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Cosmetic Packaging Resins
The information presented here is provided as a general guide for many of the resin types available. This guide is not intended, nor should it be used, as the selection criteria for your application. Each application should be evaluated by a well-qualified engineer and tested to ensure that the product is compatible with the container. Roberts Container makes no claim or warrantee as to the completeness or accuracy of the information provided.

There are many resins available for cosmetic packaging applications. Resins are selected based on compatibility with the product formulation, appearance, cost, moisture transmission rate, pigmentation, light or oxygen transmission, molding properties, environmental considerations as well as governmental regulatory requirements.

Selecting the correct resin for an application is an important consideration and requires an understanding of the chemical properties of what goes into the package (the product) along with the characteristics of the resin(s) selected for the application.

Acrylonitrile Butadiene Styrene (ABS)
ABS is an ideal material wherever superlative surface quality, colorfastness and luster are desired. ABS is a two-phase polymer blend. A continuous phase of styrene-acrylonitrile copolymer (SAN) gives the materials rigidity, hardness and heat resistance. The toughness of ABS is the result of sub-microscopically fine polybutadiene rubber particles uniformly distributed in the SAN matrix.

ABS standard grades have been developed specifically to meet the requirements of major customers in the cosmetic market. ABS is readily modified both by the addition of additives and by variation of the ratio of the three monomers Acrylonitrile, Butadiene and Styrene: hence grades available include high and medium impact, high heat resistance, and ABS can be electroplated. Fiber reinforcement can be incorporated to increase stiffness and dimensional stability. ABS is readily blended or alloyed with other polymers further increasing the range of properties available. The natural material is an opaque ivory color and is readily colored with pigments or dyes. Transparent grades are also available for different applications, the material is typically injection molded or extruded.

Barex (AN)
British Petroleum, the world's largest producer of acrylonitrile, a co-monomer that imparts high barrier to gases such as oxygen, aromas and fragrances as well as chemical resistance and inertness, developed Barex Resins. Barex belongs to a family of acrylonitrile-methyl acrylate copolymers grafted onto a nitrile rubber. Several grades, in natural or blue tint, are available for a variety of processes and applications. The chemistry behind Barex Resins makes them readily convertible into film, sheet, and bottles on standard equipment using extrusion, injection, calendering, and molding techniques. Whether thermoforming sheet, stretching bottles, or engineering applications, products made with Barex Resins offer uniform thickness, top to bottom. Introduced commercially in 1975, Barex Resins initially found widespread use in packaging processed meat, correction fluid, gasoline additives and agrochemicals. Since then, their use has expanded to an ever-widening range of challenging packaging applications such as medical and pharmaceutical products, personal care products, cosmetics and hair coloring.

Ethylene Vinyl Acetate (EVA)
Ethylene Copolymers are leading materials for formulating hot-melts (pressure sensitive and non pressure sensitive) in applications for the cosmetic packaging market. Good resistance to water, salt and other environments can be obtained but solvent resistance decreases with increasing vinyl acetate content. The copolymers can accept high filler and pigment loadings. Extrusion, injection, blow molding, calendering and rotational molding can be employed to form thermoplastic EVA.

Low Density Polyethylene (LDPE)
LDPE has high impact strength with excellent environmental stress crack resistance. With it's low water and alcohol permeability and resistant to many chemicals it is an ideal choice for applications in the cosmetic area. Squeezability is good, especially in the low-density grade of this thermoplastic material. It also displays better resistance to impact than the high-density grade.

LDPE is similar to HDPE in composition. It is less rigid and generally less chemically resistant than HDPE, but is more translucent. LDPE is used primarily for squeeze applications including lotions and creams. LDPE is significantly more expensive than HDPE, but will yield a glossy bottle when produced in colors. The most common household use of LDPE is in plastic bags.

Medium Density Polyethylene (MDPE)
MDPE provides intermediate properties between low- and high- density polyethylene. Bottles are less translucent than LDPE. Being flexible it is used for squeeze containers, where more rigidity than LDPE and less rigidity than HDPE is required. Like LDPE, MDPE is glossy when produced in colors. It is commonly used for inexpensive consumer products.

High Density Polyethylene (HDPE)
HDPE is more rigid than LDPE and MDPE depending on density is a flexible resin with an appearance that is wax-like, lusterless and has a natural milky color. It is the high-density version of PE plastic. It is harder, stronger and a little heavier than LDPE, but less ductile. It has good impact strength and is resistant to environmental stress cracking. HDPE has better barrier properties than LDPE and is easy to add color to.

HDPE is the most widely used resin for plastic bottles. This material provides a good moisture barrier, is economical, impact resistant and compatible with a wide range of products (including acids and caustics). It is usually supplied in FDA approved food grade. When fluorine treated, HDPE becomes an effective package for solvents (aromatic hydrocarbons) and oxygen sensitive extracts. The addition of color will make HDPE opaque although not glossy. HDPE is supplied surface-treated on a stock basis and lends itself readily to silkscreen decoration. While HDPE provides very good protection at temperatures below freezing, it cannot be used with products filled at over 180F or products requiring a hermetic seal. Outside of the cosmetic industry the most common use of HDPE is in containers for milk, liquid laundry detergent, etc.

Polycarbonate (PC)
Polycarbonate plastic is a lightweight, high-performance plastic with properties including strength, lightness, durability, high transparency, heat resistance and is easily processed. Hence, it is found in a number of products including bottles and packaging, medical devices, electronics equipment, computer housings, cars, building and construction applications as well as consumer goods. It is also extensively used in optical data storage applications (e.g. CDs, DVDs), safety equipment and lightweight, transparent roofing in building & construction.

Polycarbonate properties:

• High transparency
• High strength making it resistant to impact and fracture
• High heat resistance, making it ideal for applications that require sterilization
• Good dimensional stability - retain its shape in a range of conditions
• Good electrical insulation properties
• Biologically inert
• Readily recyclable
• Excellent processability
• Cost effective

Polyethylene (PE)
Polyethylene is probably the polymer you see most in daily life and is the most popular plastic in the world. PE is used to produce cosmetic containers, grocery bags, shampoo bottles, children's toys, and even bulletproof vests.

Polyethylene is classified according to their density, which in turn depends on the extent and type of formulation.

- LLDPE (linear low density PE) - Used for tubing applications
- LDPE (low density PE)
- MDPE (medium density PE)
- HDPE (high density PE

Polyethylene Terephthalate (PET) Polyester
PET is a rigid naturally crystal clear resin with fair water barrier properties. It provides good oil, alcohol and solvent barrier properties. PET is one of several resins in the polyester family. Bottles made from PET are injection blow molded, un-oriented or injection stretch blow molded, biaxial oriented. PET bottles have outstanding clarity, good impact and scratch resistance, high gloss finish and good barrier properties. Containers manufactured with PET resin are ideal for packaging a wide range of food products, toiletries, cosmetics and household and pharmaceutical items. PET has taken global markets by storm as the material of choice for beverage bottles. They are lightweight and safe compared to glass (no breakage on filling lines, in transit, retail stores and in homes). Last year alone (2004) 4.5 billion pounds of virgin thermoplastic polyester resin was produced in the U.S.

Superior functional properties of PET include:

• Transparency
• Lightweight
• Chemical and mechanical resistance
• Protective barrier
• 100% recyclable

Glycol Modified Polyethylene Terephthalate (PETG) Copolyester
PETG is a modified member of the PET family. It is well suited to being extrusion blow moldable with transparency better than PET particularly in thick sections. It has fair water, alcohol and solvent barrier properties along with very good oil barrier properties. It is a durable material with excellent gloss, clarity and sparkle desired for clear bottles. PETG can be processed via conventional extrusion blow molding methods, generally on machines designed to process PVC.

Applications include shampoos, soaps, and detergents. PETG exhibits a good impact strength and gas barrier. The chemical resistance of PETG is fair and compatibility testing is recommended, especially with products that contain alcohol.

Polymethyl Methacrylate (PMMA)
Polymethyl Methacrylate (PMMA), more commonly known by the generic name acrylic and is polymerized from the hydrocarbon compound Methyl Methacrylate. PMMA is a hard material and is extremely clear because of the amorphous arrangement of its molecules. As a result, this thermoplastic is used to make high quality compacts, pots and jars. PMMA products are marketed under familiar trade names, including Plexiglas, Lucite, and Acrylite. Because PMMA can be cast to resemble marble, it is also used to create some very interesting finishes. It is generally considered to be a high-end resin and is an excellent choice for premium products.

Polypropylene (PP)
Polypropylene is a very versatile polymer. Structurally, it is a vinyl polymer, and is similar to polyethylene, only that on every other carbon atom in the backbone chain has a methyl group attached to it. Polypropylene is a naturally translucent material, which provides contact clarity and an excellent moisture barrier. One major advantage of polypropylene is its stability at high temperatures (maximum temperature is 230 to 260F) and offers the potential for steam sterilization. Polypropylene's compatibility with high filling temperatures is makes it ideally suited for use with hot fill products. Polypropylene has excellent chemical resistance making it widely suited for a variety of applications. When manufactured with color, Polypropylene exhibits a glossy finish. Clear Polypropylene film is also available and is used in applications requiring flexibility and high barrier characteristics.

Polystyrene (PS)
Polystyrene may be best known as the resin used to produce foam coffee cups. For cosmetic packaging applications it is commonly used to make low-end compacts for the mass market.

Polystyrene is found in your home, office and in the cafeteria. It comes in many shapes and forms, from foam egg cartons, meat trays, soup bowls, salad boxes, and coffee cups to utensils and CD "jewel boxes." Styrene does not provide good barrier properties and exhibits poor impact resistance. It can be screen printed without being flame treated and lends itself well to offset printing.

Polyurethane (PU)
The origin of polyurethane dates back to the beginning of World War II where it is was first developed as a replacement for rubber. The versatility of this exciting new organic polymer and its ability to substitute for scarce materials, spurred numerous applications. During World War II, polyurethane coatings were used for the impregnation of paper and the manufacture of mustard gas resistant garments, high-gloss airplane finishes and chemical and corrosion resistant coatings to protect metal, wood and masonry.

Polyvinylchloride (PVC)
Polyvinylchloride (PVC) was first produced commercially in the United States in 1933. It is one of the three most important polymers currently used worldwide and has a large range of properties used to make hundreds of products.

Although a somewhat controversial resin, from an environmental standpoint, it remains the 2nd most highly used resin throughout the world with over 20 million tons produced annually. PVC is naturally clear, has extremely good resistance to oils and very low oxygen transmission. It provides an excellent barrier to most gases, but is vulnerable to certain solvents. PVC is a semi-rigid material which, when produced on extrusion blow-molding equipment, can accommodate "handled" designs. Improvements in resin formulation have increased oxygen barrier properties and chemical resistance, along with a 20-30% improvement in drop impact resistance. PVC exhibits good low temperature resistance but will distort at 160F. It is not compatible with hot filled products. Because it provides a good oxygen barrier, PVC is an excellent choice for salad oil, mineral oil, and vinegar. It is also commonly used for shampoos, hair coloring and cosmetic products.

Styrene Acrilonitrile (SAN)
SAN's brilliant surface has great depth of color make it ideally suited for cosmetic and personal care products. It looks good and feels good - an important consideration in the cosmetic industry. SAN accepts print very easily and affords diverse design possibilities. Moreover, SAN is resistant to chemicals. It is rigid, transparent, and tough. It resists stress cracking and crazing and is easily processed. SAN is a resin of choice for many Jars and Compacts.

Names & Abbreviations

ABS - Acrylonitrile Butadiene Styrene.
AN - Acrylonitrile - Barex.
EVA - Ethylene Vinyl Acetate.
HDPE - High Density Polyethylene.
LDPE - Low Density Polyethylene.
MDPE - Medium Density Polyethylene.
PC - Polycarbonate.
PE - Polyethylene.
PET - Polyester & Co-Polyester.
PETG - Polyethylene Terephthalate Glycol.
PMMA - Polymethyl Methacrylate.
PP - Polypropylene.
PS - Polystyrene.
PU - Polyurethane.
PVC - Polyvinylchloride.
SAN - Styrene Acrilonitrile.