The invention relates to a primer and a method for treating of acoustic music instruments such as string instruments e.g. comprising a resonance box made of wood such as violin, viola, cello double bass, guitar mandolin, ukulele or the like. The invention also relates to a music or string instrument obtained by the method.

Prior art

It has been known for centuries that a high number of parameters influences the acoustic quality of a string instrument comprising a resonance box made of wood, e.g.

- the non-homogeneous structure of the wood and the type of wood

- the shape of the outline of the resonance box

- the thickness and curving of the plates constituting the resonance box

- the form and fastening of the resonance bar to the front plate of the resonance box

- the positioning of the sound post between the front and back plates of the resonance box causing a change of phase between the two plates

- etc. Over time experts has discussed which features were most important in respect of forming the sound of a string instrument.

Traditionally, the wooden surface of the resonance box has been covered with a thin layer of stain, which stops the pores of the wood and prevents a varnish from penetrating into the wood.

The document JP 2006/316161 discloses a coating composition for bowed string instruments which coating forms a relatively soft coating film, is formed of a natural material and provides an improvement of both the appearance and the sound quality of the instrument. The coating composition according to this document is produced by collecting tree sap from a tree of the family Pinaceae, boiling down the obtained balsam to a concentration falling within a prescribed range and dissolving the obtained solid resin component in a solvent. Preferable the balsam is Venetian turpentine and preferable the solvent is turpentine oil. The coating material may also be used for mending of bowed string instruments.

The present invention discloses a procedure for treating an acoustic string instrument to obtain a superior quality of sound e.g. how to provide a violin having a sound spectrum almost similar to the sound spectrum of the human voice for a prolonged time interval.

The present invention relates to a treatment method for string instruments comprising a resonance box made of wood in a stage where the resonance box appears as "white" untreated wood, i.e. the treatment relates to application of a primer. The method can be used for instruments such as Violin, Viola, Cello,

Double Bass, Guitar, Mandolin and Ukulele.

The primer according to the invention can significantly improve the quality of music instruments and the product is characterized by its ability to increase the sound spectrum of the instruments to a considerable extent.

Summary of the invention

The invention relates to a primer which is able to improve the quality of music instruments comprising a resonance box made of wood as the primer is able to increase the sound spectrum of the instrument.

The primer is characterized by characteristics such as triboluminescence and fluorescence under ultraviolet light due to its crystalline structure after drying.

Wood primed with the primer shows an increased Young modulus. According to a first aspect, the invention relates to a primer for treating an acoustic string instrument which primer is to be applied to a "blank" or "white" or untreated instrument having a resonance box made of wood, the primer comprises or is constituted of juice or an extract obtained from a natural plant such as Chelidonium Majus plant material.

A primer according to the first aspect may be prepared from crude Chelidonium Majus plant material, i.e. the Chelidonium Majus plant material may be chopped or crushed or grated or pulverized or otherwise divided into pieces before extraction.

A primer according to the first aspect, may be prepared from dried plant material, but normally the Chelidonium Majus plant material has not been subjected to e.g. drying before use.

A primer according to the first aspect, wherein the Chelidonium Majus plant material may comprise a part of the plant such as root or stem or leaves or the Chelidonium Majus plant material may comprise a combination of one or more of these plant parts or the Chelidonium Majus plant material may comprise complete plants as harvested.

A primer according to the first aspect, wherein the solvent used for extraction may comprise or may be constituted of water or methanol or ethanol or propanol or another alcohol having 1-6 carbon atoms or a mixture of two or more of these liquids.

A primer according to the first aspect, wherein an extract may be prepared by submerging the Chelidonium Majus plant material in a solvent for a period of minimum 1 hour or minimum 2 hours or minimum 3 hours or minimum 4 hours or minimum 5 hours or minimum 8 hours, and a maximum of 96 hours, or 84 hours or 72 hours, normally between 12 and 80 hours, the mixture may be agitated and/or heated during preparation of the extract.

A primer according to the first aspect, wherein after finishing the extraction, the extract may be separated from solid plant material e.g. starting by pressing and possibly followed by filtration or decantation or the like.

A primer according to the first aspect, wherein solvent may be removed from the extract e.g. by distillation or another evaporation procedure to prepare the primer.

A primer according to the first aspect, wherein the primer may be prepared by crushing wet Chelidonium Majus parts such as root parts into a crushed material, placing the crushed material in a container submerged or at least partly covered by a solvent such as ethanol CH3CH20H or methanol CH30H, leaving the material at room temperature for a period of at least 3 days with frequent agitation until soluble matter has dissolved, then the mixture may be drained from solvent and the obtained liquid may be clarified by filtration or decantation after standing.

A primer according to the first aspect, wherein the primer may be prepared by moistening complete Chelidonium Majus plants with an amount of a menstruum such as ethanol CH3CH20H, the moistened material may be left for approximately 4 h in a closed container, then the material may be packed into a percolator and the top of the percolator then closed, menstruum may be added to form a shallow layer above the material, and the mixture may be allowed to macerate in the closed percolator for at least 10 h, after the at least 10 hours the outlet of the percolator can be opened, and liquid constituting the percolate may be allowed to drip slowly from the container, additional menstruum may be added during the process, at the end, the remaining material may be pressed and the expressed liquid can then be added to the percolate, then the mixed liquid may be clarified by filtration or by standing followed by decanting.

A primer according to the first aspect, wherein the primer may be prepared by countercurrent extraction (CCE) or supercritical fluid extraction (SFE). According to a second aspect the invention relates to a music instrument e.g. having a resonance box made of wood such as a Violin, Viola, Cello, Double Bass, Guitar, Mandolin and Ukulele or the like which m usic instrument is treated with a primer according to the first aspect.

A music instrument according to the second aspect, wherein the soundboard of the music instrument may be made of spruce, maple, cedar, mahogany or koa or other tonewood having similar characteristics.

According to a third aspect, the invention relates to a method for treating a music instrument comprising a resonance box made of wood by applying a primer according to the first aspect to the untreated surface of the resonance box.

A method for treating a music instrument according the third aspect, wherein a varnished may be applied to the surface of the resonance box after application of the primer.

A method for treating a music instrument according the third aspect, wherein the varnish is based on oil.

For this purpose, a Chelidonium Majus extract or any other part of the plant Chelidonium Majus (root, stem or leaves) is used.

Other products of this kind are used to stain and color the various musical instruments. The primer according to the invention is distinguished from other products with its chemical composition which are many different minerals and the ability to crystallize. The shaped crystals help increase the resonance of the acoustic "box" that is the instrument.

To prove the effect of the applied primer, several scientific studies and measurements have been conducted, such as sound spectrometer measurements of the experimental instruments, with different time intervals.

-The object of the invention is to provide an improved method for a priming process of stringed instruments, which in particular ensures a significant improvement of the acoustic properties.

- According to the first aspect of the invention a "blank" (untreated) instrument is subject to a treatment with an extract of a plant such as an extract of Chelidonium Majus. The plant extract crystallizes during drying and triboluminescence and fluorescence under ultraviolet light because of its crystalline structure.

- A liquid medium obtained from the Chelidonium Majus applied on the surface of the instrument will penetrate deep in the pores of the wood. By drying it will have a crystalline formation.

- A liquid medium constituting a primer according to the invention contains complex mineral elements such as Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Fig, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Ti, V, and Zn, which have a crucial role of increasing the modulus of elasticity (Young modulus) and a high speed of sound. Our experiment proves that by using the primer according to the invention the Young modulus is increased by 9,15%, and the loss factor is decreased by 22,6% corresponding to an overall improvement of over 31%.

A primer according to the invention have qualities or characteristics such as triboluminescence and fluorescence under ultraviolet light because of its crystalline structure.

A test piece of primed spruce must have an increased Young modulus, (the real part)

Norway or European spruce (picea abies) is used in forestry for (softwood) timber, and paper production and the tree is valued as a source of tone wood by violin makers. One form of the tree, Flazel-spruce, grows in the European Alps and has been recognized by UN ESCO as intangible cultural heritage. This form was used by Stradivarius for instruments.

Norway or European spruce (picea abies) is a commonly used material for construction of resonance boxes for violins. Flowever, the primer of the present invention may be used on other sorts of tonewood while the effect of the present invention is still obtained. E.g. back and/or sides the resonance box may be made of maple, rosewood, mahogany, or koa, e.g. soundboards can be made of spruce, cedar, mahogany or koa. The choice of wood may determine the sonic character of an instrument, but no matter which combination is chosen, the present invention will improve the sound quality of an instrument subjected to the treatment of the present invention. The primer will improve the sound quality of the resonance box no matter which type of wood is used for the resonance box.

Preferably, the minimum active content is DEV 1: 1 liquid extract. (DEV is Drug Extract Ratio). Extraction Strength (Drug Extract Ratio).

The strength of herbal extracts is generally expressed as a ratio of plant material e.g. dry plant material to final extract quantity, also known as the drug extract ratio (DER). It is expressed in the following format: X : Y, where X = weight of plant material, e.g. dry plant material, and Y = weight or volume of extract (depending upon whether extract is a solid/dry extract, or a liquid extract). The concept is that the essential activity of the plant material (X) is found in the quantity of extract (Y). Or in other words, Y quantity of the extract is equivalent to X quantity of the dry plant.

The primer according to the invention may be applied in multiple layers e.g. to obtain a desired tint.

A paint or varnish such as an oil paint or varnish may be applied on top of the primer layer(s).

Experiments

In our experiments we have used resonant spruce without any "defects" with a normal humidity degree of 15% and it was debited from the territory of Romania.

Juice from different parts of the plant may be applied directly on the resonance box of an instrument to obtain the desired effect, e.g.

- A surface of a raw root of a plant may be exposed, and then the exposed surface of the root may be rubbed against the wooden surface of the resonance box of the instrument

- The stem of the plant may be cut or broken and the outcoming juice of the plant may be applied on the resonance box of the instrument

- The root and/or the stem may be crushed and applied as a paste on the surface of the resonance box of the instrument.

For a cleaner and more commercial product which is easier to dose, the content of the plant may be extracted.

The following methods are suggested for extraction of the primer:

Method 1

MACERATION:

A traditional method, in which the wet rude Chelidonium Majus (root) is crushed, placed in a stopped container with the solvent (in our case ethanol CH3CH20H or methanol CH30H) and allowed to stand at room temperature for a period of at least 3 days with frequent agitation until the soluble matter has dissolved. The mixture then is strained, the marc (the damp solid material) is pressed, and the combined liquids are clarified by filtration or decantation after standing.

Additionally, can the menstruum be evaporated to the desired density.

Infusion

Fresh infusions are prepared by macerating the crude drug for a short period of time with cold or boiling water. These are dilute solutions of the readily soluble constituents of crude drugs.

Digestion This is a form of maceration in which gentle heat is used during the process of extraction. It is used when moderately elevated temperature is not objectionable. The solvent efficiency of the menstruum is thereby increased.

Decoction

In this process, the crude drug is boiled in a specified volume of water for a defined time; it is then cooled and strained or filtered. This procedure is suitable for extracting water-soluble, heat stable constituents. This process is typically used in preparation of Ayurvedic extracts called "quath" or ukawath". The starting ratio of crude drug to water is fixed, e.g. 1:4 or 1:16; the volume is then brought down to one-fourth its original volume by boiling during the extraction procedure. Then, the concentrated extract is filtered and used as such or processed further.

Method 2

PERCOLATION:

The solid whole Chelidonium Majus plant is moistened with an appropriate amount of the specified menstruum (in this case ethanol CH3CH20H) and allowed to stand for approximately 4 h in a well closed container after which the mass is packed and the top of the percolator is closed. Additional menstruum is added to form a shallow layer above the mass, and the mixture is allowed to macerate in the closed percolator for 24 h. The outlet of the percolator then is opened, and the liquid contained therein is allowed to drip slowly. Additional menstruum is added as required, until the percolate measures about three-quarters of the required volume of the finished product. The marc is then pressed, and the expressed liquid is added to the percolate. Sufficient menstruum is added to produce the required volume, and the mixed liquid is clarified by filtration or by standing followed by decanting.

Method 3

SOXHLET:

Traditional Soxhlet method using Methanol (CH30H) as menstruum for total extraction. Polarity and the nature of phytochemical constituents present in the drug are the factors that was considered for selection of the solvent since the extract is not used for human consumption like in case of a medicinal plant.

Method 4

COUNTER CURRENT EXTRACTION:

In counter-current extraction (CCE), wet raw Chelidonium Majus root is pulverized using toothed disc disintegrators to produce a fine slurry. In this process, the material to be extracted is moved in one direction (generally in the form of a fine slurry) within a cylindrical extractor where it comes in contact with extraction solvent. The process is highly efficient, requiring little time and posing no risk from high temperature. Finally, sufficiently concentrated extract comes out at one end of the extractor while the marc (practically free of visible solvent) falls out from the other end.

Method 5

SUPERCRITICAL FLUID EXTRACTION

Supercritical fluid extraction (SFE) is an alternative sample preparation method with general goals of reduced use of organic solvents and increased sample throughput. The factors to consider include temperature, pressure, sample volume, analyte collection, modifier (cosolvent) addition, flow and pressure control, and restrictors. Generally, cylindrical extraction vessels are used for SFE and their performance is good beyond any doubt.

The collection of the extracted analyte following SFE is another important step: significant analyte loss can occur during this step, leading the analyst to believe that the actual efficiency was poor. There are many advantages to the use of C02 as the extracting fluid. In addition to its favorable physical properties, carbon dioxide is inexpensive, safe and abundant. But while carbon dioxide is the preferred fluid for SFE, it possesses several polarity limitations. Solvent polarity is important when extracting polar solutes and when strong analyte-matrix interactions are present. Organic solvents are frequently added to the carbon dioxide extracting fluid to alleviate the polarity limitations. Of late, instead of carbon dioxide, argon is being used because it is inexpensive and more inert. The component recovery rates generally increase with increasing pressure or temperature: the highest recovery rates in case of argon are obtained at 500 atm and 150° C.

The extraction procedure possesses distinct advantages:

i) The extraction of constituents at low temperature, which strictly avoids damage from heat and some organic solvents, ii) No solvent residues,

iii) Environmentally friendly extraction procedure.

The largest area of growth in the development of SFE has been the rapid expansion of its applications. SFE finds extensive application in the extraction of pesticides, environmental samples, foods and fragrances, essential oils, polymers and natural products. The major deterrent in the commercial application of the extraction process is its prohibitive capital investment.

Method 6

ULTRASOUND EXTRACTION (Sonication)

The procedure involves the use of ultrasound with frequencies ranging from 20 kHz to 2000 kHz; this increases the permeability of cell walls and produces cavitation. Although the process is useful in some cases, like extraction of rauwolfia root, its large-scale application is limited due to the higher costs. One disadvantage of the procedure is the occasional but known deleterious effect of ultrasound energy (more than 20 kHz) on the active constituents of medicinal plants through formation of free radicals and consequently undesirable changes in the plant molecules.