Bakers running high-throughput sheeting and laminating lines know that the job can be a sticky one. Doughs must be handled with care, ensuring that they don’t overheat and break apart and that layers stay intact.

“I always explain to our customers that what you put into the system is what comes out,” said Ken Zvoncheck, director, process technology, Reading Bakery Systems. “There will always be some inherent variability with batch-mixed doughs, so the closer these can be monitored and controlled, the more consistency the process will enjoy. As an example, dough temperature and hydration variability can directly affect final sheet thicknesses, so it is imperative that the operators constantly monitor this variable in order to keep it under control.”

Consistency is what every baker strives to achieve. Poor quality doughs will cause fully automated production lines to fail or deliver products of fluctuating quality.

“The higher the capacity, the more important the constancy of ingredients, dough and ambient temperature,” said Henco van den Berg, sales engineer, Verhoeven Bakery Equipment Family. “In laminating lines, constant consistency ratios and temperature between dough and fat are also important. The faster the line runs, the faster the layer structure comes together, which could affect the layer structure. For this, it is important to choose correct line layout, with corresponding reduction steps and cooling rest phases. 

Maintaining the quality of a laminated dough means the integrity of the layers cannot be compromised.

“When laminating the dough and placing the fat between the layers, you end up with a thick dough sheet,” explained John Giacoio, vice president of sales, Rheon USA. “This sheet needs to be reduced in thickness so the final product can be formed. The process of reducing the dough sheet thickness is a critical factor in the ultimate quality of the product. When this reduction is done, it is critical that the layers of dough not be damaged. With the layers intact, the fat will be trapped so when the product is baked the fat puffs up instead of running out of the damaged areas of the dough sheet.”

This is often accomplished using rollers that reduce the sheet’s thickness, although Rheon’s method is a bit different.

“We use what we call a stretcher,” Mr. Giacoio said. “This machine pulls the dough and uses rollers in an elliptical pattern to push the dough against conveyor belts that are moving at different speeds to stretch the dough. With this method we can reduce the dough sheet without doing damage to the delicate layers in laminated products.”

Dough sheets that are shaped accurately and weighed precisely ensure a consistent product.

“Homogenous dough feeding into the pre-portioner is essential in order to subsequently shape the dough sheet,” said Matt Zielsdorf, director of sales for Fritsch, a Multivac company. “Another challenge is the even and gentle discharge of butter or margarine in order to maintain a clearly defined ratio of dough-to-fat at all times.”

He also stressed the importance of uniformity when laminating the dough sheet.

“Sensitive doughs should be processed with a folding channel with motorized belts,” Mr. Zielsdorf explained. “The active forward feed and guidance of the dough sheet during the folding motion prevents any additional tensile stresses in the dough sheet. As an option, it is also possible to use a horizontal folding station.”

Whether bakers are using butter, margarine or another type of fat for laminated doughs, the amount used will have many effects on the baked goods.

“The cost is one factor. Providing the right amount of fat in a lamination process controls the cost,” said John McIsaac, vice president of strategic business development for Reiser. “More importantly, it affects product quality. Producers want — and customers demand — a nice, even, flaky texture. If the fat application is inconsistent, the product will be inconsistent.”

Many factors contribute to maintaining layer integrity.

“Careful attention is placed in the dough sheeting process as well as the introduction of the type of fat that is being used, i.e. butter, margarine or shortening,” said Nick Magistrelli, vice president of sales, Rademaker USA. “Once that is in place, the proper equipment configuration is necessary to achieve optimal layering for the end product.”

 Precision is also important to ensure that the calorie counts for products are accurate and that equipment can run at full speed without wasting ingredients.

“A Vemag can apply a thin, even sheet very accurately,” Mr. McIsaac added. “We can also spread the fat as narrow or as wide as required.”

Resting time for doughs is essential to deliver constant product quality.

“Process control and time to rest are significant challenges in high-speed production,” said Hans Besems, executive product manager, AMF Tromp. “When the process and recipes are under control, operators have an easier job running the sheeting line. With AMF Tromp technologies, the dough will sheet continuously with little to no operator adjustments.”

Every dough has its own properties and must be handled properly for lines to run as seamlessly as possible.

“There are boundaries to what runs fluently, but the capabilities are almost endless these days, including high water absorption, gluten-free and artisan-style,” Mr. Besems said. “Relaxed reduction, stress-free dough handling in multiple steps, ensures a relaxed and uniform dough sheet, even at high capacities.”

This article is an excerpt from the May 2023 issue of Baking & Snack. To read the entire feature on Sheeting & Laminating, click here.