Acc Series

The Acc series is tailored to make thin-wall parts.

Thin Wall

To save on material or weight or space, parts are made as thin as their mechanical strengths allow. Disposable items are also made as thin as possible.

The Acc series of injection moulding machine is designed to make thin-wall parts, small and big.

SD card case

Disposable thin-wall containers and lids

How thin?

Some say less than 1 mm is thin, but this would be too thick for SD card case.

A more accurate measure is the L/t ratio, which is flow length divided by wall thickness. When L/t > 150, we are in the thin-wall domain. We shall use this measure to determine if the Acc series is needed.

Problem

In thin-wall moulding, filling the cavities completely during injection is not easy.

Simply said, a high injection speed is needed to fill all the cavities before the thin flow path is frozen. Injection time is 400 mm/s or more. Injection time less than 0.5 s is a must.

More accurately, a high acceleration and a high deceleration are also needed to get up to speed fast and to stop immediately when the cavities are full.

Solution

An accumulator is a device to provide the high acceleration and speed of the screw. It stores up pressurized oil and releases it to the injection cylinders during injection. The burst of oil flow is much higher than even a turbo pump could provide. The accumulator is refilled with pressurized oil when not injecting. Acc is the short form of accumulator.

To stop precisely, a fast-scanning controller observes the screw position to close the injection valve immediately. A fast response valve is used. It is called a servo valve.

The single injection cylinder design reduces the mass to accelerate and decelerate. It is the preferred design for thin-wall moulding.

Models

Small

For small thin-wall parts, the Acc50/30 and TME50/54 Acc are recommended. Both are based on the TME50 clamping unit.

The Acc50/30 has screw diameters at 16, 18 and 20 mm. Its PS shot weight is 11 g, 13 g and 16 g. The single injection cylinder design is used.

Acc50/30

Acc50/30 injection unit. Note the accumulator and the servo valve at top. The single injection cylinder design is used. There are two carriage cylinders.

The TME50/54 has screw diameter at 22 mm. Its PS shot weight is 27 g. It uses the MA23 injection unit which has two injection cylinders.

TME50/54 Acc

Medium

For bigger parts, choose the TME110 Acc and ME150 Acc. They are TME110 and ME150 added with accumulator and other thin-wall features. The injection unit has two injection cylinders.

Accumulator and servo valve added to TME110 to become TME110 Acc

Large

Currently, only Acc200 is available. Food containers could be made on Acc200 using 2 + 2 stack moulds. It uses the single injection cylinder design which improves acceleration and deceleration.

Acc200

Part size/Clamping force	Single injection cylinder	Two injection cylinders
Small	Acc50/30	TME50/54 Acc
Medium		TME110 Acc, ME150 Acc
Large	Acc200

Selection guide for Acc models

HS200

HS stands for high speed. HS200 is like Acc200 but without accumulator, servo valve and high speed controller. It is to make food container lids which are easier to make than containers. It provides a lower price point vs Acc200.

HS200 is driven by a fast response servomotor. Injection speed of 326 mm/s can be reached at low injection pressure.