Thin wall Mould

Thin wall Mould Details

With the progress of the social era and the liberation of human labor, our time is becoming increasingly precious. The takeout market is developing rapidly, and the demand for fast food boxes used for takeout is increasing exponentially. The thin-walled mold market has emerged.

Thin walled products can be seen everywhere in life, such as packaging boxes in restaurants, disposable water cups for drinking, mom's love bento boxes, and various exquisite packaging boxes in supermarkets. Thin walled products have such a wide range of uses that it is inevitable to have a deep curiosity about their production

Disposable tableware

According to the source of raw materials, production process, degradation methods, and recycling level, it can be divided into the following three categories: 

1. Biodegradation: such as paper products (including pulp molding, cardboard coating), edible powder molding, plant fiber molding, etc;

2. Light/biodegradable materials: light/biodegradable plastic (non foaming) type, such as photo biodegradable PP;

3. Easy to recycle materials such as polypropylene (PP), high impact polystyrene (HIPS), biaxially oriented polystyrene (BOPS), and natural inorganic mineral filled polypropylene composite products.

Mold materials:

1. Mold blank materials are 2316 and 638 to prevent molds and water holes from rusting;
2. The front and rear molds are made of heat-treated steel materials such as 2344, S136, DC53, GS767, etc., and processed to HRC48-52 to extend mold life and prevent Rust;
3. Some inserts in the front and rear molds, such as hot mouth inserts using S136 or 083 and heat treatment, front mold cup bottom inserts using S136, 083, 2344, etc. and heat treatment, rear mold cup low top inserts are close to the heat immediately The temperature at the mouth is high, and the heat dissipation is not ideal, so beryllium copper is used.
4. Because the front and rear molds are made of independent columbium, the guide sleeve on the mold blank must be supported with 2510 and quenched to HRC48-52.
5. All guide posts and guide sleeves use HASCO.
6. The mold hot nozzle adopts HUSKY, and the hot nozzle assembly should be notified to the manufacturer in advance so that the manufacturer can arrange for professional installation.

Mold design:

1. When the design mold is opened, the front mold must first pop up by 0.05-0.1mm to facilitate blowing and avoid the product sticking to the front mold;
2. The mating surface of the insert and the insert, the insert and the collum must be ground with the exhaust groove, and the depth It is specified as 0.015mm;
3. The water transportation of the whole set of molds should be reasonable and sufficient, with the principle of as much as possible, and each insert should also be adequately transported;
4. According to the product structure, the characteristics of the raw materials, and the number of beers , Choose reasonable mold materials.

Processing technology:

1. All columbium and parts to be heat treated must be roughed, and the machining allowance is generally between 0.25-0.5mm on one side;
2. The workpiece after heat treatment is delivered to the grinder together with the drawing, and the shape and right angle of the workpiece are determined by the grinder. Grind to a few. As for the point where it is not difficult to process the rubber plane, reserve 0.15mm to save grinding;
3. After the workpiece is finished by the grinder, it must first be self-inspected, and then handed over to the mold QC for inspection, and then sent to the CNC lathe for processing after OK.

What are the requirements for injection machines and molds for thin-walled injection molding?

1.Injection machine

Standard injection machines can be used to produce various thin-walled products. At present, the performance of the new injection machine greatly exceeds that of 10 years ago. The progress in materials, gate technology, and design has further expanded the performance of standard injection machines for filling thin-walled parts. However, due to the continuous reduction of wall thickness, a more specialized injection machine with high-speed and high-pressure performance is needed.

Fully electric injection machines and electric/hydraulic injection machines with high-speed and high-pressure performance have also been introduced. In order to withstand the high pressure of the new injection machine, the minimum value of the locking force must be 5-7 tons/inch (projected area).

In addition, when the wall thickness decreases and the injection pressure increases, a large template helps to reduce bending. The ratio of the pull rod of the injection machine used for thin-walled products to the thickness of the template is 2:1 or lower. When producing thin-walled products, the closed-loop control of injection molding speed, pressure, and other processing parameters helps to control mold filling and pressure holding under high pressure and high speed.

2.mould

Speed is one of the key factors for the success of thin-walled injection molding. Rapid mold filling and high pressure can inject molten thermoplastic materials into the mold cavity at high speed, thereby preventing cold solidification of the gate. If a standard part completes mold filling within two seconds, reducing mold thickness by 25% may potentially reduce mold filling time by 50%, which is exactly one second.

One of the advantages of thin-walled injection molding is that when the thickness is reduced, fewer materials need to be cooled. As the thickness decreases, the forming cycle can be shortened by half. The reasonable setting of the melt conveying device ensures that the hot runner and runner do not hinder the shortening of the forming cycle. The use of hot runner and runner liners helps to minimize the molding cycle. In addition, the material used for the mold should also be considered.

P20 steel is widely used in the molding of traditional products, but due to the higher pressure of thin-walled injection molding, the mold must be made very sturdy. H-13 and other hard steels add additional safety factors to thin-walled molds. However, the cost of a sturdy mold may be 30% to 40% higher than that of a standard mold. But the increased costs are usually offset by improved production performance.

Our technical points for thin-walled molds:

1. Specially designed system for thin-walled injection molds

2. Cooling system specially designed for thin-walled molds

3. High precision machining process

4. Select steel materials for each part of the mold

5. Specially designed exhaust system for thin-walled molds

6. High speed injection molding system