Technical Information | Molding conditions

TOYOLAC® possesses superb flowability and heat stability and is easily molded using ordinary injection molding equipment. Standard predrying and molding conditions are provided below.

Ⅰ. Pre-drying

To obtain the desired ABS resin-molded product, preheat under appropriate conditions. Pellet water content should be no more than 0.1% (preferably no more than 0.05%) to obtain the desired molded product. When using a box-type hot-air dryer, dry at 80°C for 3-6 hours or 90°C for 2-3 hours. Figure 1 illustrates the drying curve for TOYOLAC®. Use higher drying temperatures than you would for standard grades to properly dry heat-resistant grade TOYOLAC® or TOYOLACPAREL*.

Figure 1: TOYOLAC® drying curve

Figure 1: TOYOLAC® drying curve

Ⅱ. Molding conditions

To set molding conditions, consider such factors as the molding equipment being used, the size and shape of the molded product and the mold structure.

Ⅲ. Cylinder temperature

A temperature setting in the range of 210-240°C is generally the most practical.
Figure 3 shows the relationship between the cylinder temperature setting and the spiral flow length of TOYOLAC®.

Ⅳ. Mold temperature

To obtain the desired surface finish and reduce residual stress, use a mold temperature in the range of 40-80°C, preferably as high within that range as possible. That said, using a higher mold temperature tends to lengthen molding cycle time, so use the mold temperature setting most appropriate for the individual product that is to be molded.

Table 1: TOYOLAC® Molding Conditions
Category Drying
temperature setting
Standard grade 80-90°C/3-5hrs 220-240°C 40-80°C
Abrasion-resistant high-sliding grade
High-gloss grade
Painting/Plating grade
Detergent-resistant grade
Transparent grade 80-90°C/3-5hrs 210-230°C 40-70°C
Scratch-resistant grade
Heat-resistant grade 90-100°C/3-5hrs 240-260°C 40-80°C
Flame-retardant grade 80-90°C/3-5hrs 190-230°C
Durable anti-static grade 85-95°C/3-5hrs 210-240°C 30-80°C
Fiber-reinforced grade 90-100°C/3-5hrs 240-260°C
ABS//PC alloy 100-110°C/4-8hrs 240-270°C 50-80°C
ABS//PBT alloy 90-110°C/3-8hrs
240-260°C 60-80°C
ABS//PA6 alloy No drying required if molding immediately after opening. If stored after opening, dry at 80-90°C for 3-8 hrs to remove moisture. 240-260°C 60-80°C

Ⅴ. Injection pressure

To reduce warpage and shrinkage, use sufficient injection pressure and holding time. Observe the appearance of the molded product to optimize injection pressure conditions.

Ⅵ. Mold design

An ordinary resin mold can be used to form TOYOLAC®. Using a slightly larger gate and runner than what is ordinarily used to mold polyethylene or polypropylene resins produces even better results. Otherwise, no special measures need be taken as far as the mold is concerned. If the mold has a rough surface or an undercut structure, use a parting agent. Otherwise, a parting agent is unnecessary because TOYOLAC® is relatively less prone to stick to the mold during molding. Mold shrinkage varies depending on molding conditions and product shape. Ordinarily, TOYOLAC® mold shrinkage falls within the range of 0.4 to 0.6%. A draft angle within the range of 1/200 to 1/100 is preferred. See Table 2 for data on TOYOLAC® mold shrinkage.