Procedure for testing beverage crates

Abstract

The invention relates to a method for testing beverage crates. The method comprises arranging (11) a crate stack (101) having at least one layer of beverage crates (102), performing a first measurement (21) of the stack height to determine a reference height of the crate stack (101) before a compression test (13) begins, a compression test (13) of the crate stack (101) by applying a compressive force to the crate stack (101), performing a second measurement (22) of the stack height during the compression test (13), and calculating (31) a predicted compression of the crate stack (101) from measured values ​​of the first measurement (21) and second measurement (22). The invention further relates to a corresponding compression testing device and a print head (110), as well as a base (120) for use in the method.

Description

[0001] The invention relates to a method for testing beverage crates.

[0002] In light of climate change, environmental awareness is increasing among the population, and the desire for sustainable packaging solutions is growing. Mineral water companies and breweries are responding to this trend by converting their bottling lines from disposable packaging to reusable systems. The demand for beverages in glass bottles is also increasing. This results in higher individual load units. At the same time, efforts are being made to stack beverage crates ever higher for efficiency reasons.

[0003] This leads to greater mechanical stress on the beverage crates when stacked. To ensure sufficient strength of the beverage crates, a reusable crate stability test is required, specifically to predict the long-term stability of the stacked load units. This test is called the "pallet impact test."

[0004] Typically, a number of pallets loaded with beverage crates are stacked on top of each other, with the height of the resulting crate stack being measured over a period of 21 days. Such a pallet impact test is described in the document "German Brewers' Association eV; pro-K Industrial Association for Durable Plastic Products and Reusable Systems eV: Special Technical Terms and Conditions of Delivery and Purchase (STLB) for Bottle Crates Made of PE-HD. Berlin; Frankfurt am Main, June 2023." Disadvantages of the known method are a long measurement period of at least 21 days and the large amount of space required, which is caused by a large pallet surface in the horizontal plane and a large stack height in the vertical direction.

[0005] The present invention is based on the object of providing a method and a pressure testing device for an improved pallet impact test, which have the same significance as conventional tests with reduced effort.

[0006] This object is achieved by a method having the features of patent claim 1, a pressure testing device having the features of claim 17, and a use according to claim 18. Embodiments of the invention are specified in the dependent claims.

[0007] According to a first aspect, the invention provides a method for testing beverage crates. The method comprises arranging a crate stack comprising several stacked layers of beverage crates, performing a first measurement of the stack height to determine a reference height of the crate stack before a crush test begins, performing a crush test of the crate stack by applying a compressive force to the crate stack, performing a second measurement of the stack height during the crush test, and calculating a predicted crush of the crate stack from measured values ​​of the first and second measurements.

[0008] The invention is based on the finding that the future compression behavior of beverage crates can be accurately predicted mathematically. By calculating a predicted compression, it is possible to conduct a pallet impact test over a shorter period of time by comparing the measured values ​​from the first and second measurements. Based on this, a statement about the compression can be made, for example, after 21 days.

[0009] Applying a compressive force to the stack of crates allows a specific load to be simulated without this actually corresponding to the structure. In this sense, it can also be referred to as a "forced pallet impact test" because a load can be forced independently of the actual stacking. This means, for example, that with just a few layers of beverage crates, a load can be simulated that is normally only achieved by stacking many beverage crates. This has the advantage of a significantly smaller test setup, in particular the advantage of a lower stack height. Furthermore, unlike conventional tests, empty beverage crates that are not filled with full bottles can be used. This makes handling much easier.The method thus allows testing over a shorter period of time and with reduced space, because the beverage crates do not need to be stacked as high.

[0010] Please note that a measurement, in the sense of the first or second measurement, is understood to mean the recording of measured values. It may be intended that a single measurement may include recording multiple measured values ​​at different measurement times.

[0011] In one embodiment of the invention, a limit value comparison is provided, which checks whether the predicted compression of the crate stack is below a predefined first value. The limit value can correspond to the limit value already existing for the 21-day test.

[0012] In a further embodiment of the invention, a base load is applied to the crate stack during the first measurement to determine the reference height, eliminating any play between the individual layers. The base load improves the repeatability of the stack measurement by minimizing the risk of the crates in the stack tipping slightly or other effects occurring that could accidentally influence the stack height. In a preferred variant, a certain period of time is waited after the base load has been applied before the first measurement is carried out. For example, it can be provided that the first measurement of the stack height is carried out 30 minutes after the base load has been applied. The base load can, for example, be 1600 N for a standard pallet, so that a pallet with an area equivalent to a quarter of this results in a base load of 400 N.

[0013] A further embodiment of the invention provides that after the compression test, the crate stack is unloaded, and after a defined time, a third measurement of the stack height is performed to determine the residual compression. During the third measurement, the residual compression is calculated from the first and third measurements. After the compression test, when the crate stack is unloaded, the material of the beverage crates returns to its original position to a certain extent, so that the height of the crate stack also increases again by a certain amount after the unloading.

[0014] The residual compression can be calculated from the first and third measurements and compared with a predefined value.

[0015] Advantageously, the third measurement is performed 24 hours after the end of the compression. The value of the first measurement is used as a reference value, with which the stack height value of the third measurement is compared.

[0016] If a base load acts on the box stack during the first measurement, it is intended to allow the same base load to act on the box stack during the third measurement to determine the residual compression, for example 400N.

[0017] The number of beverage crates in a layer can be half or a quarter of the number of beverage crates that can be arranged side by side on the modular dimensions of a standard pallet. In this respect, the support surface for the beverage crates can be halved or quartered compared to a standard pallet. The standard pallet dimensions are considered to be industry-standard pallet sizes, such as the EURO pallet or the GMA pallet.

[0018] This allows the area occupied by the test setup to be significantly reduced. This not only allows for a simpler setup but also makes it easier to test additional factors during the pallet impact test. For example, the crate stack can be subjected to additional thermal stress through heat input during the crush test. The smaller setup allows for easy placement of thermal insulation around the crate stack.

[0019] To ensure the test force per beverage crate remains consistent, the compressive force applied during the crush test can be set proportionally to the number of beverage crates in a layer. This means that, for example, if the support surface is half the size of a standard pallet, only half the compressive force will act on the beverage stack. The compressive force can be generated by weights that assume the weight of the full load.

[0020] The numerical value of the load acting on the crate stack during the crush test depends on the load capacity of the crate type specified by the manufacturer for a standard pallet. For example, the full load applied during a crush test may be: Full load: [Intended test weight for pallet impact test with standard pallet, number of box columns on a standard pallet / number of box columns on a test fixture]

[0021] If a beverage crate is stacked on top of another beverage crate, forming a stack of individual beverage crates (i.e., each layer consists of only a single crate), the resulting stack is called a "crate column." The number of crate columns therefore indicates the number of beverage crates that can be arranged next to each other in each layer.

[0022] It can be provided that when arranging the crate stack, at least two, in particular three, layers of beverage crates are arranged on top of each other to form the crate stack. Due to the plurality of layers, the behavior can be simulated when the beverage crates lie directly on top of each other, despite the reduced size structure. The advantage of three layers is that the middle layer is in contact with another layer both at the top and bottom and is therefore exemplary for corresponding layers in a structure with more than three layers. At the same time, the bottom and top layers can each be used to investigate possible influences at the top / bottom edge of the crate stack, for example from a pressure stamp, and at the bottom edge, for example from a base.

[0023] In one design variant, the crate stack is arranged with a maximum of three layers of beverage crates stacked on top of each other. Alternatively, a maximum of 4, 5, 6, 7, or 8 layers can be arranged on top of each other. The limited number of layers ensures a compact structure.

[0024] The layers can be arranged in a column stack so that the beverage crates each form individual crate columns that are arranged next to each other.

[0025] Alternatively, composite stacking can be used. This involves a different arrangement of beverage crates for each layer. This ensures that the load of the beverage crates is not directly transferred from one crate to the crate below, but rather the force is more evenly distributed within the crate stack.

[0026] In a further embodiment of the invention, the compression test is carried out over a maximum period of 14 days, preferably over a period of 7 days. Due to the shortened compression test time, the overall measurement period can be significantly shortened. This increases efficiency, as more pallet impact tests can be performed in a shorter time on a single test device.

[0027] In particular, it may be provided that a compression forecast is made for a period of 21 days based on the measured stack heights.

[0028] In an advantageous embodiment of the invention, a plurality of stack height measurements are taken at different times for the second stack height measurement during the compression test. In particular, it can be provided that the second measurement comprises three stack height measurements.

[0029] Measurements can be taken one hour after the start of the compression test, after 25 hours, and after 169 hours. A prediction of the compression can be made from these three measurement times.

[0030] Alternatively or additionally, the stack height can be measured after one hour, after 24 hours, after 48 hours and / or after 168 hours as part of the second measurement.

[0031] In a further variant of the invention, it is provided that the value of the predicted compression y is proportional to the natural logarithm of time, plus a coefficient b.

[0032] In particular, it may be provided that the calculation of the predicted compression is calculated using the following formula: y=a∗ln(x)+b

[0033] Where a and b are coefficients resulting from the measured values ​​of the first and second measurements. The value x corresponds to the number of hours of the compression test.

[0034] The calculation predicts correlations that have traditionally been determined on the basis of the classic 21-day test.

[0035] The coefficients a and b can be calculated using the least squares method. This involves the following calculation steps: 1. Calculate the natural logarithm of all x-values ​​(ie time values) using the corresponding formula: In(x i ) 2. Calculate the mean values ​​of In (x) and y using the corresponding formulas: ln(x)¯=1n∑i=1nln(xi) y¯=1n∑i=1ny1 3. Calculate the coefficients a and b by: a=∑i=1n(ln(xi)−ln(x)¯)∗(yi−y¯)∑i=1n(ln(xi)−ln(x))2 b=y¯−a∗ln(x)¯

[0036] In a further embodiment, the beverage crates in the crate stack are arranged so that the crate stack has four outer edges. The stack height is measured at two opposite outer edges of the crate stack. The average of the values ​​determined at the outer edges represents the measured stack height. Alternatively, it can be provided that a measurement is taken at all four outer edges and the corresponding average is calculated. Furthermore, it can be provided that the stack height value is determined from the distance between a print head resting on the crate stack and a base resting beneath the crate stack, so that only a single measured value is taken.

[0037] In a further embodiment, the stack height is measured electronically by automatically detecting the distance between a printing stamp and a substrate. For example, the use of a high-resolution optical-tactile measuring system is envisaged.

[0038] In one variant of the invention, the forces are applied to the crate stack by means of test weights. For this purpose, for example, an upper pressure head can be arranged above the crate stack, onto which weights are placed, exerting a corresponding compressive force on the crate stack.

[0039] In one design variant, the forces on the crate stack are applied by a compression testing device. This device uses a universal compression testing machine that can apply a defined force to the crate stack. The force can be electronically controlled. Furthermore, the compression testing device can provide integrated stack height measurement by incorporating an electronic measuring system into the compression testing device.

[0040] A further aspect of the invention relates to a pressure testing device. The pressure testing device comprises a base designed and configured to receive a stack of boxes. Furthermore, a pressure head is provided, which is designed and configured to apply a pressure force from above into the stack of boxes arranged on the base. The pressure testing device comprises a controller designed and configured to perform the following steps: - Carrying out an initial measurement of the stack height to determine a reference height of the box stack before starting a crush test, - Compression test of the box stack by applying a compressive force to the box stack using the pressure head, - Carrying out a second measurement of the stack height during the crush test, - Calculate a compression of the box stack from the first and second measurements.

[0041] A further aspect of the invention relates to the use of a base of the type discussed below in the method according to the invention. The base is intended and designed to correspond to a section of a standard pallet. The base has an upper support surface on which the bottom layer of a crate stack can be positioned, wherein the support surface corresponds to half or a quarter of a standard pallet and wherein the pallet is designed and intended to accommodate half or a quarter of the beverage crates that fit on a standard pallet. The base corresponds to the basic shape of a pallet. It comprises an underside with skid-shaped base boards that are intended and designed to support the compressive force. The base boards are arranged such that the compressive force is absorbed to a greater extent at overlap points between the base board and the support surface.For this purpose, for example, additional blocks can be arranged in the overlap area.

[0042] A further aspect of the invention relates to the use of a pressure head of the type discussed below in the method according to the invention. The pressure head has the basic shape of a pallet and is intended and configured to correspond to a section of a standard pallet and to introduce a compressive force onto the crate stack. The pressure head comprises a bottom surface configured to be in contact with the upper edge of the crate stack and to introduce the compressive force of the pressure testing device into the crate stack, wherein the bottom surface corresponds to half or a quarter of a standard pallet and is designed and configured to be in contact with half or a quarter of the beverage crates that fit on a standard pallet.

[0043] In the case of the print head and / or the base, it can be provided that the surface facing the crate stack is formed by cover boards that run transversely to the skid-shaped base boards. Additional reinforcement can be attached at the overlap points between the base boards and the support surface. For example, in the case of the print head, a block can be arranged between the base board and the support surface. Accordingly, the arrangement of a block can also be provided for the base. In this case, it can be provided that the skid-shaped base boards are arranged at corner points below the support surface and that an additional block is arranged underneath each one, so that the base only rests on the floor at the four corners of the pallet. A block is understood to be an additional layer of material that corresponds, for example, to the thickness of a board.

[0044] The base and / or the print head can be made of steel.

[0045] The invention is explained in more detail below with reference to the figures of the drawing using several exemplary embodiments. They show: Fig. 1 a flowchart of the process steps of a method for testing beverage crates; Fig. 2 a flowchart of the method steps of an embodiment of the method steps of a method for testing beverage crates; Fig. 3 a representation of a stack of boxes in two side views and an isometric representation; Fig. 4 shows a representation of a testing device for carrying out a method for testing beverage crates; Fig. 5 a representation of two layer images showing the arrangement of the beverage crates on a standard pallet; Fig.6 is a perspective view of a quarter pallet pressure head which can be placed on a stack of boxes and is designed to transmit a pressure force into the stack of boxes, with transverse boards resting on longitudinal boards via intermediate blocks; Fig. 6a a perspective view of a quarter pallet print head with a symmetrical structure in which transverse boards rest directly on longitudinal boards; Fig. 6b is a perspective view of a quarter pallet print head with an asymmetrical structure in which cross boards have different widths; Fig. 7 is a perspective view of a quarter pallet base used as a base for a stack of boxes; and Fig. 7a a perspective view of a quarter pallet base with an asymmetric structure in which cross boards have different widths.

[0046] The Fig.Figure 1 illustrates a method for testing beverage crates. It examines their behavior under compression loading. The compression of beverage crates is typically performed using a 21-day pallet impact test, in which a large number of beverage crates are stacked in stacked layers on a pallet and tested over a test period typically lasting 21 days. In contrast, the method presented allows for testing over a shorter period of time, with a simplified setup that requires less space and requires the crates to be stacked lower.

[0047] In a first step 11, the beverage crates are stacked on top of each other to form a crate stack and placed, for example, in a pressure testing device. The pressure testing device is based on the Fig.3 and serves to exert a compressive force on the stack of boxes, causing it to be compressed. The compression test device can be an electric compression test device or a device with attachable test weights.

[0048] Once the crate stack is positioned in the compression testing device, a first measurement 21 is performed. This determines the stack height of the crate stack without any applied compressive force. When measuring the stack height, it can be provided that an average of various measurements is calculated. For example, the stack height can be measured at each outer edge of the crate stack. The stack height refers to the height between the bottom and top edges of the entire crate stack. The stack height is measured, for example, using an optical-tactile measuring instrument.

[0049] After the first measurement 21, the crush test 13 begins. A test load is applied to the stack of crates. The test load acting on the stack of crates during the crush test can vary depending on the type of beverage crate. The numerical value of the test load depends on the load for which the respective crate type is intended according to the manufacturer and how many crate columns are arranged in the crate stack. If a beverage crate is stacked on top of another beverage crate to form a stack of beverage crates, with each layer consisting of only a single crate, the resulting stack is referred to as a "crate column". The number of crate columns therefore refers to the number of beverage crates that are arranged next to each other in each layer.

[0050] The full load specification is generally based on the load applied when using a standard pallet. Accordingly, the full load is reduced if the test fixture is smaller. For a half-pallet, the test load is halved, and for a quarter-pallet, it is quartered. Thus, the full load applied during a crush test can be specified as: Full load: [Intended test weight for pallet impact test with standard pallet, number of box columns on a standard pallet / number of box columns on a test fixture]

[0051] The specified test weight for pallet impact testing with standard pallets depends on the manufacturer and can typically be approximately 2400 kg or 2500 kg. However, this value can be freely selected.

[0052] Alternatively, the applied full load can also be calculated based on the number of box columns. One possible calculation for this is: 300 kg∗Number of box columns

[0053] For example, a layer can be configured to only correspond to half or a quarter of the number of beverage crates that can normally be arranged side by side on a pallet. Accordingly, if the number of crates is half, the applied compressive force is also reduced by half.

[0054] In a second measurement 22, the stack height is measured during compression. Due to the compressive force, the stack of boxes is compressed. The height of the stack of boxes decreases and is recorded by measurement.

[0055] Based on the first measurement and the second measurement, a projection 31 can be made in which a predicted future compression is calculated.

[0056] For example, it may be planned that the compression is carried out over a period of 7 days and then, based on the measurements, a compression is calculated over a period of 21 days.

[0057] The Fig. Figure 2 presents an exemplary embodiment of the method. After arranging the crates stack 11, a base load 12 is applied. The base load can be low, for example, 400 N for a standard pallet. A standard pallet can be a EURO pallet or a comparable pallet that is standard in other regions or industries (e.g., a GMA pallet). The base load ensures improved repeatability of the stack measurement by minimizing the risk of the beverage crates in the beverage stack tipping slightly or other effects occurring that could accidentally influence the stack height.

[0058] In a preferred variant, a certain period of time is waited after the base load is applied in order to perform the first measurement 21. For example, it can be provided that the first measurement 21 to determine the stack height is performed 30 minutes or 60 minutes after the base load is applied.

[0059] The compression test 13 then begins, during which a test load is applied. During the compression test, the second measurement 22 of the stack height is taken. Three individual measurements are taken at different times. The measurement times are 1, 25, and 169 hours after the test load is applied.

[0060] From the first measurement 21 and the second measurement 22, a future compression can be mathematically predicted. y=a∗ln(x)+b

[0061] Here, a and b are coefficients resulting from the measured values ​​of the first measurement 21 and the second measurement 22. The value x corresponds, for example, to the number of hours of the compression test.

[0062] To predict the compression of the crate stack after 21 days according to formula (1), the height of the stack is measured at four points in time: • Stack height H1 at the first time x1: 30 minutes after placing the base load of 400 N on the stack • Stack height H2 at the second time x2: 1 hour after applying the full load • Stack height H3 at the third time x3: 25 hours after applying the full load • Stack height H4 at the fourth time x4: 169 hours after applying the full load • Full load: [Intended test weight for pallet impact test with standard pallet, number of box columns on a standard pallet / number of box columns in a test device]

[0063] This gives the percentage compression of the stack at time x 2;3;4 calculated • After 1 hour (x1): y1=100H1−H2H1 • After 25 hours (x2): y2=100H1−H3H1 • After 169 hours (x3): y3=100H1−H4H1

[0064] The coefficients a and b of formula (1) can be calculated using the least squares method. This involves the following calculation steps: 1. Calculate the natural logarithm of all x-values ​​using the corresponding formula: In(x i ) 2. Calculate the mean values ​​of In (x) and y using the corresponding formulas: In(x)¯=1n∑i=1nIn(xi) y¯=1n∑i=1ny1 3. Calculate the coefficients a and b by: a=∑i=1n(In(xi)−In(x)¯)∗(yi−y¯)∑i=1n(In(xi)−In(x))2 b=y¯−a∗In(x)¯

[0065] The following is an example calculation for a measurement over a compression period of 169 hours.

[0066] Calculation of the predicted compression and limit value comparison according to the example calculation: Initial values: (x1; y1) = (1 h; ~0.46%) (x2; y2) = (25 h; ~0.56%) (x3; y3) = (169 h; ~0.68%) Calculating the natural logarithm of all x-values: In(1) = 0 ln(25) = ~3,219 In(169) = ~5.130 Calculating the mean values ​​of In(x) and y: In(x)¯=0+3,219+5,1303=∼2,78292 y¯=0,46+0,56+0,683=∼0,56833 Calculation of the coefficients a and b: a=(0−2,783)∗(0,46−0,57)+(3,219−2,783)∗(0,56−0,57)+(5,130−2,783)∗(0,68−0,57)(0−2,783)2+(3,219−2,783)2+(5,130−2,783)2 = ∼0,04194 ∗ b = 0,57 - 0,04194 ∗ 2,783 = ~0,45160 Logarithmic forecast formula for 21 days (504 h): 0,04194 ∗ ln(504) + 0,45160 = 0,71259 Measured percentage compression after 21 days: 0.70548% Logarithmic forecast formula for 28 days (672 h): 0.04194 ∗ In(672) + 0.45160 = 0.72466 Measured percentage compression with simple standard deviation after 28 days: 0,73352% ± 0,01985%

[0067] The calculated compression values ​​can then be compared in a limit value comparison 32 with limit values ​​from the conventional 21-day test, so that a statement on stability can be made on the basis of existing and proven stability tests.

[0068] After the compression test, the test load is removed from the crate stack. The crate stack is then unloaded 14, during which the material of the beverage crates partially returns to its original position and the overall stack height increases. During unloading, no compressive force acts on the crate stack.

[0069] Following the unloading 14, a third measurement 23 is taken, during which the stack height of the residual compression is determined. The base load applied in step 12 is then reapplied to the crate stack for the first measurement of the stack height 21. A certain time interval is provided between the unloading 14 and the third measurement 23. In this case, the third measurement 23 is taken 24 hours after the unloading, with the provision that no compressive force acts on the crate stack during this time. Alternatively, a time interval of, for example, 12 hours, 48 ​​hours, or 72 hours can also be provided.

[0070] The amount of residual compression can be compared with the values ​​of the second measurement 22 and / or the values ​​of the first measurement 21. Particularly with regard to the second measurement, it can be provided that certain limit values ​​are not exceeded.

[0071] After completing measurements 21, 22, and 23, an additional visual inspection 24 of the crate stack is planned. This involves examining the individual beverage crates for cracks or structural changes, for example. For this purpose, the crate stack is disassembled 15 into its individual components.

[0072] The Fig. Figure 3 shows an arrangement of a box stack 101 to be tested in two side views and an isometric view. The box stack 101 rests on a base 120, which serves as a foundation. A pressure head 110 is arranged on the box stack to apply the pressure force to the box stack 101. The pressure head 110 and base 120 have the basic shape of a part of a standard pallet and are in Fig. 6 and Fig. 7 is explained in more detail.

[0073] The crate stack consists of a plurality of beverage crates 102 arranged in three stacked layers 130. Two beverage crates 102 are provided for each layer 130, each of which is adjacent to the other along its longer side. However, this is only an example and may depend on the beverage crates 102 used. For example, it may be intended to test "half" beverage crates whose base area corresponds to half of a standard beverage crate 102, so that instead of two beverage crates 102 per layer, four "half" beverage crates are used.

[0074] The Fig. Figure 4 shows a side view of a pressure testing device 100. The crate stack 101 consists of beverage crates 102 arranged in three layers one above the other. The crate stack 101 rests on a base 120, which is arranged on a solid surface 121. A pressure head 110 is arranged above the crate stack 101.

[0075] The print head 110 is arranged between an upper edge of the box stack 101 and an intermediate layer 111. The intermediate layer 111 is designed to apply a downward compressive force 112 evenly to the print head. The compressive force 112 is symbolized here by the arrow. It is applied either by test weights resting on the intermediate layer 111 or by a pressure stamp of a pressure testing device.

[0076] The compression testing device can be a universal testing machine in which the intermediate layer 111 or the pressure head 110 is mechanically or hydraulically subjected to a compressive force by a stamp, which causes compression of the crate stack 101. In this case, an automatic measuring device for measuring the stack height, for example, an electronic measuring device, can be integrated into the compression testing device.

[0077] Furthermore, the compression testing device includes a controller 113. The controller 113 is designed to monitor the corresponding instructions for the compression test. The controller 113 can be designed for both a compression testing device 100 with test weights and a compression testing device.

[0078] The Fig. 5 shows two different layer images 130. The layer images 130 represent the arrangement of the beverage crates in a respective layer. The two illustrations each show a variant with which the beverage crates can be stacked on a EURO pallet.

[0079] The Fig.6 depicts a pressure head 110. The pressure head 110 corresponds to half or a quarter of a classic standard pallet and is used to introduce the compressive force into the crate stack. Two transverse boards 1101 extend along the top side of the pressure head 110. The transverse boards 1101 are designed to be in contact with the intermediate layer 111. Two skid-shaped base boards 1103 extending in a longitudinal direction are arranged underneath. The skid-shaped base boards 1103 are designed to transfer the compressive force to the upper edge of the crate stack 101. A block 1102, which has the width of a board, can be arranged between the skid-shaped base boards 1103 and the transverse boards 1101 in the overlapping area.

[0080] The Fig. 6a and Fig. 6b illustrate alternative embodiments of the printhead 110. The Fig.6a shows an embodiment in which a block between the skid-shaped floor boards 1103 and the cross boards 1101 has been omitted, so that they rest on one another.

[0081] The Fig. Figure 6b illustrates an asymmetrical design of a print head 110. The print head comprises two cross boards 1101, each of which, however, has a different width. This allows for testing under asymmetrical load conditions, for example, when beverage crates are to be tested that have an inherently asymmetrical weight distribution, so that the load conditions are also asymmetrical. The asymmetrical force application can, in particular, lead to insights being gained during a visual inspection 24 of the beverage crates after the crate stack 15 has been dismantled, since the uneven force application reveals cracks or other detectable material fatigue.

[0082] The Fig.Figure 7 shows a base 120 with the basic shape of a section of a standard pallet. The base 120 has a support surface 1201 formed from longitudinally extending bottom boards. Two lower boards 1202 are arranged below this support surface and extend transversely thereto. In the area of ​​the corners of the pallet 120, a block 1203 is additionally arranged below each of the lower boards, on which the pallet 120 stands.

[0083] Depending on the print head 110, the design of the base can also be symmetrical or asymmetrical. Fig. 7a shows an asymmetric base with two cross boards 1202 of different widths.

[0084] Both the print head 110 and the base 120 can be made of steel.

[0085] It is understood that the invention is not limited to the embodiments described above, and various modifications and improvements may be made without departing from the concepts described herein. It is further understood that any of the described features may be used separately or in combination with any other features, provided they are not mutually exclusive. The disclosure extends to and includes all combinations and subcombinations of one or more features described herein. Where ranges are defined, these include all values ​​within these ranges, as well as all subranges that fall within a range.

Claims

[1] Method for testing beverage crates, comprising the steps: - Arranging (11) a stack of crates (101) comprising at least one layer of beverage crates (102), - Performing an initial measurement (21) of the stack height to determine a reference height of the box stack (101) before a compression test (13) begins, - Compression test (13) of the box stack (101) by applying a compressive force to the box stack (101), - Performing a second measurement (22) of the stack height during the compression test (13), and - Calculating (31) a predicted compression of the box stack (101) from measurements of the first measurement (21) and second measurement (22). [2] Method according to claim 1, characterized by , that in a limit comparison (32) it is checked whether the predicted compression of the box stack (101) is below a predefined first value. [3] Method according to claim 1 or 2, characterized by , that during the first measurement (11) to determine the reference height a base load acts on the stack of boxes (101) which eliminates any play between the individual layers. [4] Method according to any of the preceding claims, characterized by , that after completion of the compression test (13) the stack of boxes (101) is relieved (14) and after a defined time a third measurement (23) of the stack height is carried out to determine a residual compression, whereby the residual compression is calculated from the first measurement (21) and third measurement (23) and compared with a predefined value. [5] Method according to claims 3 and 4, characterized by , that the base load also acts on the stack of boxes (101) during the third measurement (23) to determine the residual compression. [6] Method according to any of the preceding claims, characterized by, that the number of beverage crates (102) in each layer corresponds to half or a quarter of the number of beverage crates (102) that can be arranged side by side on the module dimension of a standard pallet. [7] Method according to any of the preceding claims, characterized by , that the compressive force (112) applied during the compression test (13) is proportional to the number of the respective beverage crates (102) in a layer. [8] Method according to any of the preceding claims, characterized by , that in the arrangement (11) of the crate stack (101) at least two, in particular three layers of beverage crates (102) are arranged one above the other, forming the crate stack (101). [9] Method according to any of the preceding claims, characterized by , that in the arrangement (11) of the crate stack (101) a maximum of three layers of beverage crates (102) are arranged on top of each other, forming the crate stack (101). [10] Method according to any of the preceding claims, characterized by , that the compression test (13) is carried out over a maximum period of 14 days, preferably over a period of 7 days. [11] Method according to any of the preceding claims, characterized by , that the second measurement (22) of the stack height during the compression test (13) comprises a plurality of measurements of the stack height at different times, in particular that the second measurement (22) comprises three measurements of the stack height. [12] Method according to claim 11, characterized by , that as part of the second measurement (22) the stack height is carried out after one hour, after 24 hours, after 48 hours and / or after 168 hours. [13] Method according to any of the preceding claims, characterized by , that in calculating (31) the predicted compression y a value is calculated which is proportional to the natural logarithm of time, plus a coefficient b. [14] Method according to claim 13, characterized by , that the calculation (31) of the predicted compression using the formula y=a∗In(x)+b this is done, whereby y the predicted compression is, x is the time, for example in hours, and a and b coefficients are derived from measured values ​​of the first measurement (21) and second measurement (22). [15] Method according to claim 14, characterized by , that the coefficients a and b are calculated using the least squares method, whereby a percentage compression is calculated at different times, which results from the reference height minus the stack heights measured at the second measurement, and an average is formed from this, which is included in the calculation. [16] Method according to any of the preceding claims, characterized by, that the stack of boxes (101) has four outer edges and the measurement of the stack height is taken at two opposite outer edges of the stack of boxes (101) and then the mean of the determined values ​​is formed. [17] Pressure testing device for carrying out the method according to one of the preceding claims, comprising: - a base (120) designed and constructed to receive a stack of boxes (101), - a print head (110) designed and configured to apply a pressure force (112) from above into the stack of boxes arranged on the base, - a controller (113) designed and trained to perform the following steps: - Performing an initial measurement (21) of the stack height to determine a reference height of the box stack (101) before a compression test (13) begins, - Compression test (13) of the box stack (101) by applying a pressure force through the print head to the box stack (101), - Performing a second measurement (22) of the stack height during the compression test (13), - Calculating (31) a predicted compression of the box stack from the first measurement (21) and second measurement (22). [18] Use of a - Support (120) for a stack of boxes (101), which is designed and configured to correspond to a section of a standard pallet and which has: • an upper support surface (1201) on which the bottom layer of a stack of boxes (101) can be positioned, • wherein the support surface (1201) corresponds to half or a quarter of a standard pallet and is designed and intended to accommodate half or a quarter of beverage crates (102) that fit on a standard pallet, • an underside having skid-shaped floorboards (1202) designed and configured to support a compressive force, wherein the floorboards (1202) are arranged such that the compressive force is increased at overlap points between the floorboard (1202) and the bearing surface (1201), or - a printhead (110) for a stack of boxes (101) which is designed and configured to correspond to a cutout of a standard pallet and to apply a pressure force to the stack of boxes (101), wherein the printhead (110) has: • a bottom surface (1103) designed to be in contact with the upper edge of the box stack (101) and to introduce the pressure force into the box stack (101), • wherein the underside (1103) corresponds to half or a quarter of a standard pallet and is designed and intended to be in contact with half or a quarter of the beverage crates (102) that fit on a standard pallet, in a method according to any one of claims 1 to 16.

Images