Patent Application
20200268212
The present invention relates to the injection molding and plastic extrusion process of manufacturing multi-layered cutting boards.
Conventional non-skid cutting board manufacturing process is a slow and costly process. Making cutting boards with decal patterns on the top face is also slow and costly. Making non-skid cutting boards with decal pattern is even slower and more costly.
In traditional plastic cutting board manufacturing, the anti-skid part of cutting board is mostly with a rubber-like material like rubber, silicone or thermo-plastic elastomer (TPE) that being attached onto the bottom or the whole circumference of main board by co-molding or overmolding or physically assemble by friction fit or fix by glue. The main cutting board body is primarily made of polypropylene or polyethylene material. After co-molding the non-skid feature, the main board was raised on top of countertop and the non-skid feet contacts with countertop and perform the anti-skid feature by the material's high coefficient of friction.
To manufacture these non-skid cutting boards would request two or more sets of injection molding for the main body and anti-skid feet. This can only be done one part by one part. Production time is long as the anti-skid part have to be co-molded or overmolded or assembly after the main body was made.
Moreover, the shape of the anti-skid part was limited too, with a very small surface area which may not provide enough friction leading to a failure of the anti-skid function. After raising the cutting board above the countertop by anti-skid feet would leave space between bottom of cutting board and the countertop. Water and fruit juice may leak into the space underneath. Once cutting the fruit or food on top face, there will be downward forces applied and squeeze the underneath water or juice out as the plastic board is flexible. This will make the food preparation work messy.
Under current production method limitation, to add pattern onto plastic cutting board surface can only be achieved by in-mold labelling technique, which is like sticking a thin decal onto the cutting board top surface during injection process. The end product is thus not cut resistant, when cutting along back and forth on the decal, it will leave cut mark and the decal will went off eventually time by time.
The new manufacturing process can improve the above weakness of current cutting boards by the multi-layer feature.
By the new ways of production, there is variety of designs and structure combinations can be chosen according to designer's need. One step production can also shorten production time and lower manufacturing costs.
A one-step production process to produce multi-layer plastic cutting boards by a new tailor-made extrusion machine set up. Combinations from two layers, three layers or as much as four layers of structures are feasible and can be freely chosen according to individual need. Layers options:
Preferred to be Polypropylene or Polyethylene material which is light weight and with medium hardness to prevent damaging the knife blade, although other materials like ABS, SAN, Tritan can also be considered. It would be preferred to be semi-translucent color (natural color of polypropylene material) so the underneath decal pattern can be easily seen. It is also feasible not to apply the decal layer so the top layer's color can be semi-translucent or solid color. Direct contact with blade to prevent damage of underneath decal. There is no limitation on the layer thickness, but if the layer is too thick, the decal underneath cannot be seen easily.
A thin decal film, thickness from 0.018-0.04 mm, polypropylene material. As much as 7-color printing, adding the individual design according to individual designer's need can make the cutting board more unique and attractive.
A thicker layer to provide necessary support to the cutting board to perform its function. It would be in the same material as the top layer but there is no limit in color option which can be semi-translucent or solid color despite the color of top layer. This layer provides necessary strength to the cutting board.
If the decal layer is not applied, the reinforcement layer can be directly bonded with the top layer and bottom anti-skid layer.
If both the decal layer and bottom anti-skid layer are not applied, the reinforcement layer can be bonded with the top layer and form a dual-layer cutting board. This would be no anti-skid function but the two-tone color can be used for distinguishing cutting different types of food. For example, the top layer for fruit and bottom layer for bread. There is no limitation on the thickness of this layer.
A rubber-like thin layer of thermo-plastic elastomer (TPE) material co-molded with the reinforcement layer to provide anti-skid function by the material feature of high coefficient of friction. The color can be natural semi-translucent or solid color. On the surface, there can be different surface texture or with tailor-made pattern applied to further increase the friction.
If the decal layer and reinforcement layer are not applied, the anti-skid layer can directly bond with the top layer and form a dual layer anti-skid cutting board. There is no limitation on the layer thickness.
Implementations of the inventive concepts disclosed herein may be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the included drawings, which are not necessarily to scale, and in which some features may be exaggerated and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numerals in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings:
Top Cutting Layer 2 can be comprised of Polypropylene or Polyethylene, which is light weight and with medium hardness to prevent damaging the knife blade, although other materials like ABS, SAN, Tritan can also be considered. It would be preferred to be semi-translucent color (natural color of polypropylene material) so the underneath decal pattern can be easily seen. It is also feasible not to apply the decal layer so the top layer's 2 color can be semi-translucent or solid color. Direct contact with blade to prevent damage of underneath decal. There is no limitation on the layer thickness, but if the layer is too thick, the decal underneath cannot be seen easily.
Decal Layer 3 comprises a thin decal film, thickness from 0.018-0.04 mm, polypropylene material. As much as 7-color printing, adding the individual design according to individual designer's need can make the cutting board more unique and attractive.
Reinforcement layer 4 comprises a thicker layer to provide necessary support to the cutting board to perform its function. It would be in the same material as the top layer 2 but there is no limit in color option which can be semi-translucent or solid color despite the color of top layer 2. This layer provides necessary strength to the cutting board.
If the decal layer is not applied, the reinforcement layer can be directly bonded with the top layer and bottom anti-skid layer 5.
If both the decal layer 3 and bottom anti-skid layer 5 are not applied, the reinforcement layer can be bonded with the top layer and form a dual-layer cutting board. This would be no anti-skid function but the two-tone color can be used for distinguishing cutting different types of food. For example, the top layer 2 for fruit and bottom layer 5 for bread. There is no limitation on the thickness of this layer.
Bottom anti-skid layer 5 can be a rubber-like thin layer of thermo-plastic elastomer (TPE) material co-molded with the reinforcement layer to provide anti-skid function by the material feature of high coefficient of friction. The color can be natural semi-translucent or solid color. On the surface, there can be different surface texture or with tailor-made pattern applied to further increase the friction.
If the decal layer 3 and reinforcement layer 4 are not applied, the anti-skid layer 5 can directly bond with the top layer 2 and form a dual layer anti-skid cutting board. There is no limitation on the layer thickness.
The poly layer cutting board is mainly a combination of plastic extrusion of thin plastic sheet and computer numerical control (CNC) machine milling process.
First, thermoplastic pellets are fed into the barrel of the extrusion machine. Color agents can be added if the end product were colorized. The thermoplastic pellets are melted under the high heat from the barrel and compressed by the turning screw inside the barrel, then squeezed out through a shaping die and passed in between two rollers, one at top and one at bottom forming thin sheet. At this stage, the plastic sheet is still hot and soft.
By the designer's need, there are as many as three barrels set up at three different levels extruding three different sheets of thermosetting plastics at the same time. From top to bottom: top cutting layer, reinforcement layer and anti-skid layer. Each layer comes from different barrel, and thus can be made with different color and different materials.
The sheets of thermoplastics are still hot and soft, can be two or three depends on designer's need, will be further compressed through a second set of rollers to from the multi-layer end product. As the plastic is still hot, the molecular bonds are still weak so after the second rolling and cooling, the bond will then be permanent. If there is a need to from different surface texture or special pattern at top and bottom, the texture can be applied on the second rollers so after compression, texture or pattern will be left on end product surfaces.
The decal film can be applied underneath the top later, just before the second rolling. After the second rolling, a multi-layer sheet in designated thickness will be formed and the current machine set up were limited to 800 mm width. The final product thickness was controlled by the distance between the roller bars. After second rolling, the multi-layer sheet will be sliced into designated length according to final product size. There will be pieces of rectangular sheets ready for the CNC machine milling process.
The whole process from melting the plastic pellet to multi-layer sheet is around 10-15 mins. Once the multi-barrel extrusion machine was set up, production is continuous.
The second production process aiming to cut and mill the multi-layer sheet into final product by a CNC machine. Metal blades will cut the multi-layer sheet into designated shape (rectangle, square, round, ellipse, triangle and any irregular shape). Miller blade will take out unnecessary plastic inside the cutting board forming the hollow handle and juice groove.
After the CNC process, dust and impurities will be removed before packaging into final product.
In the tradition way of manufacturing multi-layer cutting board 1, there would be one material injected to one mold cavity at one time. In the case, producer would request to finish each layer one time in one machine. First layer in one cavity, take it out and transfer to another cavity for second shot. This can be achieved by two injection molding machines, each with single barrel, and two sets of injection molds. Or by use of one dual-shot injection machine with two barrels and one set of specially designed injection mold for production.
The main difference of the new manufacturing process is: for current process, there is time sequence between each layer which need to be finished one by one. By use of the new process and new machinery, with use of as much as three barrels, shooting different materials or same material with different colors at the same time producing multi-layer cutting boards in a single step of production.
In addition, for the in-mold label decal, in the tradition way due to limitation of in-mold label technique, the decal was first placed on either side of the mold cavity before shooting melted plastic. Thus, the decal was limited to appear at the top cutting surface only, which is not cut-resistant.
By the new invented process, the decal was covered by the semi-translucent top layer which provide adequate protection to the decal by hiding the decal underneath preventing the direct contact with knife.
There is no limit on the shape of multi-layer cutting board due to the usage of CNC machine, it can be rectangular, square, round, ellipse, triangular or other shape like with an extended handle. There is no limit on the thickness of cutting board also. In addition, according to individual design need, there can be hang hole on the board as shown in reference drawing or one complete flat surface is also feasible.
It is an object of the present invention to provide a cutting board with a complete layer of anti-skid base 5 to perform the maximum limitation of slip when cutting to enable safer kitchen environment.
Another object of the present invention is to provide a cut-resistance decal cutting board which adding fun to cooking and increase the design flexibility for designers.
Another object of the present invention is to provide flexible manufacturing and material option to fit with individual market need. Combination of two, three or as much as four layers with different material and color choices of each layer are available due to the new way of production.
Another object of the present invention is to make manufacturing fast and cost saving way to produce multi-layer cutting boards by the one-step production.
Another object of the present invention is to provide a non-skid cutting board with a complete flat non-skid base with no gap between the cutting board and countertop. This will be prohibiting any liquid or juice to flow underneath and spilt out when cutting. Food preparation is neater and tidier.
