Guangxi Changke SAN CN4800 enters cosmetic packaging production as a transparent styrene-acrylonitrile resin whose batch-specific data are controlled by the supplier certificate of analysis; where CN4800-specific published data are limited, the processing windows below are drawn from industrial practice for transparent SAN grades with 24–28 wt% acrylonitrile content and comparable melt flow behaviour. The raw resin has a density of 1.07 g/cm³ when measured according to ISO 1183-1 and a typical light transmittance of 88–90% on a 3 mm injection-moulded plaque according to ISO 13468-1. The granules are pre-dried in a closed-loop desiccant dryer at 75–80°C for 2–4 h with supply air dew point no higher than -30°C; residual moisture above 0.05% is observable on the production floor as splay, silver streaks and gate-area haze on polished cosmetic closures.

For cream jars and powder boxes with a nominal wall thickness of 2.5–4.0 mm, process engineers set the barrel profile between 210°C and 235°C from feed throat to nozzle, verify melt condition at 220–240°C with a needle pyrometer, and hold mould surfaces at 45–65°C using pressurised water temperature controllers. In a two-platen hydraulic clamp machine with accumulator-assisted injection, a high-speed injection phase is followed by a lower-speed pack phase; if the pack phase is initiated too late, visible sink marks form on the outer wall, while overly early transfer creates flash at the parting line of multi-cavity tools. Valve-gate hot-runner systems are preferred because fast gate freeze-off and small sprue vestiges reduce gate blush on the polished surface. Mould release is assisted by polished draft angles of 0.5–1.0° on cores; texturing is avoided on visible surfaces because it reduces perceived transparency.

The compounding approach restricts additive chemistry because certain amine-functional antistatic agents can induce yellowing at melt temperatures above 240°C; the base composition for visible cosmetic packaging uses 98–99 wt% CN4800, 0.5–1.5 wt% transparent colour masterbatch with styrene-acrylonitrile carrier, and 0.1–0.3 wt% non-amine external lubricant. Regrind from sprues and nonconforming jars is limited to 10–15 wt% for optical-grade parts; beyond this level, the haze reading on a 2 mm plaque commonly exceeds 3%, and degraded gate remnants increase black speck formation. Finished articles include transparent cream jars, lip balm containers, loose-powder boxes and outer caps; cosmetic packaging safety is assessed under Regulation (EC) No 1223/2009, and where food-cosmetic dual use is claimed, the resin may be covered by a supplier statement under 21 CFR 177.1040 and EU 10/2011. Acrylonitrile monomer migration in food-contact parts is controlled to the specific migration limit of 0.01 mg/kg under EU 10/2011 Annex I.

What Changes When CN4800 Replaces PMMA in Small Appliance Transparent Bowls?

Replacement of PMMA in blender bowls and food processor containers with SAN CN4800 is usually driven by PMMA sensitivity to stress cracking from citrus oils and detergent solutions, but mould filling and impact performance change. Bowl tools with a wall thickness of 2.0–3.5 mm and a shot weight of 180–500 g run on toggle-clamp machines of 180–250 t where the projected area is 300–450 cm²; the lower viscosity of SAN compared with polycarbonate allows lower injection pressure, but fast gate freeze-off demands accurate transfer. The barrel temperature is set from 215°C in the feed section to 245°C at the nozzle, while the mould temperature is maintained at 50–70°C with water-driven cooling circuits around the threaded neck. Holding pressure is applied at 30–45 MPa hydraulic and held until the gate diameter freezes; premature transfer produces sink marks at the rim and collar, whereas delayed transfer overpacks the cavity and increases ejection force.

For transparent appliance bowls, the formula remains close to 99.0–99.5 wt% CN4800 with 0.2–0.5 wt% high-clarity processing stabiliser and, where a tint is required, 0.3–0.8 wt% masterbatch. Butadiene-grafted impact modifiers are excluded because they raise haze to 5–10% and destroy transparent appearance; the wall section and radius distribution must therefore be designed so that the part achieves an unnotched Charpy impact value of 18–25 kJ/m² according to ISO 179-1/1eU. Components that support live parts are outside the scope of an unfilled transparent bowl, but if the part functions as a barrier in an appliance, the material supplier may provide a UL 94 HB Yellow Card at a thickness of 1.5 mm or 3.0 mm; the end-product standard IEC 60335-1 clause 30.2 may require glow-wire testing on nearby current-carrying components. End products include blender bowls, juicer collector cups, vacuum cleaner dust containers and food processor lids.

Flow behaviour for transparent SAN grades in this class is commonly characterised by a melt volume rate of 20–30 cm³/10 min at 220°C under 10 kg according to ISO 1133-1. The following processing envelope is derived from commercial transparent SAN moulding guides and is provided for comparison across wall thickness classes; CN4800 batch-specific rheology must be confirmed on the user’s own capillary rheometer or injection machine.

In thin-wall electrical meter cover production, CN4800 is processed with a fast injection profile because the melt must fill the cavity before the frozen layer closes the flow path. Transparent covers with a nominal wall of 1.2–2.0 mm are typically run in 8–16-cavity tools on all-electric machines of 100–180 t clamp force; fill time measured by cavity pressure transducer is held to 0.20–0.45 s. Barrel zone settings range from 215°C in the rear zone to 250°C at the nozzle, and the hot runner manifold is held at 230–250°C with independent tip control to prevent stringing and cold slugs. Mould surface temperature is kept between 40°C and 60°C, with cooling channels placed no farther than 15 mm from cavity surfaces because non-uniform heat removal produces localised haze and asymmetric shrinkage in flat transparent covers.

The blend for electrical meter windows contains 0.1–0.2 wt% internal lubricant and, for tinted display covers, 0.5–1.0 wt% masterbatch with a refractive-index-matched SAN carrier. Dielectric performance is measured on a 1 mm plaque as a short-time dielectric strength of 20–25 kV/mm according to IEC 60243-1, with volume resistivity of 10¹⁵ Ω·cm according to IEC 62631-3-1. Water absorption after 24 h immersion according to ISO 62 is normally below 0.4%; dimensional stability in humid environments is therefore acceptable for indoor electrical housings, but outdoor exposure without substantial UV stabilisation is not recommended because the styrene moiety yellows under UV-B. The material is checked against Directive 2011/65/EU Annex II for RoHS and against the supplier’s REACH SVHC certificate under Regulation (EC) No 1907/2006. End products include smart-meter display windows, transparent relay covers, energy meter terminal covers and control cabinet inspection windows.

Office and Stationery Mouldings: Pin-Point Gate Freeze Time, Regrind Ratios and Toner-Resistant Clear Resins

Transparent writing instrument barrels and desktop accessories are produced in high-cavitation tooling where gate freeze time governs pack behaviour. A 32–64-cavity hot-runner tool with pin-point gates of 0.8–1.2 mm diameter runs pen barrels at a wall thickness of 1.0–1.6 mm; the gate freezes in 0.4–0.8 s, after which packing pressure cannot compensate for volumetric shrinkage. Transfer is therefore position-based at 95–98% of fill volume, not time-based. Barrel temperatures are maintained at 215–235°C from rear to nozzle, and mould coolant is kept at 35–55°C to permit rapid cycling without excessive frozen-in stress. Premature ejection or insufficient core cooling reveals itself as birefringent zones under polarised light and as cap-thread cracking after assembly.

Regrind from runners is limited to 15–20 wt% for transparent pens and rulers; the regrind stream is sieved, passed through a magnetic grid and dried identically to virgin pellets. For copier inspection windows and document covers, the styrene-acrylonitrile matrix provides a pencil hardness of 2H–3H under ASTM D3363, a flexural modulus of 3300–3800 MPa under ISO 178, and resistance to dry-cloth wiping. Surface scratch additives are used at 0.2–0.4 wt%; addition above 0.5 wt% increases haze and reduces notched impact strength, so the upper limit is controlled gravimetrically in the hopper feeder. End products include marker bodies, ballpoint pen barrels, mechanical pencil grip sections, translucent clipboard clips and copier document lids.

When Chlorine Contact and Sealing Torque Govern Sight Glass Design

For transparent water filter housings, sight glasses and pump strainer covers, SAN CN4800 is selected for cold-water chemical resistance and thread-holding rigidity; continuous hot-water service above 60°C is an application boundary because general-purpose SAN loses stiffness as the temperature approaches the heat deflection temperature under load. Cylindrical sight glasses with an outer diameter of 25–60 mm and wall thickness of 3.0–5.0 mm are gated with two or three edge gates to direct weld lines away from sealing threads. The melt temperature is held at 220–235°C at the nozzle, mould temperature at 50–70°C, and injection speed is set to avoid free jetting; melt temperature below 215°C produces visible cold flow lines at the flow-front junction. Mould shrinkage is in the range 0.4–0.7% when measured according to ISO 294-4, and thread inserts are dimensioned with this allowance. Post-mould annealing at 65°C for 2 h is used when the sight glass must maintain sealing torque at 1–2 N·m.

In cold-water service, the transparent grade provides rigidity and withstands mild hypochlorite-based cleaning solutions not exceeding 200 ppm free chlorine; published data for CN4800 specifically under NSF/ANSI/CAN 61 is limited, so component-specific extraction testing is the obligation of the device manufacturer rather than a resin-level claim. A supplier statement under 21 CFR 177.1040 and EU 10/2011 may support food-contact water filter housings, but the finished article remains subject to overall migration testing with the assigned food simulant. End products include filter bowls, filter housing caps, sight glass tubes and transparent covers for water pressure regulators.

The compliance matrix below lists the standard designations most frequently requested in CN4800 downstream projects. Each row is a part-specific obligation, not a resin-level certificate unless expressly stated by the supplier.

Laboratory instrument covers and diagnostic equipment inspection windows made from SAN CN4800 are specified only when the component is classified as a non-patient-contact housing or bezel; CN4800-specific biological evaluation under ISO 10993-5 is generally not available, so the resin is not selected for skin-contact or implantable medical devices. A 2.0–3.0 mm cover is moulded at a nozzle melt temperature of 220–240°C, mould temperature of 45–65°C, and a fill speed that avoids jetting from the sprue. A rectangular cover with a length of 200 mm and a width of 150 mm can be filled on a 120–180 t all-electric machine when the flow length-to-wall ratio remains below 150:1. The A-side cavity surface is polished to Ra 0.02–0.05 µm; tool surface scratches replicate in the transparent part, so demagnetised stainless inserts and cleanroom-level handling are used during mould maintenance.

The material exhibits tensile stress at break of 65–75 MPa and tensile modulus of 3300–3700 MPa under ISO 527-2. It is not suitable for autoclave sterilisation above 121°C because the heat deflection temperature under 1.8 MPa according to ISO 75-2/Af is 95–105°C for transparent SAN. Assembly should avoid solvent-based adhesives containing ketones or chlorinated hydrocarbons, which can craze the moulded surface; mechanical clamping is preferred. The end-product safety standard IEC 61010-1 applies to laboratory equipment, but the material supplier does not provide an end-product electrical safety certificate. End products include laboratory equipment bezels, diagnostic instrument inspection windows, transparent guards on analytical balances and centrifuge covers.