Point load and compression test apparatus and method

Abstract

POINT LOAD AND COMPRESSION TEST APPARATUS AND METHOD Apparatus for point load and compression testing and a method of performing point load and / or compression testing using the apparatus. The apparatus comprises: a first plate; a reconfigurable second plate having a first configuration 5 and a second configuration, wherein the separation between the first and second plates is adjustable; a testing region between the first and second plates; and a centring mechanism for centring a sample within the testing region; wherein the first and second plates are arranged in use such that, when the separation between the first and second plates is adjusted to reduce the separation, a 10 compression test is performed if the second plate is in the first configuration, and a point load test is performed if the second plate is in the second configuration.

Description

[0001] POINT LOAD AND COMPRESSION TEST APPARATUS AND METHOD

[0002] FIELD OF THE INVENTION

[0003] The present invention involves an apparatus which can be used to perform both point load and compression testing.

[0004] BACKGROUND

[0005] Mineral wool - also commonly referred to as stone wool, mineral fibre, mineral cotton and as man-made vitreous fibres (MMVF) - is able to be manufactured using a variety of different techniques. The mineral wool can also be processed in many ways and is able to be formed into various types of products. This means it is important to be able to assess the properties of the mineral wool to confirm they are as expected and meet quality control standards.

[0006] Some techniques used to assess mineral wool are destructive, causing permanent damage to a product and some techniques are non-destructive. The destructive techniques include an analysis method that tests the product to destruction or requires a sample to be taken from the product for testing. In contrast, the non-destructive techniques do not damage the product.

[0007] Conventional testing techniques for mineral wool require significant input from human operators, such as a production line operator. The standard approach is for the human operator to manually remove a product or sample of a product from the production line and place this on the machine on which a specific parameter test is to be carried out. This is usually located in a laboratory and is separated from the production line. Additionally, multiple machines are needed to perform different tests on the mineral wool to assess all relevant parameters.

[0008] The use of separate machines to perform different tests on the mineral wool is inefficient. Testing the mineral wool also requires a significant amount of operator time. There is therefore a need to reduce operator involvement and increase the efficiency of the testing process. SUMMARY OF INVENTION

[0009] A first aspect of the invention provides apparatus for point load and compression testing comprising: a first plate; and a reconfigurable second plate having a first configuration and a second configuration. The separation between the first and second plates is adjustable. The apparatus further comprises a testing region between the first and second plates; and a centring mechanism for centring a sample within the testing region. The first and second plates are arranged in use such that, when the separation between the first and second plates is adjusted to reduce the separation, a compression test is performed if the second plate is in the first configuration, and a point load test is performed if the second plate is in the second configuration.

[0010] Advantageously, the apparatus can be adapted to perform both point load and compression testing by reconfiguring the second plate. These tests are well known to the skilled person. However, as referred to below, the apparatus goes beyond this to allow the tests to be performable with a plate that is reconfigurable to allow simple switching between the two types of test.

[0011] When the separation between the first and second plates is adjusted to reduce the separation, a force is applied to the sample when the first and second plates are in contact with the sample. A point load test typically involves compression of a sample between a plate and a stamp or boss to measure point load strength, point load elasticity and / or deformation at the critical point. The behaviour of a test sample can be determined by applying an increasing force to an area of the sample and measuring the resulting deformation. A compression test typically involves compression of a sample between two plates to measure deformation at the critical point, critical compressive strength, maximum compressive strength, compressive stress at 10% deformation, compressive stress at the end of the conventional, elastic zone, compression elasticity, relative deformation at the maximum force and / or initial deformation. The behaviour of a test sample can be determined by applying an increasing force to the sample and measuring the resulting deformation. The reconfigurable second plate enables both types of tests to be performed using the same apparatus according to requirements. Accordingly, the apparatus is advantageously more efficient, occupies less space, and simplifies operation. Operation is simplified because the infrastructure requirements for sample movement within a laboratory are reduced. Such apparatus is also advantageously easier to automate, thereby reducing the requirements for manual intervention by a human operator.

[0012] The reconfigurable second plate advantageously provides enhanced flexibility because the second plate can be arranged according to the first or second configuration according to test requirements. Arranging the second plate according to the first configuration enables a compression test to be performed; arranging the second plate according to the second configuration enables a point load test to be performed. Both tests are preferably performed on a sample by reducing the separation between the first plate and the second plate when the sample is in the testing region such that a force is applied to the sample. Optionally, the position of the first plate may be adjustable and the position of the second plate may be fixed such that the separation between the first and second plates may be adjustable by moving the first plate. Alternatively, the position of the first plate may be fixed and the position of the second plate may be adjustable; or the position of both the first and second plates may be adjustable.

[0013] Preferably, the first and second plates are substantially parallel. Advantageously, this ensures the application of a uniform pressure by the first plate on a sample during a test. Preferably, the first and second plates are axially separated along a first axis substantially perpendicular to the planes of the first and second plates. Optionally, the first plate may have a flexible connection with the apparatus. In this case, the first axis is substantially perpendicular to the plane of the second plate. Typically, the first plate aligns with the sample during testing, and therefore during testing the first plate is typically substantially parallel to the second plate. Typically, the separation between the first and second plates is adjustable along the first axis. Adjusting the separation between the first and second plates therefore typically involves moving one or both plates along the first axis. Preferably, in order to perform a point load or compression test, the separation of the first and second plates is reduced such that the separation is less than or equal to the height of the sample, wherein the height of the sample is measured along the first axis. Accordingly, during the test the first and second plates are typically both in contact with the sample under test. By setting the plate separation to be less than or equal to the height of the sample, a force is applied to the sample. Optionally, the separation may be reduced further during the test until the sample is destroyed. Optionally, the separation may be reduced further at a constant speed. This advantageously provides further information about the sample. Alternatively, the test may be terminated before the sample is destroyed by increasing the separation between the first and second plates. Advantageously this enables the sample to undergo further testing. Preferably, once the test has been performed, the separation between the first and second plates is increased such that the separation is greater than the height of the sample. In this way, the sample can be removed from the apparatus.

[0014] The apparatus comprises a testing region between the first and second plates. The centring mechanism is for centring a sample within the testing region. Typically, the area of the testing region measured in a first plane parallel to the plane of the first and / or second plate may be larger than the area of the first and / or second plate. Typically, the centring mechanism is used to manoeuvre the sample to a centred testing region within the testing region. The centred testing region may be substantially central within the testing region. Typically, the area of the centred testing region measured in the first plane may be substantially the same as the area of the first and / or second plate. The centring mechanism may also be used to manoeuvre the sample away from the centred testing region, and preferably away from the testing region, following the performance of a test on a sample. Advantageously, the centring mechanism provides a repeatable ability to locate the sample in the correct position in the testing region.

[0015] Typically, the centring mechanism may comprise one or more plates. These are typically used to push the sample to manoeuvre it. Advantageously, this provides a centring mechanism which is simple to manufacture and to implement. Preferably, the centring plates are substantially parallel to a side of the sample. This advantageously avoids damage to the sample from the centring plates. Preferably, two or more plates are used. This advantageously improves the accuracy of the centring and reduces the risk of deformation of a sample by the centring mechanism. Preferably, when two or more plates are used, the plates are arranged approximately uniformly around the testing region. This advantageously increases the flexibility of the apparatus because a sample can be centred from a wider range of positions in the testing region.

[0016] Typically, movement of the centring mechanism plates is effected using actuators such as hydraulic, pneumatic, electric, electromechanical, electrohydraulic, mechanical, thermal or magnetic actuators. Advantageously, use of actuators provides improved automation and is simple to implement. Optionally, each actuator may be set up such that the required final position is pre-configured based on the sample size to centre the sample within the testing region. Advantageously, this simplifies operation because the centring mechanism does not need to rely on positional feedback of the sample. Therefore, in this case, the final position of the sample would not need to be monitored. Preferably, the actuators are pneumatic actuators. For example, each plate may have a corresponding pneumatic actuator which can be used to move that plate. The plates and pneumatic actuators of the centring mechanism may be referred to as a centring pneumatic jig. Advantageously, pneumatic actuators have quick response times, only require small pressure changes, and are cost-effective.

[0017] Preferably, each centring mechanism plate is moveable along a straight path. Advantageously, this simplifies operation relative to a more complex path, reduces the risk of operation error, and reduces the frequency of required maintenance.

[0018] Optionally, the plates of the centring mechanism may be substantially flat plates. These plates may be positioned substantially parallel to the sides of the sample and may be positioned substantially perpendicular to the first and second plates. Advantageously, flat plates are simple to manufacture. Preferably, the centring mechanism comprises one or more right-angled plates. These plates may be positioned substantially parallel to two sides of the sample and may be positioned substantially perpendicular to the first and second plates. When the plates are right-angled, or “V-shaped”, they are typically configured to align, in use, with an upright corner of a sample, i.e. an edge orientated substantially perpendicular to the plane of the first and second plates. Advantageously, this alignment increases the accuracy of the centring and decreases the likelihood of sample deformation by the centring mechanism.

[0019] Preferably, the centring mechanism is arranged to centre a sample within the testing region by moving the one or more plates inwards to push the sample towards the centre. Once centred, the centring mechanism is preferably arranged to remove the one or more plates from the testing region. Advantageously this ensures that the centring mechanism plates do not interfere with the test.

[0020] Optionally, the centring mechanism may further be configured to move the sample away from the testing region. Advantageously, this enables the sample to be removed from the testing region after the test has been performed. The sample may be moved to other testing apparatus or may be placed in a waste stream.

[0021] Alternatively, a removal mechanism comprising one or more plates may be included in the apparatus. The plates of the removal mechanism are preferably configured to remove the sample from the testing region. Advantageously, by using a removal mechanism to remove the sample instead of a centring mechanism, both the removal and centring mechanisms can be manufactured in a simpler manner because the required paths are simpler.

[0022] Typically, the apparatus may further comprise a transport mechanism for transporting the sample towards and away from the testing region. Preferably, the transport mechanism is used to deliver the sample to a position within the testing region in which the centring mechanism can reach the sample to manoeuvre it. Preferably, the centring mechanism can move the sample far enough such that the transport mechanism can receive the sample in order to transport the sample away from the testing region. Advantageously, the use of a transport mechanism further enhances automation because no user input is required to place the sample in the testing region.

[0023] Optionally, the transport mechanism may be a belt conveyor. Belt conveyors are widely used and therefore have associated advantages including ease of availability and good integration with the rest of the equipment. This further reduces the requirements for user input, thereby advantageously providing better automation.

[0024] Optionally, the transport mechanism used to transport the sample towards the testing region may comprise load cells for measuring a sample weight. Advantageously, the measured sample weight can be used for calculations relating to the sample.

[0025] Preferably, the apparatus further comprises a control unit configured to: arrange the second plate in the first configuration or the second configuration; and reduce the separation between the first plate and the second plate to perform either a point load test ora compression test depending on the configuration of the second plate. Advantageously, the use of a control unit further enhances automation because user input is not required to configure the reconfigurable second plate or to perform the test.

[0026] Preferably, the apparatus further comprises a measurement unit, wherein the measurement unit is configured to measure the deformation of the sample in response to an applied force. Optionally, the measurement unit may also be configured to measure the force applied to the sample. Advantageously, this enables the quality of the sample under test to be quantified.

[0027] Typically, the apparatus may further comprise a frame, wherein the frame supports the first and second plates. Advantageously, using a frame enables the apparatus to be standalone. The frame may be a hollow rectangular frame. Optionally, the first plate may be moveably attached to opposing sides of the frame such that the first plate is moveable in line with the frame. This provides a guide for the first plate which advantageously ensures the movement of the first plate is controlled. Optionally, the second plate may be fixedly attached to the frame. Alternatively, the second plate may be moveably attached to opposing sides of the frame and the first plate may be fixedly attached to the frame, or both plates may be moveably attached to opposing sides of the frame. Advantageously, the frame supports and guides movement of the first and / or second plate along the first axis, wherein the first axis is substantially perpendicular to the planes of the first and second plates.

[0028] Optionally, if the apparatus includes a transport mechanism, the frame may be positioned such that the transport mechanism can deliver the sample to the testing region. The testing region may be positioned along an edge of the frame, for example.

[0029] The testing region is preferably configured to receive the sample before the sample is centred in the testing region. Typically, the sample is taken from a fibrebased product, and may comprise man-made vitreous fibres (MMVF).

[0030] The testing region is positioned between the first and second plates. Preferably, the perimeter of the second plate in the first configuration matches the perimeter of the first plate. This arrangement is advantageously suitable for use in a compression test.

[0031] Preferably, the perimeter of the sample matches the perimeter of the first plate. Similarly, an advantage of this arrangement is that it is suitable for a compression test. Preferably, the perimeter of the sample matches the perimeter of the second plate in the first configuration.

[0032] A typical sample may have a 300 millimetres (mm) x 300 mm cross-section, measured in a plane parallel to the plane of the first and second plates. Each dimension may vary by up to ±10 mm. The thickness, or height, of the sample measured perpendicular to the plane of the first and second plates typically varies depending on the product being manufactured and tested and is the same as the thickness of that product. Optionally, the first plate may be 300 mm x 300 mm. Advantageously, this provides a suitable area fortesting MMVF-based samples of the same size. Optionally, with similar advantages, the second plate may be at least 300 mm x 300 mm (in the first configuration). For samples having other dimensions, typically the size of the first and second plates substantially matches the size of the sample. Typically, a first surface of the sample is configured to come into contact with the first plate and a portion of a second surface of the sample is configured to come into contact with the second plate. The second surface is preferably substantially parallel to and opposite the first surface.

[0033] Preferably, the second plate comprises a plurality of parts. Preferably, the second plate comprises one or more side parts and one stamp part positioned between the side parts. For example, the second plate may comprise one side part, wherein the side part is configured to fully or partially surround the stamp part in the first configuration, i.e. be positioned between the side part. Preferably, the second plate comprises two or more side parts. Optionally, each side part is configured to partially surround the stamp part in the first configuration. Preferably, the stamp part is substantially centrally located in the second plate. Optionally, the stamp part may be substantially cylindrical. The diameter of the stamp part may be less than 100 mm, preferably less than 80 mm.

[0034] Advantageously, the separate parts of the second plate enable the effective shape of the second plate to be modified according to requirements. For example, the one or more side parts can typically be separated from the stamp part such that the effective shape of the second plate in the testing region is just the shape of the stamp part. The stamp part may form a boss, stamp or projection. Advantageously, the shape of the stamp part is suitable for use in a point load test.

[0035] Preferably, in the first configuration, edges of adjacent parts of the second plate abut, and in the second configuration, edges of adjacent parts of the second plate are separated. The edges of the adjacent parts of the second plate are formed between the face of the part and the side of the part.

[0036] Preferably, when the edges of adjacent parts of the second plate are separated, the one or more side parts of the second plate are removed from the centred testing region. Typically, removal of the side parts of the second plate from the centred testing region means the side parts of the second plate do not come into contact with the sample when a test is performed. Therefore, when then one or more side parts of the second plate are removed from the centred testing region, the effective shape of the second plate in the centred testing region is just the shape of the stamp part. Advantageously, this means that the apparatus is fully configurable to perform a compression test or a point load test, and when the apparatus is arranged to perform a point load test it is not affected by the plates used for the compression test. Advantageously, the effective shape of the second plate in the centred testing region is just the stamp part because the one or more side parts can be fully removed from the centred testing region. Typically, the one or more side parts can be positioned near the centred testing region, supported by the apparatus. Optionally the position of the one or more side parts in the second configuration may be within the testing region, which is a larger than the centred testing region. This advantageously simplifies the process of returning the one or more side parts to the centred testing region to adopt the first configuration, in which the side parts are positioned within the centred testing region. For example, an automated control mechanism can be used to manoeuvre the side parts in and out and of the centred testing region for the first and second configurations respectively.

[0037] Optionally, the position of the one or more side parts of the second plate may be adjusted laterally, in the plane of the second plate, such that the one or more side parts can be moved laterally. In this way, in the second configuration, the one or more side parts of the second plate may be laterally separated from the stamp part. In this case, the edges of adjacent parts of the second plate are separated in the second configuration because the one or more side parts are not in contact with the stamp part in the second configuration. The term “laterally” is used to refer to the direction in the plane of the second plate and may not be horizontal. The actual direction will depend on the orientation of the apparatus. Advantageously, by adjusting the one or more side parts laterally, a sturdy base can be positioned beneath the second plate to support the second plate when large forces are applied during a test. Alternatively, the position of the one or more side parts of the second plate may be adjusted vertically, perpendicular to the plane of the second plate, such that the one or more side parts can be moved vertically. For example, the one or more side parts may be removed from underneath the sample location such that the one or more side parts do not come into contact with the sample during a test. The term “vertically” is used to refer to the direction perpendicular to the plane of the second plate and may not be vertical. The actual direction will depend on the orientation of the apparatus.

[0038] Typically, when the one or more side parts of the second plate are moved vertically, the one or more side parts are moved in a direction further away from the first plate than the stamp part such that the effective shape of the plate in the testing region is defined by the stamp part. Alternatively, the one or more side parts may remained fixed and the stamp part may be moved in a direction towards the first plate. Both of these options advantageously can be used to compress a sample between the first plate and the stamp part of the second plate to perform a point load test when the second plate is in the second configuration.

[0039] Advantageously, the movement of the one or more side parts away from the testing region provides a first effective shape of the second plate in the testing region in the first configuration and a second effective shape of the second plate in the testing region in the second configuration. The first configuration typically provides the first effective shape which is substantially equivalent to a unified plate and therefore suitable for use in a compression test. The second configuration typically provides the second effective shape which is substantially equivalent to a stamp, boss, or projection and therefore suitable for use in a point load test. Advantageously, movement of the plate parts relative to each other changes the shape of the second plate in the testing region.

[0040] Therefore, in the second configuration, the one or more side parts of the second plate may be vertically offset from the stamp part in the second configuration. In this case, the one or more side parts may (a) vertically overlap with the stamp part or (b) be vertically separated from the stamp part. When the one or more side parts vertically overlap with the stamp part in the second configuration, the edges of adjacent parts of the second plate are separated vertically even though the sides of adjacent parts of the second plate are in partial contact. When the one or more side parts are vertically separated from the stamp part in the second configuration, the edges of adjacent parts of the second plate are separated because the one or more side parts are not in contact with the stamp part in the second configuration.

[0041] Typically, the movement of each of the one or more side parts may be effected using one or more actuators such as hydraulic, pneumatic, electric, electromechanical, electrohydraulic, mechanical, thermal or magnetic actuators. Advantageously, use of actuators provides improved automation and is simple to implement. Preferably, the actuators are pneumatic actuators. For example, each side part may have a corresponding pneumatic actuator which can be used to move that part.

[0042] The one or more pneumatic actuators optionally provide movement in the plane of the second plate. Alternatively, the one or more pneumatic actuators may provide movement perpendicular to the plane of the second plate. Preferably, the extent of movement provided by the pneumatic actuators enables the one or more side parts to be fully removed from the testing region in the second configuration, and enables the one or more side parts to be brought into contact with the stamp part in the first configuration. Advantageously, reconfiguration of the second plate between the first and second configurations can be easily automated using actuators.

[0043] The one or more side parts typically move along a path and the path direction and path length may be pre-configured. This advantageously improves automation further because additional monitoring apparatus is not required (although monitoring apparatus could be beneficial to identify any issues such as mechanical issues). Pre-configuring the path direction and path length can be done prior to using the apparatus during an apparatus set-up phase, by determining the relative positions of the one or more side parts in the first and second configurations. This can advantageously be used to ensure that the side parts can be moved far enough so as not to interfere with the sample in the testing region when a test is being conducted with the second plate in the second configuration, and to ensure that the side parts and stamp part are contiguous, i.e. in contact to form a continuous surface, in the first configuration.

[0044] Preferably, the movement of each of the one or more side parts may be effected using two or more actuators, preferably pneumatic actuators.

[0045] Optionally, when the one or more side parts are fixed, movement of the stamp part may be effected using one or more actuators, preferably pneumatic actuators.

[0046] A second aspect of the invention provides a plate for use in a testing region of point load and compression testing apparatus. The plate comprises a stamp part and one or more side parts which can be separated from the stamp part, wherein the plate has a first configuration in which edges of adjacent parts of the plate abut and a second configuration in which edges of adjacent parts of the plate are separated such that only the stamp part is positioned within the testing region.

[0047] For example, the plate may comprise one side part, wherein the side part is configured to fully or partially surround the stamp part in the first configuration, i.e. be positioned between the side part. Preferably, the plate comprises two or more side parts. Optionally, each side part is configured to partially surround the stamp part in the first configuration. Preferably, the stamp part is substantially centrally located in the plate. Optionally, the stamp part may be substantially cylindrical. Preferably, the circular cross-section of the stamp part is 5000 millimetres squared (mm2), having a 79.8 mm diameter.

[0048] Advantageously, the separate parts of the plate enable the effective shape of the plate to be modified according to requirements. The one or more side parts can be separated from the stamp part such that the effective shape of the plate in the testing region is just the shape of the stamp part. The stamp part may form a boss, stamp or projection. Advantageously, the shape of the stamp part is suitable for use in a point load test, in which a substantially parallel opposing plate is brought towards the stamp part to compress a sample held in a testing region between the stamp part and the opposing plate. Alternatively, the parts of the plate may be contiguous, i.e. the sides of the parts may be in contact to form a continuous surface, in the first configuration. Advantageously, this forms a substantially flat plate which is suitable for use in a compression test, in which a substantially parallel opposing plate is brought towards the second plate to compress a sample held in a testing region between the stamp part and the opposing plate.

[0049] In the first configuration, edges of adjacent parts of the plate abut, and in the second configuration, edges of adjacent parts of the plate are separated such that only the stamp part is positioned within the testing region. The edges of the adjacent parts of the plate are preferably the top edges of the plate parts at the interface between the top surface and the side surface of the plate part.

[0050] When the edges of adjacent parts of the plate are separated, only the stamp part is positioned within the testing region, which means that the one or more side parts of the plate are removed from the testing region. When then one or more side parts of the plate are removed from the testing region, the effective shape of the plate in the testing region is just the shape of the stamp part. Advantageously, this means that the plate can be adapted to be suitable for performing a compression test or a point load test in combination with appropriate testing apparatus. When the plate is arranged to be suitable for performing a point load test, i.e. when the plate is in the second configuration, the testing region is not affected by the one or more side parts used in combination with the stamp part for performing a compression test. Advantageously, the effective shape of the plate for use in a testing region of point load and compression testing apparatus is just the stamp part because the one or more side parts can be fully removed from the testing region.

[0051] Optionally, the position of the one or more side parts of the plate may be adjusted in the plane of the plate, such that the one or more side parts can be moved away from the stamp part within the same plane for the second configuration. In this case, the edges of adjacent parts of the plate are separated in the second configuration because the one or more side parts are not in contact with the stamp part in the second configuration. Alternatively, the position of the one or more side parts of the plate may be adjusted perpendicular to the plane of the plate, such that the one or more side parts can be moved away from the stamp part out of plane for the second configuration. For example, the one or more side parts may be removed from the testing region such that the one or more side parts do not come into contact with the sample during a test.

[0052] In the second configuration, the one or more side parts of the plate may be offset from the stamp part. In this case, the one or more side parts may (a) overlap with the stamp part or (b) be fully separated from the stamp part. When the one or more side parts overlap with the stamp part in the second configuration, the edges of adjacent parts of the plate are axially separated along an axis perpendicular to the plane of the plate even though the sides of adjacent parts of the plate are in partial contact. When the one or more side parts are fully separated from the stamp part in the second configuration, the edges of adjacent parts of the plate are separated because the one or more side parts are not in contact with the stamp part in the second configuration.

[0053] The plate according to the second aspect of the invention is suitable for use as a second plate in the apparatus according to the first aspect of the invention. Preferable features and their associated advantages described in relation to the second plate of the apparatus according to the first aspect are also applicable to the plate according to the second aspect.

[0054] A third aspect of the invention provides a method of performing point load and / or compression testing using the apparatus according to the first aspect of the invention. The method comprises: centring a sample in the testing region using the centring mechanism; determining whether to perform a point load test or a compression test based on one or more input parameters; arranging the second plate in the first configuration or the second configuration based on the determined test; and performing the determined test by reducing the separation between the first plate and the second plate. Advantageously, the method can be used to perform a compression test or a point load test by arranging the second plate in the first or second configuration respectively. The relevant test is advantageously selected based on one or more input parameters, thereby enhancing the automation of the method.

[0055] Preferably, performing the determined test by reducing the separation between the first plate and the second plate comprises a first step of reducing the separation until a preloading force, Fo, is applied to the sample. Typically, for a point load test the preloading force may be between 2.0 and 3.0 Newtons (N), preferably between 2.25 and 2.75 N. This corresponds to a pressure of between 400 and 600 Pascals (Pa), preferably between 450 and 550 Pa. Typically, for a compression test the preloading force may correspond to a pressure of approximately 250 Pa.

[0056] Preferably, performing the determined test comprises a second step of determining the height, or thickness, d, of the sample as measured in an axial direction perpendicular to the second plate. This step is typically performed when the sample is under the preloading force.

[0057] Preferably, performing the determined test comprises a third step of reducing the separation at a constant speed to increase the force applied to the sample. For a point load test, the constant speed may be between 40 and 60 millimetres per minute (mm / min), preferably between 45 and 55 mm / min. For a compression test, the constant speed may be related to the measured thickness, d. For example, the constant speed for a compression test may be d / 10 mm / min ±25 %.

[0058] Preferably, a force / deformation curve, or a load deformation curve, is recorded using a measurement unit during the step of performing the determined test. The curve can advantageously be used to calculate parameters which can be used to assess the quality of the sample. For a compression test, the test may be stopped when the compression load exceeds 20 % deformation of the original thickness, d, as measured. Typically, the steps of arranging the second plate in the first configuration or the second configuration based on the determined test and performing the determined test by reducing the separation between the first plate and the second plate may be performed using a control unit.

[0059] Optionally, the method comprises: centring a first sample in the testing region using the centring mechanism; determining that a compression test is to be performed; arranging the second plate in the first configuration accordingly; performing the compression test by reducing the separation between the first and second plates; increasing the separation between the first and second plates; centring a second sample in the testing region using the centring mechanism; determining that a point load test is to be performed; arranging the second plate in the second configuration accordingly; and performing the point load test by reducing the separation between the first and second plates. Advantageously, the method can be used to automatically perform the required test on samples.

[0060] Typically, the method may further comprise a step of receiving a sample in the testing region before the step of centring the sample in the testing region using the centring mechanism. The sample may be taken from a fibre-based product, and may comprise man-made vitreous fibres (MMVF).

[0061] Preferably, the method further comprises receiving one or more input parameters, and determining whether to perform a point load test or a compression test preferably comprises determining whether to perform a point load test or a compression test based on the one or more input parameters.

[0062] Optionally, the one or more input parameters may comprise a sample identifier; a test identifier; and / or a sample weight or sample density. This advantageously improves automation of the testing process. Typically, when the sample density is less than 75 kg per cubic metre, a compression test is appropriate; and when the sample density is more than 75 kg per cubic metre, either a point load test or a compression test is appropriate. The sample weight may be determined based on the sample density and the dimensions of the sample. Preferably, the same test is performed on at least three samples taken from the same product. In this way, the average, i.e. mean, values can be calculated for the product to advantageously reduce the uncertainty in the measured values. Furthermore, this advantageously can provide a measure of product uniformity.

[0063] BRIEF DESCRIPTION OF DRAWINGS

[0064] Embodiments of the invention will now be described with reference to the accompanying drawings in which:

[0065] Figure 1 A is a top view of a plate in a first configuration;

[0066] Figure 1 B is a top view of a plate in a second configuration;

[0067] Figure 2A is a side view of a plate in a first configuration;

[0068] Figure 2B is a side view of a plate in a second configuration;

[0069] Figure 2C is a side view of a plate in a second configuration;

[0070] Figure 3 is an illustration of an apparatus for point load and compression testing;

[0071] Figure 4A is an illustration of an apparatus in which the base plate is in a first configuration;

[0072] Figure 4B is an illustration of an apparatus in which the base plate is in a second configuration; and

[0073] Figure 5 is a flow chart of a method of performing point load and / or compression testing.

[0074] DETAILED DESCRIPTION

[0075] Figures 1A and 1 B provide top views of a plate 10 in a first configuration 11 and a second configuration 12 respectively. The plate is in accordance with the second plate of the apparatus according to the first aspect of the invention and with the plate according to the second aspect of the invention. In this example the plate has a substantially square cross-section, measuring 300 mm x 300 mm, is made of aluminium, and is 10 mm thick. This thickness provides a suitably rigid plate such that the plate will not bend when a compression or point load test is performed on a sample using the plate. The plate is sufficiently hard, dense and rigid so as not to interact with the results of the tests. In other examples, the plate may be thicker than 10 mm. The plate 10 includes a stamp part 13, a first side part 14 and a second side part 15. The stamp part 13 is positioned between the first and second side parts 14, 15. The first and second side parts 14, 15 are shaped to fit around the stamp part 13. In other examples, there may be one side part surrounding the stamp part, or three or more side parts. In each case, the plurality of parts of the plate are configured to fit together in a continuous manner. In this example, the stamp part 13 is cylindrical with a diameter of 79.8 mm. In other examples, the stamp part may be another shape suitable for use in a point load test. In the first configuration 11 shown in Figure 1A, the edges of adjacent parts of the plate 10 abut. A first joint 171 and a second joint 172 are formed between edges of the first and second side parts 14, 15. A third joint 18 is formed between edges of the first side part 14 and the stamp part 13. A fourth joint 19 is formed between edges of the second side part 15 and the stamp part 13. At each of the joints 171 , 172, 18, 19, the shape of the adjacent parts is substantially matched such that the edges of the respective parts conform to each other.

[0076] In this example, the stamp part 13 is positioned substantially centrally within the plate 10. In alternative examples, the stamp part 13 may be positioned anywhere within the testing region 16.

[0077] In the first configuration 11 , all elements of the plate 13, 14, 15 are positioned within a testing region 16. In this example, the sample has a square cross-section which substantially matches that of the plate 10.

[0078] In the second configuration 12 shown in Figure 1 B, only the stamp part 13 is positioned within the testing region 16. The first and second side parts 14, 15 are positioned outside the testing region 16 in the second configuration 12. That is to say that in the second configuration 12, edges of adjacent parts of the plate are spatially separated. In this example, the parts of the plate 13, 14, 15 are within the same plane in the second configuration 12. In other examples, different parts of the plate may be arranged in different planes relative to each other.

[0079] The plate 10 is reconfigurable according to the first configuration 11 or the second configuration 12 in accordance with experimental or testing requirements. When the plate is used in a testing region of suitable point load and compression testing apparatus, a compression test can be performed when the plate 10 is in the first configuration 11 and a point load test can be performed when the plate is in the second configuration 12.

[0080] In this example the plate 10 can be separated into three parts 13, 14, 15. In other examples the plate can be separated into more parts. In this example the side parts 14, 15 are substantially mirrored, however in other examples the side parts may take any suitable form.

[0081] Figures 2A, 2B and 2C provide side views of a plate 20 in a first configuration 21 , a first second configuration 221 and a second second configuration 222. The plate is in accordance with the second plate of the apparatus according to the first aspect of the invention and with the plate according to the second aspect of the invention.

[0082] The plate 20 includes a stamp part 23 having an edge 231 and a side part 24 having an edge 241 . The edges 231 , 241 of the parts 23, 24 of the plate 20 are formed between the faces of the plate parts (not shown in Figures 2A-2C) and the sides of the plate parts. In this example the side part 24 is formed as a single unit with a hole shaped to match the shape of the stamp part 23. The hole and the stamp part are circular in this example. In the first configuration 21 shown in Figure 2A, the stamp part 23 is arranged to sit between the side part 24, i.e. in the hole in the side part 24. The stamp part 23 is indicated in dashed lines to show that the stamp part is not visible in this view. In the first configuration 21 , the circumferential edge 231 of the stamp part 23 abuts the circumferential edge 241 of the hole in the side part 24 to form a joint 27. Therefore in the first configuration 21 , all parts 23, 24 of the plate 20 are positioned within the testing region 26 such that a compression test can be performed when the plate is part of point load and compression testing apparatus. The testing region 26 includes the surface of the parts 23, 24 of the plate 20.

[0083] Figures 2B and 2C depict two different second configurations 221 , 222. In both examples, edges 231 , 241 of adjacent parts 23, 24 of the plate 20 are separated such that only the stamp part 23 is positioned within the testing region 26. That is to say that the surface of the stamp part 23 is positioned within the testing region 26. In the first second configuration 221 shown in Figure 2B, the edge 231 of the stamp part 23 is separated from the edge 241 of the side part 24 in a direction perpendicular to the plane of the plate 20. However, the stamp part 23 and the side part 24 overlap in that the edge 231 of the stamp part 23 is still in contact with a side face of the side part 24. The portion of the stamp part 23 depicted in dashed lines indicates that that portion of the stamp part is not visible in this view, and the non-visible part of the side part 24 is also shown in dashed lines. Importantly, the separation is such that in the first second configuration 221 , only the stamp part 23 is positioned within the testing region 26 such that a point load test can be performed when the plate is part of point load and compression testing apparatus. If a sample were compressed between the plate 20 in the first second configuration 221 and an opposing plate, the only part of the plate 20 in contact with the sample would be the stamp part 23. Compression of a sample between an opposing plate and the plate 20 in the first second configuration therefore provides a point load test on the sample.

[0084] In the second second configuration 222 shown in Figure 2C, the stamp part 23 is fully separated from the side part 24 such that there is no overlap between the sides of the parts 23, 24 of the plate 20. Consequently, edges 231 , 241 of adjacent parts 23, 24 of the plate 20 are separated such that only the stamp part 23 is positioned within the testing region 26. The walls of the space left by absence of the stamp part 23 in the side part 24, which are not visible in the view shown in Figure 2C, are depicted in dashed lines to indicate their location. The arrangement of the second second configuration means that if a sample were compressed between the plate 20 in the second second configuration 222 and an opposing plate, the only part of the plate 20 in contact with the sample would be the stamp part 23. Compression of a sample between an opposing plate and the plate 20 in the second second configuration therefore also provides a point load test on the sample. Therefore in the both second configurations 221 , 222, only the stamp part 23 of the plate 20 is positioned within the testing region 26 such that a point load test can be performed when the plate is part of point load and compression testing apparatus. The side part 24 of the plate 20 is outside the testing region 26 in both second configurations 221 , 222. This is to ensure that a sample would not come into contact with the side part 24 during a point load test.

[0085] Figure 3 is an illustration of apparatus 300 for point load and compression testing. The apparatus 300 includes a first plate 301 and a second plate 302. The first and second plates 301 , 302 are substantially parallel and substantially opposite each other during testing. That is, the first plate 301 is directly above the second plate 302 when the apparatus is orientated as shown in Figure 3. Prior to testing, the first plate 301 is tiltable, able to rotate about its connection point to the apparatus 300. The second plate 302 is reconfigurable into first and second configurations as described in relation to Figures 1 A, 1 B and 2A-2C. In Figure 3, the second plate 302 is in a first configuration 303 as shown in Figure 1A. Accordingly, the second plate 302 has the effect of a single, uniform plate. Both the first and second plates 301 , 302 are rigid and designed not to flex under the forces applied during the performance of compression and point load tests, so as not to influence the measurements obtained during a test.

[0086] The apparatus 300 includes a testing region 304 between the first and second plates 301 , 302. The testing region 304 is suitable for receiving a sample 312. In this example, the sample 312 is cut from a manufactured fibre-based product comprising man-made vitreous fibres, and has a substantially square crosssection. Consequently, each of the first and second plates 301 , 302 and the testing region 304 also have a substantially square cross-section. The perimeter of the first and second plates 301 , 302 substantially matches that of the sample 312. In other examples, the sample may have a substantially rectangular crosssection, a substantially circular cross-section, or any other cross-section including a non-uniform cross-section. The perimeter of the first plate and the second plate in the first configuration typically match that of the sample. The testing region is not physically embodied, rather it is defined to encompass the sample between the first and second plates.

[0087] A frame 311 is used to support the first and second plates 301 , 302. The frame 311 is a frame suitable for a universal testing machine. The frame 311 comprises two columns connected at both ends to form a hollow rectangular frame. The base of the frame 311 is wider to provide stability to the apparatus and to support the second plate 302 and other parts of the apparatus 300 as described below. The first plate 301 is supported between the two columns of the frame 311. In this example, the second plate 302 is fixedly attached to the base of the frame 311 and the first plate 301 can be adjusted in the direction of the two columns, towards and away from the second plate 302. The first plate 301 is attached to a crossbar 320 which is moveably attached to the frame 311. In this example the crossbar 320 is attached to servo motors (not shown) provided in each column of the frame. The servo motors are used to raise and lower the crossbar 320. In other examples, alternative actuators may be used. The first plate 301 is attached to the crossbar 320 using a flexible connection such as a ball connection which enables the first plate 301 to tilt relative to the crossbar. The point of connection of the first plate 301 to the crossbar 320 remains fixed relative to the crossbar 320. In this way, the position of the first plate 301 can be adjusted by moving the crossbar 320 up and down the frame 311 using the servo motors. In other examples, the crossbar may be fixedly attached to the frame and the first plate may be moveably attached to the crossbar such that the separation between the first plate and the second plate can be adjusted by moving the first plate relative to the crossbar to apply a force to a sample positioned in the testing region.

[0088] A centring mechanism 305 comprising four centring plates 306 (one only partially visible in Figure 3) and four corresponding pneumatic actuators 307 (one not visible in Figure 3) is used for centring the sample 312 within the testing region 304. Each centring plate 306 is a right-angled plate. That is to say that each centring plate 306 has a first plate portion and a second plate portion connected by an edge, the first and second plate portions angled approximately 90 degrees from each other. In this example, a right-angled plate is suitable for use as a centring plate 306 because this matches the shape of the sample 312. Therefore, the centring plates 306 can be used to engage with sample 312 by making contact with the sides and edges of the sample. In other examples, the plates of the centring mechanism may be flat or may have a more complex shape. The centring plates are designed to engage with the sample. This typically means that the shape of the centring plates will match the shape of the sample, however this is not required. For example, a flat plate may be used to manoeuvre a curved sample surface. In such a case, when the centring plate is engaged with the sample, only a portion of the plate would be in contact with the sample.

[0089] Each centring plate 306 is connected to one pneumatic actuator 307 which is used to move that centring plate 306 along a straight path 308. Each centring plate 306 has a centred position which is based on the size of the sample 312. When all the centring plates 306 are in their respective centred positions, each centring plate 306 is in contact with a portion of two adjacent sides of the sample 312 and with an edge of the sample 312. The edges of the sample 312 in contact with the centring plates 306 are orientated substantially perpendicular to the planes of the first and second plates 301 , 302. When all the centring plates 306 are in their respective centred positions, the sample 312 is centred within the testing region 304.

[0090] The pneumatic actuators 307 utilise compressed air to control the movement and are well known in the art. Controlled air pressure pulses can be used to provide controlled movement.

[0091] The path 308 of each centring plate 306 is substantially linear. In this example, the path 308 of each centring plate 306 is angled at approximately 45 degrees relative to first and second plate portions of that centring plate 306. The first and second plate portions of each centring plate 306 are substantially parallel to the sides of the sample 312 that that centring plate 306 is configured to contact when the centring mechanism 305 performs a centring operation on the sample 312, to centre the sample 312 within the testing region 304. The range of motion of each centring plate 306 extends from an innermost position to an outermost position, passing through the centred position described above. The centring mechanism 305 is configured to centre the sample 312 within the testing region 304. The centring mechanism 305 is configured to receive the sample 312 in the testing region 304 from a first transport mechanism. In this example, the centring mechanism 305 is also configured to remove the sample 312 from the testing region 304 to a second transport mechanism. In an alternative example, the apparatus comprises a removal mechanism with one or more plates (typically two plates) that can be used to push the sample from the testing region to the second transport mechanism.

[0092] In Figure 3, the first and second transport mechanisms are first and second belt conveyors 309, 310. The first belt conveyor 309 is configured to deliver the sample 312 to the testing region. The first belt conveyor 309 may receive the sample from another position within the testing laboratory, typically from a manufacturing area from which the sample is cut and removed for testing. The first belt conveyor 309 comprises load cells (not shown in Figure 3) for measuring the weight of the sample 312.

[0093] The edge of the testing region 304 is defined by the extent of the centring plate 306 motion. When the sample 312 is in the testing region 304, one or more centring plates 306 can contact and manoeuvre the sample 312. When the sample 312 is delivered by the first belt conveyor 309 to the testing region 304, the sample 312 is received by the centring mechanism 305 and the sample 312 moved by the centring mechanism 305 to a centred position of the testing region 304. With the sample 312 in this position, the first plate 301 can be lowered such that a test is performed on the sample 312 by compressing the sample 312 between the first and second plates 301 , 302. In this case, the test is a compression test because the second plate 302 is in the first configuration 303. Following performance of the test, the centring mechanism 305 can be used to move the sample 312 towards the second belt conveyor 310. The centring mechanism 305 thus moves the sample 312 away from the centred position within the testing region 304, and away from the testing region 304. The centring mechanism 305 delivers the sample 312 to the second belt conveyor 310. Once the sample is received by, i.e. engages with, the second belt conveyor 310, the second belt conveyor 310 transports the sample 312 to another area, such as a waste area.

[0094] Therefore, the innermost and outermost positions of each centring plate 306 are defined so as to enable a sample 312 to be received in, moved within, and removed from, the testing region 304. The required positions for each centring plate 306 are pre-configured. The centring mechanism 305 will adopt a first configuration for receiving the sample 312 in the testing region 304 from the first belt conveyor 309; move to a second configuration in which all centring plates 306 are in their centred position to centre the sample 312 within the testing region 304; move to a third configuration in which all centring plates 306 are in their outermost position before a test is performed using the apparatus 300; and move to a fourth configuration for removing the sample 312 from the testing region and delivering the sample 312 to the second belt conveyor 310.

[0095] In the third configuration of the centring mechanism 305, the centring plates 306 are all in their outermost position. The outermost positions are set such that the centring plates 306 do not interfere with the first and second plates 301 , 302 of the testing apparatus 300 when a test is performed. When in the outermost positions, the centring plates 306 are not in contact with the sample 312.

[0096] As described above and in relation to Figure 1A, the reconfigurable second plate 302 is in the first configuration 303. The second plate 302 comprises a stamp part 313, a first side part 314 and a second side part 315. The parts of the second plate 302 are arranged as described in Figure 1A and are reconfigurable in a second configuration (not shown), as shown in Figure 1 B.

[0097] In Figure 3, pneumatic actuators 316-319 are attached to each of the first and second side parts 314, 315 of the second plate 302. First and second pneumatic actuators 316, 317 are attached to the first side part 314, one on each side of a column of the frame 311. Third and fourth pneumatic actuators 318, 319 are attached to the second side part 315, one on each side of the opposing column of the frame 311. The first and second pneumatic actuators 316, 317 are configured to act simultaneously. This means that the first and second pneumatic actuators 316, 317 are configured to move the first side part 314 in a direction substantially perpendicular to the side of the first side part 314 to which the pneumatic actuators

[0098] 316, 317 are connected. This arrangement provides controlled movement.

[0099] Similarly, the third and fourth pneumatic actuators 318, 319 are configured to act simultaneously. This means that the third and fourth pneumatic actuators 318, 319 are configured to move the second side part 315 in a direction substantially perpendicular to the side of the second side part 315 to which the pneumatic actuators 318, 319 are connected. This similarly provides controlled movement of the second side part 315.

[0100] The pneumatic actuators 316-319 are configured to move the first and second side parts 314, 315 along a straight path to arrange the second plate 302 in the first configuration 303 or a second configuration (not shown). Similarly to the pneumatic actuators 307 connected to the centring plates 306, the first to fourth pneumatic actuators 316-319 utilise compressed air to control the movement and are well known in the art. Controlled air pressure pulses can be used to provide controlled movement.

[0101] Figures 4A and 4B illustrate the apparatus 400 configured to perform a compression test and a point load test respectively. The apparatus 400 shown in Figures 4A and 4B is similar to the apparatus 300 shown in Figure 3 and similar reference numerals refer to similar elements of the apparatus, with similar functions and advantages.

[0102] The apparatus 400 comprises a first plate 401 and a reconfigurable second plate 402. In Figure 4A, the second plate 402 is in the first configuration 403. In Figure 4B, the second plate 402 is in the second configuration 423. The first plate 401 is mounted on a crossbar 420 attached to a frame 411. The connection between the first plate 401 and the crossbar 420 provides some movement in the first plate 401 as described in relation to Figure 3. The top of the frame 411 is not illustrated in Figures 4A or 4B. As in Figure 3, the height of the crossbar 420 is adjustable to adjust the separation between the first and second plates 401 , 402. The height of the crossbar 420 is adjustable using actuators such as linear motors, or servo motors. The separation between the first and second plates 401 , 402 is reduced to perform a point load or compression test (depending on the configuration of the second plate), and increased once the test has been performed. Reducing the separation between the first and second plates 401 , 402 increases the force applied to the sample 412. During a test, a force is applied by moving the plates together at a given speed in an axial direction perpendicular to the major faces of a squarely cut square sample 412, i.e. in an axial direction perpendicular to the second plate 402. For a point load test, the compressive force at the critical point and / or the force for a given deformation is calculated. For a compression test, a load deformation curve is drawn and compression behaviour is calculated based on the curve.

[0103] Figures 4A and 4B illustrate a sample 412 received from a first belt conveyor (not shown) in a testing region 404 between the first and second plates 401 , 402. A centring mechanism 405 comprising right-angled centring plates 406 moveable using pneumatic actuators 407 is provided to manoeuvre the sample 412 along respective straight paths 408, including centring the sample 412 within the testing region 404. Following the performance of a test, the centring mechanism 405 is used to deliver the sample 412 to the second belt conveyor 410 so that the sample 412 can be removed from the testing region 404.

[0104] The reconfigurable second plate 402 comprises a stamp part 413, a first side part 414 and a second side part 415. The stamp part 413 is arranged between the first and second side parts 414, 415. In the first configuration 403 shown in Figure 4A, edges of adjacent parts 413-415 of the second plate 402 abut. In the second configuration 423 shown in Figure 4B, edges of adjacent parts of the second plate 402 are separated. In Figure 4B, the sample 412 is not shown in the centred testing region in order to show the detail of the second plate 402 in the second configuration 423, however typically the sample 412 is centred prior to the second plate 402 being reconfigured in the second configuration 423.

[0105] Pneumatic actuators 416-419 are attached to each of the first and second side parts 414, 415 of the second plate 402. First and second pneumatic actuators 416, 417 are attached to the first side part 414, one on each side of a column of the frame 411. Third and fourth pneumatic actuators 418, 419 are attached to the second side part 415, one on each side of the opposing column of the frame 411. The first and second pneumatic actuators 416, 417 are configured to act simultaneously as described in relation to Figure 3 to provide controlled movement of the first side part 414. Similarly, the third and fourth pneumatic actuators 318, 319 are configured to act simultaneously to provide controlled movement of the second side part 415.

[0106] In this example, the side parts 414, 415 are removed from the testing region 404 by using the pneumatic actuators 416-419 to move the first and second side parts 414, 415 laterally, in the plane of the second plate 402, away from the stamp part 413. In other examples, the stamp part 413 may be raised or the side parts 414, 415 may be lowered instead of or as well as lateral movement to ensure that only the stamp part 413 is positioned within the testing region 404 in the second configuration 423.

[0107] Figure 5 is a flow chart of a method of performing point load and / or compression testing. The method is performed using the apparatus described in relation to Figures 3, 4A and 4B.

[0108] A sample may be received in the testing region having been delivered by a transport mechanism such as the belt conveyor described in Figures 3, 4A and 4B. The sample is typically a fibre-based sample from a manufactured fibre-based product comprising man-made vitreous fibres. The method includes centring 51 a sample in the testing region using the centring mechanism, which is described in relation to Figure 3. Once the centring 51 has been performed, the sample is in the centred testing region.

[0109] Following the step of centring 51 the sample, the method includes determining 52 whether to perform a point load test or a compression test based on one or more input parameters. The one or more input parameters may be a sample identifier; a test identifier; and / or a sample weight or sample density. A sample identifier may be a reference number for a particular type of fibre-based product that is being manufactured. For some types of samples, only a point load test is appropriate, or only a compression test is appropriate. Therefore, if only one test is suitable for the identified sample, the relevant test to be performed can be determined based, at least in part, on the sample identifier. A test identifier is Boolean data in that there are only two possible values: “compression test” or “point load test”. Accordingly, it can be straightforwardly determined based on the test identifier that the test to perform is the identified test. The test identifier may be provided by a user or determined in another manner. For some weights or densities of samples, only a point load test is appropriate, or only a compression test is appropriate. Therefore, if only one test is suitable for the identified sample weight or sample density, the relevant test to be performed can be determined based, at least in part, on the sample weight or sample density. Typically, when the sample is “light” wool, i.e. the sample density is less than 75 kg per cubic metre, a compression test is appropriate; and when the sample is “heavy” wool, i.e. the sample weight is more than 75 kg per cubic metre, a point load test is appropriate. In order to determine the sample density, the weight of the sample may be determined using load cells or another integrated weighing scale. The sample density can be calculated based on the known dimensions of the sample and the measured sample weight.

[0110] Following the step of determining 52 which test to perform, the method includes arranging 53 the second plate in the first configuration or the second configuration based on the determined test. As described above, the first configuration is suitable for performing a compression test and the second configuration is suitable for performing a point load test. Therefore, if the determined test is a compression test, the step includes arranging 53 the second plate in the first configuration; and if the determined test is a point load test, the step includes arranging 53 the second plate in the second configuration. In this example, arranging 53 the second plate in the relevant configuration based on the determined test is performed by a control unit.

[0111] Following the step of arranging 53 the second plate in the appropriate configuration, the method includes performing 54 the determined test by reducing the separation between the first plate and the second plate. The separation is reduced so that the first and second plates are both in contact with the sample, positioned on opposing sides of the sample. The sample is compressed between the first and second plates. If the second plate is in the first configuration, the sample is compressed between two flat plates to perform a compression test. If the second plate is in the second configuration, the sample is compressed between a flat plate (the first plate) and a stamp (the effective shape of the second plate in the testing region in the second configuration) to perform a point load test. In this example, performing 54 the determined test is achieved using a control unit.

[0112] The method may further include measuring the output values. The output values can be recorded, for example in a database. The output values may be compared to expected output values. The expected output values can be determined based on expected output values for the identified sample. For example, each sample may have an acceptable range including minimum and maximum acceptable output values for the parameters listed above. In the event that the output values deviate from the acceptable range, a negative message may be generated. In the event that the output values fall within the acceptable range, a positive message may be generated. The messages may include one or more of: an identifier of the sample being tested; the origin of the sample; any output value or output values outside their acceptable range; and the other output values. The message may be sent to another part of the laboratory to indicate that the product from which the sample came does (for a positive message), or does not (for a negative message), meet the required quality standards.

[0113] When a compression test is performed, the output values include one or more of: deformation at the critical point, EFP, wherein the critical point is Fp; critical compressive strength, oc; maximum compressive strength, om; compressive stress at 10% deformation, a ; compressive stress at the end of the conventional, elastic zone, oe; compression elasticity, Ec; relative deformation at maximum force Fm, £m; and initial deformation, No.

[0114] In this example, when a compression test is performed, performing 54 the test includes preloading the sample with a force corresponding to a pressure of 250 Pa. When the sample is held with a preloading force, the thickness, d, of the sample is measured. Subsequently, the sample is compressed under the second plate in the first configuration at a speed of d / 10 mm / min ±25 %. During the compression of the sample, a force / deformation curve is recorded using a measurement unit.

[0115] When a point load test is performed, the output values include one or more of: point load strength, op(in Pa); point load elasticity, Ep(in Pa); and deformation at the critical point, sFp(mm).

[0116] In this example, when a point load test is performed, performing 54 the test includes preloading the sample with a force, Fo, of (2.50 ± 0.25) N, which corresponds to a pressure of (500 ± 50) Pa. When the sample is held with a preloading force, the thickness d of the sample is measured. Subsequently, the sample is compressed into the stamp part at a speed of (50 ± 5) mm / min. During the compression of the sample, a force / deformation curve is recorded using a measurement unit. The test is terminated when the critical point can be determined and / or when the deformation of the sample reaches 20 %. During the test, the load, i.e. the applied force, at a deformation of 5 mm is determined (F5).

[0117] In this example, when the test is complete, the second plate is returned to the first configuration prior to removing the sample from the testing region. In an alternative example, the sample may be removed without changing the position of the parts of the second plate.

[0118] In another example, the apparatus may require setting up. This could be performed prior to the first use of the apparatus, or during routine calibration operations to maintain operation of the apparatus. Should the apparatus require setting up, the method may include set up steps including pre-configuring the path direction and path length of the centring mechanism used in step 51 . For example, the centred position of centring plates of the centring mechanism can be set according to sample size and the outermost and innermost positions of the centring plates can be set according to requirements. Relevant requirements may include the position of the transport mechanism(s) and the size of the centring plates, for example. The method may also include set up steps including pre-configuring the path direction and path length of the side part movement to change the configuration of the second plate between the first and second configurations. For example, the relative positions of the one or more side parts in the first and second configurations would be determined in order to calculate the required path direction and path length to transition between the two configurations.

[0119] As will be appreciated, apparatus comprising a reconfigurable plate is provided which enables both point load testing and compression testing to be performed by arranging a reconfigurable plate according to a suitable configuration.

Claims

CLAIMS1 . Apparatus for point load and compression testing comprising: a first plate; a reconfigurable second plate having a first configuration and a second configuration, wherein the separation between the first and second plates is adjustable; a testing region between the first and second plates; and a centring mechanism for centring a sample within the testing region; wherein the first and second plates are arranged in use such that, when the separation between the first and second plates is adjusted to reduce the separation, a compression test is performed if the second plate is in the first configuration, and a point load test is performed if the second plate is in the second configuration.

2. The apparatus according to claim 1 , wherein the first and second plates are substantially parallel.

3. The apparatus according to claim 1 or claim 2, wherein the centring mechanism comprises one or more plates, and movement of the centring mechanism plates is effected using pneumatic actuators.

4. The apparatus according to claim 3, wherein each centring mechanism plate is moveable along a straight path.

5. The apparatus according to claim 3 or claim 4, wherein the centring mechanism plates comprise one or more right-angled plates.

6. The apparatus according to any one of the preceding claims, further comprising a transport mechanism for transporting the sample towards and away from the testing region.

7. The apparatus according to claim 6, wherein the transport mechanism is a belt conveyor.

8. The apparatus according to any of the preceding claims, further comprising a frame, wherein the frame supports the first and second plates.

9. The apparatus according to any of the preceding claims, wherein the second plate comprises one or more side parts and one stamp part positioned between the side parts.

10. The apparatus according to claim 9, wherein in the first configuration, edges of adjacent parts of the second plate abut, and in the second configuration, edges of adjacent parts of the second plate are separated.

11. The apparatus according to claim 9 or claim 10, wherein the side parts can be removed from the centred testing region.

12. The apparatus according to claim 11 , wherein the movement of each side part is effected using one or more pneumatic actuators.

13. A plate for use in a testing region of point load and compression testing apparatus, the plate comprising a stamp part and one or more side parts which can be separated from the stamp part, wherein the plate has a first configuration in which edges of adjacent parts of the plate abut and a second configuration in which edges of adjacent parts of the plate are separated such that only the stamp part is positioned within the testing region.

14. A method of performing point load and / or compression testing using the apparatus according to any one of claims 1 to 12, the method comprising: centring a sample in the testing region using the centring mechanism; determining whether to perform a point load test or a compression test based on one or more input parameters; arranging the second plate in the first configuration or the second configuration based on the determined test; and performing the determined test by reducing the separation between the first plate and the second plate.

15. The method according to claim 14, wherein the one or more input parameters comprise a sample identifier; a test identifier; and / or a sample weight or sample density.

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