Consumers often judge the quality and performance of personal-care products and cosmetics based on their textural feel and also based on the performance of the applicator. Durable packaging — both attractive and practical in design — is another aspect that has to project a high-quality exterior to protect the contents and reflect a company’s brand message.
In order to help companies meet the rigorous quality-assurance expectations of their customers, Mecmesin offers an array of force and torque test systems to cover everything, right from analyzing the texture of a cosmetic product, the performance and durability of its applicator, through to the openability of the packaging.
Mecmesin products are used widely in R&D facilities, production areas, and QC laboratories. Mecmesin is renowned for its economical range of torque and force testing systems and the all-significant grips specially developed for the cosmetics industry, providing good value for money and backed up with support and technical advice by a team of trained international distributors.
Delivering to leading cosmetics companies worldwide, Mecmesin’s systems are particularly configured to fulfill companies’ specific application needs, aiding them to ensure consistent and repeatable quality at each point of production. This will help them to continuously comply with cosmetics and personal-care industry standards and will also help to save costs by:
- Improving the use of materials to decrease volumes and meet recycling targets
- Discarding faulty supplier batches before production
- Guaranteeing suitability of packaging to cut down spillages and damage
- Ascertaining the durability of products to guarantee customer satisfaction until end of use
- Ensuring product consistency for continual quality and building customer loyalty
Mecmesin’s automated torque tester allows us to enhance our existing test methods and create new ones for our quality-control records. It is accurate, provides good reproducibility and we can totally rely on it for the results we get. Furthermore, I recommend Mecmesin as a nice company to work with and very helpful staff who assisted us with getting the tester and it’s software set-up to meet our needs.
Jérôme Villeval, Homologation Packaging, L’Oréal
Torque
For a majority of the cosmetic products, the packaging is important to their added value and has a vital role to play in the decision-making process of consumers. Moreover, the packaging is usually incorporated with the product contents, serving as a dispenser or applicator, like a mascara brush or lipstick barrel.
The application of new forms and shapes developed from a host of stiff and flexible materials is suitable for producing aesthetic designs for the consumer. However, improved aesthetic packaging itself can make it more difficult to grip and test.
To make sure that both cosmetic applicators and packaging fulfill their functional purpose easily, Mecmesin test systems cater to a variety of torque capacities and provide various gripping fixtures to fulfill the challenges of holding the cosmetic products.
Mecmesin offers test equipment on two levels:
1. Manually operated torque testers are usually employed as a quick, affordable, and easy method to check release torque. However, such devices are increasingly recognized to have certain disadvantages because operators need to operate them by hand.
- Inaccurate and inconsistent results induced by the inconsistent speed of testing, varying “axial-load” on closures, and varying lateral gripping forces
- Operators who must test regularly experience repetitive strain injury
2. Automated torque testers are increasingly being employed as the “master” tester to establish the packaging’s torque properties. A constant speed of rotation delivered by the motorized test frame eliminates inconsistencies caused by operators testing at variable speeds. A constant axial-load is applied by the measuring head and the custom-gripping fixtures (called “mandrels”) fit tightly around the applicators and closures gripping them evenly without any deformation. Even though the preliminary cost is higher compared to a manual tester, the consistency and repeatability of results, along with the added advantage of being more convenient to use for the operator, make the return on investment worthwhile within a reasonable period of time.
Packaging
Closures and caps form an integral part of cosmetic packaging. When these are used on containers, they should be easy to open by both young and old consumers. Caps and closures should also retain an effective seal that safeguards the product from leakage and external contamination when the package is being re-closed under standard conditions.
The quantification of applied torque and release torque (also called “closing” and “opening” torque) is a reliable and commonly used indicator of the integrity and performance of packaging across the personal care and cosmetics sectors. When torque parameters are tested from a set of samples soon after application and at a given time interval (typically 24 hours), the capping machines and their separate capping heads can be checked to verify that they are performing according to expectations.
Testing release torque of plastic closure using Tornado manual tester
Testing opening torque of closure/dispenser using Vortex automated tester
Testing release torque of dropper bottle using a dedicated mandrel on Helixa automated tester
Applicators and Dispensers
Nowadays, the applicator plays a much more critical role. It is integral to a product because it provides and applies the formula and, at the same time, needs to be both functional and attractive. In addition, it should be fast and easy to use; nowadays, consumers do not have much time and therefore they want the applicator to work instantly.
Cosmetic dispensers and applicators should have the same usage and protective characteristics as that of packaging in terms of maintaining an effective seal when being tightened and re-closed and being easy to use for consumers. However, they need much lower levels of torque to be determined and therefore present certain challenges when it comes to gripping, requiring the use of lightweight fixtures and having a torque sensor that has adequate accuracy and sensitivity to determine even the finest of loads.
Testing the free-running torque and end-stop torque of a lipstick barrel in both opening and closing directions.
Testing the tightening torque of the wand to overcome the ramp in the threaded mascara container.
Force
Subjecting the materials and products to compression and tensile forces is an important way to make sure that cosmetics packaging and applicators are sufficiently strong to fulfill the needs and expectations of customers.
Specializing in exclusive fixtures and grips for the cosmetics sector, Mecmesin's range of versatile tensile testers provides a cost-effective testing solution to help companies determine their materials’ mechanical strength and thus ensure that their products meet their quality control specifications.
Whether the application is top-load/tension, compression, flexure, or peel, companies can depend on the performance and accuracy of a Mecmesin tester to meet their requirements.
Packaging Test Methods
Since there are only a few international standards dedicated to cosmetics packaging and applicators, a majority of companies tend to draw upon generic packaging standards along with their own in-house test approaches. Standard generic standards cover the following:
Coefficient of Friction
Packaging materials are typically cut, fed, and passed through production at extreme speeds. Films and cardboard are usually coated with inks and lacquers, which impact their surface characteristics. Materials that have an uneven or rough surface texture will generate a considerable amount of friction and are likely to affect the production line efficiency. Testing the surface’s frictional qualities would not only ensure that the raw materials used are appropriate for machinery but would also prevent the possibilities of damage or jams caused at the time of the packaging process.
Top-Load
Aluminum containers and plastic bottles have to tolerate top-load — the downward axial force — at the time of the filling, capping, and stacking procedures. Empty containers and bottles are generally tested to destruction for their mechanical strength, and this is done to correlate their performance when filled and utilized in actual scenarios. Top-load testing can enable finding the exact balance between making materials lightweight to meet cost targets and maintaining adequate strength of cosmetic containers to be viable for use.
Peel and Adhesion
A hermetic aluminum seal is adopted by products like gels and creams as part of their packaging. Cosmetics have a fixed shelf life just like food, and while these products are not ingested, they are used on sensitive parts of the body. Accomplishing a balance between a robust seal that keeps contents sterile and fresh yet easy to remove by consumers is highly crucial to both the user experience and thus the company’s brand reputation.
Burst Tests on Seal Strength
For products like hair gels and toothpaste that are packaged in tubes, force is needed to squeeze out the contents. The strength of the seal on the welded seam is checked using compressive burst testing. This helps in preventing leaks by checking that it can tolerate the force applied during application and also withstand the pressures from transportation and stocking when the product is not in use.
Flip-Cap Opening
For a number of “semi-solid” cosmetics like moisturizers, gels, and shampoos, flip caps are a standard closure. Tension and compression testing is done to evaluate opening and closing. This process helps in ensuring that leaks are prevented at the time of use (usually when contents are upside-down and their weight is used on the flip-cap), while being easy enough to be opened and closed by the end user. Moreover, the hinge strength can also be tested to check whether it can withstand frequent use without breaking off.
Foldability of Cardboard Packaging
Cardboard packaging properties have to be tested for fold and crease strength because these are considered as vital factors in terms of the performance of cartons on high-speed packaging lines. Tensile testers with specialized fixtures can be used to make sure that creases in boards are uniform and correct.
Applicator Test Methods
Products like aerosol sprays, dispenser pumps, and mascara brushes are just some of the applicators tested to establish their integrity and performance. Due to the wide range of applicators, usually involving an intricate multi-part construction, test methods are often created in-house according to the brand’s specific requirements. The manner in which a product is used is important to overall customer experience and affects the way in which its quality is judged by the end user. If a pump is expected to dispense the product from its container in a smooth and easy way, this is exactly what needs to be delivered.
Brushes and Containers
Brush manufacture is known to be a highly specialized process in which numerous rubber or synthetic fiber materials of varying density and lengths are used. For products like lip glosses and mascaras, the applicator is important to the way the product is delivered. Applicators are available in many different designs with innovations like “flexible” wipers, “soft” flocking tips, “soft” bristles with “shed-resistant” characteristics, and so on — all the features are defined by their mechanical strength.
Tensile testing provides an important means of quality control and helps guarantee that the raw material as well as the finished applicator fulfills the specifications to tolerate the process of being removed from the packaging and being used repeatedly to apply the formula — be it testing the force of separate bristles or their strength as a whole, or testing the assembly strength of connected applicator components.
Eye Liner and Lip Pencils
Pencil cosmetic products are typically applied as applicators. A lid is the key packaging element for this kind of product, protecting the tip from being contaminated or damaged. A pull-off test is best used to establish the force needed to remove the lid effortlessly when in use, while remaining secure when not in use. Brittleness can be tested by adopting a bend test, which ensures if the pencil can sustain the force applied during the application of the product.
Dip Tubes
Dip tubes represent an important part of numerous multi-part applicators used for delivering sprays and liquids. The integrity of the joint between the spray head/dispenser and the dip tube is checked using a pull-off test.
Aerosols and Pump Dispensers
The performance of the standard aerosol decides the delivery of fragrances, mousse, and body sprays. Compression testing of aerosols and pumps to a predetermined displacement enables accurate determination of the actuation force of spring-operated dispensers.
Texture
The physical properties of a product and the way it delivers the anticipated performance based on the manufacturer’s claim largely govern customer acceptance. With the majority of cosmetic products developed for the skin, their texture properties are equally significant as the subsequent feel.
Texture, appearance, and odor of a cosmetic product are integral to its sensory experience. As a measure of its quality, testing processes have been developed to make sure that the consistency and physical texture of the products are met.
Semi-Solid Cosmetics
Viscous semi-solid cosmetics include products containing lipids, hydrocolloids, polyols, emollients, and emulsions. While these products are expected to have some degree of firmness, they should also be easy enough to spread and flow easily. Products include:
- Shampoos
- Sun-protection/tanning lotions
- Moisturizers
- Creams
- Gels
- Liquid soaps
- Shaving creams
- Waxes
- Bath/shower gels
Skin creams are anticipated to have a rich, smooth, and creamy texture, and need to be light but not greasy or slippery. This balance can be achieved by formulating them in such a way that they hydrate and moisturize, but not create oiliness on the skin in spite of the presence of oils.
Solid Cosmetics
Solid cosmetics are usually produced in the form of cohesive blocks. For instance:
- Lip balms
- Bar soaps
- Eye/lip liners in the form of lipsticks and pencils
- Solid block antiperspirants/deodorants
These products are expected to deform and wear off over use, but at the time of application, they are required to stay hard and maintain their structure without crumbling, flaking, or breaking.
Powder Cosmetics
Powder cosmetic products — loose or compacted — have a dry consistency and need the use of brushes, sponges, and similar applicators, for example:
- Blushes
- Foundation powders
- Eye shadows
With the formulation of the products and the force applied at the time of application, these items specifically have to be tested for flow in a controlled and consistent way, without clumping or caking.
Test Methods for the Cosmetics Sector
A suitably shaped probe is used to replicate the movement of fingers at the time of handling and application of cosmetic products. Many different test techniques may be needed to assess the physical properties.
Compression
Compression testing is used to evaluate textural properties like firmness, fracturability, and cohesiveness. This is carried out with the help of cylindrical or spherical probe fixtures.
Product applications include:
- Crush resistance of carved soap bars
- Firmness or runniness of moisturizers
Extrusion
Extrusion testing is particularly applied for testing semi-solids in isolation, with the help of extrusion fixtures. Using forward or back extrusion techniques, it is possible to evaluate the interaction of semi-solid cosmetics with the dispenser and packaging.
Product applications include:
- Dispensability of creams and shampoos (forward extrusion)
- Flow properties of bath creams
- Spreadability as well as ease of applying pastes, masks, moisturizers, and hair waxes (back extrusion)
Shear, Snap, Bend and Break
Assessing the performance of cosmetic products exposed to stress at the time of usage can help in evaluating their formulation and the ensuing texture.
Product applications include:
Penetration and Puncture
Testing of the strength of solid samples is done by penetrating them with small cylinders, cones, and needles, while the firmness and thickness of a semi-solid can be assessed using a ball probe. Penetration and puncture testing can also be used to evaluate powder cosmetics and the cake strength and compaction of talc. Some other properties that can be assessed through this technique include:
- Firmness of moisturizers and crumbling resistance of liner pencils
- Hardness and fracture strength of soap, lipstick, and solid deodorants
Tension
The adhesive force indicates a product’s stickiness. This force is determined by the tension encountered during the test’s return stroke.
Product applications include:
- Stickiness of moisturizers
Gel Testing
Gelling agents are increasingly being used in many cosmetic product formulations. A range of standard tests has been proposed by the gel sector for final products or raw ingredients that take the form of a gel.
Product applications include:
- Hold strength of hair gels
- Bloom strength
Test Standards
An array of test methods has been adopted within the cosmetics and personal-care product sector. These methods could be in-house standards developed by a company within the industry, which are mainly focused on the testing of a certain type of cosmetic product (for example, lipstick) and implementing test parameters created by the company itself. On the other hand, the adopted test methods could be more generic international standards in relation to a wide range of products (for example, plastic containers), which are believed to be pertinent to the cosmetics industry and therefore for relevant for use.
Mecmesin’s powerful easy-to-use and intelligent VectorPro test analysis software, has flexible programming capabilities that truly comes to the fore to generate a step-by-step test routine to fulfill the exact needs of in-house as well as international test methods for force and torque testing. Recall and storage of test methods are very simple and perfect for operators who may need to test a range of diverse products in small batches all through the working day.
Special Grips and Fixtures
With continuous innovations fueling the cosmetics and personal care sector to deliver state-of-the-art designs, a host of different shapes and sizes of applicators and packaging is there to be tested. This implies that a normal range of grips cannot invariably hold all potential combinations, and therefore, it is required to apply specialized fixtures. This is where Mecmesin’s four decades of experience really comes to the fore, providing solutions for torque and force measurement. The company’s team of Special Application Engineers can be consulted by customers to design and develop the best gripping solution for their product, be it to hold one item or a more “universal” method to hold a variety of products.
In order to meet the challenges of exact testing at low forces, the grips have to be lightweight but rugged. Mecmesin has a lot of experience in creating fixtures using the newest 3D printer technology that uses nylon with integrated carbon micro-fibers for extra strength — simply perfect for testing the mini torque, which is involved in precision applicators, including lipsticks.
Testing the extraction force of the threaded plug of mascara
Testing retention force of the mascara brush to its wand
Torque testing lids of face powder pots
About Mecmesin
Established in 1977, Mecmesin is a global brand renowned worldwide for delivering reliable, affordable and innovative force, materials, and torque testing equipment for quality control.
Mecmesin is part of the Physical Properties Testers Group (PPT Group), a multi-national group of brands expert in the design and production of solutions for testing a range of physical properties including compression, light fastness, moisture, dry rate, water repellency, abrasion, flammability, texture, tensile and torque properties.
The PPT Group has regional offices in the UK, France, Germany, the USA, Thailand and China. The Mecmesin brand is also supported by a global network of distributors in more than 50 countries able to provide technical expertise and after-sales support to customers locally.
The focus of the brand has always been to provide high-quality test solutions, which are an affordable alternative to the many higher-priced systems available, enabling small and large businesses alike to undertake quality control checks on their products without compromising on precision and accuracy.
The rugged design of these systems means they can withstand tough factory conditions and perform tests at the point of production rather than having to use expensive laboratories to ensure consistent manufacture.
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