Adhesive Tricks: Attaching Plastics To Skin

There are many ways to stick plastic to skin, depending on the use case. For example, makeup artists use a special glue to stick special effects elements to the skin, such as Spock ears. This glue is based on mastic, the resin of the mastic tree. For flexible plastics used in household items such as shoes or toys, adhesives such as Loctite Vinyl, Fabric & Plastic Flexible Adhesive are ideal. This type of adhesive is a clear liquid that is waterproof, dries clear, and creates a flexible bond that won't break down or yellow from UV/sunlight exposure. For medical applications, 3M's 2476P medical silicone is a popular choice as it is breathable, repositionable, and fluid-resistant.

Characteristics of sticking plastic to skin

Using a sticky polymer sheet

If you are looking for a way to stick plastic to skin, one option is to use a sticky polymer sheet. This method offers a few advantages over other adhesive options, such as glues or fluids. Firstly, sticky polymer sheets are easy to use and can be applied directly to the skin. They are also thin and flexible, making them comfortable to wear and less noticeable than other adhesives. Additionally, they can be easily removed without causing harm or irritation to the skin.

When choosing a sticky polymer sheet, opt for a generic brand as these tend to be thinner and stickier. If thickness is a concern, avoid using the central part of the sheet that may have an embedded gauze pad. Before applying the sheet, ensure that your skin is clean and dry for the best adhesion. You can cut the sheet to the desired size and shape, making it customizable for your specific needs.

It is important to note that while sticky polymer sheets are safe for skin contact, they may not be certified as such. Always perform a patch test on a small area of your skin before using it on a larger area to ensure that you don't experience any irritation or allergic reactions. Additionally, always store the sheets in a cool, dry place, away from moisture, to ensure they maintain their adhesive properties.

One example of a sticky polymer sheet is the adhesive film offered by Grafix Plastics. Their products, such as DuraLar, have a pressure-sensitive adhesive coating on one side, making them suitable for lamination and surface protection. However, they are not recommended for outdoor use as exposure to ultraviolet light or moisture can cause the adhesive to break down.

Overall, using a sticky polymer sheet is a convenient and effective way to stick plastic to skin, offering a thin, flexible, and comfortable solution that is also easy to remove.

Skin-safe glues

When it comes to sticking plastic to skin, it is important to use skin-safe glues to avoid any harm to the skin. Here are some options for skin-safe adhesives:

Mastic-Based Glues

Mastic-based glues are made from the resin of the mastic tree, usually dissolved in alcohol. They are strong and safe for skin use, and can be easily removed by pulling them off. Makeup artists often use this type of glue to attach special effects to the skin, such as Spock ears.

Water-Soluble Skin Glues

Water-soluble skin glues are another option for temporary adhesion. These glues are designed to be safe for skin contact and can be easily removed with water.

Adhesive Bandages

Thin, flexible adhesive bandages can also be used to attach objects to the skin. They are easy to remove and can be found at most drugstores or pharmacies.

Temporary Adhesives for Clothing

For temporary adhesion of plastic objects to clothing, fishing line or magician's thread can be used to sew the object onto the fabric. Alternatively, a small piece of Velcro can be sewn onto the clothing, allowing for easy removal.

It is important to note that when using any type of adhesive, it is crucial to follow safety precautions and instructions provided by the manufacturer. Always test the adhesive on a small area of the skin first to ensure no allergic reactions occur.

Skin-safe tapes

There are two main types of skin-safe tapes: silicone and acrylic. Silicone adhesives typically form weaker bonds with the skin, making them ideal for delicate or fragile skin. They are also suitable for repositioning. Acrylic adhesives, on the other hand, are used for higher-strength applications, such as holding wearable devices like glucose monitors or heavy wound dressings in place. However, due to their stronger adhesion, they may not be suitable for sensitive skin as they can increase the risk of tearing upon removal. Acrylic adhesives may also leave behind adhesive residue.

When choosing a skin-safe tape, it is essential to consider the specific use case and the condition of the skin. For example, medical tape 1526 has a liquid barrier that makes it fluid-resistant, while Mactac's TM8101 is suitable for long-term applications where moisture vapour transmission is desired. Avery Dennison's MED 5634 is a powerful adhesive that resists moisture and forms a strong bond with the skin, making it suitable for mounting electrodes and other devices.

In addition to silicone and acrylic tapes, other materials such as rubber, hydrocolloid, and elastic polymers are also used for skin-safe applications. It is important to research the different materials and choose the one that best suits the specific requirements and skin type.

Plastic type and glue compatibility

Plastic is a versatile material used in everything from toys to medical applications and even bulletproof vests. However, its unique composition can make gluing plastic challenging. The best glue for plastic depends on the type of plastic being used.

The easiest way to identify the type of plastic is by its recycling symbol, usually a triangle of arrows with a number or letter in the centre. For example, plastics marked with a 6 or "PS" are polystyrenes, which can be glued using a poly cement or a specialised plastic glue. Polyethylene and polypropylene plastics, on the other hand, require a special adhesive designed for use on these plastics, such as Loctite Superglue All Plastics.

Hard, high-density plastics, such as those used to make buckets, crates, or containers, fall into this category. Ordinary white glues, wood glues, or common adhesives won't react well or form permanent bonds with these plastics. For a strong, water-resistant bond that sets in seconds, try a two-part cyanoacrylate adhesive like Loctite Plastics Bonding System.

Flexible plastics, commonly found in household items like shoes or toys, require adhesives specially formulated for use with these materials. Loctite Vinyl, Fabric & Plastic Flexible Adhesive is a clear liquid adhesive that's waterproof, dries clear, and creates a flexible bond that resists UV/sunlight degradation.

For bonding materials such as polycarbonate, acrylic, Nylon, Mylar, Delrin, phenolic, aluminium, and stainless steel, a strong adhesive like Loctite Plastic Bonder is recommended. Its specialised acrylic formula combines two components to produce a strong, impact-resistant bond that sets in less than half an hour and is resistant to water and common shop fluids.

Other types of glue for plastic include super glues (cyanoacrylate adhesives), epoxy adhesives, acrylic adhesives, and hot-melt adhesives. Super glues are a popular choice for quick fixes and minor plastic repairs, but they can also damage certain plastics. Epoxy adhesives are versatile and create a durable, long-lasting bond, making them ideal when strength is a priority. Acrylic adhesives are great for hidden repairs as they cure to form a clear join. Hot-melt adhesives are applied with a glue gun and are useful when speed and flexibility are important, but they may not work on all plastic types.

When gluing plastic, it's important to prepare the surface properly. Degrease the plastic with soap or isopropyl alcohol, dry thoroughly, and sand the surfaces to create a rough surface for the glue to bond to. Always follow the manufacturer's instructions for the best results and take the necessary safety precautions, such as working in a well-ventilated area and wearing gloves.

Preparing the plastic surface

Firstly, identify the type of plastic you are working with. Different types of plastics require different types of adhesives. The easiest way to identify the plastic type is by looking for a recycling symbol on the plastic itself, the label, or the packaging. This symbol is typically a triangle formed by three arrows, containing a number, letter, or a combination of both. For instance, plastics marked with a "6" or "PS" are polystyrenes, which are best glued with a poly cement or a specialized plastic glue like Loctite Epoxy Plastic Binder or Super Glue Plastic Fusion. On the other hand, plastics labelled "2," "4," "5," "HDPE," "LDPE," "PP," or "UMHW" are types of polyethylene or polypropylene, which require specific adhesives like Loctite Superglue All Plastics.

Once you've identified the plastic type, it's time to choose the right adhesive. Consider the flexibility and durability of the plastic and select an adhesive that is compatible. For instance, flexible plastics used in items like shoes or toys require adhesives specially formulated for flexibility, such as Loctite Vinyl, Fabric & Plastic Flexible Adhesive. On the other hand, for bonding materials like polycarbonate or acrylic, you'll need a strong adhesive like Loctite Plastic Bonder, which forms a strong, impact-resistant bond.

Before applying the adhesive, ensure the plastic surface is clean and dry. Degrease the plastic using soap or isopropyl alcohol, and then thoroughly dry it. This step is crucial for ensuring a proper bond between the adhesive and the plastic surface.

Finally, sand the plastic surface with fine-grit sandpaper, typically 120-200 grit. This process creates a rough surface for the glue to grip onto, enhancing the strength of the bond. Make sure to sand evenly and not create any deep scratches or grooves on the plastic surface. Once the surface is prepared, you can proceed to apply the adhesive according to the manufacturer's instructions.

By carefully identifying the plastic type, choosing the right adhesive, and preparing the surface through cleaning, drying, and sanding, you'll maximize the chances of achieving a strong and lasting bond when gluing plastic surfaces.

Frequently asked questions