Effects Of Different Copper Reagents On The Color-keeping Of Pressed Flower

The art of pressed flower, which uses pressed dry vegetative organs as basic source materials to make ornamental and practical vegetative products such as exquisite cards, decorative patterns and daily use articles etc., becomes popular in recent days. The characteristic of the art is to cleverly realign the unique patterns and natural colors of plant organs by artistic conception and design so as to reappear natural forms. There are several shortages in the pressed flower manufacture recently in our country, such as the key technology of color reservation is unripe, the relative implements are lack. These restrictive factors slow down the development of pressed flower art and industrialization. It is necessary to do further study on the technologies of keeping the original colors and ideal shapes of vegetative materials, and improving ornamental quality of the handicrafts by using those methods.Leaves of 6 species(nandina, peony, trefoil, pteridophyte, camellia sasanqua, laurel) were taken as experimental materials, which were treated combinatively with chemical and physical methods based on the comprehension of the reactive mechanism of chlorophyll. Firstly the leaves were soaked in heated copper sulfate solutions with 1%, 2.5%, 5% saturated concentrations and acetic copper solutions with 1 : 4 and 2 : 3 concentrations progressively. Secondly, the leaves of trefoil and pteridophyte, which appeared not so good in heated solutions, were treated again with cold solutions, and the leaves of camellia sasanqua and laurel, which were failed in the former treatments, were injured artificially and treated with the same solutions again. Finally the ideal color-keeping methods for different types of leaves were determined after testing the stability of the leaves which were treated successfully by former methods. The results of the test showed:1. The color of the leaves, which dried physically alone, can keep fresh for a relative long period of time under ideal conditions, but with the lapse of time the leaves will become colorfast due to the lack of color-preserving treatment. So the ideal program for color-keeping is to combine physical method with chemical treatment.2. The ideal method for color-keeping of the leaves of nandina and peony is firstly soaking in heated solution of 5% Cu SO4 or Cu(CH3COO)2 and then drying with microwave. The greater the density of the solution is, the shorter of the time for color preservation will be. The leaves appeared blue green as treated with copper sulfate, while treated with acetic copper, the leaves appeared fresh green. Because of its irritant smell, the acetic copper is used on special demand for leaf color, meanwhile the protective measure must be taken.3. The leaves of trefoil and pteridophyte were easily softened and shrunk in the heated solution, so soaking in cold solution and drying with thermostat oven is the best method for these leaves. Due to the green color of the solution, great attention should be paid to the change of leaf color.4. The leaves of camellia sasanqua and laurel, the surfaces of which are covered with wax, are difficult to be permeated by color-preserving solution. So for these kinds of leaves, the best method is treated by the combination of rubbing the back of the leaves and soaking in heated 5% Cu SO4 solution, especially to the leaves of laurel, the time of returning green is shorter after rubbing.The study filled some gaps in color-fading for several kinds of leaves, and the achievements can be applied to the production of pressed flower articles. There are thousands of species of plants in the nature, and each has its own speciality. The suitable treatment for each kind of plants Should be continued to study, so as to supply more plant materials to the production of pressed flower articles.