A jet of water with a thickness between 0.1 and 0.2 mm (0.004” and 0.008”) passes through the cake at a speed two and a half times the speed of sound. The resulting jet cuts cleanly the product, no matter if it is fresh or frozen, respecting the cold chain. The waterjet machine needs a water pump that works according to the hydraulic pressure intensifier.
Given that we have a water jet there can be straight or curve cuts. The cutting quality depends on the product itself, the product temperature and the cutting speed. An average cutting speed could be about 50 – 80 mm/s. For some very hard products, this cutting speed can be reduced to 15 mm/s, while for some semifreddo, mousse or cakes the speed can go up to 300 mm/s.
The water pumps we use in our Watercut machines were developed in the 70s. In this day and age, our main high-pressure component supplier is the company that developed this technology. Since then, water has been used for cutting metal, plastic, glass, marble, stone and many other materials. The big difference is that for cutting these materials, abrasive sand must be added to the waterjet, while for cutting food products we use just water.
In the 80s there were built high performance industrial waterjet installations. The technology was really expensive and the machines were customized for each product.
It is the major advance in many years to improve the profitability of a bakery. The operator puts the cake sheet on a special tray made of blades, he opens the door of the machine, introduces the tray into the machine, closes the door and presses the START button. While the cake is being cut, the operator may package other cakes. Within minutes he can return to the machine, open the door, and take the tray with the cake already cut. So easy.
Water crosses the cake at 2.5 times the speed of sound. The small trace of residual moisture is much lower than the result of cutting with a wet knife. No problem whatsoever if the product is distributed refrigerated or frozen.
The patented mechanism is based on a static jet that goes through the cake and it goes directly to the drain. The strength of the jet is so big that it drags air and humidity out of the room. Besides, in order to avoid water beneath the product and backsplash, the tray is built up in sharpened blades that hold the product and redirect the water to the drain. We have two tray models with different gap between blades.
The variety of products that can be cut by this method is higher than with any other method of cutting, especially if we consider that it is a suitable technique for cutting products at -20 °C (-4 °F).
A great variety of pastries, sponge cakes, tarts, millefeuilles, chocolate decorations, brownies or cookie dough can be perfectly cut by waterjet. This technology is very suitable if we have a wide and changing product selection. As a working method, it has some limitations: it is not recommended to pack immediately fresh product just after cutting that will be kept at room temperature. For chocolate, depending on the composition we can cut up to 1 cm of pure chocolate, given that the results vary on its composition. Many cut thicker chocolate layers and they cover them later with more chocolate. Thin layers, in general, don't have any problems to be cut.
Another point is the cutting of creams at temperature above freezing. They might re-stick if the consistency is low or the stream can absorb some of the cream, leaving a bigger gap between the pieces. With these general notes, some of which can be easily solved by drying a few minutes, a cold shock in the freezer, or a small change in the composition, we claim that the flexibility of the machine regarding the cutting of different products is one of its strongest points.
There are 2 main parameters that change the waterjet energy available to cut: nozzle diameter and water pressure. According to this, the bigger nozzle diameter and the bigger water pressure will result on bigger cutting power. At the same time, it can be got the same cutting power level by using a big nozzle and low pressure compared to a waterjet coming from a smaller nozzle at higher pressure. This graphic shows the relationship between the pressure (horizontal axis) and the different nozzle diameters, which determines the cutting power (vertical axis).
For example, a Watercut LX working at a fixed pressure of 2700 bar with a 0.17 mm nozzle diameter gets a similar cutting power than if we were working at 3300 bar with a 0.15 mm nozzle diameter. The Watercut LX maximum cutting power working at 2700 bar with a 0.20 mm nozzle diameter is like working at 3200 bar with 0.17 mm or at 4000 bar with 0.15 mm.
Either the Watercut LX Advance or the Watercut XS can change the water pressure from 1400 to 3500 bar thanks to the variable pressure hydraulic intensifier they work with. Both machines can work with up to 0.20 mm nozzle diameter in the full pressure range, being the most powerful waterjet cutting machines in the market.
This cutting power uses its power to cut the product. It losses energy along with the product thickness. Thus, it is not the same cutting the same product whether it is 5 mm or 80 mm thick. Watercut machines can let you also play with cutting speed. For very hard products (a frozen cake) we will need more energy during more time than for other thinner or softer products.
The machine is supplied along with our program generator. It includes the most common shapes, such as rectangles, circles, ellipses, flags. The customer chooses the portion size and pastry size.
It’s also possible to use images to create new contours and create patterns with them.
With the cutter, the production capacity is no longer limited by our ability to cut. Those hours of skilled labor become minutes of unskilled labor. We estimate an average production between 10 and 12 full sheets per hour with the standard one-nozzle machine. This is only an estimate because the time varies from less than two minutes for a frozen or fresh sponge cake to up to 12 or 15 minutes for a thicker cake, fresh, cut in small and complex shaped portions.
The first days of working with the machine, it is often used to cut in the same way as before having the machine, that is, straight cuts. From this moment the savings begin to be remarkable. The first change we notice is that there is no need to raise the temperature to cut. You may cut the amount of product you need in every moment and the rest remains in the freezer. The cold chain is maintained. Most of the products can be cut and get back to the freezer. Cutting quality is uniform, vertical, with a spotless top edge and no color movement between the layers of cake. The machine can be used by anyone in the workshop and the result is always the same.
Once the client gets used to the machine, they start the cut with shapes. We can avoid the purchase of molds, with all the added savings that it entails. In addition, we can change the size of each pie by program. We will not make size errors because of bad shaped molds. We edit a couple of millimeters longer, or a couple narrower and in two minutes we have new shapes ready to be cut. From this moment the machine is a key part of the business. The cutting time is significantly reduced compared to the previous days and we get more qualified staff to perform other operations.
Although any change process is progressive, Watercut changes happen quickly. The reduction in production costs is so obvious that customers soon redirect its entire production to pass through the machine. On the basis of working frozen, the machine will reduce the production of round cakes, promoting the use of full sheets. From these sheets you obtain both individual portions and family cakes, which become square or rectangular. This means savings in freezing cabinets, handling, packaging ... We continue to serve individual portions like those coming from round cakes, but you get them from sheets! Professional clients appreciate that all pieces are equal, and most of all, they know that from a cake box they get an exact number of servings, thus knowing well the exact cost per serving.
Forms previously made with molds that involve some waste of material when cut with water are gradually being removed from the catalog (i.e. octagons), and they changed by forms with no waste (hexagons or flags). The reason is not the loss of material, but the additional work needed to remove these small pieces at the time of packing. We accept these small losses in special forms such as Valentine's hearts or other special shapes. The cutting machine is so precise that when cutting circles, the loss among the circles does not exceed 17% of the material.
The baker's imagination with this machine has a new weapon to create new products. You can cut pieces of chocolate or candy to decorate cakes as a basis for new creations, pieces to put in cups, cookies or biscuits before baking, canapés, plus all the usual products such as pastries, parfaits or mousses.
Although every Watercut model has enough power to cut frozen cakes and chocolate decorations, machines are sorted depending on how important cutting complex chocolate decorations is for you.
If cutting pastry pieces is the most important task, we recommend either the Watercut LZ or the Watercut LX, being the second one more powerful than the first one.
Both machines can cut chocolate decorations, but if we want to cut complex desings, we can just add an ON/OFF valve to the Watercut LX to cut holes.
The Watercut LX Advance always has the ON/OFF valve and it can also set the pressure from 1400 to 3500 bar. At last, the Watercut XS mechanics are designed focused on complex chocolate decoration cut at the highest precision and speed in the market. It can also, at the same time, cut deep frozen cakes given the huge cutting power it has.
The tray has references to place the product correctly. The operator must place the cake always in relation to the marks on the grid. It is easy. You do not need any special training to use the machine as an operator, just some general ideas of security.
The most convenient is to use large spatula (palettes) to remove various portions in each movement, especially if they are to be distributed without prior separation in collective boxes.
You have two trays to introduce the products into the machine, and the products just touch their tray and the water, so no cross-contamination of flavors or colors between different products is possible. To choose a program you press its name in the touch screen, and each program will have memorized the thickness of the cake (in the Watercut LX Advance and Watercut XS), the cutting speed for that particular product and with what shape it should be cut. The machine can store more than 2500 programs organized into 64 different folders.
With a production of about one tray every 2 to 5 minutes (depending on cuts and products), the one-jet machine ensures the production of an enterprise without having to worry about increases in production. On the other hand, production of an hour and a half per day is sufficient to amortize the machine from the standpoint of the cost of labor. From this production on, the machine is, from the economic point of view, essential.
First, the machine replaces the cutting hand work, doing the work faster and with a better quality. In a workshop, cutting accounts for 20% of the work. With a workforce of 5 people, payment is made in 4 or 5 years, in case there are 10 persons working then the machine is paid in two years just thinking of the hand work savings.
Secondly, the machine can change the way of work, and also allows the creation of new products. Read mold removal, preparation of cakes, canapés cutting. Experience shows that increasing the added value of products is more important than the savings in the cost of direct labor (hand work). Machine customers earn up to 50% more in some products with shapes in comparison with the same product cut in rectangles. In other cases, the selling price is maintained, obtaining very substantial growth in sales.
Then, we can say that taking into account the increase in production capacity and the increase in the added value of products, the benefits of a Watercut are much higher than the mere calculation of savings in labor. Anyway, the repayment period is very interesting by itself. In practice, most customers have increased the manpower of the workshops because their profit aspirations become much higher than before buying the machine.
The actual cost of maintenance, energy and amortization apart, extracted from historical data for a one nozzle machine, is under 4 euros per each hour of effective cutting. In one hour we estimate a production of 10 or 12 trays, then we have a cost of 40 cents per tray. We must be warned about receiving bills of more than 1,000 euros at certain times (including in the estimated cost). These figures should be viewed in the context of all the work that the machine makes, and do not compare it to the maintenance of other machines (blenders and refrigerators). With proper maintenance, the machine has a high duration. The first machine installed in 2003 is still working two shifts for several months a year. After the first year, maintenance costs will remain fairly stable, with some cost peaks every 2 to 3 years.
The implementation period of a standard Watercut model is 2 days. In less than 4 hours, plumbers and electricians from the client connect the machine to the water intake (you need a water softener and filters), compressed air, drainage and electricity. The moist air out of the machine can be connected later. The first day the machine is operating at 100% and the first cuts are made. The second day our technician teaches how to use the machine and production may start. He also teaches how to use the software Watercut Creator and how to perform basic maintenance to the machine. In remote installations we can stay a longer to reinforce the knowledge acquired while production is taking pace.
Metronics Technologies has a team with 6 engineers available to solve any problem. The pieces which will need more frequent maintenance are the components related to high pressure: water pump, valves and nozzles. We have stock of high pressure components and technicians in Pamplona (Spain) and Strasbourg (France). The components we use are supplied by a very well-known American company, which provides high quality and reliability. They have offices in a number of countries around the world and can serve in 24 hours in most cases.
During the commissioning, depending on the time and the availability of the customers, our technicians will train them in the maintenance of the machine. It is not compulsory that our technicians perform maintenance. After the first service, a large number of clients learn to make their own maintenance.
Cutting by mechanical cutters, ultrasonic cutters, molds and knife techniques are available to us at the workshop. Let's review their characteristics. Mechanical and ultrasound cutting blades: They are suitable for packaged products that must be kept at room temperature, water is not recommended for that. Production costs are low with simple blades and closer to waterjet in the case of ultrasound. The product range is more limited than with the cut by water, because some products just break or move over the trays. In general, knives are appropriate in a limited number of products of high cadence, at temperatures not too low, with low flexibility of use with different products, and provided that the cut is straight, of course.
Regarding the use of molds, costs are dramatically lower with water jet cutting. Savings come from the purchase of the molds, labor, mold cleaning, possible contamination, flexible forms with immediate dimension changes... Watercut cutters can make all the production at a lower cost than cutting straight. When cutting with knives you need qualified personnel to mark properly the cakes and also cutting staff, and you get low uniformity in cut quality, variations in staff performance, in some cases rupture of the cold chain, a possibility of contamination by the tool and by the person, and most important from the standpoint of sales: Every competitor has a knife. We cannot differentiate from the competition in any other way than lowering prices. In markets where the waterjet cutters are well known, professional customers (restaurants, hotels) prefer the pastry cut to customized shapes.
This way, price is no longer the issue, we can now customize products to each customer, so no comparison in prices is possible.
If you’re interested in the Watercut services, don’t hesitate to contact us. Send us an e-mail and your telephone and we will answer you as soon as we can