming equipment can produce a widerange of bars, including soft candy; hard-boiled sugar mass like nut brittle and tof-fee; fruit bars; and protein bars as well ascereal and granola bars (Figure 1). All ofthese products can be single or multilayer oreven a sandwich format. In addition, rope-forming capabilities can be used and this iscommon in the bakery industry to add lay-ers of stripes on cookies.

A continuous bar-forming line layout con-sists of various components (Figure 2). Itstarts with a mixer to feed the mass into theformer. The former creates an endless slab.Multiple formers can layer different types of

Bar ExtrusionAdvantages of pressureless extrusion include constant productweight and preservation of fragile ingredients, but the biggestone is its precooling capability.

Peter KochSollich KG

Peter Koch is the areasales manager forSollich, having joinedthe company in2001. He has workedin the food industryas an electronic tech-nician with a Euro-pean chocolateequipment supplier.

Figure 1

Continuous Bar FormingCandy Bars, Cereal Bars, Brittle Bars, Fruit Bars, Rope Forming