What Is a Plastic Adhesive?
A plastic adhesive is an adhesive that is particularly suitable for bonding plastics.
Some plastics can be bonded with general adhesives, but there are some materials that are difficult to bond with general adhesives. In such cases, a special adhesive or primer is necessary.
In some cases, even plastics made of easily bondable materials can be bonded more firmly using plastic adhesives. There are various types of plastic adhesives, so it is important to choose the right one depending on the application and situation.
Uses of Plastic Adhesives
Plastic is a resin material that is widely used in everyday items around us.
Plastic adhesives have the following applications:
- Repair of kitchenware, bath components, and other water-related items
- Interior repairs
- Repair of toys
- Various daily necessities and small articles
- Electronic devices
- Home appliances
- DIY and crafts
In DIY and crafts, adhesives are used to make plastic models and figures. Some types of adhesives can also be used for works that are expected to be exposed to water (e.g. snow globes).
Adhesives for professional-use are used for joining gaskets, bonding various plastic components, fixing parts, and laminating large areas and flat plates.
Principles of Plastic Adhesives
One method of bonding difficult-to-bond plastics is to use a primer. Primer is used to improve the adhesion of material surfaces.
It is a low-viscosity liquid with low non-volatile content. In addition to improving adhesion, it also stabilizes the surface, prevents corrosion of metal surfaces, improves adhesion, and prevents deterioration of the adhesive. Primer must be allowed to sufficiently dry before applying the adhesive, and must not be mixed with the adhesive. The type of primer required depends on the type of adherend and adhesive.
Some acrylic adhesives using methacrylate, etc., can adhere to difficult-to-bond plastics without a primer by using a mechanism that fills gaps with microbeads or other contained particles.
Types of Plastic Adhesives
Plastic adhesives are available for household and commercial use. Different types of products are used depending on the material and application.
1. Household Plastic Adhesives
There are various types of household-use plastic adhesives, such as those that come with a primer set and can easily bond PE and PP, and those that can be used with only one adhesive. There are also adhesives with different characteristics, such as heat-resistant, water-resistant, and impact-resistant adhesives, as well as adhesives that can be used for metals and woods other than plastics.
Heat- and water-resistant products are particularly effective for repairing parts exposed to heat and water in kitchens, baths, and other areas, and for crafting works that are exposed to water. Regular instant adhesives can also be used for ABS and PVC.
2. Professional-Use Plastic Adhesives
Plastic adhesives for professional-use include synthetic rubber-based adhesives and acrylic adhesives using methacrylate, etc. In particular, adhesives for hard-to-bond plastics can be used. Some adhesive products, especially those for hard-to-bond plastics, contain microbeads or other fine particles to improve adhesive performance.
Cyanoacrylate adhesives, epoxy adhesives, polyurethane adhesives, and silicone adhesives are also used for plastics that are easy to bond, such as ABS, acrylics, and nylon. The appropriate one should be selected according to the application.
Other Information on Plastic Adhesives
Types of Plastics
There are various types of plastics made of different materials, and the ease of joining them with adhesives depends on the type. Polyesters such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) are thermoplastic and used in a variety of applications, but all are difficult plastics to bond.
Acetal resins such as POM (polyoxymethylene) and PTFE (polytetrafluoroethylene) are also known as difficult plastics to bond.
ABS resin, polyvinyl chloride (PVC), acrylic resin, and nylon are other known materials that are relatively easy to bond and can be used with ordinary adhesives. All of these materials have high plasticity and are commonly used for building materials, household goods, and equipment components.
However, in the case of acrylic materials, since many products utilize the transparency of the material, high transparency and non-yellowing characteristics are basically required for the adhesive as well. In the case of PVC, the ease of adhesion differs depending on the formulation of the same polyvinyl chloride. In particular, recyclable polyvinyl chloride manufactured using relatively new formulations is a relatively difficult material to bond.