About Us

From day one DPC has been contacted to manufacture dental disposable devices in England.

DPCs’ 30 years experience in the engineering and injection moulding field has honed the skills required to provide cost effective products for customers.

The main types of machinery we use are Injection Moulding and below are a list of equipment we use and an introduction into the Injection moulding process:

Machinery we Use

3 x Boy Injection Moulding Machines - 20 Tonne Lock
1 x Central Lathe Machine
2 x CNC Machine + Tool Room Facilities

The IM Process

The essential elements are as follows:

Material is introduced into the injection moulding machine via a Hopper. The injection moulding machine consists of a heated barrel equipped with a reciprocating screw (driven by a hydraulic or electric motor), which feeds the molten polymer into a temperature controlled split mould via a channel system of gates and runners.

The screw melts (plasticises) the polymer, and also acts as a ram during the injection phase. The screw action also provides additional heating by virtue of the shearing action on the polymer.

The polymer is injected into a mould tool that defines the shape of the moulded part.

The pressure of injection is high, dependant on the material being processed; it can be up to one thousand atmospheres. Tools tend to be manufactured from steels, (which can be hardened and plated), and Aluminium alloys for increased cutting and hand polishing speeds. The costs associated with tool manufacture means that injection moulding tends to lend itself to high volume manufacture.

The tool can be used to manufacture one consistent part in a repeating process or incorporate multi cavities (a multi impression tool), that is many components can be manufactured on the same tool repeatedly with a single injection.

Dental Plastics processes the following Injection Moulding materials and which are commonly used in the manufacturing trade:

Acrylonitrile-Butadiene-Styrene (ABS)

Properties:

Rigid, opaque, glossy tough, good low temperature properties, good dimensional stability and easily electroplated, low creep.

Applications:

Telephone handsets, rigid luggage, domestic appliance housings (food mixers), electroplated parts, radiator grills, handles, computer housings.

Nylon PA

Properties:

The majority of nylons tend to be semi-crystalline and are generally very tough materials with good thermal and chemical resistance. The different types give a wide range of properties with specific gravity, melting point and moisture content tending to reduce as the nylon number increases.

Applications:

Nylon fibres are used in textiles, fishing line and carpets. Nylon films is used for food packaging, offering toughness and low gas permeability, and coupled with its temperature resistance, for boil-in-the-bag food packaging.

Polycarbonate PC

Properties:

Polycarbonates are strong, stiff, hard, tough, transparent engineering thermoplastics that can maintain rigidity up to 140oC and toughness down to -20°C or special grades even lower.

Applications:

In recent years Polycarbonate blends have become increasingly commercially important. PC is widely used in blends due to its excellent compatibility with a range of polymers.

Polypropylene PP

Properties:

Rigid, opaque, good dimensional stability at high temperature and humidity conditions, difficult to process (blended to ease injection moulding), tough.

Applications:

Coffee pot and washing m/c parts (where high temperature and moisture are critical), replacement for die castings, drink vending machines, microwave components.

Polystyrene GPPS

Properties:

Brittle, rigid, transparent, low shrinkage, low cost, excellent X-ray resistance, free from odour and taste, easy to process.

Applications:

Toys and novelties, rigid packaging, refrigerator trays and boxes, cosmetic packs and costume jewellery, lighting diffusers, audio cassette and CD cases

Polystyrene (High Impact) HIPS

Properties:

Hard, rigid, translucent, impact strength up to 7 x GPPS, other properties similar.

Applications:

Yoghurt pots, refrigerator linings, vending cups, bathroom cabinets, toilet seats and tanks, closures, instrument control knobs.