Dip Moulding Materials

Caplugs specialises in plastisol dip-coating and dipping moulding. A plastisol is a dispersion of polyvinyl chloride (also known as vinyl or PVC) beads in a liquid plasticiser. When heated, the vinyl granules absorb the plasticiser, swell and merge into a liquid substance, this can be compared to resin. The plastisol can then be coloured with pigment. By default, we use the colours black, yellow and red. Once the liquid cools down to below 60 °C (140 °F), it hardens into a flexible rubbery cap.

Hardness or Shore

PVC is incredibly versatile, it can be thick or thin, rigid or pliable and made in virtually any colour. The amount of plasticiser determines the vinyl’s hardness. The more plasticiser, the more flexible the plastic. This hardness is determined by the level of plasticiser and is measured by the Shore A scale from a supple 40 Shore A to a dimensionally stable 95 Shore A.

Applications

Depending on the composition and the resulting product, plastisol can be dipped, sprayed or cast, as well as used as a liquid for screen printing. Besides the plasticiser, other ingredients can be added to vinyl plastisol such as heat and UV light stabilisers, flame retardants and additives that affect the surface (matt/gloss).

Dip moulding moulds

Aluminium moulds have a long service life and can mould a huge number of vinyl products. Unlike metal moulds, aluminium moulds do not rust over time, so the caps always come off the mould properly and there is little rejection. Depending on the size of the product, several caps can be produced at the same time. There are moulds of 3 caps and up to 200 caps fit on a rack at a time.

Plastisol Qualities

The favourable qualities of vinyl plastisol make it a perfect material for product protection:

• Electrical resistance – PVC does not conduct heat or electricity and is often used in the electrical industry as an insulator for power tools, sheaths and connectors on wiring and rails.
• Flame retardant – Effective flame retardant and specially adapted properties according to UL94 / V0.
• Grip – Vinyl feels nice and comfortable when gripped. It is used for tool handles, bicycle handlebars and furniture.
• Noise reducing – Soft, impact-resistant surface which is noise reducing. Ideal for reducing squeaking or rattling from metal to metal.
• Chemical resistant – Plastisol’s resistance to alkali and acid makes it ideal for racks and tools exposed to chemicals.
• Shockproof and abrasion-resistant – Plastisol is tough and long-lasting. Ideal for latches and pull handles.
• Corrosion and UV radiation resistant – Excellent for outdoor applications such as use on agricultural machinery.
• Wide temperature range – plastisol withstands high and low temperatures from -50°C to +120°C.
• Oil resistant – the ideal property for use in the oil and gas industry.