CN108638410B

CN108638410B - Production method of reconstructed amber

Info

Publication number: CN108638410B
Application number: CN201810400483.2A
Authority: CN
Inventors: 代荔莉; 施光海; 熊珍喜
Original assignee: China University of Geosciences Beijing
Current assignee: China University of Geosciences Beijing
Priority date: 2018-04-28
Filing date: 2018-04-28
Publication date: 2020-05-01
Anticipated expiration: 2038-04-28
Also published as: CN108638410A

Abstract

A production method of a reproduced amber comprises the following steps: heating and pressing the raw materials in a sectional pressurizing mode; and annealing the pressed amber under the protective gas and pressurized environment. The invention realizes the pressing of the amber waste into different types of reproduced amber, such as reproduced golden amber, reproduced beeswax and reproduced golden brown amber. The produced reconstructed amber has the following characteristics: firstly, the size and the weight of the obtained reconstructed amber are large, and the subsequent processing requirements of the jewelry or artware can be met; secondly, the color of the reproduced amber is uniform and bright, the problems of dark and light color and different color tones of different amber wastes are well solved, and the reproduced amber handicraft with beautiful color is well praised by consumers; thirdly, the finished product of the reconstructed amber has high purity, no lock crack, compact structure and good durability, solves the problems of a large amount of dark impurities and part of lock crack in the amber waste, and improves the purity and the durability of the reconstructed amber handicraft.

Description

Production method of reconstructed amber

Technical Field

The invention belongs to the technical field of jewelry production, and relates to a method for producing a reproduced amber by using crushed amber materials.

Background

Amber is a precious organic gem and has extremely high ornamental value and economic value. Amber is a natural resource and has the characteristics of rare yield, non-regeneration and the like. The natural amber stone is usually crack development, uneven color, irregular size and poor cleanliness, the actual utilization rate is only about 65% according to statistics, the rest parts are mostly amber waste materials which are mixed cracks, dark inclusions or too small size and cannot be utilized, the waste materials are difficult to be directly processed into jewelry or artware as natural amber, and the natural amber stone is usually directly discarded. Meanwhile, in the processing process of the amber jewelry or artware, a large amount of leftover materials and scraps are usually generated, and the leftover materials and the scraps cannot be directly recycled, so that serious resource waste exists.

In the prior art, the reproduced amber is produced by adding a resin adhesive to the waste material, leftover material or chippings of amber and subjecting the amber to a pressing treatment. However, this technique has the following disadvantages: firstly, the existence of the adhesive causes the very big difference of the components between the reproduced amber and the natural amber, which seriously affects the quality and the price of the product; secondly, the added adhesive is easy to age, and the amber particles are easy to crack along the adhesive part, so that the beauty and the durability of the reconstructed amber are influenced; thirdly, the pressing time is too long, about 15 days are needed for pressing and forming at normal temperature, and a large amount of manpower and material resources are consumed; fourthly, the contact surface of the particles of the finished product amber is obvious, a large amount of dense bubbles can be formed among the particles, the particles and the powder and among the particles and during stirring, and the dense bubbles are distributed at the combination part and the vicinity of the boundary of the particles, so that the polishing of the amber handicraft is influenced, and the attractiveness is reduced; fifthly, the purity of the pressed amber is not improved, wherein impurities or dark inclusions are obvious, and the quality of amber jewelry or artware is seriously influenced.

In actual work, an attempt is also made to directly press the amber by using a pressure furnace under the condition of not adding a binder, but the external part of a pressed finished product is in a recrystallization state after sintering, but the bonding between internal raw material particles is not tight, obvious gaps or bubbles exist among particles visible to naked eyes, and higher artistic value and economic value are difficult to realize.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the method for producing the reconstituted amber, which has the advantages of simple operation steps, short time consumption, low production cost, no artificial additives and controllable finished product type.

In order to achieve the purpose, the invention adopts the following technical scheme:

a production method of a reproduced amber comprises the following steps: (a) heating and pressing the raw materials in a sectional pressurizing mode; (b) and annealing the pressed amber under the protective gas and pressurized environment. The term "annealing" as used herein refers to metal working, and is similar to the "annealing" step in the metal working process, and aims to further optimize the internal structure of the pressed amber.

Further, the step (a) includes the steps of: (a1) pretreating raw materials, including cleaning, crushing and impurity removal; (a2) placing the raw material in a mold, and applying a first pressure to the raw material; (a3) pressurizing and heating the raw materials in sections; the step of pressurizing is to increase the fixed pressure every time when the first time interval passes until the second pressure is reached; the heating process is that the temperature of the raw material is increased from room temperature to a first target temperature in a first time, and the temperature is kept for a second time; (a4) and naturally cooling and demolding. In the step (a 3), the amber particles are sintered at high temperature, and the stacking volume of the amber raw material is reduced along with the discharge of the air bubbles in the joint surfaces between the particles and the amber, so that a certain pressure needs to be increased at intervals; namely, the sectional pressurizing mode is adopted, so that the air bubble discharge can be better promoted, the compactness of the raw material is further increased, and the produced reconstructed amber has a more uniform and compact structure. Meanwhile, the problem of raw material fragmentation caused by directly increasing the maximum value of the pressure increase value can be avoided by adopting a sectional pressurization mode, because the amber raw material is gradually melted and deformed or flows along with the increase of the temperature, and then the fragmentation can not be caused by gradually increasing the pressure. In step (a 3), the second pressure is preferably 50-100 tons, and the first target temperature is preferably between 120 ℃ and 190 ℃; through adjusting the values of the second pressure and the first target temperature, the sintering degree and the compactness degree of the crushed particles of the raw material of the amber can be adjusted, so that the production of different types of reproduced amber is realized, for example, golden amber, beeswax or golden brown amber and the like.

Further, the step (b) comprises the steps of: (b1) putting the amber formed by pressing in the step (a) into a closed environment, and pressurizing to a first air pressure; (b2) heating; the heating process is that the temperature of the amber is increased from the room temperature to the second target temperature in the third time, and the temperature is kept for the fourth time; (b3) and (5) naturally cooling. The purpose of the annealing treatment is to further optimize the amber structure. The second target temperature adopts high temperature to shorten the treatment time, and the preferable range is 140-210 ℃; because the amber is in the closed environment, the air pressure in the closed environment can be gradually increased by adopting a slow temperature rise mode, so that the pressure on the amber is gradually increased along with the temperature rise, and the internal structure of the amber is more uniform and compact.

Further, the pressurizing method in the step (b 1) is as follows: and filling and discharging protective gas into the closed environment for multiple times, and finally pressurizing to the first air pressure. Through repeated air inflation and air deflation, substances such as oxygen, moisture and the like in the closed environment can be rapidly and thoroughly discharged, and the chemical reaction between the substances such as oxygen, moisture and the like and amber in the annealing treatment process is avoided.

Further, the first pressure of the gas in step (b 1) generates a pressure on the amber that is greater than the first pressure applied to the feedstock in step (a 2). In the annealing treatment process, the pressure generated by the air pressure in the closed environment on the amber raw material is greater than the first pressure (compared with the pressure generated by the circular pressure applying surface in the inner cavity of the die) applied by the pressure device on the amber raw material in the pressing process, and the purpose of the method is to further refine particles, stabilize the size and adjust the structure, and the optimal value is 35 MPa.

Further, in the step (b 1), the protective gas is nitrogen or inert gas. The aim is to avoid the chemical reaction between the high-pressure gas and the amber.

Further, the inner cavity of the die is cylindrical, the diameter of the circular pressing surface of the inner cavity of the die is 25-30cm, and the height of the inner cavity of the die is 6-10 cm. If the area of the pressure applying surface is increased or reduced, the pressing pressure can be proportionally enlarged or reduced; if the height of the inner cavity is increased or reduced, the pressing time can be properly prolonged or shortened, and the same technical effect as the technical scheme can be obtained.

Further, the size of the pulverized raw material in the step (a) is 3mm, the first pressure is 50 tons, the first time interval is 1 hour, the fixed pressure is 5 tons, the second pressure is 70 tons, the first time is 1.5 hours, the first target temperature is 190 ℃, and the second time is 2.5 hours; in the step (b), the first air pressure is 35MPa, the third time is 2.5 hours, the second target temperature is 210 ℃, and the fourth time is 4.5 hours; the obtained reproduced amber is golden amber. The amber raw material becomes soft from about 140 ℃ under the condition of high pressure (physically, pressure applied in the longitudinal direction is not air pressure), and is sintered and shaped under the action of the high pressure. In order to shorten the production time and control the type of the pressed amber finished product, the amber raw materials are closely fused by adopting the high temperature of 190 ℃ to finally produce the golden amber finished product; meanwhile, in order to avoid the amber raw material from being oxidized and blackened, the heating time is properly shortened when the pressing is carried out at a high temperature of 190 ℃.

Further, the size of the pulverized raw material in the step (a) is 1mm, the first pressure is 60 tons, the first time interval is 0.5 hour, the fixed pressure is 3 tons, the second pressure is 96 tons, the first time is 3 hours, the first target temperature is 120 ℃, and the second time is 3 hours; in the step (b), the first air pressure is 35MPa, the third time is 1.5 hours, the second target temperature is 140 ℃, and the fourth time is 8.5 hours; the obtained reconstructed amber is beeswax.

Further, the size of the pulverized raw material in the step (a) is 200 meshes, the first pressure is 50 tons, the first time interval is 1 hour, the fixed pressure is 5 tons, the second pressure is 70 tons, the first time is 1.5 hours, the first target temperature is 190 ℃, and the second time is 2.5 hours; the first air pressure in step (b) is 35MPA, the third time is 2.5 hours, the second target temperature is 210 ℃, and the fourth time is 4.5 hours; the obtained reproduced amber is golden brown amber. By increasing the height of the raw material of the amber under the same pressing condition, the finished product of the reproduced amber can be controlled to be golden brown amber.

The production method of the reconstituted amber realizes the pressing of the amber waste into different types of reconstituted amber such as reconstituted golden amber, reconstituted beeswax, reconstituted golden brown amber and the like by a high-temperature and high-pressure pressing and annealing treatment mode. The innovation of the invention is that firstly, a mode of gradually increasing in sections is adopted, so that the discharge of air among raw material particles and air bubbles in the raw materials can be better promoted, and the problem of raw material fragmentation caused by directly increasing the air to the maximum can be avoided; secondly, the pressing is carried out in an open space (namely under the atmospheric environment), which is more beneficial to quickly discharging air among raw material particles compared with the pressing in a pressure furnace; the reason is that the amber raw material is pressed by adopting a pressure furnace under the conditions of high temperature and high pressure, although the high-pressure protective gas can apply larger pressure to the amber raw material, the high-pressure protective gas can fill gaps among raw material particles, the formed pressure can only act on each raw material particle independently, but adjacent raw material particles cannot be extruded together, and thus the dispersed amber raw material cannot be compacted into a whole; the method can lead the gas between the particle gaps to be pressurized and then discharged into the air. The reproduced amber produced by the invention has the following characteristics: firstly, the size and the weight of the obtained reconstructed amber are large, and the subsequent processing requirements of the jewelry or artware can be met; secondly, the color of the reproduced amber is uniform and bright, the problems of dark and light color and different color tones of different amber wastes are well solved, and the reproduced amber handicraft with beautiful color is well praised by consumers; thirdly, the finished product of the reconstructed amber has high purity, no lock crack, compact structure and good durability, solves the problems of a large amount of dark impurities and part of lock crack in the amber waste, and improves the purity and the durability of the reconstructed amber handicraft.

Drawings

FIG. 1 is a schematic view showing the overall flow of a method for producing a reconstituted amber in example 1;

FIG. 2 is a schematic view showing the overall structure of the amber-reproducing press of example 2;

FIG. 3 is a schematic view showing the overall structure of a mold of the amber-producing press of example 2;

FIG. 4 is a schematic diagram of the electrical connections of the reproduced amber wafer press of example 2.

Detailed Description

The following will further describe a specific embodiment of the method for producing reconstituted amber according to the present invention with reference to the accompanying drawings 1 to 4. The production method of a reconstituted amber of the present invention is not limited to the description of the following examples.

Example 1:

this example shows a method for producing a reconstituted amber, as shown in fig. 1, comprising the following steps: (a) heating and pressing the raw materials in a sectional pressurizing mode; (b) and annealing the pressed amber under the protective gas and pressurized environment.

Wherein the step (a) is carried out by using the reproduced amber wafer press of embodiment 2, and comprises the following steps: (a1) pretreating raw materials, including cleaning and crushing; concretely, after the amber crushed aggregates with uneven sizes are cleaned and impurities are removed, the crushed aggregates are placed in a food-grade crusher to be crushed into particles (powder), and the crusher can crush the particles or powder with the size of 5mm to 200 meshes to meet the requirement. (a2) Placing the raw material in a mould of a reproduced amber cake press, and applying a first pressure to the raw material; the size of the mould is a cylinder with the diameter of 25-30cm and the height of 6-10 cm. (a3) The raw materials are pressurized in sections and heated and pressed by a pressurizing device of a reproduced amber cake press; the step of pressurizing is to increase the fixed pressure every time when the first time interval passes until the second pressure is reached; the heating process is that the temperature of the raw material is increased from room temperature to a first target temperature in a first time, and the temperature is kept for a second time; in the pressurizing process, along with the sintering of raw material particles, air among the particles is gradually extruded out of the amber round cake and discharged out of the die, gaps among the particles are gradually reduced until the gaps disappear, and the particles are tightly combined. (a4) Naturally cooling to room temperature, and taking the pressed amber out of the mold to complete demolding. The pressure in the step (a) refers to the physical pressure applied to the raw materials by the cake press, and the direction of the pressure is vertical.

The pressing parameters for the 3 samples were as follows:

the pressure furnace adopted in the step (b) is Kapex AB/3/KAP and consists of a pressure tank, a tank inner chamber, pressure fittings, an automatic control and protection system and protection fittings. The pressure tank is provided with a tank neck flange and a cylindrical tank with a flat tank cover, and the tank cover is fixed by 8 stud screws; the tank inner chamber comprises an electric heater fixed on the tank shell; the pressure fitting comprises a stop valve and a pressure gauge of a liquid nitrogen tank and is used for pressurizing the inner chamber of the tank; the automatic control and protection system is used for automatically adjusting and controlling pressure and temperature; the protective accessory includes a safety head or valve. The step (b) comprises the steps of: (b1) cutting 3 amber samples formed by pressing in the step (a) into small blocks with the length of 5cm, the width of 5cm cm and the thickness of 3cm cm, putting the small blocks into a feeding basket, integrally placing the feeding basket into an inner chamber of a pressure tank of a pressure furnace, and closing a sealing cover of the pressure tank to form a closed environment; the air outlet pipe of the nitrogen barrel is connected with the air inlet pipe of the pressure furnace, and the air outlet of the pressure furnace is sealed. And (4) inflating the pressure tank until the air pressure reaches 5MPa, closing the air inlet, and then opening the air outlet of the pressure furnace to release the air. After repeated inflation and deflation for 3 times, completely exhausting the air in the inner chamber of the pressure tank, and sealing the air outlet of the pressure furnace; and filling nitrogen into the pressure tank through the air inlet until the air pressure condition reaches a first air pressure. (b2) Heating; the method comprises setting heating time and maximum temperature on an automatic control box, and automatically cutting off the power supply of the pressure furnace after the heating time is reached; the specific heating process is that the temperature of the amber is increased from the room temperature to a second target temperature in a third time, and the temperature is kept for a fourth time; during this time, the pressure in the interior of the pressure tank increases further under the influence of the temperature. (b3) Naturally cooling; and after the pressure furnace is powered off, slowly cooling the pressure furnace for 12 hours to room temperature, discharging nitrogen in the pressure tank through the air outlet, opening the sealing cover of the pressure tank, and taking out the amber sample. The "pressure" in step (b) refers specifically to the gas pressure in the pressure furnace.

The annealing parameters for the 3 samples were as follows:

numbering	Atmosphere environment	Temperature of	Time of heating	Time of temperature reduction	Product(s)
						1	Nitrogen, initial pressure 35MPa	210℃	7 hours (2.5 hours are needed for uniform temperature rise from 28 ℃ to 210 ℃ in Constant temperature at 210 ℃ for 4.5 hours	Naturally cooling, slowly cooling for 12 hours	Reproduced golden amber
2	Nitrogen, initial pressure 35MPa	140℃	10 hours (the uniform temperature rise at 28 ℃ to 140 ℃ requires 1.5 hours, constant temperature at 140 ℃ for 8.5 hours)	Naturally cooling, slowly cooling for 12 hours	Reconstructed beeswax
						3	Nitrogen, initial pressure 35MPa	210℃	7 hours (2.5 hours are needed for uniform temperature rise from 28 ℃ to 210 ℃ in Constant temperature at 210 ℃ for 4.5 hours	Naturally cooling, slowly cooling for 12 hours	Reproduced golden brown amber

Example 2:

this example shows a specific structure of the machine for producing a reconstituted amber patty used in example 1, and as shown in fig. 2, comprises a mold 2 and a pressing device 3 provided in a frame 1. The frame 1 is of a cubic structure and comprises a flat upper seat 11 and a base 12, wherein the upper seat 11 and the base 12 are detachably connected through a plurality of vertical beams 14; a mould 2 and a pressurizing device 3 are coaxially arranged in the middle inside the frame 1. The vertical beam 14 of the frame 1 is detachably connected and fixed with the upper seat 11 by screws.

As shown in fig. 3, the mold 2 is a cylindrical structure, and includes a steel cylinder 22, and an upper top plate 25 and a lower top plate 26 cooperating with the steel cylinder 22; the steel cylinder 22, the upper top plate 25 and the lower top plate 26 enclose a mold cavity 21. And a heating device 23 and a heat preservation device 24 are sequentially arranged on the outer side of the steel cylinder 22 and used for heating an object arranged in the inner cavity 21 of the mold. The heating device 23 is a resistance wire or a heating plate, and a temperature sensor is arranged inside the heating device 23 or between the heating device 23 and the steel cylinder 22 and used for automatically controlling the temperature in the inner cavity 21 of the mold.

The pressurizing device 3 is an electric control hydraulic machine or an electric control jack integrated with a pressure sensor, so that the pressure output value can be measured and automatically controlled. The pressure output end 32 of the pressurizing device 3 applies pressure to the mold 2, so as to press the amber raw material in the cavity 21 of the mold 2. Specifically, the body 31 of the pressurizing device 3 is arranged on the base 12 of the frame 1 in a manner that the center is upward, and the mold 2 is vertically arranged above the pressurizing device 3; the pressure output end 32 of the pressurizing device 3 is opposite to the lower top plate 26 of the mold 2.

Preferably, the frame 1 further comprises a positioning plate 13 for limiting and fixing the die 2, so as to improve the stability and the detachability of the die 2 in the pressing process; the lower part of the upper top plate 25 is also provided with a cylindrical top pillar 15, the lower side of the top pillar 15 is just opposite to the upper top plate 25 of the die 2, and the bottom pillar is used for downwards propping against the upper top plate 25 of the die 2, so that the object arranged in the die inner cavity 21 is pressed together by matching with the pressure output end 32 of the pressurizing device 3. During pressing, air in the inner cavity of the mold can be exhausted through the gaps between the steel cylinder 22 and the upper top plate 25 and the lower top plate 26.

The amber cake press for reconstruction also comprises a controller 4 for automatically controlling the pressing process. Fig. 4 is a schematic diagram showing the electrical connection relationship of the reproduced amber wafer press in this embodiment. The controller 4 is electrically connected with the heating device 23 and the temperature sensor of the mold 2, and the pressurizing device control interface and the pressure sensor of the pressurizing device 3, obtains the temperature value and the pressure value in the mold cavity 21 through the temperature sensor and the pressure sensor, and controls the temperature and the pressure in the mold cavity 21 through the heating device 23 and the pressurizing device control interface in a negative feedback mode to enable the temperature and the pressure to be in an expected state all the time. Preferably, the controller 4 further comprises an input/output device for setting and displaying parameters of the pressing setting and the pressing process, wherein the parameters at least comprise a pressure value, a temperature value and time; the input and output device is a keyboard and a display or an integrated touch screen.

The reconstructed amber cake press of the embodiment adopts a detachable frame type structure, so that the installation and the arrangement and the reverse mould treatment of amber raw materials are facilitated; the pressurizing device and the heating device are controlled by the controller in the pressing process, so that the automatic processing of the pressing process is realized, and the labor cost is saved; meanwhile, the pressure and temperature feedback control mode is adopted, and the adjustment control precision of the pressing pressure and temperature is improved.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. The production method of the reconstructed amber is characterized by comprising the following steps: the method comprises the following steps:

(a) the raw materials are heated and pressed by adopting a sectional pressurizing mode, and the specific mode is as follows:

(a1) pretreating raw materials, including cleaning and crushing;

(a2) placing the raw material in a mould with a cylindrical inner cavity, wherein the diameter of a circular pressure application surface of the inner cavity of the mould is 25-30cm, the height of the inner cavity of the mould is 6-10cm, and applying first pressure to the raw material;

(a3) pressurizing and heating the raw materials in sections; the step of pressurizing is to increase the fixed pressure every time when the first time interval passes until the second pressure is reached; the heating process comprises the steps of raising the temperature of the raw material from room temperature to a first target temperature within a first time, and maintaining the temperature for a second time, wherein the second pressure is 50-100 tons, and the first target temperature is 120-190 ℃;

(a4) naturally cooling and demoulding;

(b) annealing the pressed amber under the environment of protective gas and pressurization, wherein the specific mode is as follows:

(b1) putting the amber formed by pressing in the step (a) in a closed environment, filling nitrogen or inert gas into the closed environment for multiple times, discharging the nitrogen or inert gas, and pressurizing to a first air pressure, wherein the first air pressure is 35 MPa;

(b2) heating; the heating process is that the temperature of the amber is increased from the room temperature to a second target temperature in a third time, and the temperature is kept for a fourth time, wherein the second target temperature is 140-210 ℃;

(b3) and (5) naturally cooling.

2. The method for producing a reconstituted amber according to claim 1, wherein: the size of the crushed raw materials in the step (a) is 3mm, the first pressure is 50 tons, the first time interval is 1 hour, the fixed pressure is 5 tons, the second pressure is 70 tons, the first time is 1.5 hours, the first target temperature is 190 ℃, and the second time is 2.5 hours; in the step (b), the first air pressure is 35MPa, the third time is 2.5 hours, the second target temperature is 210 ℃, and the fourth time is 4.5 hours; the obtained reproduced amber is golden amber.

3. The method for producing a reconstituted amber according to claim 1, wherein: the size of the crushed raw materials in the step (a) is 1mm, the first pressure is 60 tons, the first time interval is 0.5 hour, the fixed pressure is 3 tons, the second pressure is 96 tons, the first time is 3 hours, the first target temperature is 120 ℃, and the second time is 3 hours; in the step (b), the first air pressure is 35MPa, the third time is 1.5 hours, the second target temperature is 140 ℃, and the fourth time is 8.5 hours; the obtained reconstructed amber is beeswax.

4. The method for producing a reconstituted amber according to claim 1, wherein: the size of the crushed raw materials in the step (a) is 200 meshes, the first pressure is 50 tons, the first time interval is 1 hour, the fixed pressure is 5 tons, the second pressure is 70 tons, the first time is 1.5 hours, the first target temperature is 190 ℃, and the second time is 2.5 hours; in the step (b), the first air pressure is 35MPa, the third time is 2.5 hours, the second target temperature is 210 ℃, and the fourth time is 4.5 hours; the obtained reproduced amber is golden brown amber.