Method of creating a cosmetic spray

Abstract

A method of spraying a liquid cosmetic composition onto the surface of the human body comprising: (i) mechanically pressurising a free-flowing liquid cosmetic composition to a pressure of from 1.0 to less than 5.0 MPa; (ii) passing said composition through a swirl chamber, and (iii) expelling said composition through a 100 to 200 micron outlet nozzle onto the surface of the human body.

Description

[0001] The present is in the field of cosmetic spray products and methods of generating sprays. In particular, the invention concerns the generation of a spray from a liquid cosmetic composition without the use of a volatile propellant. [0002] Cosmetic spray devices of the prior art have utilised a variety of means for creating the spray. A widely used option has been to formulate a liquid cosmetic composition with a volatile propellant, such as a liquefied hydrocarbon or chlorofluorocarbon. However, it is increasingly recognised that the addition to the atmosphere of VOCs / greenhouse gases may have detrimental environmental consequences and alternative means of spray generation have been sought. [0003] As an alternative to the use of a volatile propellant, mechanical pressure may be used to expel a liquid cosmetic composition through a nozzle, thereby creating a cosmetic spray. Currently marketed cosmetic spray devices that operate in this manner are squeeze sprays and trigger spray...

AI Technical Summary

Benefits of technology

[0013] The present invention describes a method of creating a cosmetic spray that has good sensory properties on application to the human body, without the use of a volatile propellant. The good sensory properties result from the good spray quality attained by the combination of suitable device components and suitable mechanical pressurisation as described herein. In addition, the invention enables the cosmetic spray to be applied to the surface of the human body at a flow rate that is appropriate.

[0018] The swirl chamber is an important element of the present invention. It causes the liquid cosmetic composition to swirl around and thereby enhances its atomisation on exit from the outlet nozzle. A typical swirl chamber has one or more radial inlet holes or slots. Preferably, such holes or slots are tangentially disposed to the cross-section of the swirl chamber; the cross-section preferably being essentially circular. For optimum efficacy, the holes or slots, of which there are preferably two or more, in particular from two to four, are present in the bottom of the swirl chamber, i.e. the part furthest from the outlet nozzle. Multiple inlets, when present, are arranged to all promote swirling in the same direction, whether that be clockwise or counter-clockwise.

[0020] The relative dimensions of the inlet(s) to and outlet from the swirl chamber can effect the quality of the spray produced. It is preferred that the total cross-sectional area of the inlet(s) is greater than that of the outlet nozzle; in particular, it is preferred that the inlet:outlet area ratio, i.e. the ratio of the total cross-sectional area of the inlet(s) to the area of the outlet nozzle, is from 2.5:1 to 3:1. In measuring the cross-sectional areas referred to, one should take the minimum inlet / outlet areas linking the swirl chamber with the non-swirl chamber space.

Problems solved by technology

However, it is increasingly recognised that the addition to the atmosphere of VOCs / greenhouse gases may have detrimental environmental consequences and alternative means of spray generation have been sought.

Unfortunately, such devices tend not to produce good quality sprays, partly as a result of limited pressure that may be applied to the composition.

The poor spray quality often results in poor sensory properties on application to the human body.

Unfortunately, these publications contain no description of how a cosmetic spray suitable for application to the surface of the human body might be generated.

The devices described in these publications operate at pressures that are higher than would be desired in a cosmetic spray applicator and / or would not deliver the spray at sufficient rate or spray quality for cosmetic application.

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