Cutlery Mould Maker

The mold steel for plastic cutlery mold

Tableware mold is widely used in daily use. Spoon molds are the most used in disposable tableware. The requirements are also relatively high. The surface must be high-gloss, the parting surface must be perfect and there must be no flashing, and the surface effect must be good. Long life, steel is one of the keys. In the process of manufacturing cutlery mold, the commonly used mold steels are 718/S136/H13/2738 etc. H13 mold steel has almost become the most commonly used cavity material for plastic molds.

1. Pre-hardened plastic mold steel

H13: suitable for PP, PS plastics, hardened to about 45-48HRC.

2. Corrosion-resistant mirror mold steel

S136: suitable for mirror molds, high acid resistance after quenching, suitable for PS, PLA plastics, can be hardened to about HRC 40-45, generally used to make transparent cutlery molds, the mold life can reach 200W shot life.

3. Pre-hardened high-quality plastic mold steel

DIN1.2738: steel with nickel content, uniform hardness, good cutting, used for high-demand plastic molds, especially suitable for electro-erosion operations, hardened and fired to HB 290~330

The gate design of plastic cutlery mold

The location of the gate is of importance with respect to the way in which the plastic flows into the mold impression. Other factors have to be taken into consideration when choosing a gate location, it must be apparent that the positioning of the gate must be determined relatively early on and before the design build-up has started. If the forks, spoon, and knife component is to be conventionally fed, i.e. non-hot runner, the gate location options are further restricted due to the limitations of the two-plate mold design. Restrictions exist because of the necessity of having to gate on a single plane about the mold split line. When confronted with gating requirements outside the scope of the two-plate design，the mold designer has the choice of selecting either the three-plate or the runner-less mold design formats in order to achieve the desired gate position.

The cycle time of plastic cutlery mold

About the cycle time, a complete cycle is: mold close — injection — cooling ( charging at the same time) — mold open — ejection — mold close.

Normally, the machine dry cycle (mold open-ejection-mold close) takes about 3 sec, the injection will take about 2 sec. rest time is for cooling, spoon with 24 cavities, about 8-10 sec for cooling is normal.

So in total cycle time, 13-15 sec is normal cycle time.

Above is some experience QX Mould get during mold testing, if you have any comments, or questions, welcome to discuss with us. and also welcome to QX Plastic Mould Co. Ltd, let’s work together to get a good solution.