WO2017192064A1

WO2017192064A1 - Mould (variants) and method (variants) for filling moulds using a 3d pen

Info

Publication number: WO2017192064A1
Application number: PCT/RU2017/000288
Authority: WO
Inventors: Алексей Владимирович ЛЫСЕНКО
Original assignee: Алексей Владимирович ЛЫСЕНКО
Priority date: 2016-05-05
Filing date: 2017-05-04
Publication date: 2017-11-09
Also published as: RU2016117469A

Abstract

The group of inventions relates to moulds and methods for filling same which make it possible to achieve greater accuracy in the manufacture of small parts using a 3D pen. The present moulds are open, single-piece moulds made of a heat-resistant elastomer and contain at least one moulding element, the depth of which is not greater than the length of a nozzle of a 3D pen. In a mould for filling, the volume and dimensions of the moulding element are not greater than the size of the maximum volume of a plastic in which the pen is able to generate a pressure which causes the expansion of said volume (Vmax), and an opening via which filling takes place is covered by the nozzle of the 3D pen. The mould is filled using a directed filling method, in which: the nozzle of a pen is directed into a moulding element, covering the hole therein, a plastic is extruded, and the cooled part is extracted from the mould. The moulding element is shaped such that at any point in the bottom layer, in at least one direction, the distance between opposing walls is less than the size of Vmax. In another embodiment, a mould for laminar filling has an opening which can be covered by the nozzle of a 3D pen, and a moulding element which is a functionally equivalent mould and additionally contains a partition arranged such that at any point in the bottom layer, at least in one direction, the distance between opposing walls is less than the size of Vmax. During laminar filling the nozzle is directed toward the bottom of the moulding element and the bottom layer is filled, fixing a plastic. Layers are gradually built up and, in order to from the walls of a part, the nozzle is successively moved toward each point of a wall to a distance not greater than Vmax. The cooled part is then extracted from the mould.

Description

FORM (OPTIONS) AND METHOD (OPTIONS) FOR COMPLETING FORMS USING A ZO-HANDLE

The group of inventions relates to the field of application of tools for the additive production of plastic parts, in particular hand-held devices for three-dimensional drawing or drawing (also known as ZO-pens) and can be used in the manufacture of small parts, for example, elements of mechanical joints of parts.

Additive manufacturing hand tools (ZO-pens) are mainly used for single-dimensional manufacturing of three-dimensional parts from thermoplastic materials. Parts are manufactured by manually adjusting the extrusion of molten material from the spinneret assembly (nozzle) of the tool onto the surface of the part and its subsequent rejection by cooling. In some devices, instead of thermoplastic materials, fluid materials that cure under the influence of ultraviolet radiation are used. ZO-pens do not provide accurate repeatability of the result and therefore are used mainly for creativity. When creating with their help designs containing moving elements, problems arise associated with the need for precise mating of parts made by hand.

In plastic toys of serial production, often moving parts are used that allow you to realize additional degrees of freedom of the product, for example, ball and cylindrical joints.

The ability to create these and other movable joints with the help of a ZO-handle significantly expands the possibilities of creative use of this tool. In a known manner [Stencils - Scribbler 3D pen // URL: http://www.scribbler3Dpen.com/stencils/ (accessed date 15.1 01.2015)] to increase the accuracy of manufacturing parts using the ZO-handle is the assembly of parts using flat fragments, obtained by extruding the material along the contours previously depicted on paper. This method allows to achieve repeatability of the general form of large parts, but does not solve the problem of creating small assemblies in which surface details are important commensurate with the diameter of the extruder nozzle.

In a known manner [for example, http://www.himekb.ru/user/opis/metodichka.pdf (accessed 04.25.2016)] precision manufacturing of parts is by casting the filler into elastic molds made of silicone or another elastomer. The advantage of flexible injection molds is the ability to extract complex castings through holes whose size in the free state is smaller than the size of the part to be removed. This feature allows you to use fewer parts of the form, up to one part in some cases. For molding in elastic forms, as a rule, two-component fluid mixtures are used, silicones and polyurethanes that do not require injection molding. Thermoplastics are not molded into elastic molds due to the high pressures and temperatures of this process that cause the deformation of the mold.

Information on the use of the ZO-handle in conjunction with elastic forms and in special forms designed for this, was not found.

The design features of the ZO-handle and extrudable material (ABS or PLA plastic) do not allow to implement known methods of manufacturing parts using elastic forms. In particular, the plastic used does not have sufficient fluidity for self-distribution in the mold. The inventive group of inventions aims to develop a number of forms as a tool for quick and accurate manufacturing of parts, as well as methods for filling them, which can improve accuracy in the manual manufacture of small elements of mechanical joints.

The technical result achieved using the group of inventions consists in the manufacture of small parts, for example, elements of mechanical joints using a mold, with the help of a ZO-handle.

The implementation of the group of inventions will make it possible, in particular, to produce movable mechanical joints, ball joints of small (up to 10 mm) diameters, plastic axles, cylindrical parts, and also shaped protrusions of plastic, which perform mechanical articulation of manufactured parts with parts of commercially available plastic designers, for example, series designers LEGO and compatible with them. A form for easy filling with the help of a ZO-handle, characterized in that: it is made open, from an elastic material,

- contains at least one forming element, - and the depth of the forming element cannot significantly exceed the nozzle length of the ZO-handle, and the volume of the forming element and its dimensions should not exceed the size of the maximum volume of plastic in which the handle can create pressure that causes expansion of this volume, the hole through which the forming element is filled has such a size and shape that it can be blocked by the nozzle of the ZO-handle.

The forming element can be made in the form of a sphere, while the hole for filling the form has a size less than the diameter of the sphere. In addition, the forming element can be made in the form of a prism or cylinder, for example, in the form of an axis as a cylinder with a small base area.

Preferably, the mold is made of an optically transparent elastomer, for example silicone, and may further comprise at least one embossed element for cleaning the nozzle of the ZO handle.

The method of simple directional filling of the form using the ZO-handle, characterized in that:

- the nozzle of the tool is sent to the forming element, while blocking the hole in it,

- plastic is extruded, which under the action of pressure created in the forming element takes the form of its inner surface.

- remove the cooled part from the mold due to the elasticity of the mold material.

At the end of the process, an element can be formed from the thread to extract the part from the mold, for which they increase the additional length of the thread, which can be subsequently removed (for example, cut off), or they attach a finished part to the still plastic in the form that is not frozen, with which the formed element will be combined during operation.

A form for layer-by-layer filling with the help of a ZO-handle, characterized in that:

- it is made open, from an elastic material, contains at least one forming element, and the depth of the forming element cannot significantly exceed the length of the nozzle of the ZO-handle, while the forming element has such a shape that at least one point of the lower layer in one direction, the distance between the opposite walls is less than the size of the maximum volume of plastic in which the handle can create pressure, causing the expansion of this volume,

The forming element may take the form of a corridor of constant width with vertical walls, as well as a closed loop.

- it is made open, from an elastic material,

- contains at least one forming element, and the depth of the forming element cannot significantly exceed the nozzle length of the ZO-handle, - the hole through which the forming element is filled has such a size and shape that it can be blocked by the nozzle of the ZO-handle, moreover, the forming element has a shape that is functionally equivalent to the shape of the manufactured parts, but additionally contains a partition located so that

- at any point of the lower layer in at least one direction, the distance between the opposite walls is less than the size of the maximum volume of plastic in which the handle can create pressure, causing the expansion of this volume.

Preferably, the mold is made of an optically transparent elastomer, for example silicone, and may further comprise at least one embossed element for cleaning the nozzle of the ST handle.

The method of layer-by-layer filling of the form using the ZE-handle, characterized in that:

- the nozzle of the tool is directed to the bottom of the forming element and fill the bottom layer by moving the tool along the perimeter of the horizontal section,

- in this case, the plastic of the first layer is fixed between the walls of the forming element, after which the layers are gradually built up by moving the handle along the path filling the layer, - and for forming the walls of the part, the nozzle is successively approached to each wall point at a distance not exceeding the size of the maximum volume of plastic, in where the handle can create pressure that causes the expansion of such a volume,

- remove the cooled part from the mold using the elasticity of the mold material.

At the end of the process, an element can be formed from the thread to extract the part from the mold, for which they increase the additional length of the thread, which can be subsequently removed (for example, cut off), or attach the finished part to the still plastic in the mold, with which the formed element will be combined during operation. The essence of the group of inventions is illustrated by figures, each of which shows the manufactured part and the process of filling the forming element of the corresponding type in the context, in particular:

- in FIG. 1 is a simple directional filling of a forming element in the form of a sphere, in FIG. 2 - layer-by-layer filling of a forming element with a crescent section, in FIG. 3 - layer-by-layer filling of a thin-walled forming element with a closed loop, - in FIG. 4 - filling the forming element in the form of a ball with an additional element - the central rod as an example of using a functionally equivalent form,

- in FIG. 5 - filling the forming element in the form of an axis with a latch-latch. In the figures, as an example of one of the stages of the filling process, the following main elements are indicated: 1 - manufactured part, 2 - mold, 3 - forming element, 4 - nozzle (spinneret assembly) of ZO-handle (extruder, tool), 5 - extruded into the forming element 3 plastic, 6 - hole through which the forming element is filled 3, 7 - the partition of the functionally equivalent part 1, 8 - the width of the corridor (the distance between the inner walls of the forming element 3), 9 - an additional element for removing the part.

The inventive form 2 is made open and single-part from a heat-resistant elastic material (elastomer) and contain at least one forming element 3.

For visual control of the process of filling and moving the nozzle 4 of the tool, the mold 2 can be made of optically transparent material.

For servicing the used hand tool (ZO-handles), Form 2 may additionally contain a relief surface (relief element), allowing, for example, to clean the outer surface of the nozzle 4 from excess molten plastic 5, which may interfere with further work.

The configuration of the forming element 3 and the method of filling it depends on the dimensions of the manufactured part 1, as well as the characteristics of the ST handle used and the source material (plastic 5). Among the parameters that determine the configuration of the forming element 3, the following can be distinguished: the temperature of the plastic 5 during extrusion, the feed speed of plastic 5, the shape and size of the outlet nozzle 4 of the ZO-handle and the corresponding pressure at the inlet of the plastic 5. At the same time, most existing models of ZE-handles do not have the ability to adjust these parameters.

To determine the permissible configuration of the forming element 3, it is rational to use a relative indicator, which can be determined for a particular WE handle or group of tools with similar characteristics. Such an indicator is the maximum volume (size) of plastic 5 (Vmax), in which the handle can create pressure, causing the expansion of this volume.

In practice, Vmax can be defined as the maximum diameter of the ball, which can be made with a handle and a simple mold 2, which is a spherical forming element 3 with a hole 6 for filling, overlapped by the nozzle 4 of the handle (for example, see Fig. 1). When trying to fill a ball with a larger volume, the pre-extracted after filling will, as a rule, have a smaller diameter or a poor surface quality caused by insufficient pressure of the plastic 5 in the region of the walls of the mold 2.

Thus, if the volume and dimensions of the forming element 3 correspond to Vmax, the forming element 3 can be effectively filled by the method of simple directional filling due to the pressure created inside. In this case, the pressure can only be created in a closed volume, therefore, the hole 6 through which the extrusion is carried out must be of such shape and size that it can be blocked by the nozzle 4 of the 3-handle. If the forming element 3 is larger than Vmax, the extrudable plastic 5, which does not have sufficient fluidity for self-distribution along the bottom within the walls of the mold 2, forms a volume viscous cooling material. Plastic 5 does not acquire the shape specified by the walls, starting to push the nozzle 4 of the handle outward, since it is not able to create enough pressure inside such a volume of plastic 5 to expand it further. In addition, the resulting volume of plastic 5 sticks to the nozzle 4 of the handle and moves after it inside the mold 2, preventing the extrusion from continuing.

The method of simple directional filling can mainly be used for the following types of forming elements 3: spheres (for example, see Fig. 1), the diameter of which does not substantially exceed Vmax, filled through the hole 6 less than the diameter of the sphere,

- prismatic or cylindrical elements

- with a small base area, in particular not significantly exceeding Vmax,

- small height, i.e. the depth of such forming elements 3, as a rule, should not exceed the length of the nozzle 4 extruder,

- filled through an opening 6 of such a size and shape that can be blocked by the nozzle 4 of the ZO-handle.

Most existing models of ZO-handles are able to effectively fill a ball with a diameter of 4 mm, since a forming element 3 of such a volume will be filled before the plastic cools 5. Filling a ball of a larger volume (for example, 8 mm) should be done at a higher speed and can be carried out using the device with adjustment of the plastic feed rate 5. If there is no possibility to increase the feed rate, filling is carried out by the method of layer-by-layer filling, including in a functionally equivalent form 2.

Accordingly, the method of simple directional filling will not be effective in cases:

- a significant amount or size of the forming element 3, - the size of the outlet 6 of the forming element 3, exceeding the size of the nozzle 4 of the ZE-handle, the complex shape of the forming element 3.

The depth of the forming element 3 should not be significantly greater than the length of the spinneret assembly protruding from the body of the 3-handle (nozzle 4) for directed effective extrusion of the plastic 5 into the forming element 3. Otherwise, the volume of material and pressure necessary for the distribution of plastic 5 cannot be created between the walls and taking them to a given shape.

In cases where the method of simple directional filling cannot be applied, the filling is carried out in layers.

Unlike ZO-printing, when working with the ST-pen, it is impossible to ensure the same layer thickness, as well as uniform distribution of the layer over the entire surface of the bottom of the forming element 3, especially if the bottom has a complex shape. Layered filling here characterizes mainly the basic principle - bottom-up filling.

It should be borne in mind (especially when filling the lower layer) that the extrudable material (molten plastic 5) has good adhesion to the material of the previous layer, but extremely poor adhesion, for example, to the silicone of which form 2 is made. With simple filling under pressure, this the fact does not play such a significant role, as with layer-by-layer filling. Low adhesion makes it easy to remove part 1 from mold 2, but can create difficulties when filling the outer part of part 1 adjacent to the walls of the forming element 3.

In this case, the forming element 3 should have such a size and shape that at any point of the lower layer in at least one direction, the distance between the opposite walls of the forming element 3 was less than the size Vmax. In this case, the volume of plastic 5, expanding, will be fixed under the action of pressure created by the handle between the walls of the forming element 3, taking the shape of the bottom at the extrusion point. This allows you to move the nozzle 4 of the handle along the bottom, gradually creating the first layer. If the distance between the walls of the forming element 3 exceeds Vmax, a functionally equivalent form 2 can be created (for example, see Fig. 4) containing an auxiliary element 7 (jumper 7, partition 7), which reduces the distance between the walls of the forming element 3 and thereby allows layer by layer filling.

After filling the first layer, a further increase in volume is made by moving the nozzle 4 of the handle along the path filling the layer, examples of which can be seen in figures 2-5.

Particular attention should be paid to filling the parts adjacent to the walls of the forming element 3 and defining the outer surface of the part 1. To accurately repeat the contours of the wall with plastic 5, the nozzle 4 is successively brought closer to each point of the wall at a distance not exceeding Vmax so that the plastic 5 is evenly distributed along the walls, repeating their shape.

It is preferable to use forms 2, in which each new layer is filled by moving the handle once in one direction along the line of the layer of form 2. That is, the number of operations necessary for efficient filling should be minimized, otherwise the process will require a significant investment of time, which casts doubt on the rationality of use forms 2 and 3O-pens as tools for creating such parts 1.

A special case of forms 2, for which the layer-by-layer filling method can be applied, are forms 2 (for example, see Fig. 3), which basically have a closed loop and form a simple geometric figure (circle, rectangle). That is, the forming element 3 has the shape of a corridor of constant width 8 with vertical walls, the distance between which obeys a common criterion for this type of form 2 - no more than Vmax. Such forms 2 can be used for the manufacture of various kinds of thin-walled parts 1.

To produce a thin-walled part 1, the nozzle 4 of the tool extends the elastic walls of the forming element 3, extrudes into the main part of the forming element 3, and molding occurs due to the narrowing of the walls of the forming element 3 after passing through the nozzle 4. Some complex forming elements 3 can be formed from two or more relatively deep elements connected by jumpers with less depth. If parts 1 of this kind must withstand strong mechanical loads (for example, a hinge cup, a latch), then the dimensions of part 1 are preferable that when filling its individual parts in form 2, the plastic 5 of the filled part did not have time to cool down so that it reduces its connection with other parts.

Thus, the filling of the claimed forms 2 can be carried out as follows. With simple directional filling, the nozzle 4 of the tool is directed into the forming element 3, while blocking the hole 6 in it and extruded. Plastic 5 under the pressure created in the forming element 3, takes the form of its inner surface.

Carrying out layer-by-layer filling, the nozzle 4 of the tool is directed to the bottom of the forming element 3 and the lower layer is filled. To do this, the tool is moved along the perimeter of the horizontal section of the forming element 3. Plastic 5 is thus fixed between the walls of the forming element 3, which allows further gradual build-up of layers by moving the nozzle 4 of the handle along the path filling the layer. To form the walls of the part 1 of the required shape, the nozzle 4 is sequentially brought closer to each point of the wall at a distance not exceeding the size Vmax.

The elastic material of mold 2 allows you to remove part 1 after cooling the plastic 5. To do this, after completing the filling of mold 2, an additional length 9 of the thread is increased (additional element 9) and after cooling of the plastic 5, it is used to remove the part 1. Such additional element 9 can subsequently be easily deleted, for example, cut off.

In addition, to remove the part 1 to the still not frozen plastic 5 in the form 2, a part can be attached to which the moldable element will be combined during operation. The essence of the group of inventions can be illustrated by the following examples. Example 1 (Fig. 4). It is necessary to make a ball with a diameter of 6 mm for a ball joint, which can be used, for example, when modeling joints of constructor elements imitating a human figure. The diameter of the ball significantly exceeds Vmax, therefore, it cannot be formed by the method of simple directional filling. The optimal solution in this situation is the implementation in the forming element 3 of the auxiliary vertical rod (partition 7), which will allow you to create part 1, functionally equivalent to the original.

In a circular motion, the first layer of plastic 5 is extruded, which is fixed between the walls of the forming element 3 and the vertical rod (partition 7), and then the layer-by-layer volume growth is continued. Before removing the part 1 (until the plastic 5 is completely cooled), a mating finished part is attached to it or an additional element 9 is formed, extending the thread to the required length. Part 1 is removed after solidification of the plastic 5 due to the elastic stretching of the inlet 6 of the forming element 3.

Example 2 (Fig. 2). The reciprocal part for the ball joint (see example 1) is the cup of the hinge - a part of a rather complex shape, which also cannot be formed by simple extrusion of plastic 5 into mold 2. Each horizontal section of this mold 2 resembles a thin crescent. The forming element 3 will be in the form of a corridor of constant width 8 with vertical walls as a special case of form 2, which can be effectively filled in layers.

Filling takes place using the arc movements of the nozzle 4. In this case, the plastic 5 of the first layer is fixed at the bottom between the closely located opposite walls of the forming element 3. Form 2 is filled by layer-by-layer building up of plastic 5 until it is completely filled. Removing parts 1 produce as described in example 1.

Example 3 (Fig. 5). The following example illustrates the method of filling the forming element 3 with the sequential filling of its individual cavities. Part 1 to be manufactured — the axis with a latch on the end, is similar to the axes used in LEGO constructors and can be used to fix rotating structural parts. The latch is implemented using an extension and a longitudinal cut on the end of the axis to give the part the necessary elasticity properties. Although the part has a small volume, its complex shape (the presence of narrow pockets) does not allow it to be formed qualitatively by simple filling. The pressure of the plastic 5 will not be enough for its distribution in the cavities corresponding to the bifurcated axis ends. Therefore, to fill the form 2, the nozzle 4 is first introduced into the first cavity, and after filling it into the second. In this case, the elasticity of the septum between the cavities plays an important role. After filling both cavities from above, they are connected with plastic 5 and molding is completed similarly to the previous examples.

Claims

FORMULA

Point 1. A form for easy filling with 3D-py4KH, characterized in that:

- it is made open, from an elastic material,

- contains at least one forming element,

- moreover, the depth of the forming element cannot significantly exceed the length of the nozzle ZO-handle,

- and the volume of the forming element and its dimensions should not exceed the size of the maximum volume of plastic in which the handle can create pressure, causing the expansion of this volume,

- the hole through which the forming element is filled has such a size and shape that it can be blocked by the nozzle of the ZO-handle.

Paragraph 2. The form for filling with the help of the ZO-pen according to claim 1, characterized in that the forming element is made in the form of a sphere and has an opening for filling the form, the size of which is less than the diameter of the sphere.

Clause 3. The form for filling with the help of the ZO-handle according to claim 1, characterized in that the forming element is made in the form of a prism or cylinder.

Paragraph 4. A form for filling with the help of a ZO-handle according to item 3, characterized in that the forming element is made in the form of an axis.

Paragraph 5. The form for filling with the help of the ZO-pen according to claim 1, characterized in that it is made of an optically transparent elastomer.

Paragraph 6. The form for filling with the help of the ZO-pen according to claim 1, characterized in that it is made of silicone.

Paragraph 7. The form for filling with the help of the ZO-pen according to claim 1, characterized in that it further comprises at least one relief element for cleaning the nozzle of the ZO-pen.

Paragraph 8. The method of simple directional filling of the form according to claim 1 using

SUBSTITUTE SHEET (RULE 26) ZO-handles, characterized in that: the nozzle of the tool is directed into the forming element, while blocking the hole in it,

- produce extrusion of plastic, which under the action of pressure created in the forming element, takes the form of its inner surface,

Clause 9. The method of filling out the form according to claim 8, characterized in that, upon completion of the process, the additional length of the thread is increased to extract the part.

Paragraph 10. The method of filling out the mold according to claim 8, characterized in that at the end of the process, a part is attached to the plastic which has not yet solidified in the mold, with which the moldable element will be combined during operation.

Paragraph 11. Form for layer-by-layer filling with the help of a ZO-handle, characterized in that:

- it is made open, from an elastic material,

- contains at least one forming element,

- moreover, the depth of the forming element cannot significantly exceed the length of the nozzle of the 3D pen, while the forming element has such a shape that at any point of the lower layer in at least one direction the distance between the opposite walls is less than the size of the maximum volume of plastic in which the handle can create pressure causing an expansion of this volume.

Paragraph 12. A form for filling with the help of a ZO-handle according to item P, characterized in that the forming element has the form of a corridor of constant width with vertical walls.

Clause 13. The form for filling with the help of the ZO-pen according to claim 12, characterized in that the forming element has a closed loop.

SUBSTITUTE SHEET (RULE 26) Paragraph 14. A form for filling with the help of a ZO-pen according to claim P, characterized in that it is made of an optically transparent elastomer.

Paragraph 15. A form for filling with the help of a ZO-pen according to claim P, characterized in that it is made of silicone. Clause 16. The form for filling with the help of the ZO-pen according to claim P, characterized in that it further comprises at least one relief element for cleaning the nozzle of the ZO-pen.

Clause 17. Form for (layer-by-layer) filling with the help of a ZO-handle, characterized in that: - it is made open, from an elastic material,

- contains at least one forming element,

- moreover, the depth of the forming element cannot substantially exceed the length of the nozzle of the ZO-handle, the hole through which the filling of the forming element is of such a size and shape that it can be blocked by the nozzle of the ZO-handle,

- moreover, the forming element has a shape that is functionally equivalent to the shape of the manufactured parts, but additionally contains a partition located so that

Clause 18. The form for filling with the ZO-pen according to claim 17, characterized in that it is made of an optically transparent elastomer.

Clause 19. The form for filling with the help of the ZO-pen according to claim 17, characterized in that it is made of silicone.

Clause 20. The form for filling with the help of the ZO-pen according to claim 17, characterized in that it further comprises at least one relief element for

SUBSTITUTE SHEET (RULE 26) cleansing nozzle ZO-handle.

Clause 21. The method of layer-by-layer filling of a form according to claim 11 or according to claim 17 using an ST-pen, characterized in that:

- the nozzle of the tool is directed to the bottom of the forming element, - the bottom layer is filled, moving the tool along the perimeter of the horizontal section,

- while the plastic of the first layer is fixed between the walls of the forming element,

- after which a gradual build-up of layers is made by moving the handle along the path filling the layer, and for forming the walls of the part, the nozzle is successively brought closer to each point of the wall at a distance not exceeding the size of the maximum volume of plastic in which the handle can create a pressure causing expansion of such a volume, the cooled part is removed from the mold using the elasticity of the mold material.

Clause 22. The method of filling out the form according to claim 21, characterized in that, upon completion of the process, the additional length of the thread is increased to extract the part. Paragraph 23. The method of filling out the mold according to claim 21, characterized in that at the end of the process, a part is attached to the plastic that has not yet solidified in the mold, with which the moldable element will be aligned during operation.

SUBSTITUTE SHEET (RULE 26)