Rotary Moulder Belts – Everything You Need to Know

What are Rotary Moulder Belts?

Rotary moulder belts are a type of woven conveyor belt, predominantly made from cotton weave, used in biscuit manufacturing. The rotary moulder conveyor belt is usually used for short dough and cracker lines to substitute the process of ‘sheeting’, ‘cutting’ and ‘gauging’, which are traditionally hand-based manufacturing methods.

Rotary belts are  ‘endless belts’ in nature due to their ‘seamless’ production properties and are usually run on a ‘knife edge conveyor system’.

What are Knife Edge Conveyors?

The knife edge conveyor system is a section of a conveyor system uniquely designed to transfer small objects (in this case, biscuit dough) from one part of the conveyor system to the next for the continuing production of biscuits. The ‘knife edge’ is often rounded and may be referred to as the ‘nosebar’.

The beauty of the knife edge section of the conveyor system is its ability to lightly transfer products through the conveyor system without breakage or falling into gaps. This is a perfect solution for biscuit production. This limits the number of cracks and breakages within the dough during biscuit production.

How are Rotary Moulder Conveyor Belts Used in Biscuit Making?

Once the dough for the biscuit or cracker is made, the next phase of the production is to move it into ‘shaping’. This is where you see the famous ‘McVities print on biscuits or the unique design of a Malted Milk’.

These unique designs result from the rotary moulding process of biscuit production. The rotary conveyor belt must have the optimum ‘pull’ and ‘release’ abilities to peel off the dough from the roller press onto the bel. A quality-manufactured rotary conveyor will ensure a ‘seamless transfer’ has been made whereby 100% of the dough is successfully ‘released’ from the conveyor belt at the nosebar point and onto the next phase of biscuit production.

Key Requirements for Rotary Moulder Belts

Endless belts such as rotary moulder belts are typically made from three key materials. These vary between cotton, nylon and polyester. The belting material type used is based on the biscuit manufacturer’s requirements. For example, depending on the biscuit’s fat and grease content within the dough, specific material may be required depending on the density of the dough.

This is because of the requirements mentioned above for optimum pull and release between the different phases of the conveyor belt. Nylon, with a 6% moisture regain, or polyester, with a 4% moisture regain, is more suitable for less fatty dough biscuits and crackers.

Conversely, cotton conveyor belts, with higher moisture regain, are naturally more suitable for biscuits and crackers with a higher fat density. This is due to the belt’s ability to absorb the dough perfectly onto the conveyor from the rollers and release the biscuits seamlessly at the other end.

Typically, for thinner biscuits or crackers, a thinner conveyor belt with less ‘ply’ will allow for a perfect release from the knife edge/nosebar. Most belting will have some form of nylon incorporated into the belt weave itself, as this helps avoid abrasion and increases the shelf life of the biscuit conveyor belt.

Types of Weaves for Conveyor Belts

To help with the requirement for pull and release, different types of weaving of the conveyor belt can be used. You will notice a pattern when viewing a non-coated biscuit or cracker from the bottom. This is the pattern from the weave of the conveyor belt imprinted onto the biscuit. There are three main types of weaving methods for woven conveyor belts:

Plain Weave

They are traditionally used on conveyor belting, the most common weave form. The plain weave provides consistent biscuit production performance, making it a versatile solution for all conveyor belting requirements.

Twill Weave/Herringbone Weave

Twill weave and herringbone weave mean the same thing within conveyor belt weaving. This distinct pattern is reflective of herringbone stitched materials in fashion. The twill weave is a useful solution for heavy dough biscuits as the weave helps extract the biscuit/cracker from the mould roller.

Cross Twill Weave/Broken Twill Weave

Again, these belting weaves have two names; the cross twill weave and the broken twill weave. Both refer to the same type of belting weave. The cross twill weave provides an easier release from the nosebar due to its air permeability, which allows pockets of air to form, and reduces the contact area between the conveyor belt and the biscuit

Getting the Best Out of Your Rotary Belt Manufacturer

When sourcing a rotary belt manufacturer, you identify the rotary conveyor belt requirements before procurement of the belt. The best conveyor belt manufacturers will look to assess your manufacturing situation upfront to deliver a bespoke and high-quality conveyor belt system for your production needs.